Neocarya macrophylla ethyl acetate fraction attenuates oxidative stress and inflammation in high-fat diet and streptozotocin-induced diabetic rats

Oxidative stress and inflammation drive diabetes. Conventional treatments inadequately target these. Neocarya macrophylla shows preliminary antioxidant promise. This study aims to investigate its antioxidant and anti-inflammatory effects in a diabetic rat model to address this research gap. Thirty-six male Wistar rats were randomised into four groups (n=6 per group): Normal Control, Diabetic Control, Neocarya macrophylla Ethyl Acetate Fraction (120 mg/kg), and Metformin (200 mg/kg). Type 2 diabetes was induced using a 60% HFD for four weeks, followed by a single intraperitoneal injection of STZ (40 mg/kg). Treatment was administered orally for four weeks. Post-treatment, oxidative stress biomarkers—Superoxide Dismutase (SOD), Catalase (CAT), Glutathione Peroxidase (GPx), and Malondialdehyde (MDA)—were quantified using spectrophotometric assays. Pro-inflammatory cytokines—Interleukin-6 (IL-6) and Tumour Necrosis Factor-alpha (TNF-α)—were evaluated using ELISA, while Catalase mRNA expression was assessed via RT-qPCR. Statistical analysis was performed using GraphPad Prism 9, applying One-way ANOVA followed by Tukey’s post hoc test, with p<0.05 considered significant.Treatment with the ethyl acetate fraction significantly increased SOD activity by 19% (p=0.007), GPx by 54% (p=0.04), and CAT by 136% (p<0.001) compared to diabetic controls, while reducing MDA levels by 41% (p<0.001), indicative of reduced lipid peroxidation. Pro-inflammatory cytokines IL-6 and TNF-α levels were reduced by 58% and 62%, respectively, in the treatment group compared to diabetic controls. Catalase mRNA expression showed a 1.4-fold increase (p < 0.001). Notably, the ethyl acetate fraction’s effects were comparable to Metformin in modulating oxidative stress and inflammatory markers.This study demonstrates that the ethyl acetate fraction of Neocarya macrophylla leaves exerts significant antioxidant and anti-inflammatory effects in HFD/STZ-induced diabetic rats, supporting its therapeutic potential as an adjunctive natural remedy in managing oxidative stress and inflammation associated with diabetes.