Rhus longipes (Engl.) infusions improve glucose metabolism and mitigate oxidative biomarkers in ferrous sulfate-induced renal injury

Objective:To explore the antioxidant and antidiabetic activities of Rhus longipes(R.longipes)leaf and stem bark aqueous infusions.Methods:R.longipes leaf and stem bark infusions were characterized via gas-chromatography mass-spectroscopy(GC-MS)analysis.In vitro antioxidant and carbohydrate and lipid digestive enzyme inhibitory activities of R.longipes infusions were determined.Additionally,the modulatory effects of R.longipes infusions on intestinal glucose absorption,muscle glucose uptake,and biomarkers of renal oxidative injury were evaluated.Molecular docking was performed to determine the binding affinities of the identified compounds from the leaf and stem bark infusions on carbohydrate and lipid digestive enzymes.Results:GC-MS analysis revealed the presence of several phytocompounds,including palmitoleic acid,octadecanamide,24,25-dihydroxyvitamin D and L-ascorbic acid.The bark infusion had significantly higher total phenolic contents compared with the leaf infusion,with better DPPH scavenging[IC_(50):(10.50±1.03)μg/mL]and ferric reducing[IC_(50):(9.85±0.32)μg/mL]activities(P<0.05).Both R.longipes infusions at their highest concentrations significantly increased glucose uptake in yeast suspension and rat psoas muscle with marked suppression of glucose absorption in the rat jejunum(P<0.05).With no cytotoxicity on Vero cells,the infusions lowered lipid peroxidation,increased cellular reduced glutathione concentration,and the activities of superoxide dismutase and catalase in renal homogenate treated with FeSO_(4).Conclusions:R.longipes shows antioxidant and antidiabetic activities and could be a potential therapeutic candidate for diabetes.

STUDIES ON THE SAPONIN CONSTITUENTS OF GYNOSTEMMA LONGIPES

Two new cornpounds,saponin I and saponin II,were isolated from Gynostemma longipes f.Y.Wu. The struetures have been characterized on the basis of cbenical and speetroseopie evidence. ^-~.

Biotransformation ofα-asarone by Alternaria longipes CGMCC 3.2875

Biotransformation ofα-asarone by Alternaria longipes CGMCC 3.2875 yielded two pairs of new neolignans,(+)(7 S,8 S,7’S,8’R)iso-magnosalicin(1 a)/(-)(7 R,8 R,7’R,8’S)iso-magnosalicin(1 b)and(+)(7 R,8 R,7’S,8’R)magnosalicin(2 a)/(-)(7 S,8 S,7’R,8’S)magnosalicin(2 b),and four known metabolites,(±)acoraminol A(3),(±)acoraminol B(4),asaraldehyde(5),and 2,4,5-trimethoxybenzoic acid(6).Their structures,including absolute configurations,were determined by extensive analysis of NMR spectra,X-ray crystallography,and quantum chemical ECD calculations.The cytotoxic activity and Aβ_(42)aggregation inhibitory activity of all the compounds were evaluated.Compound 2 displayed significant anti-Aβ_(42)aggregation activity with an inhibitory rate of 60.81%(the positive control EGCG:69.17%).In addition the biotransformation pathway ofα-asarone by Alternaria longipes CGMCC 3.2875 was proposed.

Pollen and resource limitations to lifetime seed production in a wild population of the endangered plant Disanthus cercidifolius var.longipes H.T.Chang(Hamamelidaceae)

Disanthus cercidifolius Maxim.var.longipes H.T.Chang,a plant species that only occurs in a few counties in Hunan,Jiangxi and Zhejiang Provinces and with a relatively small number of individuals,is ranked as a second Class endangered species for conservation in China.We have studied the effect of pollen and resources available to female reproduction,and the reproductive mechanism of“excess flowers with low fruit set”in Disanthus cercidifolius Maxim.var.longipes H.T.Chang was discussed.Results are as follows:Pollen from different sources has significant effects on fruit set and seed set of Disanthus cercidifolius Maxim.var.longipes H.T.Chang.The pollen source rather than pollen numbers significantly affected reproduction of this species.In wild populations,producing one fruit needs about 54.8 flow-ers,and one satiation seed needs about 6.60 flowers or 83.19 ovules.After fertilizing,which was propitious to flower develop-ment,the abortion rate of flower buds was decreasing,but the flowering rate was increasing.The fruit set and seed set was also significantly increasing,while abortion rate of fruit was significantly decreasing.With the increasing percentages of cutting leaves,the fruit set decreased,but the abortion rate of fruit shows no significant differentiation among treatments.After cutting branches that were puny,broken and insect-infested branches,the flower number seemed to be decreas-ing,but the fruit set and seed set all increased significantly.After removing some flowers,the fruit set was calculated with respect to the number of flowers remaining after the treatment increased with increasing of percentages of flower removal,whereas fruit set calculated with respect to the initial number of flowers remained constant,and the mean weights of per fruit and per seed all decreased significantly.Sufficient spatial or temporal heterogeneities in nutrient levels might allow limitation of seed set by resources and pollen in a natural population,while supplying resources may indirectly affect pollination by increasing attraction of the flowers to pollinators.There were very low fruit and seed sets in natural populations of Disanthus cercidifolius Maxim.var.longipes H.T.Chang.Different factors may have interacted to effect a low fruit set.A joint adoption of the“selection abortion hypothesis”,“ovary reserve hypothesis”and“male function hypothesis”seems to be the most likely explanation for the reproductive strategy of“excess flowers with few fruit sets”in Disanthus cercidifolius Maxim.var.longipes H.T.Chang.

Dammarane-type triterpenoids from Gynostemma longipes and their protective activities on hypoxia-induced injury in PC12 cells

Sixteen new dammarane-type triterpenoid saponins(1-16)featuring diverse structural variations in the side chain at C-17,along with twenty-one known analogues(17-37),have been isolated from the rhizomes of Gynostemma longipes C.Y.Wu,a plant renowned for its medicinal and edible properties.The structural elucidation of these compounds was accomplished through comprehensive analyses of 1D and 2D NMR and HRMS spectroscopic data,supplemented by comparison with previously reported data.Subsequent assays on the isolates for their protective effects against hypoxia-induced damage in pheochromocytoma cells(PC12 cells)revealed that nine saponins exhibited significant anti-hypoxic activities.Further investigation into the anti-hypoxia mechanisms of the representative saponins demonstrated that compounds 22 and 36 markedly reduced the levels of hypoxia-induced apoptosis.Additionally,these compounds were found to decrease the release of lactate dehydrogenase(LDH)and malondialdehyde(MDA),while increasing the activity of superoxide dismutase(SOD),thereby indicating that the saponins could mitigate hypoxia-induced injuries by ameliorating apoptosis and oxidative stress.These findings offer substantial evidence for the future utilization and development of G.longipes,identifying dammarane-type triterpenoid saponins as its active anti-hypoxic constituents.