Vernonia amygdalina is commonly used for food and health purposes. Processing of the leaf for food is aimed at removing bitter tasting antinutritional principles like saponins. This study was designed to determine the antipyretic and antinociceptive property of the crude saponin from Vernonia amygdalina leaf. Standard procedure for antipyretic study using Saccharomyces cerevisiae induced pyrexia in rats; and acetic acid induced writhe, hot plate and cold tail flick tests for antinociceptive study in mice were used. Data for the crude saponin showed significant (P ≤ 0.05) dose dependent anal temperature decrease. The antinociceptive data in mice was significant (P ≤ 0.05) in the writhing test contrary to the cold tail flick test. In acute toxicity study, an LD 50 of 5.1523 g/kg using oral route indicated it was practically non-toxic. Finding suggests that Vernonia amygdalina leaf prepared as diet could be of potential benefit to ailing persons with fever and/or pains, if processing technique adopts minimal loss of principles like saponins.

Vernonia amygdalina is commonly used for food and health purposes. The processing of the leaf for food is usually aimed at removing bitter tasting principles like saponins. This study was designed to determine the antipyretic and antinociceptive properties of the aqueous extract, crude saponin and the chromatographic fraction of the crude saponin from the leaf. In the antipyretic evaluation, anal temperature change in fasted rats with prior induced pyrexia using intra-peritoneal administered 15% w/v Saccharomyces cerevisiae, was measured four hours after dose administration. In the antinociceptive evaluation, 0.6% acetic acid solution administered by intra peritoneal route at a dose of 15 ml/kg was used to induce writhing in the writhing test; hot plate at 55 °C ± 1 to induce thermal pain in the hot plate test; and cold mixture of water and ethylene glycol (1:1) maintained at -10 °C to initiate pain sensation in the cold tail flick tests. Antipyretic data showed significant (P ≤ 0.05) anal temperature decrease for all the test doses compared to the placebo. This was markedly observed with the aqueous extract at 0.55 oC ± 0.03 anal temperature decrease, compared to the 0.29 0C ± 0.01 of the crude saponin, at a similar dose level of 400 mg/kg. At 200 mg/kg dose, the crude saponin induced an anal temperature decrease of 0.14 0 C ± 0.02. This was higher than the response obtained with the chromatographic fraction which produced 0.06 0C ± 0.01 anal temperature decrease. Antinociceptive data was significant (P ≤ 0.05) for the crude saponin in the writhing (52.58 % antinociceptic effect) and hot plate tests (14.24 maximum percent analgesia), contrary to observation in the cold tail flick test. Findings showed the antipyretic and non-steroid like antinociceptive property of the crude saponin, which may support the rationale for the use of Vernonia amygdalina leaf to reduce fever and/or pain.

Studies have shown that Vernonia amygdalina possess saponin as one of the bitter phyto-constituents. This study was aimed at determining the anti-inflammatory and antipyretic activity of the aqueous extract of the leaf, root and saponin fraction from the herb. Standard procedures using ear thickness measurement in xylene induced inflammation and anal temperature readings in Saccharomyces cerevisiae induced pyrexia in rats were followed. Data indicated significant (p≤0.05) inhibitory activity for all the dose levels of the extracts in the antiinflammatory and antipyretic evaluations. Saponin fraction at the dose of 100 and 200 mg/kg with 10.5 and 19.6% inhibition respectively, showed significant (p≤0.05) anti-inflammatory activity. The antipyretic evaluation of the saponin fraction showed no anal temperature reduction at 50 mg/kg dose level. Finding suggests the antipyretic and non-steroid like anti-inflammatory activity of the saponin fraction. This may partly explain the observed activity of the herbal extract which has found use traditionally as remedy for similar ailments.

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