Analysis of the role of dihydromyricetin derived from vine tea(Ampelopsis grossedentata)on multiple myeloma by activating STAT1/RIG-I axis

Multiple myeloma(MM)is a plasma cell malignancy and remains incurable as it lacks effective curative approaches;thus,novel therapeutic strategies are desperately needed.The study aimed to explore the therapeutic role of dihydromyricetin(DHM)in MM and explore its mechanisms.Human MM and normal plasma samples,human MM cell lines,and normal plasma cells were used for in vitro experiments.Cell counting kit-8(CCK-8),flow cytometry,and trans-well assays were performed for the assessment of cell viability,apoptosis,migration,and invasion,respectively.Quantitative real-time polymerase chain reaction(qRT-PCR)was employed to assess the mRNA expression of signal transducer and activator of transcription 1(STAT1)and retinoic acid-inducible gene I(RIG-I).Western blotting was employed to assess E-cadherin,N-cadherin,signal transducer,STAT1,p-STAT1,and RIG-I protein expression.A tumor xenograft model was used for in vivo experiments.Here,dihydromyricetin(DHM)dose-dependently restrained viability,apoptosis,migration,and invasion,and facilitated apoptosis of U266 cells.After DHM treatment,the Ecadherin level was increased and the N-cadherin level was decreased in U266 and RPMI-8226 cells,suggesting the inhibitory effects of DHM on epithelial-mesenchymal transition(EMT)in MM.Besides,the levels of p-STAT1/STAT1 and RIG-I were down-regulated in MM.However,the STAT1 inhibitor fludarabine undid the suppressive effect of DMH on the malignant characteristics of U266 cells.Also,DHM inhibited MM tumor growth and EMT,and activated STAT1/RIG-I pathway in vivo.Collectively,this study first revealed that DHM can restrain EMT and tumor growth in MM by activating STAT1/RIG-I signaling,which provides a novel drug for the treatment of MM.

A magnetic biocatalyst based on mussel-inspired polydopamine and its acylation of dihydromyricetin

A support made of mussel-inspired polydopamine-coated magnetic iron oxide nanoparticles （PD-MNPs） was prepared and characterized. The widely used Aspetyillus niger lipase （ANL） was immobilized on the PD-MNPs （ANL@PD-MNPs） with a protein loading of 138 mg/g and an activity recovery of 83.6% under optimized conditions. For the immobilization, the pH and immobilization time were investigated. The pH and thermal and storage stability of the ANL@PD-MNPs significant- ly surpassed those of free ANL. The ANL@PD-MNPs had better solvent tolerance than free ANL. The secondary structure of free ANL and ANL@PD-MNPs was analyzed by infrared spectroscopy, A kinetic study demonstrated that the ANL@PD-MNPs had enhanced enzyme-substrate affinity and high catalytic efficiency. The ANL@PD-MNPs was applied as a biocatalyst for the regioselective acylation of dihydromyricetin （DMY） in DMSO and gave a conversion of 79.3%, which was higher than that of previous reports. The ANL@PD-MNPs retained over 55% of its initial activity after 10 cycles of reuse. The ANL@PD-MNPs were readily separated from the reaction system by a magnet. The PD-MNPs is an excellent support for ANL and the resulting ANL@PD-MNPs displayed good potential for the efficient synthesis of dihydromyricetin-3-acetate by enzymatic regioselective acylation.

Dihydromyricetin inhibits migration and invasion of hepatoma cells through regulation of MMP-9 expression

AIM: To investigate the effects of dihydromyricetin (DHM) on the migration and invasion of human hepatic cancer cells.

Dihydromyricetin alleviates carbon tetrachloride-induced acute liver injury via JNK-dependent mechanism in mice

AIM: To assess the effects of dihydromyricetin(DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride(CCl4) treatment.METHODS: C57 BL/6 mice were used in this study. Mice were orally administered with DHM(150 mg/kg) for 4 d after CCl4 treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl4 treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase(AST), alanine aminotransferase(ALT), albumin, and superoxide dismutase(SOD). Inflammatory cytokines, such as interleukin(IL)-1β, IL-6 and tumor necrosis factor-α(TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen(PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis wasmeasured by TUNEL assay.Furthermore,apoptosis proteins Caspases-3,6,8,and 9 were detected by Western blot.SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-αpathways.RESULTS:DHM showed a strong anti-inflammatory effect on CCl4-induced liver injury in mice.DHM could significantly decrease serum ALT,AST,IL-1β,IL-6 and TNF-αand increase serum albumin,SOD and liver SOD compared to the control group after CCl4 treatment(P<0.05).PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control(348.9±56.0 vs 107.1±31.4,P<0.01).TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control(365.4±99.4 vs 90.5±13.8,P<0.01).Caspase activity detection showed that DHM could reduce the activities of Caspases-8,3,6 and 9 compared to the control(P<0.05).The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-αexpression.However,DHM could not affect TNF-αexpression after SP600125 treatment.Furthermore,DHM could significantly improve the survival rate of acute liver failure(ALF)mice(73.3%vs 20.0%,P<0.0001),and SP600125 could inhibit the effect of DHM.CONCLUSION:These findings demonstrate that DHM alleviates CCl4-induced liver injury,suggesting that DHM is a promising candidate for reversing liver injury and ALF.

Dihydromyricetin-mediated inhibition of the Notch1 pathway induces apoptosis in QGY7701 and Hep G2 hepatoma cells

AIM To investigate whether Dihydromyricetin(DHM) inhibits cell proliferation and promotes apoptosis by downregulating Notch1 expression.METHODS The correlation between Notch1 and Hes1(a Notch1 target molecule) expression in hepatoma samples was confirmed by q RT-PCR. In addition, MTT assays, flow cytometry and TUNEL analysis showed that DHM possessed strong anti-tumor properties, evidenced not only by reduced cell proliferation but also by enhanced apoptosis in QGY7701 and Hep G2 hepatocellular carcinoma(HCC) cells. The expressions of Notch1, Hes1, Bcl-2 and Bax were determined by Western blot.RESULTS Among the tested samples(n = 64), the expression levels of Notch1(75% of patients) and Hes1(79.7% of patients) m RNA in tumor tissues were higher than in the normal liver tissues. There was a negative correlation between the expression of Notch1 and the degree of differentiation and positively correlated with the Alpha Fetal Protein concentration. The viability of HCC cells treated with DHM was significantly inhibited in a dose and time-dependent manner. Apoptosis was induced in Hep G2 and QGY7701 cell lines following 24 h of DHM treatment. After treatment with DHM, the protein expression of Notch1 was downregulated, the apoptosis-related protein Bax was upregulated and Bcl2 was downregulated. Notch1 si RNA further enhanced the anti-tumor properties of DHM. CONCLUSION Notch1 is involved in the development of HCC and DHM inhibits cell proliferation and promotes apoptosis by down-regulating the expression of Notch1.

Recent advances in research on vine tea,a potential and functional herbal tea with dihydromyricetin and myricetin as major bioactive compounds

Vine tea has been used as an herbal tea by several ethnic minorities for hundreds of years in China.Flavonoids,a kind of indispensable component in a variety of nutraceutical,pharmaceutical and cosmetic applications,are identified to be the major metabolites and bioactive ingredients in vine tea.Interestingly,vine tea exhibits a wide range of significant bioactivities including anti-oxidant,anti-inflammatory,anti-tumor,antidiabetic,neuroprotective and other activities,but no toxicity.These bioactivities,to some extent,enrich the understanding about the role of vine tea in disease prevention and therapy.The health benefits of vine tea,particularly dihydromyricetin and myricetin,are widely investigated.However,there is currently no comprehensive review available on vine tea.Therefore,this report summarizes the most recent studies investigating bioactive constituents,pharmacological effects and possible mechanisms of vine tea,which will provide a better understanding about the health benefits and preclinical assessment of novel application of vine tea.

Dihydromyricetin ameliorates chronic liver injury by reducing pyroptosis

BACKGROUND Chronic liver injury(CLI) is now a worldwide disease. However, there is no effective treatment. Pyroptosis plays an essential role in CLI. Dihydromyricetin(DHM) resists oxidation and protects the liver. We hypothesize that the beneficial effect of DHM on CLI is related to its effect on the expression of pyroptosisrelated molecules. Therefore, we studied the influence of DHM on CLI and pyroptosis.AIM To study the role of pyroptosis in the pathogenesis of CLI and the therapeutic mechanism of DHM.METHODS Thirty-two mice were randomly divided into four groups: The control group was injected with olive oil, the carbon tetrachloride(CCl4) group was injected with CCl4, the vehicle group was injected with hydroxypropyl-β-cyclodextrin while injecting CCl4 and the DHM group was injected with DHM while injecting CCl4. After four weeks of treatment, liver tissues from the mice were stained with hematoxylin and eosin, and oil red O. Blood was collected from the angular vein for serological analysis. The severity of CLI was estimated. Some liver tissue was sampled for immunohistochemistry, Western blotting and quantitative reverse transcription PCR to observe the changes in pyroptosis-related molecules.RESULTS Serum total cholesterol, low density lipoprotein, aspartate aminotransferase(AST) and alanine aminotransferase(ALT) in the CCl4 group were higher than those in the control group, and serum total cholesterol, low density lipoprotein, AST and ALT in the DHM group were lower than those in the vehicle group. Hematoxylin and eosin and oil red O staining showed that there were more lipid droplets in the CCl4 group than in the control group, and there were fewer lipid droplets in the DHM group than in the vehicle group. Western blotting showed that the expression of the pyroptosis-related molecules caspase-1, NOD-, LRR-and pyrin domain-containing 3(NLRP3) and gasdermin D(GSDMD)-N in the CCl4 group was higher than that in the control group, while expression of these proteins in the DHM group was lower than that in the vehicle group. Quantitative reverse transcription PCR results showed that the expression of the pyroptosis-related genes caspase-1, NLRP3, GSDMD and interleukin-1β(IL-1β) in the CCl4 group was higher than that in the control group, while there was no significant change in NLRP3 and caspase-1 expression in the DHM group compared with that in the vehicle group, and the expression of GSDMD and IL-1β was decreased.CONCLUSION DHM improves CCl4-induced CLI and regulates the pyroptosis pathway in hepatocytes. DHM may be a potential therapeutic agent for CLI.

Investigation of in vitro antioxidant activity of dihydromyricetin and flavonoids rich extract from vine tea(Ampelopsis grossedentata)

Background:Vine tea from fermented Ampelopsis grossedentata leaves has been used as a herbal tea and folk medicine in the southern region of China for hundreds of years.The aim of this investigation was to analyze the total flavonoids found in vine tea,including three bioactive flavonoids,and the total phenolic contents in the aqueous methanol extracts of 10 vine tea samples.In addition,this study also aimed to examine the antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract.Methods:The total flavonoids and total phenolic content assay of extracts from vine tea were performed by ultraviolet-visible spectroscopy and epoch microplate spectrophotometer,respectively.Three bioactive flavonoids were quantified simultaneously using high performance liquid chromatography.The antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract was evaluated in vitro using six different methods.Results:Vine tea contained a large number of flavonoids,with dihydromyricetin as its main constituent.The flavonoid-rich extract exhibited a significant scavenging effect on superoxide anion radicals,and on 3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl radicals.It also possessed definite activity in lipid peroxidation inhibition,ferric reduction,and the moderation of Fe2+ion chelation ability.There was a significant negative correlation between dihydromyricetin content and antioxidant activity in the vine tea samples,including superoxide anion radical scavenging activity(P=−0.754,P<0.05),lipid peroxidation inhibition activity(P=−0.759,P<0.05),ferric-reducing antioxidant power(P=−0.843,P<0.01),respectively.Dihydromyricetin played a dominant role in the antioxidant activities of the flavonoid-rich extract.Conclusion:Vine tea’s flavonoid-rich extract could be used as a new antioxidant source to safeguard against oxidative stress.

Study on Extraction and Separation of Dihydromyricetin from Vine Tea [Ampelopsis grossedentata(Hand-Mazz) W. T. wang]

Ampelopsis grossedentata(Hand-Mazz) W. T. wang is a typical edible plant with important physiological health functions. Dihydromyricetin is the main active ingredient of A. grossedentata, which has good pharmacological effects such as antibacterial, anti-inflammatory, anti-oxidation, anti-tumor and liver protecting effects. This paper summarized the research progress on the extraction materials, extraction methods and separation and purification processes of dihydromyricetin in A. grossedentata to understand the best experimental method of dihydromyricetin, aiming to provide an important theoretical basis for the comprehensive development and utilization of dihydromyricetin.

Theoretical Investigation on the Relationship between the Structures and Antioxidant Activities of Myricetin and Dihydromyricetin

The geometry of myricetin and dihydromyricetin was optimized by DMol3 program based on DFT. The optimized structures have been proved to be stable by real frequencies obtained.The parameters of geometry optimization,vibration frequencies,atomic charges,thermodynamics,Fukui functions,and frontier molecular orbital had been obtained. The thermodynamic properties of 2 molecules were fitted and the relationship between the thermodynamic function and temperature was obtained. The correlation coefficient of the obtained equations is larger than 0.99,indicating that the function is approximately linear in the whole temperature range. The calculated results showed the O–H molecular structures were the main group affecting the antioxidant activity and the oxygen in the benzene ring is the electrophilic reaction site. Ortho-OH on the benzene formed intramolecular hydrogen bonds,which contributed to the stability of the benzene ring. It may be the active site for the occurrence of the reaction.

Effects of Dihydromyricetin Extracted from Ampelopsis grossedentata on Visceral Organ Indexes and Intestinal Digestive Enzyme Activities of Chickens

To provide a reference basis for reasonable development and utilization of Ampelopsis grossedentata resource and its application in production,we added 0.025%,0.05% and 0.1% dihydromyricetin（DMY）extracted from A.grossedentata into the basal diets of Yaoshan chickens,and studied the effects of DMY on visceral organ indexes and digestive enzyme activities of 40-day-old healthy Yaoshan chickens.Supplementation of DMY in basal diets influenced visceral organ weight,organ index,length and digestive enzyme activity of small intestine of chickens.Among them,0.05% DMY was the most appropriate volume for supplementation.Compared with control group（without DMY）,0.05% DMY reduced lung weight and index（P〉0.05）,significantly reduced liver weight（P〈0.05）,extremely reduced stomach weight and stomach index（P〈0.01）,increased activity of amylase in small intestine（P〉0.05）,significantly increased length of small intestine and activity of protease（P〈0.05）.Supplementation of 0.05% DMY reduced the visceral organ weight and organ index,enhanced digestion and absorption ability of gastrointestinal tract,thereby improving feed utilization rate and promoting the growth of chickens.

Determination of Dihydromyricetin in Cassia ferruginea (Schrad.) DC. by Quantitative 1H NMR (qHNMR)

Cassia ferruginea (Schrad.) DC.(Fabaceae) is a native plant widely used as an ornamental tree and for the restoration of degraded areas in Brazil. Although no previous ethnopharmacological or chemical information was available, bioprospecting studies on this species found out a high concentration of dihydromyricetin (DHM) in different parts of the plant. DHM, also known as (+)-ampelopsin, is a flavonoid that presents important pharmacological and biological activities, including anticancer, cardioprotective and hepatoprotective effects. The aim of this study was to develop and validate a simple method for the determination of DHM in hydroethanolic extracts of C. ferruginea by quantitative 1H NMR (qHNMR) using the internal standard approach. The parameters as linearity, specificity and selectivity, accuracy, precision (repeatability and intermediate) and robustness showed satisfactory results. Five ethanolic extracts from different stages and organs of C. ferruginea were investigated, the DHM concentration ranges from 52.08 ± 3.95 to 201.83 ± 4.71 mg/g. The proposed method appears to be a suitable tool for fast quality control of herbal extracts, with no need of tedious sample preparation and chromatographic separations increasing the efficiency of natural products analysis. This is the first study reporting the presence and determination of DHM in Cassia ferruginea (Schrad.) DC.

Effects of ultrasonic-assisted extraction on bioactive compounds,volatile flavors and antioxidant activities of vine tea water extracts

Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.

二氢杨梅素分子结构与性质的密度泛函理论研究

本文基于密度泛函理论(DFT),采用B3LYP泛函结合6-31G基组上对二氢杨梅素的分子几何结构进行了优化,在此基础上以水为溶剂计算二氢杨梅素分子的活性位点以及红外光谱进行分析.静电势结果表明二氢杨梅素的亲核活性位点位于酚羟基氢原子(H23)附近;而亲电活性位点位于氧原子(O32)及其附近.前线分子轨道研究结果表明二氢杨梅素分子的最高占据轨道(HOMO)都位于酮基氧(O32)和羟基氧(O20)附近,说明这些位点易与亲电试剂反应.而最低空轨道(LUMO)位于碳原子(C12、C13、C14)区域,表明这些区域可与亲核试剂反应.简缩福井函数(f)结果证实了位于C-O-C键中的氧原子的f-值的亲电活性较其他位点氧原子大;而位于C8碳原子的f^(+)值较大,因此该位点亲核活性较强.通过理论计算所得到的二氢杨梅素的红外光谱数据与实验所得到的红外光谱数据相差不大,这就说明理论计算结果是较为可靠的.从而为实验和理论研究二氢杨梅素结构与性质的关系提供了一定的理论参考.

Dihydromyricetin promotes apoptosis, suppresses proliferation and tumor necrosis factor-α-mediated nuclear factor kappa-B activation in nasopharyngeal carcinoma CNE-2 cells

OBJECTIVE: To investigate the efficacy of dihydromyricetin(DMY) on nasopharyngeal carcinoma(NPC) cell proliferation, apoptosis and to reveal the underlying mechanism in vitro experiments.METHODS: The CNE-2 cell line was treated with different concentrations of DMY and the effects of DMY on cell viability and proliferation were evaluated using cell counting kit-8(CCK-8) assay and plate colony formation assay. Cellular apoptosis was detected by flow cytometry following Annexin V fluorescein isothiocyanate/propidine iodide staining.Nuclei morphology was observed under a fluorescence microscope following Hoechst 333258 staining. The expression of phosphorylated inhibitor of nuclear factor kappa-B kinase subunit beta(p-IKKβ), phosphorylated inhibitor of nuclear factor kappa-B kinase subunit alpha(p-IKKα), inhibitor of nuclear factor kappa-B alpha(IκB-α), nuclear factor kappa-B(NF-κB)/p65 was examined by Western blot analysis and the nuclear translocation of NF-κB/p65 was observed using a confocal laser scanning microscopy.RESULTS: DMY inhibited the proliferative capability and colony formation of NPC CNE-2 cells. Meanwhile, DMY induced apoptosis of CNE-2 cells in a dose and time-dependent manner via upregulating B-cell lymphoma-2 associated X, but downregulating B-cell lymphoma-2 and pro-caspase-3. Importantly, we found that DMY suppressed tumor necrosis factor alpha(TNF-α)-mediated NF-κB activation via inhibiting p-IKKβ, p-IKKα and blocking NF-κB subunit p65.CONCLUSION: Our experiments demonstrated that DMY had significant antiproliferative and apoptosisinducing effects on CNE-2 cells. Additionally, DMY promoted inactivation of p-IKKβ, p-IKKα,and blocked the nuclear translocation of NF-κB subunit p65. These results suggest that DMY may be an important therapeutic approach for NPC.

Dihydromyricetin‑Incorporated Multilayer Nanofibers Accelerate Chronic Wound Healing by Remodeling the Harsh Wound Microenvironment

The harsh microenvironment in wound(HMW)remains a major obstacle to chronic wound healing.Although a series of bioactive materials have been developed,few of them are multi-functional and able to accelerate wound healing via precisely remodeling the HMW.Herein,a series of dihydromyricetin(DHM)-incorporated multilayer nanofibers(termed DQHP-n,n=0,2,6 and 10)are fabricated using a layer-by-layer(LBL)self-assembly technique.The average diameters of DQHP-n significantly increase from 0.30±0.16μm to 0.84±0.28μm(P<0.05)along with the n value increased from 0 to 10,the tensile strength of that is also significantly improved from 1.12±0.15 MPa to 2.16±0.30 MPa(P<0.05),and the water contact angle of that significantly decreases from 129.1±1.5°to 76.6±3.9°(P<0.05).The DQHP-n are found to be biocompatible,in which DQHP-6 promoted cell migration through activation of the epithelial–mesenchymal transformation(EMT)pathway and reconstruction of the HMW by stopping bleeding,killing bacteria,eliminating inflammation,and scavenging reactive oxygen species(ROS).The in vivo evaluation is carried out via an E.coli-infected rat skin regeneration model.The DQHP-6 group demonstrates the best effect,as it healed up to 98.5±1.0%of the wound area at day 15.DQHP-6 differentially regulates the mRNA expressions of several cytokines(FGF2,PDGF,IL-1α,IL-6,IL10,and TGF-β),which ends to reductions of total inflammatory cells(CD45^(+) cells)and M1 macrophages(CD80^(+) and CD86^(+) cells),proliferation of host cell(Ki67^(+) cells),and enhancement of collagen synthesis.In conclusion,DQHP-6 exhibits multifunctional properties for HMW,and can serve as a promising wound dressing for clinical transformation.

Dihydromyricetin Alleviates H9C2 Cell Apoptosis and Autophagy by Regulating CircHIPK3 Expression and PI3K/AKT/mTOR Pathway

Objective: To investigate the effect and potential mechanism of dihydromyricetin(Dmy) on H9C2 cell proliferation, apoptosis, and autophagy. Methods: H9C2 cells were randomly divided into 7 groups, namely control, model, EV(empty p CDH-CMV-MCS-EF1-Cop GFP-T2A-Puro vector), IV(circHIPK3 interference), Dmy(50 μmol/L), Dmy+IV, and Dmy+EV groups. Cell proliferation and apoptosis were detected by cell counting kit-8 assay and flow cytometry, respectivley. Western blot was used to evaluate the levels of light chain 3 Ⅱ/Ⅰ(LC3Ⅱ/Ⅰ), phospho-phosphoinositide 3-kinase(p-PI3K), protein kinase B(p-AKT), and phospho-mammalian target of rapamycin(p-mTOR). The level of circHIPK3 was determined using reverse transcriptase polymerase chain reaction. Electron microscopy was used to observe autophagosomes in H9C2 cells. Results: Compared to H9C2 cells, the expression of circHIPK in H9C2 hypoxia model cells increased significantly(P<0.05). Compared to the control group, the cell apoptosis and autophagosomes increased, cell proliferation rate decreased significantly, and the expression of LC3Ⅱ/Ⅰ significantly increased(all P<0.05). Compared to the model group, the rate of apoptosis and autophagosomes in IV, Dmy, and Dmy+IV group decreased, the cell proliferation rate increased, and the expression of LC3Ⅱ/Ⅰ decreased significantly(all P<0.05). Compared to the control group, the expressions of p-PI3K, p-AKT, and p-mTOR in the model group significantly reduced(P<0.05), whereas after treatment with Dmy and sh-circHIPK3, the above situation was reversed(P<0.05). Conclusion: Dmy plays a protective role in H9C2 cells by inhibiting circHIPK expression and cell apoptosis and autophagy, and the mechanism may be related to PI3K/AKT/mTOR pathway.

Dihydromyricetin improves liver fat deposition in high-fat diet-induced obese mice

It has been reported that the histone/protein deacetylase SIRT1-AMP-activated protein kinase(SIRT1-AMPK)signaling pathway may play a role in the effects of dihydromyricetin(DHM)on improving triglyceride(TG)accumulation and insulin resistance in liver cells.Therefore,we aimed to further observe the effect of DHM on liver fat deposition in high-fat diet(HFD)-induced obese mice and explore its possible mechanism.C57BL/6J mice were fed with a normal diet(ND)and HFD and were treated with or without low-dose(125 mg/kg)or high-dose(250 mg/kg)DHM for 16 weeks,respectively.During the experiment,body weight was checked every 2 weeks.After 16 weeks,the orbital vein was bled,the animals were sacrificed,and the subscapular,epididymal,and inguinal fat were collected and weighed with an electronic scale.An automatic biochemical analyzer was used to determine the levels of serum triglyceride(TG),serum total cholesterol(TC),serum high-density lipoprotein(HDL),and serum low-density lipoprotein(LDL).The livers were stained with hematoxylin-eosin staining(H&E)and Oil Red O to detect liver fat deposition.A colorimetric method was used to detect liver MDA and SOD contents.Quantitative real-time PCR(q RT-PCR)was used to detect the gene expressions of related indicators,such as interleukin-6(IL-6),interleukin-8(IL-8),tumor necrosis factor-α(TNF-α),acetyl-Co A carboxyl acetyl-Co A carboxylase(ACC),sterol regulatory element-binding protein-1c(SREBP-1),fatty acid synthetase(FAS),peroxisome proliferator activation receptor alpha(peroxisome proliferator-activated receptor-alpha,PPARα),palmitoyltransferase 1(carnitine palmitoyltransferase 1,CPT1),SIRT1,and AMPK.Western blotting analysis was used to detect the protein expression levels of SIRT1,AMPK,SIRT1-AMPK,ACC,SREBP-1,FAS,PPARα,and CPT1.Results showed that compared with the ND group,the weight and body fat of the mice in the HFD group were increased significantly.The levels of TG,TC,and LDL were increased,the level of HDL was decreased,the volume of hepatocytes was increased,the number of lipid droplets,fat deposition,MDA,IL-6,IL-8,TNF-α,SREBP-1c,FAS,ACC1,SIRT1,and AMPK protein levels were significantly increased,and the SOD activity,PPARα,CPT1,SIRT1 m RNA,AMPK m RNA,PPARα,CPT1 levels were significantly decreased.DHM could significantly reverse the changes of the above indexes in HFD mice,while DHM had no significant effect on the above indexes in ND mice.Collectively,our findings revealed that DHM improved liver fat deposition in HFD-induced obese mice,and the mechanism might be related to inhibition of oxidative stress,inflammation,lipid synthesis,and promotion of lipid decomposition.

二氢杨梅素对高糖刺激下心肌细胞坏死性凋亡的影响

目的探究二氢杨梅素(DHY)对高糖刺激下心肌细胞损伤的影响。方法原代心肌细胞用DHY(80μmol/L预处理4 h,用正常葡萄糖(NG)5.5 mmol/L或高糖(HG)33.3 mmol/L刺激48 h。随后利用MTT法评估细胞活性,测定乳酸脱氢酶(LDH)评估细胞损伤程度,二氢乙锭(DHE)和MitoSOX染色评估氧化应激水平,蛋白印迹和免疫荧光检测受体相互作用蛋白激酶3(RIPK3)蛋白表达,原位末端转移酶标记(TUNEL)法检测心肌细胞凋亡程度。结果与HG组相比,DHY显著增强高糖刺激下心肌细胞活性(P=0.003),减少LDH释放(P=0.001),减弱DHE和MitoSOX染色荧光强度,显著抑制RIPK3蛋白表达(P<0.01),减少TUNEL染色阳性细胞数量(P<0.01)。结论DHY增强高糖刺激下心肌细胞活性,减轻损伤程度,可能与DHY抑制氧化应激和减弱坏死性凋亡有关。

二氢杨梅素结构修饰及生物活性研究进展

二氢杨梅素是一种二氢黄酮醇,具有抗菌、抗炎、抗肿瘤以及保肝护肝等多种生物活性。由于其结构中的6个羟基导致其脂溶性差及生物利用度低,因此对其进行结构修饰以期提高生物利用度和生物活性。本文综述了二氢杨梅素的化学法结构修饰及其生物活性等研究工作,化学修饰方法涉及醚化反应、酯化反应和金属配合物等方法,合成的衍生物具有抗病毒、抗菌、抗氧化、神经保护以及抑制肿瘤细胞增殖等活性,并且提出二氢杨梅素结构修饰过程中存在的挑战及发展方向,为更好地开发二氢杨梅素衍生物提供技术服务。