The Study of the Effects of Menthol and Thymol on Kidney and Liver Lesions Caused by Chronic Mercury Poisoning in Zebrafish (Danio rerio)

Rahmati-Holasoo, Hooman; Darabiyan, Ali; Shokrpoor, Sara; Rezaee, Alireza

doi:10.22034/jmpb.2025.369444.1968

The Study of the Effects of Menthol and Thymol on Kidney and Liver Lesions Caused by Chronic Mercury Poisoning in Zebrafish (Danio rerio)

Articles in Press

Document Type : Research Paper

Authors

¹ Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

² Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

³ Department of Pathology and Clinical Pathology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

10.22034/jmpb.2025.369444.1968

Abstract

Heavy metals represent a significant form of environmental pollution, accumulating over time and posing serious risks to human health. Among these, mercury is particularly concerning, as it primarily enters the human body through the consumption of contaminated aquatic animals. The ingestion of mercury-laden fish can lead to severe health issues. Therefore, it is essential to explore strategies to mitigate the adverse effects of this pollution. Natural plant compounds, known for their antioxidant and chelating properties as well as their biodegradability, offer promising solutions for addressing heavy metal contamination. Thymol and menthol are two such compounds that exhibit beneficial effects in this context. Zebrafish (Danio rerio) have gained significant attention as a model organism in biological research due to their genetic similarity to humans, ease of breeding, and high reproductive capacity. This study aimed to compare the protective effects of thymol and menthol against chronic mercury poisoning in the liver and kidney tissues of zebrafish. A group of zebrafish was exposed to 0.44 mg/L of mercury to assess the therapeutic effects of thymol and menthol on chronic mercury toxicity. Pathological sampling was performed, and tissue sections were examined microscopically. The findings revealed that the mercury-exposed group exhibited the highest level of tissue damage. While the severity of injuries in the mercury-thymol group was less pronounced than in the mercury-menthol group, neither treatment fully resolved the damage caused by mercury exposure. These results underscore the importance of investigating various substances to mitigate the effects of environmental pollutants. Notably, this study demonstrated that thymol was slightly more effective than menthol in reducing the severity of mercury-induced injuries.

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