Evaluation of the in vitr o and in viv o antioxidant activity of Albizia adianthifoli a Schumach (Fabaceae) stem bark

Objectives: This study assessed the in vitro and in vivo antioxidant activities of the methanol extract of A. adianthifolia stem bark (MEAA). Materials and Methods: The in vitro antioxidant parameters assayed included diphenylpicrylhydrazine (DPPH), ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), metal ion chelating activity, thiobarbituric acid reactive species (TBARS) and nitric oxide (NO) while superoxide dismutase (SOD), reduced glutathione (GSH), malondialdehyde (MDA) and catalase (CAT) were evaluated in vivo in adult Wistar albino rats after oral administration of the extract (100, 200 and 400 mg/kg) and distilled water (5 ml/kg) for 14 days. Acute toxicity test and phytochemical analysis were also conducted. Results: The acute toxicity (LD50) was estimated to be 4246 mg/kg. Phytochemical analysis of the extract revealed the presence of flavonoids, phenolic compounds, tannins, alkaloids, saponin, terpenoids and steroids. The IC 50 values of the in vitro antioxidant studies were 4.1 ± 0.23, 8.70 ± 2.48, 232.10 ± 69.11, 32.29 ± 16.70, 27.99 ± 5.96, and 73.32 ± 49.39 µg/ml for DPPH, FRAP, TAC, metal ion, TBARS, and NO, respectively. The extract significantly ( p <0.05) elevated SOD, GSH and CAT levels, whereas MDA was significantly ( p <0.05) reduced when compared to the negative control. The MEAA showed considerable in vitro and robust in vivo antioxidant properties. Conclusion: Our findings justify the use of A. adianthifolia for the management of oxidative stress-related conditions in traditional medicine. Studies are ongoing to isolate the active molecule(s).