Optical coherence tomography as an alternative tool for evaluating the effects of glyphosate on hybrid catfish (Clarias gariepinus × Clarias macrocephalus)

Abstract

Glyphosate contamination in fresh water is a major problem in agricultural countries. It affects many vital organs in freshwater organisms that are important in the food chain. Hence, the effects of glyphosate on living organism organs are of particular interest. However, several existing techniques for evaluating the effect of glyphosate on aquatic organisms require stained tissue. To study organ tissue with minimal processing, alternative technique is demanded. Here, we investigated the used of optical coherence tomography (OCT) as an alternative tool for ex vivo evaluation of the effect of glyphosate on organ tissues of aquatic organisms, i.e., hybrid catfish (Clarias gariepinus × Clarias macrocephalus). The targeted samples were organ tissues from the brain, gill, and liver of hybrid catfish after glyphosate exposion at concentration of 10 mg L−1 for 24 h. The alteration was then verified by histology, and immunohistochemistry. The study found that all three techniques provide correlated results. We observed that OCT clearly showed damage to the brain and gill tissues of glyphosate-exposed hybrid catfish. However, the alteration in liver tissue was observable but not clear for this low concentration of exposure. The results from histology and immunohistochemistry confirmed the effect of glyphosate on brain, gill, and liver tissues of hybrid catfish. The results suggest that all three techniques could be used to examine the effects of glyphosate exposure in hybrid catfish. However, the choice of a suitable technique depends upon the purpose of the study.