Polyphenol Contents, Cytotoxicity and Antioxidant Activities of Some Selected Nigerian Vegetable FoodsAuthor(s): Omale James, Okafor Polycarp Nnacheta and Omede Ameh
The present investigation was carried out to evaluate the relative antioxidant activity, cytotoxicity and some polyphenol contents in selected Nigerian vegetable foods. The flavouoid contents varied from 1.55± 4.23 to 17.300 ± 0.200% in the extracts. Total phenol contents were between 0.263 ± 0.00 to 1.328 ± 0.318% in the plant extracts. 2,2- Diphenyl-1- picrylhydrazyl (DPPH) radical scavenging effects of the extracts was determined spectrophotometrically. Rapid radical scavenging screening using thin layer chromatographic plate (TLC) was also performed. The highest radical scavenging effect was observed in C. esculenta leaf extract with IC50 = 180.20 >g/mL. This is comparable to the standards quercetin and ascorbic acid used. The higher amount of the polyphenolic compounds is attributable to more potent radical scavenging effects as demonstrated by C. esculenta leaf extract. The extracts possessed very low cytotoxicity to brine-shrimp, when compared with the reference standard (Potassium dichromate, LC50 = 180.142 >g/mL). The results obtained in the present study indicate that these vegetables can be potential sources of natural antioxidant agents and are relatively safe for the purposes utilized.