PHARMACOLOGICAL ASSESSMENT OF ANTIPYRETIC EFFECTS OF EXTRACTS, SOLVENT FRACTIONS AND ISOLATED COMPOUNDS FROM ALSTONIA CONGENSIS ENGL (APOCYANCEAE) ROOT BARK IN EXPERIMENTAL SWUISS ALBINO MICE

This study was conducted to evaluate the antipyretic activity or effects of extracts, solvent fractions, crude polysaccharides and isolated compounds from Alstonia congensis. Engl. root bark against the fungus Brewer’s yeast induced pyrexia in Swiss albino mice. Firstly, it was observed that the subcutaneous injection of Brewer’s yeast at dose of 10 ml/kg bw induced significant elevation of rectal temperatures from 37.8±0.08 in 1h to 4039.83°C from 1 to in 5h. Secondly and inversely, it was perceived the oral administration of Aspirin as reference antipyretic drug caused significant lowering of rectal temperature from 37.5±0.4 to 34.6±0.8°C at the same times. Thirdly, in the same way, the oral administration of aqueous Ac-1 and methanol Ac-2 extracts at high dose of 400 mg/kg bodyweight induced also significant reduction of rectal temperatures at all administered dose of 200 and 400 mg/kg bodyweight in dose-dependent manner. Administered at high dose of 400 mg/kg bodyweight, they lowered rectal temperatures to values of 38.2±0.6 and 37.5±0.5°C in 1h and 37.05±0.2 and 36.58±0.7°C I after 5 respectively, compared to test test toxic negative control Brewer’s yeast showing high rectal temperatures of 37.8±0.8 and 4039.83±0.5°C in 1 and 5h respectively. Fourthly, it was the same for soluble fractions chloroform, ethylacetate, n-butanol and residual aqueous solvent fractions induceding significant decrease of rectal temperatures between 38.4±0.6 and 37.5±0.5°C in 1h and between 36.5±0.6 to 37.5 ±0.5°C after 5h. Crude polysaccharide CPms reacted the same manner by lowering rectal temperatures from 38.4±0.7 to 36.8±0.8°C in 1 and 5h respectively compared to test toxic negative control Brewer’s yeast presenting high rectal temperatures of 40.3±0.05°C after 5h. Although sSome increase of rectal temperatures was observed for some samples in some hours without important signification since they falled immediately in normal 36.5-37.5°C and the last rectal temperature induced by each test sample remained significant and determinative as it was all found to be in acceptable physiological limits 36.5-37.5°C. Isolated compounds Boonein, Echintamine, 6,7 Secangustilobine and β-Amyrin also exhibited good antipyretic activity by reducing significantly rectal temperatures induced by the test toxican Brewers’s yeast in treated Swiss albino mice from 38.2±0.6 to 37.0±0.60°C in 1h and between 36.5±0.5 to 37.5±0.5°C remaining normal limits compared to text toxican Brewer’sy yeast showing greater rectal temperatures between 37.8±0.08 in 1h and 40.3°C in 5h. These results lowering effects of high rectal temperatures caused by the toxixcn Brewer’s yeast, showed clearly that extracts, solvent fractions, crude polysaccharides and isolated compounds from Alstonia congensis root bark as well asand Aspirin as reference antipyretic drug used were endowed with appreciable and interesting antipyretic activity, exploitable in traditional medicine mainly for aqueous extract used to treat fever.