Background High environmental temperatures induce heat stress in broiler chickens,affecting their health and pro-duction performance.Several dietary,managerial,and genetics strategies have been tested with some succes...Background High environmental temperatures induce heat stress in broiler chickens,affecting their health and pro-duction performance.Several dietary,managerial,and genetics strategies have been tested with some success in mitigating heat stress(HS)in broilers.Developing novel HS mitigation strategies for sustaining broiler production is critically needed.This study investigated the effects of pre-hatch thermal manipulation(TM)and post-hatch baica-lein supplementation on growth performance and health parameters in heat-stressed broilers.Results Six hundred fertile Cobb 500 eggs were incubated for 21 d.After candling on embryonic day(ED)10,238 eggs were thermally manipulated at 38.5℃ with 55%relative humidity(RH)from ED 12 to 18,then transferred to the hatcher(ED 19 to 21,standard temperature)and 236 eggs were incubated at a controlled temperature(37.5℃)till hatch.After hatch,180-day-old chicks from both groups were raised in 36 pens(n=10 birds/pen,6 replicates per treatment).The treatments were:1)Control,2)TM,3)control heat stress(CHS),4)thermal manipulation heat stress(TMHS),5)control heat stress supplement(CHSS),and 6)thermal manipulation heat stress supplement(TMHSS).All birds were raised under the standard environment for 21 d,followed by chronic heat stress from d 22 to 35(32–33℃ for 8 h)in the CHS,TMHS,CHSS,and TMHSS groups.A thermoneutral(22–24℃)environment was maintained in the Control and TM groups.RH was constant(50%±5%)throughout the trial.All the data were analyzed using one-way ANOVA in R and GraphPad software at P<0.05 and are presented as mean±SEM.Heat stress significantly decreased(P<0.05)the final body weight and ADG in CHS and TMHS groups compared to the other groups.Embryonic TM significantly increased(P<0.05)the expression of heat shock protein-related genes(HSP70,HSP90,and HSPH1)and antioxidant-related genes(GPX1 and TXN).TMHS birds showed a significant increment(P<0.05)in total cecal volatile fatty acid(VFA)concentration compared to the CHS birds.The cecal microbial analysis showed significant enrichment(P<0.05)in alpha and beta diversity and Coprococcus in the TMHSS group.Conclusions Pre-hatch TM and post-hatch baicalein supplementation in heat-stressed birds mitigate the detrimental effects of heat stress on chickens’growth performance,upregulate favorable gene expression,increase VFA produc-tion,and promote gut health by increasing beneficial microbial communities.展开更多
In this work,p⁃phenylenediamine and L⁃cysteine were used as raw materials,and water⁃soluble N,S co⁃doped carbon dots(N,S⁃CDs)with excellent performance were prepared through a one⁃step solvothermal method.The morpholo...In this work,p⁃phenylenediamine and L⁃cysteine were used as raw materials,and water⁃soluble N,S co⁃doped carbon dots(N,S⁃CDs)with excellent performance were prepared through a one⁃step solvothermal method.The morphology and structure of N,S⁃CDs were characterized by transmission electron microscope,X⁃ray diffrac⁃tion,Fourier transform infrared spectroscopy,and X⁃ray photoelectron spectroscopy,and the basic photophysical properties were investigated via UV⁃Vis absorption spectra and fluorescence spectra.Meanwhile,the N,S⁃CDs have excellent luminescence stability with pH,ionic strength,radiation time,and storage time.Experimental results illus⁃trated the present sensor platform exhibited high sensitivity and selectivity in response to baicalein with a detection limit of 85 nmol·L-1.The quenching mechanism is proved to be the inner filter effect.In addition,this sensor can also detect baicalein in biofluids(serum and urine)with good accuracy and reproducibility.展开更多
Current colorectal cancer (CRC) treatments exhibit unwanted cytotoxicity against healthy proliferating cells. Hence, these therapeutics demand higher specificity upon drug delivery, a task that may be facilitated by t...Current colorectal cancer (CRC) treatments exhibit unwanted cytotoxicity against healthy proliferating cells. Hence, these therapeutics demand higher specificity upon drug delivery, a task that may be facilitated by the discovery of anticancer agents bearing critical mechanisms of action. Baicalein is a flavonoid with promising anticancer activity, among other pharmacological benefits, and has therefore been of high clinical interest. We tested baicalein in vitro for its effect on several CRC hallmarks, including the suppression of metastasis (the spread of cancer cells from their initial site), the ability to induce apoptosis (cell death), and the inhibition of proliferation (the growth of cells). The suppression of the metastasis of CRC cells was recorded via two studies: the cell migration assay and the in silico docking of baicalein with toll-like receptor 4 (TLR4) and matrix metalloproteinase-9 (MMP-9). Results from the cell migration assay showed that baicalein inhibited metastasis by up to 25.76% (p 0.01) in a concentration-dependent manner. We then reinforced these results by docking baicalein with TLR4 (binding affinity: -8.4 kcal/mol) and docking baicalein with MMP-9 (binding affinity: -7.9 kcal/mol), classifying strong binding affinities as those less than -6.0 kcal/mol. The induction of cell death was measured using a caspase activity assay. Again, a docking study was done to reinforce the findings from the primary in vitro experiment, though this time between baicalein and caspase-3 (binding affinity: -7.1 kcal/mol). Despite mixed observations in concentration dependence, caspase activity, relative to control, reached a maximal increase of 88.6% (p 0.01), and results from the MTT assay demonstrated a survival rate, relative to control, of as low as 59.64%. Considerations for future studies include the testing of baicalein in vivo and on more aberrative CRC cell lines.展开更多
Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in hig...Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.展开更多
To investigate the metabolites of baicalein 6,7-diacetate in rats. HPLC-DAD and LC/MS^n methods were used to analyze the metabolites in intestinal tract and plasma after oral administration of baicalein 6,7-diacetate ...To investigate the metabolites of baicalein 6,7-diacetate in rats. HPLC-DAD and LC/MS^n methods were used to analyze the metabolites in intestinal tract and plasma after oral administration of baicalein 6,7-diacetate to rats. Baicalein 6,7-diacetate was degraded into baicalein 6-monoacetate and baicalein in rat intestinal tract, and four baicalein glucuronides, baicalein 6-0- glucuronide, baicalein 6-methoxyl-7-O-glucuronide, baicalein 6,7-di-O-glucuronide, and baicalein 6-O-glucose-7-O-glucuronide were detected and tentatively identified in rat plasma. This is the first time to report the metabolites of baicalein 6,7-diacetate in rats. Six metabolites were identified in rat intestinal tract and plasma.展开更多
Baicalein(BE) is one of the main active flavonoids representing the variety of pharmacological effects including anticancer, anti-inflammatory and cardiovascular protective activities, but it's very low solubility...Baicalein(BE) is one of the main active flavonoids representing the variety of pharmacological effects including anticancer, anti-inflammatory and cardiovascular protective activities, but it's very low solubility, dissolution rate and poor oral absorption limit the therapeutic applications. In this work, a nano-cocrystal strategy was successfully applied to improve the dissolution rate and bioavailability of BE. Baicalein-nicotinamide(BE-NCT) nanococrystals were prepared by high pressure homogenization and evaluated both in vitro and in vivo. Physical characterization results including scanning electron microscopy, dynamic light scattering, powder X-ray diffraction and differential scanning calorimetry demonstrated that BE-NCT nano-cocrystals were changed into amorphous state with mean particle size of 251.53 nm. In the dissolution test, the BE-NCT nano-cocrystals performed 2.17-fold and 2.54-fold enhancement than BE coarse powder in FaSSIF-V2 and FaSSGF. Upon oral administration, the integrated AUC0-t of BE-NCT nano-cocrystals(6.02-fold) was significantly higher than BE coarse powder(1-fold), BE-NCT cocrystals(2.87-fold) and BE nanocrystals(3.32-fold). Compared with BE coarse powder, BE-NCT cocrystals and BE nanocrystals, BENCT nano-cocrystals possessed excellent performance both in vitro and in vivo evaluations.Thus, it can be seen that nano-cocrystal is an appropriate novel strategy for improving dissolution rate and bioavailability of poor soluble natural products such as BE.展开更多
AIM:To investigate the hepatoprotective effect of baicalein against carbon tetrachloride(CCl 4)-induced liver damage in mice.METHODS:Mice were orally administered with baicalein after CCl 4 injection,and therapeutic b...AIM:To investigate the hepatoprotective effect of baicalein against carbon tetrachloride(CCl 4)-induced liver damage in mice.METHODS:Mice were orally administered with baicalein after CCl 4 injection,and therapeutic baicalein was given twice a day for 4 d.The anti-inflammation effects of baicalein were assessed directly by hepatic histology and serum alanine aminotranferease and aspartate aminotransferase measurement.Proliferating cell nuclear antigen was used to evaluate the effect of baicalein in promoting hepatocyte proliferation.Serum interleukin(IL)-6,IL-1β and tumor necrosis factor-α(TNF-α) levels were measured by enzyme-linked immunosorbent assay and liver IL-6,TNF-α,transforming growth factor-α(TGF-α),hepatocyte growth factor(HGF) and epidermal growth factor(EGF) genes expression were determined by quantitative real-time polymerase chain reaction.RESULTS:CCl4-induced acute liver failure model offers a survival benefit in baicalein-treated mice.The data indicated that the mRNA levels of IL-6 and TNF-α significantly increased within 12 h after CCl 4 treatment in baicalein administration groups,but at 24,48 and 72 h,the expression of IL-6 and TNF-α was kept at lower levels compared with the control.The expression of TGF-α,HGF and EGF was enhanced dramatically in baicalein administration group at 12,24,48 and 72 h.Furthermore,we found that baicalein significantly elevated the serum level of TNF-α and IL-6 at the early phase,which indicated that baicalein could facilitate the initiating events in liver regeneration.CONCLUSION:Baicalein may be a therapeutic candidate for acute liver injury.Baicalein accelerates liver regeneration by regulating TNF-α and IL-6 mediated pathways.展开更多
The excited state intramolecular proton transfer (ESIPT) coupled charge transfer of baicalein has been investigated using steady-state spectroscopic experiment and quantum chemistry calculations. The absence of the ...The excited state intramolecular proton transfer (ESIPT) coupled charge transfer of baicalein has been investigated using steady-state spectroscopic experiment and quantum chemistry calculations. The absence of the absorption peak from S1 excited state both in the experi-mental and calculated absorption spectra indicates that S1 is a dark state. The dark excited state S1 results in the very weak fluorescence of solid baicalein in the experiment. The fron- tier molecular orbital and the charge difference densities of baicalein show clearly that the S1 state is a charge-transfer state whereas the S2 state is a locally excited state. The only one stationary point on the potential energy profile of excited state suggests that the ESIPT reaction of baicalein is a barrierless process.展开更多
AIM To investigate the effects of combined use of emodin and baicalein(CEB) at the cellular and organism levelsin severe acute pancreatitis(SAP) and explore the underlying mechanism.METHODS SAP was induced by retrogra...AIM To investigate the effects of combined use of emodin and baicalein(CEB) at the cellular and organism levelsin severe acute pancreatitis(SAP) and explore the underlying mechanism.METHODS SAP was induced by retrograde infusion of 5% sodium taurocholate into the pancreatic duct in 48 male SD rats. Pancreatic histopathology score, serum amylase activity, and levels of tumour necrosis factor alpha(TNf-α), interleukin 6(IL-6), and IL-10 were determined to assess the effects of CEB at 12 h after the surgery. The rat pancreatic acinar cells were isolated from healthy male SD rats using collagenase. The cell viability, cell ultrastructure, intracellular free Ca2+ concentration, and inositol(1,4,5)-trisphosphate receptor(IP3 R) expression were investigated to assess the mechanism of CEB.RESULTS Pancreatic histopathology score(2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05) and serum amylase activity(2866.2 ± 617.7 vs 5241.3 ± 1410.0, P < 0.05) were significantly decreased in the CEB(three doses) treatment group compared with the SAP group(2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05). CEB dose-dependently reduced the levels of the pro-inflammatory cytokines IL-6(466.82 ± 48.55 vs 603.50 ± 75.53, P < 0.05) and TNF-α(108.04 ± 16.10 vs 215.56 ± 74.67, P < 0.05) and increased the level of the anti-inflammatory cytokine IL-10(200.96 ± 50.76 vs 54.18 ± 6.07, P < 0.05) compared with those in the SAP group. CEB increased cell viability, inhibited cytosolic Ca2+ concentration, and significantly ameliorated intracellular vacuoles and IP3 m RNA expression compared with those in the SAP group(P < 0.05). There was a trend towards decreased IP3 R protein in the CEB treatment group; however, it did not reach statistical significance(P > 0.05).CONCLUSION These results at the cellular and organism levels reflect a preliminary mechanism of CEB in SAP and indicate that CEB is a suitable approach for SAP treatment.展开更多
Summary: This paper aimed to study the ability of baicalein to block human cytomegalovirus (HCMV) infection in extravillous cytotrophoblasts (EVT) and its effect on the vasoactive intestinal peptide (VIP) expre...Summary: This paper aimed to study the ability of baicalein to block human cytomegalovirus (HCMV) infection in extravillous cytotrophoblasts (EVT) and its effect on the vasoactive intestinal peptide (VIP) expression in HCMV-infected EVT in vitro. A human trophoblast cell line (HPT-8) was chosen in this study. HCMV with 100 TCIDs0was added into culture medium to infect HPT-8 cells, and then HCMV pp65 antigen was assayed by immunofluorescence staining. The infection status was determined by vi- rus titration. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect virus DNA load in the infected cells. The expression of VIP mRNA and protein in the infected cells was measured by qRT-PCR, immunocytochemistry and Western blotting. Concentration of VIP secreted in supernatants was determined by ELISA. Red-stained HCMV pp65 antigens were found in infected HPT-8 cells 48 h after infection. HCMV replicated in large quantity in infected HPT-8 cells 4 days after infection, reaching a peak at day 6 post-infection. After treatment with baicalein, virus DNA load in in- fected HPT-8 cells was decreased (P〈0.05), and the levels of VIP mRNA and protein, and the concen- tration were raised to the normal (P〉0.05). Our study suggested that baicalein exerts a positive effect on the VIP expression in HCMV-infected EVT at maternal-fetal interface.展开更多
OBJECTIVE To investigate the anti-tremor effect and mechanism of baicalein on oxotremorine-induced muscle tremor in mice.METHODS The acute model of muscular tremor was induced by intraperitoneal injection of oxotremor...OBJECTIVE To investigate the anti-tremor effect and mechanism of baicalein on oxotremorine-induced muscle tremor in mice.METHODS The acute model of muscular tremor was induced by intraperitoneal injection of oxotremorine,and the latency,duration and frequency of muscle tremor in mice were measured immediately;the saliva of mice was measured to reflect the correlation between tremor and peripheral nerve function;the aim of this study was to determine the content of MDA and the activity of GSH-PX,and to investigate the anti-oxidation of mice with tremor model.The activity of acetylcholinesterase(AchE)and acetylcholine transferase(ChA T)can indirectly reflect the level of acetylcholine in the brain.The level of monoamine neurotransmitters in brain tissue was determined by high performance liquid chromatography(HPLC-ECD).RESULTS The animals in the model group appeared obvious tremoring,salivating and erecting and other symptoms.Compared to the model group,there was no obvious inhibitory effect on the administration of each dose.After 7,14,21 and 28 d of continuous administration,the latency,duration and tremor frequency of tremor mice were significantly shortened,the levels of acetylcholine were significantly decreased,the changes of DOPAC and DA neurotransmitters in the brain of model group were recovered,regulate the dynamic balance of acetylcholine and dopamine in the brain.CONCLUSION Long-term administration can improve the tremor behavior of mice,the mechanismmay be related to the regulation of neurotransmittersin brain.展开更多
Objective: To determine the in vitro and in vivo absorption properties of active ingredients of the Chinese medicine, baicalein, to enrich mechanistic understanding of oral drug absorption.Methods: The Biopharmaceutic...Objective: To determine the in vitro and in vivo absorption properties of active ingredients of the Chinese medicine, baicalein, to enrich mechanistic understanding of oral drug absorption.Methods: The Biopharmaceutic Classification System(BCS) category was determined using equilibrium solubility, intrinsic dissolution rate, and intestinal permeability to evaluate intestinal absorption mechanisms of baicalein in rats in vitro. Physiologically based pharmacokinetic(PBPK) model commercial software GastroPlus~(TM) was used to predict oral absorption of baicalein in vivo.Results: Based on equilibrium solubility, intrinsic dissolution rate, and permeability values of main absorptive segments in the duodenum, jejunum, and ileum, baicalein was classified as a drug with low solubility and high permeability. Intestinal perfusion with venous sampling(IPVS) revealed that baicalein was extensively metabolized in the body, which corresponded to the low bioavailability predicted by the PBPK model. Further, the PBPK model predicted the key indicators of BCS, leading to reclassification as BCS-II. Predicted values of peak plasma concentration of the drug(C_(max)) and area under the curve(AUC)fell within two times of the error of the measured results, highlighting the superior prediction of absorption of baicalein in rats, beagles, and humans. The PBPK model supported in vitro and in vivo evidence and provided excellent prediction for this BCS class II drug.Conclusion: BCS and PBPK are complementary methods that enable comprehensive research of BCS parameters, intestinal absorption rate, metabolism, prediction of human absorption fraction and bioavailability, simulation of PK, and drug absorption in various intestinal segments across species. This combined approach may facilitate a more comprehensive and accurate analysis of the absorption characteristics of active ingredients of Chinese medicine from in vitro and in vivo perspectives.展开更多
The interaction of baicalein with bovine serum albumin(BSA) was investigated with the help of spectroscopic and molecular docking studies.The binding affinity of baicalein towards BSA was estimated to be in order of...The interaction of baicalein with bovine serum albumin(BSA) was investigated with the help of spectroscopic and molecular docking studies.The binding affinity of baicalein towards BSA was estimated to be in order of 10~5 M^(-1) from fluorescence quenching studies.Negative ΔH°(-5.66 + 0.14 kJ/mol) and positive(ΔS°)(+ 79.96 + 0.65J/mol K) indicate the presence of electrostatic interactions along with the hydrophobic forces that result in a positive ΔS°.The hydrophobic association of baicalein with BSA diminishes in the presence of sodium dodecyl sulfate(SDS) due to probable hydrophobic association of baicalein with SDS,resulting in a negative ΔS°(-40.65 + 0.87 J/mol K).Matrix-assisted laser desorption ionization/time of flight(MALDI-TOF) experiments indicate a 1:1 complexation between baicalein and BSA.The unfolding and refolding phenomena of BSA were investigated in the absence and presence of baicalein using steady-state and fluorescence lifetime measurements.It was observed that the presence of urea ruptured the non-covalent interaction between baicalein and BSA.The presence of metal ions(Ag~+,Mg^(2+),Ni^(2+),Mn^(2+),Co^(2+) and Zn^(2+)) increased the binding affinity of ligand towards BSA.The changes in conformational aspects of BSA after ligand binding were also investigated using circular dichroism(CD) and Fourier transform infrared(FT-IR) spectroscopic techniques.Site selectivity studies following molecular docking analyses indicated the binding of baicalein to site 1(subdomain MA) of BSA.展开更多
Aim To study the effects of baicalein (BC), a phenolic flavonoid extracted mainly from Scutellaria ba- icalensis Georgi, on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and the molecular mech...Aim To study the effects of baicalein (BC), a phenolic flavonoid extracted mainly from Scutellaria ba- icalensis Georgi, on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and the molecular mecha- nisms underlying. Methods Mice were administrated intranasally with LPS (20 mg · kg^-1/body weight) to estab- lish the ALI model. Then the mice were treated twice with BC (50,100 and 200 mg · kg^-1, p. o. ) 0. 5 hour and 12 hours after LPS stimulation, following another 12 hours, the lungs were collected for histological study. Results LPS caused marked inflammatory cell infiltration and myeloperoxidase activation in lungs, accompanied by significantly in- creased lung W/D ratio, from 7.97±0. 60 in normal group to 12. 49 ± 1.49 in the model. 77.88% reduction in the lung W/D ratio was observed in 200 mg· kg^-1 dose of baicalein. The myeloperoxidase activity was reduced to 40. 14% in mice treated with 200 mg · kg^-1. The number of total cells, neutrophils, and macrophages in BALF de- creased with increasing concentration of baicalein. Inflammatory cytokines level in serum declined significantly while insignificant changes of the same in BALF was observed in mice treated with 50,100 and 200 mg · kg^-1 doses of ba- icalein. Furthermore, LPS induced markedly the expression of inflammasomes and other inflammation-related genes in lung tissue. Treatment of LPS-exposed mice with BC significantly reduced the expression levels of these genes and al- leviated the pathological changes in lungs. Moreover, 1 μmol · L^-1 and 10 μmol · L^-1 BC inhibited remarkably the nuclear translocation of NF-kappaB p65 in Raw264.7 cells. Conclusion Baicalein alleviates LPS-induced acute lung injury in mice by suppressing NF-KB-mediated inflammatory responses and downregulation of inflammasomes.展开更多
Aim Baicalein is the major flavonoid obtained from the Scutellaria root. Our previous studies have dem- onstrated that baicalein has a clear positive effect on recovery in an experimental model of Parkinsonism. The pu...Aim Baicalein is the major flavonoid obtained from the Scutellaria root. Our previous studies have dem- onstrated that baicalein has a clear positive effect on recovery in an experimental model of Parkinsonism. The put- pose of this study was to investigate the role of baicalein in modulating dopamine (DA) metabolism in PC12 cells and to explore possible mechanisms of its actions. Methods The intracellular content and extracellular release of DA in both rotenone-treated and untreated PC12 cells were examined. Second, PC12 cells were first pretreated with baicalein ( 10 μmol · L^-1 ) for 10 rain, and then incubated with or without ionomycin (5 μmol · L^-1 ) for 10 rain to test whether short-term exposure to baicalein affected calcium-dependent or spontaneous DA release. Third, the intracellular and extracellular contents of DA and its related metabolites were examined. After treatment with baica- lein for 24 h, the The tyrosine hydroxylase (TH), monoamine oxidase B (MAOB), catechol-O-methyltransferase (COMT) and dopamine transporter (DAT) were detected by immunoblot analysis. Results The results showed that baicalein prevented rotenone-induced cytotoxicity and significantly increased the DA content in both rotenone- treated and untreated PC12 cells. Furthermore, it had no effect on ionomycin-induced or spontaneous DA release after short-term exposure but significantly increased DA content in a time- and dose-dependent manner after treat- ment for 6 h. Baicalein also significantly decreased the intracellular and extracellular homovanillic acid (HVA) content but increased the intracellular 3,4-dihydroxy phenylacetic acid (DOPAC) content. Finally, baicalein sig- nificantly decreased the expression of COMT and DAT, but it had no effect on the expression of TH and MAOB. Conclusion These data suggest that bacalein has the ability to increase DA content and modulate DA metabolism by inhibiting the expression of COMT and DAT. Our study provides evidence that baicalein may be a potential anti- PD drug that merits further study.展开更多
The in vitro effects of baicalein,wogonin,baicalin and Na_2MoO_4 on N-nitrosation reaction have been studied. The N-nitrosation reaction has been determined by the amount of dimethylnitrosamine(DMN) and diethylnitrosa...The in vitro effects of baicalein,wogonin,baicalin and Na_2MoO_4 on N-nitrosation reaction have been studied. The N-nitrosation reaction has been determined by the amount of dimethylnitrosamine(DMN) and diethylnitrosamine(DEN) produced using the UV-photclysis spectrophotometric and pyrolysis gas chromatography test. Baicalein,wogonin and Na_2MoO_4 showed varing extents of inhibition of the formation of DMN and DEN. Baicalin promoted the formation of DMN and DEN under the condition of simulating gastric Juices. It is also found that E. coli showed a remarkable promoting effect on the formation of DMN and DEN,but this promoting effect could be blocked to some extent by baicalein,wogonin,baicalin and Na_2MoO_4. Besides, Na_2MoO_4 and wogonin have shown synergic effect on the blocking of N-nitrosation reaction.展开更多
基金The research was funded by a USDA Multistate(2052R)grant from the CTAHR University of Hawaii at Manoa to B.M.
文摘Background High environmental temperatures induce heat stress in broiler chickens,affecting their health and pro-duction performance.Several dietary,managerial,and genetics strategies have been tested with some success in mitigating heat stress(HS)in broilers.Developing novel HS mitigation strategies for sustaining broiler production is critically needed.This study investigated the effects of pre-hatch thermal manipulation(TM)and post-hatch baica-lein supplementation on growth performance and health parameters in heat-stressed broilers.Results Six hundred fertile Cobb 500 eggs were incubated for 21 d.After candling on embryonic day(ED)10,238 eggs were thermally manipulated at 38.5℃ with 55%relative humidity(RH)from ED 12 to 18,then transferred to the hatcher(ED 19 to 21,standard temperature)and 236 eggs were incubated at a controlled temperature(37.5℃)till hatch.After hatch,180-day-old chicks from both groups were raised in 36 pens(n=10 birds/pen,6 replicates per treatment).The treatments were:1)Control,2)TM,3)control heat stress(CHS),4)thermal manipulation heat stress(TMHS),5)control heat stress supplement(CHSS),and 6)thermal manipulation heat stress supplement(TMHSS).All birds were raised under the standard environment for 21 d,followed by chronic heat stress from d 22 to 35(32–33℃ for 8 h)in the CHS,TMHS,CHSS,and TMHSS groups.A thermoneutral(22–24℃)environment was maintained in the Control and TM groups.RH was constant(50%±5%)throughout the trial.All the data were analyzed using one-way ANOVA in R and GraphPad software at P<0.05 and are presented as mean±SEM.Heat stress significantly decreased(P<0.05)the final body weight and ADG in CHS and TMHS groups compared to the other groups.Embryonic TM significantly increased(P<0.05)the expression of heat shock protein-related genes(HSP70,HSP90,and HSPH1)and antioxidant-related genes(GPX1 and TXN).TMHS birds showed a significant increment(P<0.05)in total cecal volatile fatty acid(VFA)concentration compared to the CHS birds.The cecal microbial analysis showed significant enrichment(P<0.05)in alpha and beta diversity and Coprococcus in the TMHSS group.Conclusions Pre-hatch TM and post-hatch baicalein supplementation in heat-stressed birds mitigate the detrimental effects of heat stress on chickens’growth performance,upregulate favorable gene expression,increase VFA produc-tion,and promote gut health by increasing beneficial microbial communities.
文摘In this work,p⁃phenylenediamine and L⁃cysteine were used as raw materials,and water⁃soluble N,S co⁃doped carbon dots(N,S⁃CDs)with excellent performance were prepared through a one⁃step solvothermal method.The morphology and structure of N,S⁃CDs were characterized by transmission electron microscope,X⁃ray diffrac⁃tion,Fourier transform infrared spectroscopy,and X⁃ray photoelectron spectroscopy,and the basic photophysical properties were investigated via UV⁃Vis absorption spectra and fluorescence spectra.Meanwhile,the N,S⁃CDs have excellent luminescence stability with pH,ionic strength,radiation time,and storage time.Experimental results illus⁃trated the present sensor platform exhibited high sensitivity and selectivity in response to baicalein with a detection limit of 85 nmol·L-1.The quenching mechanism is proved to be the inner filter effect.In addition,this sensor can also detect baicalein in biofluids(serum and urine)with good accuracy and reproducibility.
文摘Current colorectal cancer (CRC) treatments exhibit unwanted cytotoxicity against healthy proliferating cells. Hence, these therapeutics demand higher specificity upon drug delivery, a task that may be facilitated by the discovery of anticancer agents bearing critical mechanisms of action. Baicalein is a flavonoid with promising anticancer activity, among other pharmacological benefits, and has therefore been of high clinical interest. We tested baicalein in vitro for its effect on several CRC hallmarks, including the suppression of metastasis (the spread of cancer cells from their initial site), the ability to induce apoptosis (cell death), and the inhibition of proliferation (the growth of cells). The suppression of the metastasis of CRC cells was recorded via two studies: the cell migration assay and the in silico docking of baicalein with toll-like receptor 4 (TLR4) and matrix metalloproteinase-9 (MMP-9). Results from the cell migration assay showed that baicalein inhibited metastasis by up to 25.76% (p 0.01) in a concentration-dependent manner. We then reinforced these results by docking baicalein with TLR4 (binding affinity: -8.4 kcal/mol) and docking baicalein with MMP-9 (binding affinity: -7.9 kcal/mol), classifying strong binding affinities as those less than -6.0 kcal/mol. The induction of cell death was measured using a caspase activity assay. Again, a docking study was done to reinforce the findings from the primary in vitro experiment, though this time between baicalein and caspase-3 (binding affinity: -7.1 kcal/mol). Despite mixed observations in concentration dependence, caspase activity, relative to control, reached a maximal increase of 88.6% (p 0.01), and results from the MTT assay demonstrated a survival rate, relative to control, of as low as 59.64%. Considerations for future studies include the testing of baicalein in vivo and on more aberrative CRC cell lines.
基金supported by National Natural Science Foundation of China(32072212)Multi-Year Research Grant of University of Macao(MYRG2018-00169-ICMS)+5 种基金Science and Technology Development Fund of Macao(FDCT)(0098/2020/A)MICINN supporting the Ramón y Cajal grant for M.A.Prieto(RYC-201722891)Jianbo Xiao(RYC2020-030365-I)Xunta de Galicia supporting the Axudas Conecta Peme,the IN852A 2018/58 Neuro Food Project,the program EXCELENCIA-ED431F 2020/12the pre-doctoral grants of P.García-Oliveira(ED481A-2019/295)to Ibero-American Program on Science and Technology(CYTED-AQUA-CIBUS,P317RT0003).
文摘Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.
文摘To investigate the metabolites of baicalein 6,7-diacetate in rats. HPLC-DAD and LC/MS^n methods were used to analyze the metabolites in intestinal tract and plasma after oral administration of baicalein 6,7-diacetate to rats. Baicalein 6,7-diacetate was degraded into baicalein 6-monoacetate and baicalein in rat intestinal tract, and four baicalein glucuronides, baicalein 6-0- glucuronide, baicalein 6-methoxyl-7-O-glucuronide, baicalein 6,7-di-O-glucuronide, and baicalein 6-O-glucose-7-O-glucuronide were detected and tentatively identified in rat plasma. This is the first time to report the metabolites of baicalein 6,7-diacetate in rats. Six metabolites were identified in rat intestinal tract and plasma.
文摘Baicalein(BE) is one of the main active flavonoids representing the variety of pharmacological effects including anticancer, anti-inflammatory and cardiovascular protective activities, but it's very low solubility, dissolution rate and poor oral absorption limit the therapeutic applications. In this work, a nano-cocrystal strategy was successfully applied to improve the dissolution rate and bioavailability of BE. Baicalein-nicotinamide(BE-NCT) nanococrystals were prepared by high pressure homogenization and evaluated both in vitro and in vivo. Physical characterization results including scanning electron microscopy, dynamic light scattering, powder X-ray diffraction and differential scanning calorimetry demonstrated that BE-NCT nano-cocrystals were changed into amorphous state with mean particle size of 251.53 nm. In the dissolution test, the BE-NCT nano-cocrystals performed 2.17-fold and 2.54-fold enhancement than BE coarse powder in FaSSIF-V2 and FaSSGF. Upon oral administration, the integrated AUC0-t of BE-NCT nano-cocrystals(6.02-fold) was significantly higher than BE coarse powder(1-fold), BE-NCT cocrystals(2.87-fold) and BE nanocrystals(3.32-fold). Compared with BE coarse powder, BE-NCT cocrystals and BE nanocrystals, BENCT nano-cocrystals possessed excellent performance both in vitro and in vivo evaluations.Thus, it can be seen that nano-cocrystal is an appropriate novel strategy for improving dissolution rate and bioavailability of poor soluble natural products such as BE.
基金Supported by The Fundamental Research Funds for the Central Universities No.JKQ2011008,JKQ2011010Postdoctoral Science Foundation of Jiangsu Province,China,No.1101029C
文摘AIM:To investigate the hepatoprotective effect of baicalein against carbon tetrachloride(CCl 4)-induced liver damage in mice.METHODS:Mice were orally administered with baicalein after CCl 4 injection,and therapeutic baicalein was given twice a day for 4 d.The anti-inflammation effects of baicalein were assessed directly by hepatic histology and serum alanine aminotranferease and aspartate aminotransferase measurement.Proliferating cell nuclear antigen was used to evaluate the effect of baicalein in promoting hepatocyte proliferation.Serum interleukin(IL)-6,IL-1β and tumor necrosis factor-α(TNF-α) levels were measured by enzyme-linked immunosorbent assay and liver IL-6,TNF-α,transforming growth factor-α(TGF-α),hepatocyte growth factor(HGF) and epidermal growth factor(EGF) genes expression were determined by quantitative real-time polymerase chain reaction.RESULTS:CCl4-induced acute liver failure model offers a survival benefit in baicalein-treated mice.The data indicated that the mRNA levels of IL-6 and TNF-α significantly increased within 12 h after CCl 4 treatment in baicalein administration groups,but at 24,48 and 72 h,the expression of IL-6 and TNF-α was kept at lower levels compared with the control.The expression of TGF-α,HGF and EGF was enhanced dramatically in baicalein administration group at 12,24,48 and 72 h.Furthermore,we found that baicalein significantly elevated the serum level of TNF-α and IL-6 at the early phase,which indicated that baicalein could facilitate the initiating events in liver regeneration.CONCLUSION:Baicalein may be a therapeutic candidate for acute liver injury.Baicalein accelerates liver regeneration by regulating TNF-α and IL-6 mediated pathways.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.61137005 and No.10974023), the Program for Liaoning Excellent Talents in University (No.LJQ2012002), and the Program for New Century Excellent Talents in University (No.NCET-12-0077).
文摘The excited state intramolecular proton transfer (ESIPT) coupled charge transfer of baicalein has been investigated using steady-state spectroscopic experiment and quantum chemistry calculations. The absence of the absorption peak from S1 excited state both in the experi-mental and calculated absorption spectra indicates that S1 is a dark state. The dark excited state S1 results in the very weak fluorescence of solid baicalein in the experiment. The fron- tier molecular orbital and the charge difference densities of baicalein show clearly that the S1 state is a charge-transfer state whereas the S2 state is a locally excited state. The only one stationary point on the potential energy profile of excited state suggests that the ESIPT reaction of baicalein is a barrierless process.
基金Supported by National Natural Science Foundation of China,No.30901945Science Research Foundation of Shaanxi Administration of Traditional Chinese Medicine,No.15-ZY029Science Research Foundation of the Second Affiliated Hospital of Xi’an Jiaotong University,No.RC(XM)201602
文摘AIM To investigate the effects of combined use of emodin and baicalein(CEB) at the cellular and organism levelsin severe acute pancreatitis(SAP) and explore the underlying mechanism.METHODS SAP was induced by retrograde infusion of 5% sodium taurocholate into the pancreatic duct in 48 male SD rats. Pancreatic histopathology score, serum amylase activity, and levels of tumour necrosis factor alpha(TNf-α), interleukin 6(IL-6), and IL-10 were determined to assess the effects of CEB at 12 h after the surgery. The rat pancreatic acinar cells were isolated from healthy male SD rats using collagenase. The cell viability, cell ultrastructure, intracellular free Ca2+ concentration, and inositol(1,4,5)-trisphosphate receptor(IP3 R) expression were investigated to assess the mechanism of CEB.RESULTS Pancreatic histopathology score(2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05) and serum amylase activity(2866.2 ± 617.7 vs 5241.3 ± 1410.0, P < 0.05) were significantly decreased in the CEB(three doses) treatment group compared with the SAP group(2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05). CEB dose-dependently reduced the levels of the pro-inflammatory cytokines IL-6(466.82 ± 48.55 vs 603.50 ± 75.53, P < 0.05) and TNF-α(108.04 ± 16.10 vs 215.56 ± 74.67, P < 0.05) and increased the level of the anti-inflammatory cytokine IL-10(200.96 ± 50.76 vs 54.18 ± 6.07, P < 0.05) compared with those in the SAP group. CEB increased cell viability, inhibited cytosolic Ca2+ concentration, and significantly ameliorated intracellular vacuoles and IP3 m RNA expression compared with those in the SAP group(P < 0.05). There was a trend towards decreased IP3 R protein in the CEB treatment group; however, it did not reach statistical significance(P > 0.05).CONCLUSION These results at the cellular and organism levels reflect a preliminary mechanism of CEB in SAP and indicate that CEB is a suitable approach for SAP treatment.
基金supported by grants from the National Natural Science Foundation of China (Nos. 39970769, 30371488,30672243, and 81200354)the Natural Science Foundation of Hubei Province (No. 2009CDD216)
文摘Summary: This paper aimed to study the ability of baicalein to block human cytomegalovirus (HCMV) infection in extravillous cytotrophoblasts (EVT) and its effect on the vasoactive intestinal peptide (VIP) expression in HCMV-infected EVT in vitro. A human trophoblast cell line (HPT-8) was chosen in this study. HCMV with 100 TCIDs0was added into culture medium to infect HPT-8 cells, and then HCMV pp65 antigen was assayed by immunofluorescence staining. The infection status was determined by vi- rus titration. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect virus DNA load in the infected cells. The expression of VIP mRNA and protein in the infected cells was measured by qRT-PCR, immunocytochemistry and Western blotting. Concentration of VIP secreted in supernatants was determined by ELISA. Red-stained HCMV pp65 antigens were found in infected HPT-8 cells 48 h after infection. HCMV replicated in large quantity in infected HPT-8 cells 4 days after infection, reaching a peak at day 6 post-infection. After treatment with baicalein, virus DNA load in in- fected HPT-8 cells was decreased (P〈0.05), and the levels of VIP mRNA and protein, and the concen- tration were raised to the normal (P〉0.05). Our study suggested that baicalein exerts a positive effect on the VIP expression in HCMV-infected EVT at maternal-fetal interface.
文摘OBJECTIVE To investigate the anti-tremor effect and mechanism of baicalein on oxotremorine-induced muscle tremor in mice.METHODS The acute model of muscular tremor was induced by intraperitoneal injection of oxotremorine,and the latency,duration and frequency of muscle tremor in mice were measured immediately;the saliva of mice was measured to reflect the correlation between tremor and peripheral nerve function;the aim of this study was to determine the content of MDA and the activity of GSH-PX,and to investigate the anti-oxidation of mice with tremor model.The activity of acetylcholinesterase(AchE)and acetylcholine transferase(ChA T)can indirectly reflect the level of acetylcholine in the brain.The level of monoamine neurotransmitters in brain tissue was determined by high performance liquid chromatography(HPLC-ECD).RESULTS The animals in the model group appeared obvious tremoring,salivating and erecting and other symptoms.Compared to the model group,there was no obvious inhibitory effect on the administration of each dose.After 7,14,21 and 28 d of continuous administration,the latency,duration and tremor frequency of tremor mice were significantly shortened,the levels of acetylcholine were significantly decreased,the changes of DOPAC and DA neurotransmitters in the brain of model group were recovered,regulate the dynamic balance of acetylcholine and dopamine in the brain.CONCLUSION Long-term administration can improve the tremor behavior of mice,the mechanismmay be related to the regulation of neurotransmittersin brain.
基金supported by the National Natural Science Foundation of China (81473362)。
文摘Objective: To determine the in vitro and in vivo absorption properties of active ingredients of the Chinese medicine, baicalein, to enrich mechanistic understanding of oral drug absorption.Methods: The Biopharmaceutic Classification System(BCS) category was determined using equilibrium solubility, intrinsic dissolution rate, and intestinal permeability to evaluate intestinal absorption mechanisms of baicalein in rats in vitro. Physiologically based pharmacokinetic(PBPK) model commercial software GastroPlus~(TM) was used to predict oral absorption of baicalein in vivo.Results: Based on equilibrium solubility, intrinsic dissolution rate, and permeability values of main absorptive segments in the duodenum, jejunum, and ileum, baicalein was classified as a drug with low solubility and high permeability. Intestinal perfusion with venous sampling(IPVS) revealed that baicalein was extensively metabolized in the body, which corresponded to the low bioavailability predicted by the PBPK model. Further, the PBPK model predicted the key indicators of BCS, leading to reclassification as BCS-II. Predicted values of peak plasma concentration of the drug(C_(max)) and area under the curve(AUC)fell within two times of the error of the measured results, highlighting the superior prediction of absorption of baicalein in rats, beagles, and humans. The PBPK model supported in vitro and in vivo evidence and provided excellent prediction for this BCS class II drug.Conclusion: BCS and PBPK are complementary methods that enable comprehensive research of BCS parameters, intestinal absorption rate, metabolism, prediction of human absorption fraction and bioavailability, simulation of PK, and drug absorption in various intestinal segments across species. This combined approach may facilitate a more comprehensive and accurate analysis of the absorption characteristics of active ingredients of Chinese medicine from in vitro and in vivo perspectives.
基金Department of Science and Technology(DST,Project no.SR/SO/BB-54/2007),Government of India for financial support
文摘The interaction of baicalein with bovine serum albumin(BSA) was investigated with the help of spectroscopic and molecular docking studies.The binding affinity of baicalein towards BSA was estimated to be in order of 10~5 M^(-1) from fluorescence quenching studies.Negative ΔH°(-5.66 + 0.14 kJ/mol) and positive(ΔS°)(+ 79.96 + 0.65J/mol K) indicate the presence of electrostatic interactions along with the hydrophobic forces that result in a positive ΔS°.The hydrophobic association of baicalein with BSA diminishes in the presence of sodium dodecyl sulfate(SDS) due to probable hydrophobic association of baicalein with SDS,resulting in a negative ΔS°(-40.65 + 0.87 J/mol K).Matrix-assisted laser desorption ionization/time of flight(MALDI-TOF) experiments indicate a 1:1 complexation between baicalein and BSA.The unfolding and refolding phenomena of BSA were investigated in the absence and presence of baicalein using steady-state and fluorescence lifetime measurements.It was observed that the presence of urea ruptured the non-covalent interaction between baicalein and BSA.The presence of metal ions(Ag~+,Mg^(2+),Ni^(2+),Mn^(2+),Co^(2+) and Zn^(2+)) increased the binding affinity of ligand towards BSA.The changes in conformational aspects of BSA after ligand binding were also investigated using circular dichroism(CD) and Fourier transform infrared(FT-IR) spectroscopic techniques.Site selectivity studies following molecular docking analyses indicated the binding of baicalein to site 1(subdomain MA) of BSA.
文摘Aim To study the effects of baicalein (BC), a phenolic flavonoid extracted mainly from Scutellaria ba- icalensis Georgi, on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and the molecular mecha- nisms underlying. Methods Mice were administrated intranasally with LPS (20 mg · kg^-1/body weight) to estab- lish the ALI model. Then the mice were treated twice with BC (50,100 and 200 mg · kg^-1, p. o. ) 0. 5 hour and 12 hours after LPS stimulation, following another 12 hours, the lungs were collected for histological study. Results LPS caused marked inflammatory cell infiltration and myeloperoxidase activation in lungs, accompanied by significantly in- creased lung W/D ratio, from 7.97±0. 60 in normal group to 12. 49 ± 1.49 in the model. 77.88% reduction in the lung W/D ratio was observed in 200 mg· kg^-1 dose of baicalein. The myeloperoxidase activity was reduced to 40. 14% in mice treated with 200 mg · kg^-1. The number of total cells, neutrophils, and macrophages in BALF de- creased with increasing concentration of baicalein. Inflammatory cytokines level in serum declined significantly while insignificant changes of the same in BALF was observed in mice treated with 50,100 and 200 mg · kg^-1 doses of ba- icalein. Furthermore, LPS induced markedly the expression of inflammasomes and other inflammation-related genes in lung tissue. Treatment of LPS-exposed mice with BC significantly reduced the expression levels of these genes and al- leviated the pathological changes in lungs. Moreover, 1 μmol · L^-1 and 10 μmol · L^-1 BC inhibited remarkably the nuclear translocation of NF-kappaB p65 in Raw264.7 cells. Conclusion Baicalein alleviates LPS-induced acute lung injury in mice by suppressing NF-KB-mediated inflammatory responses and downregulation of inflammasomes.
文摘Aim Baicalein is the major flavonoid obtained from the Scutellaria root. Our previous studies have dem- onstrated that baicalein has a clear positive effect on recovery in an experimental model of Parkinsonism. The put- pose of this study was to investigate the role of baicalein in modulating dopamine (DA) metabolism in PC12 cells and to explore possible mechanisms of its actions. Methods The intracellular content and extracellular release of DA in both rotenone-treated and untreated PC12 cells were examined. Second, PC12 cells were first pretreated with baicalein ( 10 μmol · L^-1 ) for 10 rain, and then incubated with or without ionomycin (5 μmol · L^-1 ) for 10 rain to test whether short-term exposure to baicalein affected calcium-dependent or spontaneous DA release. Third, the intracellular and extracellular contents of DA and its related metabolites were examined. After treatment with baica- lein for 24 h, the The tyrosine hydroxylase (TH), monoamine oxidase B (MAOB), catechol-O-methyltransferase (COMT) and dopamine transporter (DAT) were detected by immunoblot analysis. Results The results showed that baicalein prevented rotenone-induced cytotoxicity and significantly increased the DA content in both rotenone- treated and untreated PC12 cells. Furthermore, it had no effect on ionomycin-induced or spontaneous DA release after short-term exposure but significantly increased DA content in a time- and dose-dependent manner after treat- ment for 6 h. Baicalein also significantly decreased the intracellular and extracellular homovanillic acid (HVA) content but increased the intracellular 3,4-dihydroxy phenylacetic acid (DOPAC) content. Finally, baicalein sig- nificantly decreased the expression of COMT and DAT, but it had no effect on the expression of TH and MAOB. Conclusion These data suggest that bacalein has the ability to increase DA content and modulate DA metabolism by inhibiting the expression of COMT and DAT. Our study provides evidence that baicalein may be a potential anti- PD drug that merits further study.
文摘The in vitro effects of baicalein,wogonin,baicalin and Na_2MoO_4 on N-nitrosation reaction have been studied. The N-nitrosation reaction has been determined by the amount of dimethylnitrosamine(DMN) and diethylnitrosamine(DEN) produced using the UV-photclysis spectrophotometric and pyrolysis gas chromatography test. Baicalein,wogonin and Na_2MoO_4 showed varing extents of inhibition of the formation of DMN and DEN. Baicalin promoted the formation of DMN and DEN under the condition of simulating gastric Juices. It is also found that E. coli showed a remarkable promoting effect on the formation of DMN and DEN,but this promoting effect could be blocked to some extent by baicalein,wogonin,baicalin and Na_2MoO_4. Besides, Na_2MoO_4 and wogonin have shown synergic effect on the blocking of N-nitrosation reaction.