Epimedium-Derived Flavonoids Modulate the Balance between Osteogenic Differentiation and Adipogenic Differentiation in Bone Marrow Stromal Cells of Ovariectomized Rats via Wnt/β-Catenin Signal Pathway Activation

Objective： To observe the function of wnt/β-catenin signal pathway on the process that epimedium-derived flavonoids （EFs） regulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal ceils of ovariectomized rats, and to provide an experimental evidence for the mechanism of EFs on treating postmenopausal osteoporosis. Methods： Bone marrow stromal cells from ovariectomized rats were separated and cultivated in the condition of osteoinductive medium or liquid medium for 15 days. Low- （1 μg/mL）, medium- （10 μg/mL） and high- （100 μg/mL） dose EFs were administrated correspondingly. Alkaline phosphatase （ALP） staining, ALP activity determination, oil red O staining and real- time polymerese chain reaction （RT-PCR） were used to determine the effect of EFs on osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats. Moreover, in order to explore the mechanism of EFs on osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats, Dickkopf-related protein 1 （DKK1） was used in the medium group. Enzyme linked immunosorbent assay （ELISA） and RT-PCR were used to determine mRNA levels of 13-catenin, low density lipoprotein receptor-related protein 5 （LRP5） and T cell factor （TCF） protein, known as wnt/β-catenin signal pathway related factors. Results： EFs increased mRNA expression levels of ALP and early osteoblast differentiation factors, such as runt-related transcription factor 2 （Runx2）, osteocaicin and collagen I, and decreased mRNA expression levels of fat generation factors, such as peroxisome proliferator activated receptor gamma 2 （PPAR r/-2） and CCAAT enhancer-binding protein-α （C/EBP α） in a dose-dependent manner. While osteobiast differentiation factors were down-regulated, fat generation factors were up-regulated when DKK1 was applied. Also EFs up-regulated mRNA expression levels of β-catenin, LRP5 and TCF protein which could be blocked by DKK1. Conclusion： EFs regulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats by activating wnt/13-catenin signal pathway, which may be an important molecular mechanism of EFs on treatinq DostmenoDausal osteoDorosis.

Functional metabolomics analysis of the protective mechanism of total flavonoids of Scutellaria baicalensis on acute myocardial ischemia rats

Background:The study aimed to investigate the protective effect and mechanism of total flavonoids of Scutellaria baicalensis(TFSB)on acute myocardial ischemia(AMI)rats by using functional metabonomics.Methods:Rats were divided into the Control,Model,AMI positive control(Propranolol hydrochloride,30 mg/kg),low dose TFSB(50 mg/kg),and high dose TFSB(100 mg/kg)groups.Rats received the corresponding treatment by intragastric administration once daily for 10 consecutive days.Electrocardiogram,myocardial enzyme,triphenyltetrazolium chloride staining,hematoxylin-eosin,and enzyme-linked immunosorbent assay were performed to evaluate the protective effect of TFSB on AMI rats.Then,the UHPLC-Q-Orbitrap MS method based on serum metabolomics was utilised to search for metabolic biomarkers and metabolic pathways.Subsequently,Western blot and RT-PCR techniques were employed to identify the respective genes and proteins.Results:Pharmacodynamics revealed that TFSB could ameliorate AMI in rats.The results of the metabolomics analysis indicated that the alterations in metabolic profile observed in rats with AMI were partially improved by treatment with TFSB.Moreover,the mRNA expression levels of 5-lipoxygenase(5-LOX)and 15-lipoxygenase(15-LOX)and the protein expression levels of 5-LOX,15-LOX,interleukin-1β(IL-1β),and NF-κB p65 were reduced following treatment with TFSB.Conclusion:The potential treatment of TFSB in AMI may be ascribed to its ability to regulate arachidonic acid metabolism.

Dendrobium offi cinale flowers flavonoids enriched extract protects against acute ethanol-induced gastric ulcers via AMPK/PI3K signaling pathways

Gastric ulcer is a widespread disease caused by various etiologies.Dendrobium offi cinale flowers exert several health benefits owing to their rich flavonoid content.In this study,protective effects and possible action mechanisms of D.offi cinale flowers’flavonoid enriched extract(DOFF)were assessed against gastric ulcer.The result of sodium nitrite-aluminum nitrate colorimetry showed that 52.34%of the total extractive was flavonoid,and ultra-high performance liquid chromatography time of flight mass spectrometer(UPLC-QTOF/MS)revealed the presence of 28 components in DOFF of which 14 belonged to flavonoids.In addition,in vivo assay revealed DOFF potential in reducing the formation of ethanol-induced gastric mucosal lesions,with drop-in ulcer index from 64.33±8.76 to 32.00±4.47.Similar results were revealed in human gastric mucosal epithelia cells,with cells viability to increase from 27.2%to 61.6%post DOFF administration.To analyzed the protect effect of DOFF,we used Western blotting and immunofluorometric assay to revealed the expression levels of key proteins in cell pathways.The results showed that DOFF(320μg/mL)could increase the level of oxidation marker protein(HO-1),apoptosis regulatory protein(Bcl-2)and autophagy marker(LC3β)by 50.84%,43.85%,and 59.21%compared with ethanol-treated group respectively.Further analyzed of the mitochondrial activity and apoptosis pathway,we found that DOFF appeared to mitigate against ethanolinduced gastric mucosal injury via AMPK/mTOR/ULK1 and PI3K/AKT autophagy signaling pathways.

Quantification of Total Phenols, Total Flavonoids, Total Anthocyanins and Evaluation of Antioxidant and Antiradical Activities of Detarium Senegalense Extracts from Chad

The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity of Detarium Senegalense extracts. For this purpose, sequential extraction using solvents of increasing polarity was essential. The various extracts obtained underwent phytochemical and biochemical analyses. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthocyanins and steroids/terpenes. Quantitative analysis of total polyphenols, total flavonoids and total anthocyanins yielded the following results: total flavonoids (0.803 ± 0029 mg EQ/100g P for acetone extract of roots and 0.871 ± 0.401 mg EQ/100g P for methanol extract of leaves);total polyphenols (23.298 ± 12.68 mg EAG/100g P for acetone extract of roots and 24.69 ± 0.49 401 mg EAG/100g P for methanol extract of leaves);total monomeric anthocyanins (44.697 ± 0.939 mg EC3G/100g P and 16.699 ± 0.193 mg EC3G/100g P respectively for acetone and methanol extracts of stem bark). DPPH free radical scavenging activity was 1.674 ± 0.023 mg/mL for the acetone extract and 0.934 ± 0.24 mg/mL for the methanol extract of roots. .

Antiglycating effects of citrus flavonoids and associated mechanisms

Glycation of proteins and DNA forms advanced glycation end products(AGEs)causing cell and tissue dysfunction and subsequent various chronic diseases,in particular,metabolic and age-related diseases.Targeted AGE inhibition includes scavengers of reactive carbonyl species(RCS)such as methylglyoxal(MG),glyoxalase-1 enhancers,Nrf2/ARE pathway activators,AGE/RAGE formation inhibitors and other antiglycatng agents.Citrus flavonoids have demonstrated antioxidant and anti-inflammatory effects and are also found to be effective antiglycating agents.Herein,we reviewed the up to date progress of the antiglycation effects of citrus flavonoids and associated mechanisms.Major citrus flavonoids,hesperedin and its aglycone,hesperetin,inhibited glycation by scavenging MG forming mono-or di-flavonoid adducts with MG,enhanced the activity of glyoxase-1,activated Akt/Nrf2 signal pathway while inhibiting AGE/RAGE/NF-κB pathway,reduced the formation of Nε-(carboxylmethyl)lysine(CML)and pentosidine,inhibited aldol reductase activity and decreased the levels of fructosamine.The antiglycating activity and mechanisms of other flavonoids was also summarized in this review.In conclusion,citrus flavonoids possess effective antiglycating activity via different mechanisms,yet there are many challenging questions remaining to be studied in the near future such as in vivo testing and human study of citrus flavonoids for efficacy,effectiveness and adverse effects of citrus flavonoids as a functional food in managing high levels of AGEs and controlling AGE-induced chronic diseases,diabetic complications in particular.

Analysis of Lavandulyl Flavonoids from Sophora flavescens with Antiinflammatory Activity Based on Molecular Network Technology

[Objectives]This study was conducted to screen lavandulyl flavonoids with anti-inflammatory activity from Sophora flavescens.[Methods]35 compounds were screened from traditional Chinese medicine S.flavescens using the nitric oxide(NO)anti-inflammatory activity model.[Results]Five components,8(xanthohumol),13(kurarinol),27(4-methoxysalicylic acid),28(b-resorcic acid)and 30(b-resorcic acid),exhibited significant anti-inflammatory activity,with IC 50 values of 5.99,4.76,6.96,3.41 and 5.22μM,respectively.Especially,8(xanthohumol)and 13(kurarinol)were typical lavandulyl flavonoids in S.flavescens,which were worth further exploration.Furthermore,UPLC-Q-Exactive and GNPS molecular networking technique were used for rapid analysis of lavandulyl flavonoids from S.flavescens.A total of 15 components were identified.[Conclusions]This work lays a theoretical foundation for further separation and analysis of lavandulyl flavonoids with anti-inflammatory activity from S.flavescens.

Establishment of an in vitro Tissue Culture and Rapid Propagation System using Lonicera hypoglauca and Content Assessment of Total Flavonoids and Chlorogenic Acid

Lonicera hypoglauca is a traditional Chinese medicinal plant.In this study,the tender young leaves of L.hypoglauca were used for the first time as the explants to establish a rapid in vitro propagation and regeneration system.The results revealed that the optimal time for disinfection of the explants was 8 min and the optimal medium for callus induction was MS+2,4-D 4.0 mg·L^(-1)+sucrose 30 g·L^(-1),with an average callus induction rate of 86.67%.The optimal medium to induce differentiation of callus to bud was MS+6-BA 1.0 mg·L^(-1)+NAA 0.10 mg·L^(-1)+sucrose 30 g·L^(-1),with an average germination rate of 83.33%.The optimal medium to induce multiplication was MS+6-BA 1.5 mg·L^(-1)+NAA 0.05 mg·L^(-1)+sucrose 30 g·L^(-1),with a multiplication coefficient of 5.42.The optimal medium for root induction was 1/2 MS+NAA 0.15 mg·L^(-1)+activated carbon 0.3 g·L^(-1)+sucrose 15 g·L^(-1),with an average rooting rate of 91.11%.The survival rate of tissue-cultured seedlings in nutrient soil cultivation medium was as high as 100%.The total flavonoid content and chlorogenic acid content in the explant,callus tissue and regenerated plant were 1.83%,2.27%,1.33%and 2.77%,1.83%,1.74%respectively.This study provides novel insights into the rapid propagation and mass production of L.hypoglauca seedlings at an industrial scale and that it exhibits important application value and future prospects.

Research Progress of Deep Eutectic Solvents in Extraction of Plant Flavonoids

As a new type of green solvents,deep eutectic solvents(DESs)have the advantages of strong extraction ability,designability,simple preparation,low price,recoverability and biodegradation,and show great application potential in the field of plant flavonoid extraction.In this paper,the definition,classification and preparation methods of DESs were introduced.The effects of DES composition,molar ratio of DES components,water content of DES systems,liquid-material ratio,extraction temperature,extraction time and extraction auxiliary techniques on the extraction yield of plant flavonoids were expounded.The recycling methods of DESs were summarized.Existing problems of DESs in the field of plant flavonoids extraction were pointed out,and further research direction and trend were analyzed and prospected.

Optimization of Extraction Process for Total Flavonoids from Penthorum chinense Pursh and Comparison of Their Contents from Different Parts

[Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experiments were designed to optimize the extraction process of total flavonoids from P.chinense Pursh with the volume fraction of ethanol,the ratio of material to liquid,heating reflux extraction time and extraction times as factors,and the content of total flavonoids as the index.A verification test was carried out.The optimized extraction process was adopted to compare the contents of total flavonoids from different parts of P.chinense Pursh.[Results]The best extraction process was extracting the powder of P.chinense Pursh for 2.0 h with 20 times of 55%ethanol by reflux twice.Under this condition,the contents of total flavonoids were 3.63%,8.90%,11.28%,and 4.36%from stems,leaves,flowers and whole grass of P.chinense Pursh,respectively.[Conclusions]The process is reasonable,feasible and stable,and can effectively extract total flavonoids from P.chinense Pursh.The contents of total flavonoids from different parts of P.chinense Pursh were quite different,and the value was higher in the leaves and flowers,so the proportions of leaves and flowers should be paid attention to in the industrial processing of P.chinense Pursh.

The Protective Effects of Flavonoids from Scutellaria Baicalensis Georgi Stems and Leaves on Oligodendrocyte Damage Induced by Aβ1-42

Aim: This study aimed to investigate the protective effects of flavonoids from the stem and leaves of Scutellaria baicalensis Georgi (SSFs) against Aβ1-42-induced oligodendrocytes (OL) damage. Methods: Immunofluorescence was used for the detection of myelin-associated glycoprotein (MAG), a characteristic protein of rat oligodendrocytes (OLN-93 cells). To evaluate the potential protective effects of SSFs on OLN-93 cells injured by Aβ1-42, an injury model was established by subjecting OLN-93 cells to Aβ1-42 exposed. Cell morphology was examined using an inverted microscope, while cell viability was assessed using the colorimetric method of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Additionally, lactate dehydrogenase (LDH) was measured using the pyruvic acid reduction assay. The Ginkgo biloba leaf extract (GBE) injection was used as a positive control. Results: A total of >95% of the MAG immunofluorescence-positive cells were identified as oligodendrocytes. Gradually increasing concentrations of SSFs impaired the cells, and the maximum nondetrimental dose for OLN-93 cells was 75 mg/L. This study assessed the effects of SSFs on OLN-93 cells damaged by Aβ1-42. The results indicated that SSFs significantly improved OLN-93 cell morphological abnormal changes, increased the OLN-93 cell survival rate, and reduced LDH release. Conclusion: SSFs can alleviate Aβ1-42-induced damage of OL.

Determination of Total Flavonoids in Acanthopanax senticosus(Rupr. et Maxim.) Harms by Enzymolysis and Its Technological Optimization

In order to optimize the ultrasonic extraction technique for the total flavonoid of leaf yellows plus, the contents of 21 leaf yellows plus total flavonoid from four regions in Heilongjiang Province were comparatively analyzed. The ultrasonic extraction technology was optimized by Box-Behnken response surface method, and the total flavonoid content of 21 kinds of Acanthopanax senticosus(Rupr. et Maxim.) Harms from different producing areas were analyzed by cluster analysis. The optimal process conditions were determined as ultrasonic time 30 min, solid-liquid ratio 1 : 12 and ultrasonic power 250 W, and the average yield of the total flavonoid was 1.453 mg·g^ (-1). By optimizing the ultrasonic-assisted extraction method, the total flavonoid content from different producing areas was compared in the experiment, which provided certain data support for the optimization of the extraction process in the future and laid a certain theoretical foundation for the quality analysis of Chinese medicinal materials.

Pilot study on the effect of flavonoids on arterial stiffness and oxidative stress in chronic kidney disease

BACKGROUND Flavonoids,the main class of polyphenols,exhibit antioxidant and antihypertensive properties.AIM To prospectively investigate the impact of flavonoids on arterial stiffness in patients with chronic kidney disease(CKD)stagesⅠ-Ⅳ.METHODS In this prospective,single-arm study,CKD patients with arterial hypertension and diabetes mellitus were enrolled.Baseline demographic,clinical,and laboratory variables were recorded.Patients received daily treatment with a phenol-rich dietary supplement for 3 months.Blood pressure,arterial stiffness(carotidfemoral pulse wave velocity,central pulse pressure),and oxidative stress markers(protein carbonyls,total phenolic compound,total antioxidant capacity)were measured at baseline and at study end.RESULTS Sixteen patients(mean age:62.5 years,87.5%male)completed the study.Following intervention,peripheral systolic blood pressure decreased significantly by 14 mmHg(P<0.001).Carotid-femoral pulse wave velocity decreased from 8.9 m/s(baseline)to 8.2 m/s(study end)(P<0.001),and central pulse pressure improved from 59 mmHg to 48 mmHg(P=0.003).Flavonoids also reduced oxidative stress markers including protein carbonyls(P<0.001),total phenolic compound(P=0.001),and total antioxidant capacity(P=0.013).CONCLUSION Flavonoid supplementation in CKD patients shows promise in improving blood pressure,arterial stiffness,and oxidative stress markers.

Determination of total flavonoids content in buckwheat and inhibition of α-amylase activity

Diabetes is one of the most difficult chronic diseases to cure in the world,which seriously affects people’s health and quality of life.Flavonoids in buckwheat can regulate blood glucose levels by inhibitingα-amylase activity.Therefore,sweet buckwheat produced in Inner Mongolia was used as the research object,and buckwheat fl avonoids were extracted by ultrasonic-assisted extraction method.Total fl avonoids content was determined by ultraviolet-visible spectrophotometry.With acarbose as the positive control,the inhibition test ofα-amylase was carried out by DNS colorimetry to study the inhibition behavior of fl avonoids onα-amylase activity.The results showed that the extraction process of flavonoids was stable and reliable,and the established method for the determination of flavonoids was simple,accurate and reproducible.The total flavonoids content of buckwheat samples was 2.706 mg/g,buckwheat total fl avonoids extraction solution had an inhibitory eff ect onα-amylase,and its median inhibition concentration(IC_(50))was 38.53 mg/mL.The results of this experiment provide a technical reference for the development and utilization of fl avonoids in Inner Mongolia sweet buckwheat,and provide a theoretical reference for the development and application of flavonoid-rich hypoglycemic food.

Mechanism of Rosae Rugosae Flos flavonoids in the treatment of hyperlipidemia and optimization of extraction process based on network pharmacology

This study aims to identify a natural plant chemical with hypolipidemic effects that can be used to treat high cholesterol without adverse reactions.Through network pharmacology screening,it was found that Rosae Rugosae Flos(RF)flavonoids had potential therapeutic effects on hyperlipidemia and its mechanism of action was discussed.TCMSP and GeneCards databases were used to obtain active ingredients and disease targets.Venn diagrams were drawn to illustrate the findings.The interaction network diagram was created using Cytoscape 3.8.0 software.The PPI protein network was constructed using String.GO and KEGG enrichment analysis was performed using Metascape.The results revealed 2 active flavonoid ingredients and 60 potential targets in RF.The key targets,including CCL2,PPARG,and PPARA,were found to play a role in multiple pathways such as the AGE-RAGE signaling pathway,lipid and atherosclerosis,and cancer pathway in diabetic complications.The solvent extraction method was optimized for efficient flavonoid extraction based on network pharmacology prediction results.This was achieved through a single factor and orthogonal test,resulting in an optimum process with a reflux time of 1.5 h,a solid-liquid ratio of 1:13 g/mL,and an ethanol concentration of 50%.

Optimization of extraction process for total flavonoids of Sophorae Flos for the treatment of hyperlipidemia based on network pharmacology and molecular docking

This study aimed to investigate the mechanism of action of Sophora Flos(SF)in the treatment of hyperlipidemia(HLP)using network pharmacology and molecular docking methods,and to optimize the extraction process of the predicted active components.The STRING database was used for protein interaction analysis and PPI network construction via Cytoscape 3.9.1.Pymol was employed for docking and visualization.An extensive review of SF identifi ed 6 active ingredients,297 related objectives,84 disease objectives,and 57 total objectives.After protein interaction and topology analysis,18 core targets were identified.These included 146 gene function entries(P<0.05).Active compounds,mainly flavonoids,can modulate the expression of various proteins such as TNF,IL-6,IL-1β,PPARG,and TGFB1 to achieve therapeutic effects on HLP.The network pharmacology and molecular docking results suggested that the active fl avonoids component in SF may be related to the treatment of hyperlipidemia.Therefore,the orthogonal experiment method was used to optimize the extraction process of total fl avonoid from SF using ethanol refl ux extraction,based on a single factor experiment.The effects of refl ux time,solid-liquid ratio,ethanol concentration,and other factors on the extraction of total fl avonoid from SF were investigated.The optimum process conditions were refl ux time of 1.25 h,solid-liquid ratio of 1:15 g/mL and ethanol concentration of 60%.Using these conditions,the purity of total fl avonoid extracted from SF was 70.33±0.22%.

Therapeutic potential of the citrus flavonoid hesperidin and its aglycone hesperetin against chemotherapy-induced toxicity

Chemotherapy-induced toxicity(CIT)remains a major concern in cancer patients undergoing chemotherapy.New approaches to ameliorate the side effects of chemotherapy are urgently needed.Recently,the nutritional value of citrus fruits has attracted wide attention.Hesperidin and its aglycone hesperetin are the main active components in citrus fruits.Hesperidin and hesperetin have a wide range of pharmacological activities,including antioxidant and anti-inflammatory properties.This review aims to provide insights into the potential application of citrus flavonoids in CIT and summarize the underlying mechanisms of hesperidin and hesperetin in alleviating CIT.We have collected and collated relevant scientific articles on hesperidin and hesperetin and their treatment of CIT from different scientific databases.Hesperidin and its glycosides can reduce the toxicity of chemotherapeutic drugs,and their therapeutic effects are mainly through anti-inflammatory and antioxidant effects.At present,modern medical treatment is the main treatment method for CIT,but hesperidin,as an extract of food and medicinal materials,can greatly alleviate CIT.While killing tumor cells,chemotherapeutic drugs also damage normal cells leading to toxic effect on various organs.The pathological mechanism of CIT has not been fully elucidated,but current evidences indicate that cellular stress plays a key role.The citrus flavonoids hesperidin and hesperetin have the protective effect against CIT,highlighting its potential as an adjuvant in chemotherapy regimens.Hesperidin may also have synergistic anti-tumor activity with chemotherapeutic agents.We believe that more functional foods and anti-CIT drugs based on natural foods will be developed.

Preliminary Research of the Regular Pattern between Flavonoids Content and the Age of Erect Type Ophiopogon jaonicus

[Objective] The experiment aimed to inquire into the regular pattern of the flavonoids content in erect type Ophiopogon jaonicus preliminarily.[Methods]In the main Ophiopogon jaonicus-producing area,we use the method of home position dynamic method to gather sample for experiments,use UV to determine the flavonoids content in Ophiopogon jaonicus and use correlation and regression method to analyze the relation between flavonoids content and the growth period of Ophiopogon jaonicus.[Results]The relation between flavonoids content(y1)and the growth period(x∥d)of erect type Ophiopogon jaonicus is:y=1.235 6lnx-4.748 9(n=7,50≤x≤730,0≤y≤3.128,r0.001=0.950 7,r=0.954 2).[Conclusion]During a determinate time(50≤x≤730),positive correlation exists between flavonoids content and the growth period of Ophiopogon jaonicus.Our research has a great importance in directing the scientific harvest and GAP production of erect type Ophiopogon jaonicus.

Optimization of Preparative Separation and Purification of Total Flavonoids from Radix Puerariae by Macroporous Resin Method

Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed （BV） with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% （V/V） ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs.

Effect of total flavonoids of epimedium on liver microsomal CYP 1A2,CYP3A4 and CYP2E 1 activities in rats

To assess the potential effect of total flavonoids of epimedium （TFE） on cytochrome P450 and activity of its main isoforms in rat liver microsomes. TFE （300 mg/kg） was administered once daily to male Sprague-Dowley rats by gavage for fifteen days. The total cytochrome P450 content and its main isoforms CYP1A2, CYP3A4 and CYP2E1 activities in rat liver microsomes were detected. The activity of CYP1A2 was measured by fluorometry and the activities of CYP3A4 and CYP2E1 were determined by measuring the amount of methanal and p-aminophenol formed using UV/Vis spectrophotometer, respectively. Administration of TFE significantly increased the total CYP450 content and activities ofCYP1A2, CYP3A4 and CYP2E1 in rat liver microsomes, compared with the control group. Particularly, the activities of CYP1A2 and CYP2E1 were enhanced significantly （P〈0.01）. TFE induced the increase in total CYP450 content and its main isoforms CYP1A2, CYP3A4 and CYP2E1 activities in rat liver microsomes.

Oxidation Resistance of Flavonoids in Chinese Jujube Stone

[Objective] The aim was to study on the oxidation resistance of flavonoids in Chinese jujube stone. [Method] The extract of flavonoids from Chinese jujube stone was added to fresh rapeseed oil and lard to explore the oxidation resistance of flavonoids; the removal rates of it to O2-·,DPPH· and ·OH were also studied. [Result] The flavonoids from Chinese jujube stone had good oxidation resistance on rapeseed oil and lard,and the effects showed dose-dependent; citric acid and vitamin C appeared synergistic effects to the flavonoids; in free-radical reaction experiment,the flavonoids from Chinese Jujube stone also showed strong scavenging ability on O2-·,DPPH· and ·OH,in addition,the scavenging ability increased with concentration increasing. [Conclusion] The result of this study had provided theoretical basis for the further development and utilization of Chinese jujube resource.