<i>Ocimum gratissimum</i> diet inclusion abrogates N-methyl-N-nitrosourea-induced colorectal toxicity in male Wistar rats via attenuating oxidative stress and colonic mucosa injuries
DOI:
https://doi.org/10.51412/psnnjp.2026.023Keywords:
N-methyl-N-nitrosourea, Carcinoembryonic antigen, Colorectal, Antioxidant, Ocimum gratissimum Leaf, ChemopreventionAbstract
Background: Colorectal toxicity disrupts intestinal homeostasis, undermining treatment efficacy and diminishing patient quality of life. The preventive effects of dietary inclusion of graded levels of Ocimum gratissimum leaf on N-methyl-N-nitrosourea (MNU)-induced colorectal toxicity were evaluated in male Wistar rats.
Methods: Thirty male rats (70–90 g) were acclimatized for two weeks and randomly assigned to six groups (n = 5). All groups, except the Normal control, and the 10% diet control received intrarectal MNU (9mg/kgbw) for 10 weeks together with diets containing 0%, 2.5%, 5%, or 10% O. gratissimum leaf. At the end of the experiment, rats were sacrificed and blood and organ tissues were collected for carcinoembryonic antigen (CEA) determination, histopathological examination, and biochemical assays.
Results: Carcinoembryonic antigen (CEA) levels were significantly higher in the MNU control group than in normal controls (P < 0.05), but decreased progressively with graded dietary O. gratissimum supplementation. Dietary O. gratissimum significantly suppressed the MNU-induced rise in colonic malondialdehyde (P < 0.05) and concomitantly improved the activities of endogenous catalase and superoxide dismutase. Histopathological analysis of MNU-treated rats revealed disrupted colonic architecture characterized by distorted blood vessels, hyperchromasia, cellular pleomorphism, glandular atrophy, and lamina propria necrosis compared with normal and diet controls; these alterations were progressively ameliorated with higher levels of O. gratissimum leaf in the diet. Dietary inclusion of O. gratissimum increased the intake of crude fiber, polyphenols, and flavonoids. Crude fiber levels positively correlated with antioxidant enzyme activities (catalase and superoxide dismutase), while polyphenol and flavonoid contents correlated inversely with CEA.
Conclusion: These findings suggest that O. gratissimum leaf exerts protective effects against MNU-induced colorectal injury, which may be associated with its dietary fiber and antioxidant polyphenolic content.
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