Anxiolytic Effects, Antioxidant and Anti-inflammatory Activities of the Methanol Extract of Jatropha tanjorensis Leaf

Abstract

The methanol leaf extract of Jatropha tanjorensis was analyzed for its bioactive components, in-vitro antioxidant, antidepressant, anxiolytic and anti-inflammatory activities using established methods. The phytochemicals detected were saponins, tannins, terpenoids, phenolic compounds, alkaloids, flavonoids and eugenols. The total phenolic content (TPC) was 36.48 mgGAE/g, while the total flavonoid content (TFC) was 145.92 mgQE/g of the extract. 1, 1-diphenyl-2-picrylhydrazyl radical scavenging activity gave an IC₅₀ of 185.02 and 5.15 µg/mL for the extract and ascorbic acid (standard), respectively. The 50% lethal dose (LD₅₀) was greater than 5000 mg/kg, while graded doses of 50, 100 and 200 mg/kg of the plant extract relieved depression in mice to 93.3, 100 and 80.8%, respectively when compared with 10 mg/kg amitriptyline (positive control). A significant anxiety reduction, exemplified by a decrease in the frequency of head dip, was observed for animals administered with the plant extract compared with untreated control (p < 0.05). The reduction of formalin-induced paw edema was significant (p < 0.01) at 50 mg/kg of the plant extract, when compared with the control. The methanol extract of J. tanjorensis leaf is therefore a potential source of plant medicine with remarkable pharmacological activities.

Keywords:    Jatropha tanjorensis; anxiolytic; antidepressant; anti-inflammatory; antioxidant; phytochemicals