Abstract
Uranium compounds, particularly uranyl acetate, are known to cause significant genotoxic and oxidative damage in biological systems due to their high chemical reactivity. In recent years, plant-based antioxidants, such as those found in Abelmoschus esculentus (L.) Moench, have attracted considerable attention for their potential to mitigate the toxicity of heavy metals. The present study was conducted to investigate the mitigative effect of A. esculentus (L.) Moench extract on the toxicity induced by uranyl acetate in the model organism Allium cepa L. Tap water, 250 mg L(- 1) A. esculentus extract, 500 mg L(- 1) A. esculentus extract, 0.1 mg mL(- 1) uranyl acetate, 0.1 mg mL(- 1) uranyl acetate + 250 mg L(- 1) A. esculentus extract, and 0.1 mg mL(- 1) uranyl acetate + 500 mg L(- 1) A. esculentus extract were administered to the six groups of A. cepa bulbs. The group treated with tap water served as control group. Uranyl acetate caused a significant reduction in rooting percentage, root elongation, weight gain, mitotic index and the levels of chlorophyll a and chlorophyll b. There was a notable increase in the frequency of micronuclei and chromosomal aberrations (CAs), as well as a rise in malondialdehyde level following the uranyl acetate administration. The uranyl acetate-induced CAs included fragment, sticky chromosome, vagrant chromosome, bridge and unequal distribution of chromatin. The group treated with uranyl acetate also exhibited elevated levels of DNA damage, meristematic cell injury and superoxide dismutase and catalase enzyme activities. The meristematic damage induced by uranyl acetate was observed in the epidermis, cortex and nucleus of epidermal cells. The A. esculentus extract was observed to possess high levels of phenolic compounds and exhibited dose-dependent efficacy in mitigating the adverse effects of uranyl acetate. According to LC/MS analysis, the most abundant phenolic compounds in A. esculentus extract were rutin, caffeic acid, quercetin, salicylic acid and 4-OH benzoic acid. It was concluded that the capacity of A. esculentus extract to reduce uranyl acetate-induced multidirectional toxicity may be related to the ability of its phenolic compounds to chelate and scavenge radicals.