Histological and biochemical effects of Lutein on the liver of adult Wistar rats following Paraquat-induced toxicity

Abstract

BACKGROUND AND AIM: Paraquat is a common herbicide worldwide with potentials for human poisoning through the generation of reactive oxygen species. There is presently dearth of evidence-based cure for paraquat (PQ) poisoning, which is associated with significant hepatic injury and a high mortality globally. Lutein is a carotenoid with free radical-scavenging and antioxidant effects. The study is aimed at investigating the mitigating effect of lutein on paraquat-induced hepatic toxicity in Wistar rats.

MATERIALS AND METHODS: Forty male Wistar rats weighing 150-180 g were randomly grouped (A to E) for this study. Paraquat (PQ) toxicity was induced in groups B to E, at a dose of 5mg/kg through oral route. Lutein was administered at graded doses of 50 mg/kg, 100 mg/kg and 150 mg/kg to groups C to E through oral route for twenty-one days respectively. Group A (negative control) was given only normal saline, while group B (positive control) had only paraquat. Twenty-four hours after the last administration, blood samples were collected for the biochemical analyses of plasma aspartate and alanine transaminases; thereafter, the animals were sacrificed before the excision of the liver for histological examination.

RESULTS: There was significant increase in the plasma alanine transaminase (ALT) and aspartate transaminase (AST) (p=0.01) in group B when compared with the treated groups. The concentrations of catalase and glutathione in group B were significantly lower (p=0.01 and 0.009 respectively) relative to the negative control and lutein-treated groups, especially at higher doses. Malondialdehyde concentration was significantly higher in group B than others (p=0.043). There was marked histological distortion with a reduction in hepatocyte count through the use of image J software in group B, which was given PQ only. However, the lutein-treated groups had dose-dependent improvement in hepatocyte count similar to the control. Group E, which had the highest dose of lutein, had remarkable similarity in histo-architectural and biochemical findings when compared to the negative control.

CONCLUSION: This study showed significant alteration in the hepatic biochemical analyses and histo-architecture following paraquat toxicity. However, the groups treated with high doses of lutein showed remarkable similarity with the control group. Hence, study underscores the potentials of lutein to mitigate paraquat-induced toxicity in Wistar rats.