Molecular docking supported investigation of antioxidant, analgesic and diuretic effects of Costus speciosus rhizome

ABSTRACT. The aim of the current study was to analyze the polyphenols and determines the antioxidant, analgesic and diuretic properties of the methanolic extract of C.speciosus rhizome. DPPH and ferric reducing antioxidant power (FRAP) assays were used to determine the antioxidant activity. Acetic acid-induced writhing and formalin-induced licking experiments were used to assess the analgesic effect. The total phenolic, flavonoid and flavonol contents were found 51.73± 0.25 mg GAE/g dry weight, 3.41± 0.07mg QE/g dry weights and 44.19± 2.24 mg QE/g dry weight, respectively. The plant extract exhibited weak antioxidant activity in the DPPH and FRAP assays, with an IC50 value of 1699±62 μg/mL and an EC50 value of 125±2 μg/mL, respectively. The extract significantly reduced the number of writhes at both doses (200 and 400 mg/kg body weight) as compared to the control. The extract (400 mg/kg) also significantly reduced the percent inhibition of licking by 31.96 and 62.69% compared to the control in the early and late phase, respectively. Compared to the standard drug furosemide, the plant extract also showed a weak diuretic effect. The docking study supported the analgesic activity of rhizome extract. The potent analgesic activity of the plant extract justifies the traditional and medicinal aspects.   KEY WORDS: Costus speciosus, Analgesic activity, Diuretic effect, Molecular docking Bull. Chem. Soc. Ethiop. 2022, 36(3), 627-640.                                                                 DOI: https://dx.doi.org/10.4314/bcse.v36i3.12