Benzo(a)pyrene induces oxidative stress, pro-inflammatory cytokines, expression of nuclear factor-kappa B and deregulation of wnt/beta-catenin signaling in colons of BALB/c mice. (September 2016)

• Record Type: Journal Article
• Authors: Ajayi, Babajide O.; Adedara, Isaac A.; Farombi, Ebenezer O.
• Is Part Of: Food and chemical toxicology. Volume 95(2016)
• Page Start: 42
• Page End: 51
• Publication Date: 2016-09
• Subjects: Benzo(a)pyrene -- Colon toxicity -- Oxidative stress -- Inflammation -- wnt signaling; Toxicology -- Periodicals; Food poisoning -- Periodicals; Food Poisoning -- Periodicals; Toxicology -- Periodicals; Toxicologie -- Périodiques; Intoxications alimentaires -- Périodiques; Food poisoning; Toxicology; Periodicals; Electronic journals; 615.9
• DOI: 10.1016/j.fct.2016.06.019
• Languages: English
• ISSNs: 0278-6915

Abstract

Abstract: The incidence of colonic toxicity has been epidemiologically linked to the consumption of foods contaminated with benzo(a)pyrene (B[a]P). The present study investigated the effects of B[a]P on biomarkers of oxidative stress, inflammation and wnt-signaling in colon of BALB/c mice following exposure to 62.5, 125 and 250 mg/kg of B[a]P for 7 days by oral gavage. Exposure to B[a]P significantly decreased the colonic antioxidant enzymes activities and glutathione level with concomitant significant increase in myeloperoxidase activity, nitric oxide and lipid peroxidation levels. Colon histopathology results showed treatment-related lesions characterized by atrophy, mucosal ulceration and gland erosion in the B[a]P-treated mice. Immunohistochemistry analysis showed that B[a]P treatment increased the protein expression of nuclear factor kappa B, pro-inflammatory cytokines namely tumor necrosis factor alpha and interleukin-1β, as well as cyclooxygenase-2 and inducible nitric oxide synthase in the mice colon. Altered canonical wnt-signaling was confirmed by strong diaminobenzidine staining for p38 mitogen activated protein kinase, β-catenin expression and absence of adenomatous polyposis coli following B[a]P administration. The present data highlight that exposure to B[a]P induces colon injury via induction of oxidative and nitrosative stress, inflammatory biomarkers and dsyregulation wnt/β-catenin signaling, thus confirming the role of B[a]P in the pathogenesis of colonic toxicity. Highlights: Effects of benzo(a)pyrene (B[a]P) on colon was studied in rats. B[a]P treatment increased the protein expression of inflammatory biomarkers. Mutagenic doses of B[a]P induced colonic oxidative and nitrosative damage in rats. B[a]P exposure induced dsyregulation of wnt/β-catenin signaling in rats.