Evaluation of antioxidant, anti-inflammatory, analgesic and antipyretic activities of the stem bark of Sapindus mukorossi

BACKGROUND: Saponins are the main constituents of genus Sapindus and have the therapeutic potential for inflammatory disorders. In this study the antioxidant, anti-inflammatory, analgesic and antipyretic potential of the stem bark of soap nut (Sapindus mukorossi) methanol extract and its derived fractions has been investigated. METHODS: Powder of stem bark of the S. mukorossi was extracted with methanol (SMM) and fractionated in order of n-hexane (SMH), chloroform (SMC), ethyl acetate (SME), n-butanol (SMB) and the remaining as aqueous fraction (SMA). Quantitative estimation for the total phenolic and total flavonoid content was carried out in all the extract/fractions. Further, various in vitro antioxidant assays were also performed. Anti-inflammatory (Carrageenan induced paw edema), analgesic (hot plate latency test) and antipyretic (rectal temperature) were determined in Sprague-Dawley rat. RESULTS: Quantitative estimation of total phenolic contents in extract/fractions varied between 252.3 ± 2.41 mg of GAE/g - 594.16 ± 4.3 mg of GAE/g while the total flavonoids estimated were from 11.02 ± 1.3 mg of RUE/g to 96.9 ± 3.2 mg of RUE/g. Standard antioxidant assays such as scavenging of DPPH, hydroxyl radical, nitric oxide, phosphomolybdenum assay, reducing power, inhibition of β-carotene bleaching, iron chelation activity and inhibition of heat induced protein denaturation indicated the antioxidant potential of the extract/fractions. Carrageenan induced paw edema of rat was effectively inhibited by SMA at 300 mg/kg administration to rat (84.19 ± 1.48%) after 3 h and analgesia (latency time) in hot plate test (55.78 ± 1.22%) after 120 min. SMA at 300 mg/kg distinctly decreased the rectal temperature in brewer’s yeast (Saccharomyces cerevisiae) induced pyrexia in rat. CONCLUSION: The resulted obtained in this study suggested the therapeutic importance of stem bark of S. mukorossi in inflammatory related disorders.