effects of extraction solvents on the antioxidant and phytochemical activities of manihot esculenta leaves

Background: plants contain diverse phytochemicals with different solubility levels, dependingon their molecular charges and polarity. this study was conducted to examine the effects of threeextraction solvents in their pure and aqueous forms: absolute petroleum ether, acetone and ethanolon the phytochemical profile and antioxidant activities of manihot esculenta leaves extracts.methods: the preliminary phytochemical investigations were performed, using standardprocedures. the in vitro antioxidant properties were estimated by: 1,1-diphenyl-2-picryl-hydrazyl(dpph), hydrogen peroxide (h2o2) scavenging activity, ferric reducing antioxidant power(frap) and ferric thiocyanate (ftc).results: the phytochemical analyses revealed the occurrence of an array of compounds: alkaloids,flavonoids, cardiac glycosides, tannin phenols, saponins and anthraquinones, the concentration ofwhich varied with the solvent type. a considerable presence of all phytochemicals was found in theaqueous ethanol. the extracts from pure solvents were much less effective against dpph syntheticradical than those 50% diluted. the petroleum ether extract provided the least antiradical activity,while the aqueous ethanol was the richest. the scavenging effect of the extracts on h2o2variedin this order: 50% ethanol > absolute ethanol > ascorbic acid > 50% acetone > absolute acetone> 50% petroleum ether > absolute petroleum ether. similarly, the results of the frap and ftcmethods agreed largely with those of the dpph and h2o2. thus, the results of antioxidant activitypositively correlated with the phytochemical results, with the aqueous ethanol showing themaximum activity overall.conclusion: the results indicated that the extraction solvents considerably affected thephytochemical contents and the antioxidant activities of the tested extracts. these extracts canpotentially serve as the alternative sources of natural antioxidant preparations.