Evaluation of Aster bakerianus Burtt Davy ex C.A. Sm. Crude Root Extract for Acute Antiinflammatory Activity in Rats

Abstract

The crude extract of Aster bakerianus roots used for treatment of a variety of ailments in Lesotho was evaluated for anti-inflammatory activity and phytochemical content. Extract was first tested for toxicity at oral dosages of 0 (negative control), 1000, 2000, 3000 and 5000 mg/kg bw with five groups of female mice, each group having four mice. Negative control group received sterile distilled water (1.0 ml/kg bw). Mice were observed for general symptoms of toxicity for 24 hours and left for a further 14 days for any delayed toxicity. None of the extract doses induced toxicity. Anti-inflammatory activity of A. bakerianus was determined using the carrageenan-induced rat paw oedema assay. Five groups of six mice each were orally pre-treated as follows: Negative control group (group 1) received sterile distilled water (1.0 ml/kg bw). Positive control group (group 2) received indomethacin (10mg/kg bw). Three test groups (group 3, 4 and 5) received A. bakerianus extract, 100, 200 and 400 mg/kg bw respectively. After one hour of pre-treatment, all test groups and controls were injected with 0.1 ml carrageenan subcutaneously in the right hind paw and paw thicknesses recorded at the following time intervals: 0, 1, 2, 3, 4, 5, 6, and 24 hours. Statistically (p<0.05) there was no difference observed in the antiinflammatory activity profile of A. bakerianus and that of the drug indomethacin at the different time intervals of the study, implying same efficacy. The anti-inflammatory activity of extract was attributed to presence of terpenoids, saponins, sterols, simple phenols, coumarins, polyphenols, flavonoids, tannins, phlobatannins, anthocyanins, alkaloids, glycosides and amino acids. The results of this study justified the documented use of this plant by Basotho for treatment of inflammatory disorders.