摘要 : The phenolic content, antioxidant activity and toxicity of three varieties of extracts of rizga flour on white albino male rats was evaluated. The antioxidant activities of the extracts as determined by the quantities of phenols p... 展开 The phenolic content, antioxidant activity and toxicity of three varieties of extracts of rizga flour on white albino male rats was evaluated. The antioxidant activities of the extracts as determined by the quantities of phenols present and scavenging activities on 2,2-Diphenyl-l-picrylhydrazyl (DPPH) radical indicated that all three varieties of rizga flour contained significant quantities of antioxidants and phenols. However, the total antioxidant capacity and polyphenolic contents of langaat was lower than that of beebot and riyom (p<0.05) with an IC50 of 90.16 jag mLr1 for langaat, 30.28 jxg mLr1 for beebot and 60.27 ju.g mLr1 for riyom as compared with the standard (Quercetin) that had an IC50 of 23.17 jxg mL"1. The phytochemical screening of the flours was determined using standard qualitative methods indicated the presence of cyanogenic glucosides, tannins and flavonoids in all the three varieties studied but beebot and riyom contained alkaloids in addition. The extracts of the 3 varieties of rizga had a low toxic effect on the rats studied in addition with an LD50 of 630.1 mg kg'1 for Riym, 398.1 mg kg""1 for Langaat and 446.7 mg kg""1 for Beebot. Correlation between the total antioxidant capacity and polyphenolic composition of the 3 varieties of rizga was found to be significant (R2 = 0.917). These findings suggest rizga to be a natural source of antioxidants and thus could be used in the treatment of ailments implicating free radicals. In addition, it is safe for consumption. 收起