Evaluations of cytogenotoxic and nutrient composition of three commonly consumed vegetables in south-western Nigeria

Abstract

Consumption of leafy vegetables provides health benefits but sometimes may turn out to be the cause of certain health problems. Thus, adequate toxicological screening is needed to ensure safety of their consumption. Aqueous extracts of Corchorus olitorius L., Celosia argentea L., and Ocimum gratissimum L. were evaluated for cytogenotoxic effects on Allium cepa L. root cells using 0.5, 1.0, 2.5, 5.0, 10.0, 25.0 and 50.0 part per thousand (ppt), each of the vegetable extracts. The levels of macronutrients (moisture, ash, protein, fibre, fat and carbohydrate) in the vegetables and some minerals (cadmium, copper, iron, lead, magnesium, nickel and zinc) of their aqueous extracts were determined. The carbohydrate values were in the order O. gratissimum > C. olitorius > C. argentea with 48.17% as the highest. The values obtained for ash, protein, fat, Mg and Zn contents were in the order C. argentea > C. olitorius > O. gratissimum , with the highest values of 19.98%, 30.79%,, 0.22% ,226.4 mg/L and 2.57mg/L, respectively obtained for C. argentea. The concentration of Cu and Pb were in the order of O.gratissium> C. argentea> C. olitorius with 0.67 and 0.21mg/L obtained for O.gratissium (P<0.05). The aqueous extracts of the three vegetables inhibited root growth and cell division in the A. cepa root tips, with the highest inhibitory effects observed in C. argentea at 50.0 ppt. Induced chromosomal aberrations were significant only at 1.0 and 25 ppt of O. gratissimum, whereas there were no significant differences in aberrant cells in C. olitorius and C. argentea compared to the control. Chromosomal aberrations observed in the treated A. cepa roots include c-mitosis, Chromosome bridge and sticky chromosome. The results showed that the three vegetables have nutritive qualities but with root growth and mitotic inhibitory activities, which were severe in C. argentea. Although the result indicates that chromosomal aberrations might be induced at higher concentrations, the antimitotic potential of the extract of C. argentea may favour its uses in the development of drugs to prevent the uncontrolled proliferation of cancer cells of which investigation is required.