Pathophysiological Effect of Aqueous Extract of Moringa Oleifera Leaves on Clarias Gariepinus Challenged with Ichthyophthirius Multifillis

Abstract

Icthyophthirius multifilis (Ich), a dangerous ectoparasite causes white spot disease and economic losses in fish farms. A majority of the chemotherapeutic agents of ichthyophthiriasis are either pollutants of the environment, banned or lack efficacy. The present work was focused on evaluating different immersion treatments of ichthyophthiriasis of African catfish (Clarias gariepinus) with non-chemical and environmental friendly parasiticide, Moringa oleifera. A total of 800 apparently healthy parasites-free post juvenile catfish were disinfected with 0.5% potassium permanganate. They were challenged with about 44,000 theronts obtained through serial passages by cohabitation. Seven groups (A - G) of post juvenile fish were used in the experiment in randomized complete block design with groups A, B and C as the uninfected control, Ich-infested not treated and Ich-infested treated with standard drug (fish cure), respectively, whereas, the groups D - G exposed to aqueous extract of M. oleifera leaves (EMOL) in dip (1,500 mg/L - 4,500 mg/L for 1h), short term (150 mg/L – 450mg/L for 24h – 96h) and prolonged bath treatment (15 mg/L – 45 mg/L for 5 – 15days). The adult parasite (trophont) burdens on the experimental fish were determined in one time point, two time points and four time points. Gross examination, histopathological alterations, hematological parameters, antioxidants enzymes and biochemical parameters were determined using standard protocols. Data obtained were subjected to analysis of variance at 5% probability while differences between means were partitioned using the Duncan New Multiple Rang Test. The results showed almost complete elimination of the trophonts both in the gills and the body smear of Ichthyophthirius multifilis infested fish. The observed curative potential of the various extract-treated groups and standard drug-treated groups were all significantly different from the infected non-treated group (p < 0.05). The knockout efficacy in short term bath treatment was significantly different (p<0.05) from the control. The ich-infested fish had visible lesions and histop athological alterations in the gills and skin among the groups. Packed cell volume, haemoglobin, white blood cell, red blood cell, differential count and the blood bicarbonate, chloride, potassium and sodium had significant (p < 0.05) changes among the experimental groups. Some of the observed changes during the immersion treatments did not differ significantly with the fish cure treatment (p > 0.05).The antioxidant parameters (catalase, superoxide dismutase, glutathione peroxidase and lipid peroxidations in the gills and muscles of ich-infested fish among the groups) and biochemical parameters (total protein, albumin, globulin, urea, creatinine, lactate dehydrogenase, aspartate and alanine aminotransferase) showed significant changes (p < 0.05) among the ich infested fish. In conclusion, aqueous extract of Moringa oleifera leves has proved to be an effective botanical in controlling the skin-parasitic ciliate, Ichthyophthirius multifilis of Clarias gariepinus.