Oleic acid from Marine seaweed Caulerpa scalpelliformis induced toxicity in Oreochromis niloticus

Abstract

Background/Objective: Oleic acid is an unsaturated fatty acid, abundant in plants and animals. It accounts for 49% to 83% of total fatty acids, and altered oleic acid leads to diabetes, liver damage, and atherosclerosis. Alteration in oleic acid consumption leads to hepatotoxicity in humans. Macro algae named Caulerpa scalpelliformis is well-known for its bioactivity properties like antimicrobial and anti-cancer activity. Oreochromis niloticus (Nile tilapia) is a freshwater breed considered a protein-rich fish also it has a fast-growing capacity, easy farm management, and pleasant flavor with fewer bones, used as a study tool in scientific research. This study aims to determine the toxic effect in O. niloticus by inducing oleic acid from seaweed C. scalpelliformis. Methods: In the present study, oleic acid was extracted from C. scalpelliformis by column chromatography and analyzed using Thin Layer Chromatography (TLC). Toxicity analysis in O. niloticus was performed by exposing the C.scalpelliformis methanol extract in a freshwater fish tank in five different concentrations. Findings: The mortality rate was measured after 24 hours of exposure. Fish died at 250µg/ml and 100µg/ml. In histopathology analysis, hemorrhages in the inner lamellar space, moderate lamellar epithelial cell necrosis, and sloughing of the lamellar epithelium were observed in the gill. Cerebral congestion, multifocal vacuolar degeneration, and infiltration of mononuclear cells were observed in the brain. Periportal necrosis and hypertrophy of hepatocytes were observed in the liver. Renal hemorrhage, multifocal degeneration of tubular epithelium, and sinusoid expansion were observed in the kidney. Sloughing of epithelial villi, villous atrophy, cellular infiltration, and focal necrosis of epithelial cells was observed in the kidney. Novelty: This is the first report from this particular study site. Even though Oleic acid has some impact on the fish, the optimum level of oleic acid from this particular seaweed can be used as a natural medicine for human society.