Methods: In this study, AA was administered orally at an individual dose of 300 and 2000 mg/kg body weight to group 1 and 2 respectively, while group 3 served as normal control. All the animals were observed for 2 weeks to determine any behavioral and physical changes. On day 15, blood was collected for hematological and biochemical investigation, later animals from all the three groups were euthanized to harvest and store essential organs for histopathological analysis. Four different staining techniques; hematoxylin and eosin, Masson trichrome, Periodic acid Schiff and Oil O Red were used to investigate any alterations in different tissues through microscopical observation.

MATERIALS AND METHODS: The antioxidant effect of these compounds was initially performed in vitro using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay methods before subjecting them to in vivo experiments. Compounds showing potent antioxidant activity (CS-1 and CS-2) were investigated further for their antidepressant activity using the forced swim test (FST) and tail suspension test (TST). Ascorbic acid (AA) and fluoxetine (20 mg/kg, p.o) were used as reference drugs for comparison in the antioxidant and antidepressant experiments, respectively.

RESULTS: It was observed that CS-2 and CS-3 exhibited highest DPPH (half maximal inhibitory concentration [IC50]: 16.22 and 25.18 μg/mL) and ABTS (IC50: 17.2 and 28.86 μg/mL) radical scavenging activity, respectively, compared to AA (IC50: 15.73 and 16.79 μg/mL) and therefore, both CS-2 and CS-3 were tested for their antidepressant effect using FST and TST as experimental models. Pretreatment of CS-2 and CS-3 (20 mg/kg) for 10 days considerably decreased the immobility time in both the FST and TST models.