Introduction: Acrylamide (ACR) is commonly polluting the nearby environment as it is formed during high-temperature food cooking conditions. Several previous studies have confirmed its toxic potential on different body organs.
Aim of the Work: The current study aims to investigate the possible hepatoprotection elicited by vitamin E (vit E), alpha-tocopherol, melatonin (MT), and combined vit E/MT in a rat model of ACR-induced liver toxicity. The putative mechanisms involved in such protection were also examined using histological and immunohistochemical studies.
Material and Methods: Forty-nine male Wistar albino rats were divided into seven equal groups; control, vit E alone (100 mg/kg/d), MT alone (10 mg/kg/d), ACR-exposed (5 mg/kg/day), ACR/vit E-treated, ACR/MT-treated, and ACR/vit E/MT-treated groups. All treatments were given daily via oral gavage for 8 weeks. At the end of the study, blood samples were collected for measurement of the liver enzymes. Liver lobes were collected for preparation of the tissue homogenates to measure the hepatic concentrations of the oxidative/antioxidative markers. Also, liver samples were prepared for paraffin microtechniques and stained by Hematoxylin & Eosin (H & E) and Masson trichrome staining. Immunohistochemical assays for the detection of Bax, Bcl2, and iNOS immunoexpressions were performed.
Results: ACR-exposed rats showed marked disruption of the biochemical assays, in addition to the hepatocytes disorganization and vacuolar degenerative changes observed in the H & E findings. Moreover, fibrotic changes in the Masson-stained sections and disturbed immunoexpressed proteins were noticed. Either vit E and/or MT treatment improved the histological and biochemical parameters with normalization in the combined therapy group.
Conclusion: Vit E and or MT protected against ACR-mediated liver toxicity by reestablishing of the oxidant/antioxidant balance, downregulation of pro-apoptotic proteins, upregulation of anti-apoptotic proteins, and suppression of the inflammatory pathways. Both combined had a synergistic action.