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 [IC50: (10.50 +/- 1.03) +/- g/mL] and ferric reducing [IC50: (9.85 +/- 0.32) +/- g/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 FeSO4. Conclusions: R. longipes shows antioxidant and antidiabetic activities and could be a potential therapeutic candidate for diabetes.