Antioxidant, Analgesic and Anti-inflammatory Activities of Bark of Oroxylum indicum Vent: An Endemic Medicinal Plant of Northeast India

Abstract

The aim of this study is to examine possible antioxidant, analgesic and anti-inflammatory activities of the stem bark of Oroxylum indicum, an endemic plant of Northeast India. The hydro-alcoholic extract was evaluated for their antioxidant activity by using DPPH scavenging method and phenolic and flavanoid content was estimated. The analgesic and anti-inflammatory assays were carried out on adult male Wistar albino rats by hot plate and carrageenan-induced paw edema method. The content of phenolic and flavanoid compound in hydro-alcoholic extract in terms of gallic acid and quercetin equivalent (GAE) is 52.67 mg/L and 64.63 mg/L respectively. The extract showed antioxidant activity with IC₅₀ value of 39.82 μg/mL as compared to the ascorbic acid which exhibited IC₅₀ value of 26.17 μg/mL. The analgesic activity was assayed by hot plate method using diclofenac as a standard drug at a dose of 10 mg/kg body weight and the results were expressed as mean increase in latency after drug administration. The anti-inflammatory activity was evaluated by carrageenan-induced rat paw edema model using indomethacin standard drug at a dose of 10 mg/kg body weight. The results were expressed in terms of mean increase in paw volume ± SEM. The extract of the stem bark was given in doses of 250 and 500 mg/kg body weight. All the doses were administered per orally. Results revealed that Oroxylum indicum posseses remarkable analgesic and anti-inflammatory activities. Further studies are needed for isolation of active molecule and establishment of mechanism of action.