Histological and Biochemical Effects of Lutein on Paraquat-induced Renal Toxicity in Wistar Rats

Introduction: Paraquat (PQ) poisoning in humans predominantly results from the generation of reactive oxygen species (ROS). To date, no proven antidote exists for PQ poisoning, which is characterized by severe kidney injury and high mortality rates globally. However, free radical scavengers and antioxidant agents have shown potentials to mitigate PQ toxicity.

Aim: The study is aimed at investigating lutein, an antioxidant, for possible mitigation of paraquat-induced renal toxicity.

Study Design: Preclinical experimental study.

Place and Duration of Study: Department of Anatomy, Obafemi Awolowo University (OAU), Nigeria, between 2022 and 2023.

Methods: Forty wistar rats weighing 150-180 grammes were randomly grouped (A to E) for this study. Paraquat (PQ) toxicity was induced in groups B to E. Lutein was administered at graded doses of 50 mg/kg, 100 mg/kg and 150 mg/kg to groups C to E for twenty-one days respectively. Group A (positive control) was given only normal saline, while group B had paraquat only. Twenty-four hours after the last administration, urine and blood samples were collected and the animals were sacrificed before the excision of the kidneys.

Results: A marked histological distortion, which was characterized by compromised Bowman's space and renal tubule dimensions, was observed in Group B. In contrast, the lutein-treated groups exhibited dose-dependent improvements, with outcomes comparable to the control group. Notably, Group B showed significant elevations in plasma creatinine (P = 0.003) and urine protein (P = 0.001), accompanied by reduced plasma protein (P = 0.004), relative to the treated groups. However, Group E, which received the highest lutein dose, demonstrated substantial improvement in histoarchitectural and biochemical findings similar to the control group."

Conclusion: This study demonstrated significant alterations in the histoarchitecture and biochemical profiles of renal tissue following paraquat exposure. Notably, the lutein-treated groups exhibited substantial improvement, with results comparable to the control group. These findings suggest that lutein may possess potential therapeutic properties to mitigate paraquat-induced renal toxicity.