In vitro Antioxidant and Analgesic Properties of Methanolic Extracts of the Fruits of Xylopia aethiopica on Formalin-Induced Nociception
Xylopia aethiopica, negro pepper, is commonly used in traditional medicine to treat different kinds of diseases and infections. Methanolic extract of the fruit of Xylopia aethiopica was evaluated for its antioxidant and analgesic properties. Qualitative and quantitative phytochemical screening of the extract was done according to standard procedures. Antioxidant potential was investigated using 2,2-diphenyl-1-picryl hydrazyl (DPPH) scavenging activity. Analgesic activity was carried out using formalin-induced paw licking test in albino rats at 100, 200 and 400 mg extract per kg body weight. Qualitative phytochemical screening revealed the presence of tannnins, saponins, flavonoids, glycosides and steroids in the extract. The extract significantly inhibited DPPH scavenging activity with percentage inhibition of 147.35% as compared to ascorbic acid (147.15%) at a concentration of 0.20 mg/mL. The methanolic fruit extract of Xylopia aethiopica significantly reduced (p < 0.05) formalin-induced paw licking in both early and late phases, with 28.31 and 64.90% inhibition at 400 mg/kg, in rats in a dose-dependent manner. It can be concluded that methanolic fruit extract of Xylopia aethiopica showed marked antioxidant potential which could be linked to its ability to reduce formalin-induced paw licking. The fruits of X. aethiopica could, therefore, be suggested for use as an analgesic.