Malachite green, a multi-purpose dye induces cyto-toxicity upon its entry and bioaccumulation in tissues. A semi-static chronic (60 days) bioassay was conducted by exposing Cyprinus carpio to sublethal concentration of the dye and Emblica officinalis in four experimental groups viz control, malachite green, E. officinalis, and malachite green + E. officinalis. Effect of dye on the cornea was investigated considering ultra-structural alterations owing to its direct contact to the pollutant in the aquatic medium. SEM studies on corneal epithelium revealed broken continuity of pavement cells, shrunk microplicae, increased intra-microplicae distance, globularization and epithelial uplifting, thereby affecting the integrity of corneal surface and tear film adherence. Whereas dietary supplementation with the plant extract served to restore cytoarchitecture with appearance of large number of regenerating cells. Both lesions and restoration were found to be duration dependent. Thus, E. officinalis can be considered as an effective ameliorant against malachite green induced toxicity.
Keywords: Cornea; Cyprinus carpio; Emblica officinalis; Malachite green; Toxicity; Ultrastructure.