Inhibition of Fish Nodavirus by Gymnemagenol Extracted from Gymnema sylvestre

Viral nervous necrosis(VNN)has emerged to become a major problem in the culture of larval and juvenile marine fish worldwide.Bioactive phytochemicals isolated from commonly available medicinal plants are often screened for their efficacy in controlling fish viral diseases.Occurrence of newer viral strains and resistance to existing antiviral drugs are problems currently as-sociated with treatment of VNN,which necessitates looking for alternate sources for effective antiviral drugs.The aim of the present study was to screen antiviral potential of gymnemagenol(C30H50O4)previously extracted from leaves of Gymnema sylvestre.The fish nodavirus,grouper nervous necrosis virus(GNNV)in infected Sahul Indian Grouper Eye(SIGE)cell lines were used to study the antiviral activity of gymnemagenol under in vitro conditions.The susceptibility of the virus to gymnemagenol was confirmed by measuring the viral titre(TCID50 mL?1)in virus-infected SIGE cells every 24 h.Gymnemagenol at 20 μg mL?1 inhibited the prolifera-tion of GNNV to 53% at the end of the 6th d by inhibiting the proliferation of GNNV-infected SIGE cells.The viable SIGE cells were reduced to 47% as determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.The viral titre(TCID50 mL?1)was also reduced to log 2.8 at the end of the 7th d in gymnemagenol-treated SIGE cells after inoculated with GNNV when compared to untreated control SIGE cell viral titre(log 4.1).Based on our results it can be concluded that gymnemagenol could be used as an antiviral agent against GNNV infection.

Combined effects of Gymnema sylvestre and Pergularia daemia on letrozole-induced polycystic ovarian syndrome in rats

Objective:To investigate the combined therapeutic potential of Gymnema(G.)sylvestre and Pergularia(P.)daemia on letrozole-induced polycystic ovarian syndrome(PCOS)in rats.Methods:Thirty six healthy female Wistar rats with regular estrus cycles were randomly divided into six groups each of 6.GroupⅠreceived 1 mL of 0.5%carboxyl methyl cellulose orally and served as the vehicle control group,while groupsⅡtoⅥwere treated with letrozole(1 mg/kg body weight p.o.)for 21 days to induce PCOS.After induction of PCOS,groupⅡserved as the PCOS control group,without treatment;groupⅢreceived metformin(20 mg/kg body weight p.o.)as the standard group,and groupsⅣtoⅥreceived G.sylvestre(100 mg/kg body weight p.o.),P.daemia(300 mg/kg body weight p.o.),and the combination of G.sylvestre and P.daemia,respectively,for 28 days.Vaginal smears were collected from all rats daily throughout the study to determine the phases of the estrus cycle.After completing the treatment schedule,oral glucose tolerance test,serum lipid profile and reproductive hormonal analysis were carried out.Subsequently,the rats were sacrificed to collect ovary and uterus for histopathological examination.Results:The PCOS control rats showed a significant irregularity in the estrus cycle,hyperglycemia,and the altered serum lipid profile such as the increased low and very low density lipoprotein,triglyceride,and decreased high density lipoproteins.In addition,the PCOS control rats showed a significant increase in serum luteinizing hormone,testosterone,and estrogen,and decrease in follicle stimulating hormone and progesterone.These changes were significantly revoked in all the treatment groups.The test drugs also significantly reduced the gained ovary weight(P<0.001),and histopathology of the ovary showed almost normal ovary.Among the treatment groups,the group of combination treatment of G.sylvestre and P.daemia showed superior ameliorative results in PCOS parameters.Conclusions:Combination of G.sylvestre and P.daemia presents potent synergistic activity against hyperandrogenism,hyperinsulinemia,anovulation and follicular cysts in letrozole-induced PCOS rats.

Distribution of gymnemic acid in various organs of Gymnema sylvestre

The gymnemic acid contents in various organs of Gymnema sylvestre were investigated by High Performance Liquid Chromatography （HPLC） method. The results shows that the content of gymnemic acid in various organs, obviously different, was 54.29, 31.66, 28.82, 27.67, 25.39, 20.56 and 1.31 mg.g^-1 DW in shoot tips, flowers, nodes, leaves, internodes, roots and seeds, respectively. The highest gyrrmemic acid content （54.29 mg.g^-1 DW） was found in shoot tip, 1.96 fold higher than that in leaves （27.67 mg.g^-1DW）. Maximum quantity of gymnemic acid （35.39 mg·g^-1 DW） was observed in the young leaves, which was 1.52 times higher than that in old leaves （23.07 mg.g^-1DW）. The content of gymnemic acid in young, middle and old internodes was 26.47, 25.77 and 23.94 mg.g^-1 DW, respectively, all lower than that in leaves （27.67 mg.g^-1 DW）, whereas the content of gyirmemic acid in young, middle and old nodes was 27.96, 28.81 and 29.66 mg.g^-1 DW, respectively, all higher than that in leaves. The study provides the scientific evidences for the rational development and utilization of Gymnema sylvestre resources, since over exploitation of natural stands has caused depletion of these plants in nature.

匙羹藤酸在匙羹藤(Gymnema sylvestre)不同器官的分布

The gymnemic acid contents in various organs of Gymnema sylvestre were investigated by High Performance Liquid Chromatography (HPLC) method. The results shows that the content of gymnemic acid in various organs, obviously different, was 54.29, 31.66, 28.82, 27.67, 25.39, 20.56 and 1.31 mg·g-1 DW in shoot tips, flowers, nodes, leaves, internodes, roots and seeds, respectively. The highest gymnemic acid content (54.29 mg·g-1 DW) was found in shoot tip, 1.96 fold higher than that in leaves (27.67 mg·g-1 DW). Maximum quantity of gymnemic acid (35.39 mg·g-1 DW) was observed in the young leaves, which was 1.52 times higher than that in old leaves (23.07 mg·g-1 DW). The content of gymnemic acid in young, middle and old internodes was 26.47, 25.77 and 23.94 mg·g-1 DW, respectively, all lower than that in leaves (27.67 mg·g-1 DW), whereas the content of gymnemic acid in young, middle and old nodes was 27.96, 28.81 and 29.66 mg·g-1 DW, respectively, all higher than that in leaves. The study provides the scientific evidences for the rational development and utilization of Gymnema sylvestre resources, since over exploitation of natural stands has caused depletion of these plants in nature.

Comprehensive analysis of phenolic composition and antioxidant mechanisms in Gymnema sylvestre extracts using LC-MS and column chromatography

Recent studies have highlighted the potential of plant extracts as therapeutic agents for managing oxidative stress and related disorders.This study aims to elucidate the phenolic composition and antioxidant properties of Gymnema sylvestre extracts.Ethanolic reflux extraction followed by column chromatography was employed to isolate phenolic compounds.The total phenolic and flavonoid contents were quantified using the Folin–Ciocalteu and aluminum chloride colorimetric methods,respectively.Antioxidant activities were assessed by DPPH,ABTS scavenging assays and the ferric reducing antioxidant power(FRAP)assay.High-Performance Liquid Chromatography(HPLC)with a C18 column and Thermo TSQ Quantum Access Max(LC-MS)were used to determine the levels of gymnemic acid and identify other potential phenolic compounds.The analysis revealed significant antioxidant activities in the fractions.Fraction A showed the highest DPPH and ABTS scavenging activities,and Fraction C demonstrated the highest ferric reducing power.LC-MS analysis identified several phenolic compounds,indicating that these are major contributors to the antioxidant efficacy of the extract.This study provides a detailed phenolic profile and confirms the strong antioxidant potential of Gymnema sylvestre leaf extract,supporting its therapeutic use and further investigation.

Chemical constituents from the stems of Gymnema sylvestre

AIM: To study the chemical constituents of stems of Gymnema sylvestre(Retz.) Schult. METHODS: Chromatographic techniques using silica gel, C18 reversed phase silica gel, and prep-HPLC were used. The structures were elucidated on the basis of MS and spectroscopic analysis(1D and 2D NMR), as well as chemical methods. RESULTS: Seven compounds were isolated and their structures were elucidated as conduritol A(1), stigmasterol(2), lupeol(3), stigmasterol-3-O-β-D-glucoside(4), the sodium salt of 22α-hydroxy-longispinogenin-3-O-β-D-glucopyranosyl-(1→3)-β-D-glucurono-pyranosyl-28-O-α-L-rhamnopyranoside(5), oleanolic acid-3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside(6), and the sodium salt of 22α-hydroxy-longispinogenin 3-O-β-D-glucuronopyranosyl-28-O-α-L-rhamnopyranoside(7). The inhibition activities of compounds 1, 5-7 on non-enzymatic glycation of protein in vitro were evaluated. CONCLUSION: Compound 7 is a new triterpenoid saponin. It was shown that compounds 1, 5-7 have weak inhibition activities for non-enzymatic glycation of protein in vitro.

Two New Triterpenoid Saponins from Gymnema sylvestre

Two new oleanane-type triterpenoid saponins, gymnemoside-W1 and W2, together with seven known compounds were isolated from the leaves of Gymnema sylvestre R. Br. By means of spectral and chemical analysis, the structures of the new compounds were elucidated as 16 β-hydroxyl olean-12-en-3-O-[β-D-glucopyranosyl （1 →6）- β-D-glucopyranosyl]-28-O-β-D-glucopyranoside（1） and 16 β,21 β,28-trihydroxyl-olean-12-ene-3-O-glucoronopyranoside （2）. The EtOH/H2O extracts of this plant were shown to be able to inhibit glucose absorption in rats.