Studying Protective Effects of Thymol, Curcumin and Menthol on Gill Histopathological Changes in Mercury-Exposed Juvenile Common Carp (Cyprinus carpio)

Document Type : Research Paper

Authors

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

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

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

4 Department of Comparative Bioscience, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

Abstract

Heavy metal pollution, particularly from mercury, poses a significant threat to aquaculture sustainability and food safety. This study investigated the protective efficacy of dietary thymol, curcumin, and menthol against mercuric chloride (HgCl₂)-induced gill histopathology in common carp (Cyprinus carpio). A total of 240 fish (50 ± 2 g) were distributed in a completely randomized design into eight treatments for 8 weeks: Control, Hg (0.44 mg/L HgCl₂ in water), Thymol (100 mg/kg feed), Curcumin (15 g/kg feed), Menthol (2.5 g/kg feed), and three co-exposure groups (Hg+Thymol, Hg+Curcumin, Hg+Menthol). Histopathological examination revealed severe lymphoplasmacytic proliferative branchitis, necrosis, and lamellar destruction in the Hg group. Thymol supplementation demonstrated the most potent protective effect, reducing lesions to mild branchitis and edema. Curcumin provided moderate protection, notably mitigating the severity of the injury. Conversely, menthol failed to alleviate mercury-induced pathology and, when administered alone, induced mild branchitis and aneurysms. The results indicate that the protective effects of these phytochemicals are compound-specific. Thymol is highly effective in preventing HgCl₂-induced gill damage, curcumin offers significant but moderate protection, while menthol is ineffective and potentially irritating at the tested dose. Thymol is recommended as a promising dietary supplement for enhancing carp resilience in mercury-contaminated aquaculture environments.

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Main Subjects

References

  1. Ahmadivand S., Weidmann M., El-Matbouli M., Rahmati-Holasoo H. Low pathogenic strain of infectious pancreatic necrosis virus (IPNV) associated with recent outbreaks in Iranian trout farms. Pathogens. 2020; 9(10):782.
  2. Gephart J.A., Golden C.D., Asche F., Belton B., Brugere C., Froehlich H.E., Fry J.P., Halpern B.S., Hicks C.C., Jones R.C., Klinger D.H. Scenarios for global aquaculture and its role in human nutrition. Reviews in Fisheries Science & Aquaculture. 2020; 29(1):122-38.
  3. Bardach J.E. The role of aquaculture in human nutrition. GeoJournal. 1985; 10(3):221-32.
  4. Fu Z., Xi S. The effects of heavy metals on human metabolism. Toxicology mechanisms and methods. 2020; 30(3):167-76.
  5. Sonone S.S., Jadhav S., Sankhla M.S., Kumar R. Water contamination by heavy metals and their toxic effect on aquaculture and human health through food Chain. Letters in Applied NanoBioScience. 2020; 10(2):2148-66.
  6. Mustafa S.A., Al-Rudainy A.J. Impact of mercury chloride exposure on some of immunological and biochemical assays of common carp, Cyprinus carpio. Iraqi Journal of Agricultural Sciences. 2021; 52(3):547-51.
  7. Farombi E.O., Adelowo O.A., Ajimoko Y.R. Biomarkers of oxidative stress and heavy metal levels as indicators of environmental pollution in African catfish (Clarias gariepinus) from Nigeria Ogun River. International journal of environmental research and public health. 2007; 4(2):158-65.
  8. Emenike E.C., Iwuozor K.O., Anidiobi S.U. Heavy metal pollution in aquaculture: sources, impacts and mitigation techniques. Biological Trace Element Research. 2022; (10):4476-92.
  9. Rahman M.M. Role of common carp (Cyprinus carpio) in aquaculture production systems. Frontiers in Life Science. 2015; 8(4):399-410.
  10. Fathi M., Binkowski L.J., Azadi N.A., Hamesadeghi U., Mansouri B. Co-exposure effects of mercury chloride (HgCl2) and silver nanoparticles (Ag-NPs) on goldfish (Carassius auratus): Histopathological changes, oxidative stress response, and bioaccumulation. Desalination and Water Treatment. 2018; 105:264-72.
  11. Rahmati-Holasoo H., Darabiyan A., Shokrpoor S., Rezaei A. The study of the effects of menthol and thymol on kidney and liver lesions caused by chronic mercury poisoning in zebrafish (Danio rerio). Journal of Medicinal plants and By-products. 2025; 14(5):484-8.
  12. Pourabbasali M., Jafaryan H., Adineh H. Comparison of the effect of thymol on reducing stress during short-term transportation of broodstock white fish (Rutilus frisii kutum Kamenskii, 1901) caught from the Shahrud and Sardar Abad rivers. Journal of Applied Ichthyological Research. 2024; 12(4):11-20.
  13. Rahmati-Holasoo H., Nassiri A., Soltani M., Shokrpoor S. Studying protective effects of thymol on the growth factors of juvenile common carp following chronic mercury (II) chloride cxposure. Iranian Journal of Veterinary Medicine. 2025; 19(1): 41-50.
  14. Zhang Y., Li F., Yao F., Ma R., Zhang Y., Mao S., Hu B., Ma G., Zhu Y. Study of dietary curcumin on the restorative effect of liver injury induced by carbon tetrachloride in common carp, Cyprinus carpio. Aquaculture Reports. 2021; 21:100825.
  15. Giri S.S., Kim M.J., Kim S.G., Kim S.W., Kang J.W., Kwon J., Lee S.B., Jung W.J., Sukumaran V., Park S.C. Role of dietary curcumin against waterborne lead toxicity in common carp Cyprinus carpio. Ecotoxicology and Environmental Safety. 2021; 219:112318.
  16. Smirnova E., Moniruzzaman M., Chin S., Sureshbabu A., Karthikeyan A., Do K., Min T. A review of the role of curcumin in metal induced toxicity. Antioxidants. 2023; 12(2):243.
  17. Mulla A.N., Thorat S.T., Chandramore K., Kumar P., Reddy K.S., Kumar N. Curcumin as a protective agent against chromium and ammonia toxicity using molecular and biochemical approaches in fish. Scientific Reports. 2025; 15(1):12023.
  18. Hoseini S.M., Yousefi M., Hoseinifar S.H., Van Doan H. Antioxidant, enzymatic and hematological responses of common carp (Cyprinus carpio) fed with myrcene-or menthol-supplemented diets and exposed to ambient ammonia. Aquaculture. 2019; 506:246-55.
  19. Korkmaz N., Erdoğan K., Örün G.N., Erkmen B., Doğru M.I., Doğru A., Polat H., Örün İ. Mitigation effect of grape seed extract against cadmium-induced hormonal toxicity in common carp (Cyprinus carpio). BMC Veterinary Research. 2025; 21(1):412.
  20. Landis W., Sofield R., Yu MH., Landis W.G. Introduction to environmental toxicology: impacts of chemicals upon ecological systems, Crc Press. 2003.
  21. Huang Z.Y., Zhang Q., Chen J., Zhuang Z.X., Wang X.R. Bioaccumulation of metals and induction of metallo-thioneins in selected tissues of common carp (Cyprinus carpio L.) co-exposed to cadmium, mercury and lead. Applied Organometallic Chemistry. 2007; 21(2):101-7.
  22. Pelcová P., Vičarová P., Ridošková A., Dočekalová H., Kopp R., Mareš J., Poštulková E. Prediction of mercury bioavailability to common carp (Cyprinus carpio L.) using the diffusive gradient in thin film technique. Chemosphere. 2017; 187:181-87.
  23. Yeşilbudak B., Erdem C. Cadmium accumulation in gill, liver, kidney and muscle tissues of common carp, Cyprinus carpio, and Nile tilapia, Oreochromis niloticus. Bulletin of environmental contamination and toxicology. 2014; 92(5): 546-50.
  24. Morselli M.B., Reis J.H., Baldissera M.D., Souza C.F., Baldisserotto B., Petrolli T.G., Paiano D., Lopes D.L., Da Silva A.S. Benefits of thymol supplementation on performance, the hepatic antioxidant system, and energetic metabolism in grass carp. Fish Physiology and Biochemistry. 2020; 46(1):305-14.
  25. Morselli M.B., Baldissera M.D., Souza C.F., Reis J.H., Baldisserotto B., Sousa A.A., Zimmer F., Lopes D.L., Petrolli T.G., Da Silva A.S. Effects of thymol supplementation on performance, mortality and branchial energetic metabolism in grass carp experimentally infected by Aeromonas hydrophila. Microbial Pathogenesis. 2020; 139:103915.
  26. Ebrahimzadeh Mousavi H., Vatannejad A., Taheri Mirghaed A., Sharifzadeh A., Pour Mortazavi Bahambari S.M. Study of the effect of Thymol on brain tissue oxidative stress responses caused by mercury metal poisoning in common carp (Cyprinus carpio). Iranian Journal of Veterinary Medicine. 2026; In press. Doi: 10.22059/IJVM.2025.399579.1005859
  27. Karaytug S., Sevgiler Y., Karayakar F. Comparison of the protective effects of antioxidant compounds in the liver and kidney of Cd‐and Cr-exposed common carp. Environmental Toxicology. 2014; 29(2):129-137.
  28. Magouz F.I., Mahmoud S.A., El-Morsy R.A., Paray B.A., Soliman A.A., Zaineldin A.I., Dawood M.A. Dietary menthol essential oil enhanced the growth performance, digestive enzyme activity, immune-related genes, and resistance against acute ammonia exposure in Nile tilapia (Oreochromis niloticus). Aquaculture. 2021; 530:735944.
  29. Mazandarani M., Hoseini S.M. Menthol and 1, 8-cineole as new anaesthetics in common carp, Cyprinus carpio (Linnaeus, 1758). Aquaculture Research. 2017; 48(6):3041-51.
  30. Romaneli R.D., Boaratti A.Z., Rodrigues A.T., Queiroz D.M., Khan K.U., Nascimento T.M., Fernandes J.B., Mansano C.F. Efficacy of benzocaine, eugenol, and menthol as anesthetics for freshwater angelfish. Journal of Aquatic Animal Health. 2018; 30(3):210-216.
  31. Okey I.B., Keremah R.I., Gabriel U.U. The efficacy of clove (Eugenia caryophyllata) powder as anaesthesia on African catfishes (Clarias gariepinus and Heterobranchus bidorsalis) fingerlings. Journal of Aquaculture & Marine Biology. 2018; 7(4):182-188.
Journal of Medicinal plants and By-products
Volume 15, Issue 4
July and August 2026
Pages 435-439

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