Investigation of Oral Subacute Toxicity and In-Vitro Antioxidant Activity of Standardized Methanolic Extract of Quercus serrata Leaves

Background: Quercus serrata Murray leaves are traditionally used for the treatment of diabetes, dysmenorrhoea, inflammation and urinary tract infection. So, far no study has reported on the toxicological profile and antioxidant properties of the plant. Objective: The present study aimed to investigate the in-vivo toxicological profile and in-vitro antioxidant activities of the methanolic extract of standardized Quercus serrata leaves. Methods: Per-oral sub-acute toxicity study was performed in rats using three dose levels (200, 400 and 800 mg/kg b.w.) of the extract for 28 days. The control group received gum acacia suspended in water. Bodyweight was measured weekly. Biochemical parameters were analysed using the serum; the blood-cell count was performed using the whole blood. Pathological changes were also checked in highly perfused tissues. Further, in-vitro reducing power assay, nitric oxide scavenging assay, and DPPH free-radical scavenging assay were performed to evaluate the antioxidant activity of the extract. Results: There were no significant alterations found in the blood-cell count and biochemical parameters analysed in the treatment group when compared with the normal control. Histopathology study of liver, kidney, pancreas, heart and brain revealed normal cellular architecture in the treatment groups alike the control group animals. Quercus serrata also showed a significant reduction of DPPH with an IC50 value of 4.48±0.254 μg/mL, in-vitro reducing power activity with an IC50 value of 121.65±0.320 μg/mL and nitric oxide scavenging activity with an IC50 value of 106.43±0.338 μg/mL. Conclusion: The study showed that standardized methanolic extract of Quercus serrata leaves was safe after sub-acute oral administration in rats and possesses good antioxidant potential.