Mahmut Yanar

Cypermethrin-induced histopathological and biochemical changes in Nile tilapia (Oreochromis niloticus), and the protective and recuperative effect of ascorbic acid

The objective of this study was to investigate the effects of ascorbic acid on the toxicity of cypermethrins on histopathological lesions in tissues and protein, glycogen levels in Oreochromis niloticus. Nile tilapia was exposed to 0.22 and 0.44 μg/l cypermethrin+control diet, 0.22 and 0.44 μg/l cypermethrin+ascorbic acid supplemented diet for 20 days. The fish were allowed recuperation period of 15 days in pesticide-free water and fed with ascorbic acid suplementation diet. In light microscopic investigation, histopathological lesions were observed in the gill, liver and kidney. The severity of lesions accreted depending on increased pesticide concentration and control diet. Some of the lesions were reversible or at least were less pronounced after recuperation period. Protein levels decreased in some groups after treatment period according to control groups (p<0.05). The highest depletions in liver, muscle and gill protein levels were found in 0.44 μg/l cypermethrin+ascorbic acid supplemented diet group (62.23%), in 0.22 μg/l cypermethrin+control diet group (53.12%) and in 0.44 μg/l cypermethrin+control diet group (61.87%) after 10 days, respectively. These levels increased at the end of the recuperation period. The highest depletion in liver glycogen levels was found in 0.22 μg/l cypermethrin+control diet group (50.50%) after 10 days (p<0.05). At the end of recuperation period, there was no difference between the groups (except 0.22 μg/l cypermethrin+ascorbic acid supplemented diet group) and controls. The decrease of muscle glycogen, except 0.22 μg/l cypermethrin+ascorbic acid supplemented diet group, was recorded at the end of 10 and 20 days. In the recuperation period, an increase was observed at all groups. These results revealed that the histopathology, protein and glycogen can work as good indicators of stress of a toxicant on fish. Ascorbic acid serves fish as an antitoxic agent against pesticide toxicity.

The protective role of vitamin E on gill and liver tissue histopathology and micronucleus frequencies in peripheral erythrocytes of Oreochromis niloticus exposed to deltamethrin.

Deltamethrin, is a commonly used pyrethroid pesticide. Vitamin E is a antioxidant that plays an important role in protecting cells against toxicity by inactivating free radicals generated following pesticides exposure. Therefore, it was evaluated whether deltamethrin induced histopathological changes and nuclear abnormalities using micronucleus test in Oreochromis niloticus, and the possible protective effect of vitamin E against deltamethrin inducing adverse effects in O. niloticus were investigated. Fish was fed with no pesticide+control diet, no pesticide+vitamin E-supplemented diet, 1.45μg/l deltamethrin+control diet, 1.45μg/l deltamethrin+vitamin E-supplemented diet for 30 days. Pesticide and diet quality made an impact on histopathological lesions. In treatments of deltamethrin, group fed with control diet showed much greater damage in comparison with group fed with vitamin E supplemented diet. Vitamin E decreased some histopathological changes induced by deltamethrin, but did not confer complete protection. Deltamethrin treatment has been shown to results in a significant increase in the frequency of micronucleus. However, coadministration of deltamethrin and vitamin E showed decrease in the frequency of micronucleus as compared to deltamethrin treated fish. Our results indicate that, the MN assay and histopathology can be used as bioassays for monitoring pollution in aquatic medium. On the other hand, it was observed that vitamin E decreased the genotoxicity and histopathological changes induced by deltamethrin.

The protective role of vitamin E on the fatty acid composition of phospholipid structure in gill and liver tissues of Oreochromis niloticus exposed to deltamethrin

Deltamethrin is a commonly used pyrethroid pesticide. Vitamin E is a antioxidant that plays an important role in protecting cells against toxicity by inactivating free radicals generated following pesticides exposure. Therefore, in the present study, it was evaluated whether deltamethrin induced changes on the fatty acid composition of phospholipid in gill and liver tissues in Oreochromis niloticus and, the possible protective effect of vitamin E against deltamethrin was determined. Fish was fed with no pesticide+control diet, no pesticide+vitamin E-supplemented diet, 1.45 μg/l deltamethrin+control diet, 1.45 μg/l deltamethrin+vitamin E-supplemented diet for twenty days. Pesticide and diet quality made an impact on the fatty acid composition of phospholipid. In treatments of deltamethrin, group fed with control diet showed much greater damage in comparison with group fed with vitamin E supplemented diet. The results indicated that the deltamethrin led to an increase in the percentages of total SFAs (saturated fatty acids) and total MUFAs (monounsaturated fatty acids) and a decrease in total PUFAs (polyunsaturated fatty acids) in the gill tissues. However, coadministration of deltamethrin and vitamin E showed decrease in the percentages of saturated fatty acids and increase in the percentages of polyunsaturated fatty acids in the gill tissues. In group fed with control diet, deltamethrin led to a decrease in the percentage of SFAs and a increase in total MUFAs in the liver. Coadministration of deltamethrin and vitamin E showed increase in the percentages of polyunsaturated fatty acids in the liver tissues. These results have demonstrated that administration of vitamin E along with deltamethrin decreases the peroxidation of unsaturated fatty acids and thus protects the cell membranes.

Effects of Hot and Sweet Red Peppers (Capsicum annuum) as Feed Supplements on Pigmentation, Sensory Properties and Weight Gain of Rainbow Trout (Onchorhynchus mykiss)

Abstract This study was conducted to evaluate the effects of diets, including 0.5, 2 and 4.4% dried hot or sweet red pepper and a control diet without added red pepper, on pigmentation, sensory properties and weight gain of rainbow trout, with average initial weight of 60 g, for a rearing period of 80 days. Both red pepper types had similar effects on the carotenoid accumulation, weight gain and sensorial properties of the fish (P>0.05). Total carotenoid accumulation in the fish muscle increased significantly with increasing inclusion of red peppers. However, only the diet consisting of 4.4% hot or sweet red pepper provided adequate carotenoid accumulation in the fillet of the fish, that is, the desired colouration in the fish. Fish fed diets containing red peppers exhibited higher appearance and colour scores compared to control group (P<0.05). Irrespective of being hot or sweet, red pepper can be successfully used as an alternative natural carotenoid source in rainbow trout diets.

The effect of vitamin E supplementation on ovary and testis histopathology in Oreochromis niloticus exposed to deltamethrin

The effects of deltamethrin on the histology of Oreochromis niloticus testis and ovary and the protective effect of vitamin E supplementation were investigated. The fish were divided into four groups, i.e. a control group, a vitamin-E-treated group, a deltamethrin-treated group and a vitamin E+deltamethrin-treated group. In the control and vitamin-E-treated groups, the ovaries and testes were normal at the end of 7, 14, and 21 days. In the deltamethrin-treated group, deformed oocytes, atretic oocytes, melanomacrophage centers, and focal necrotic areas were noted in the ovaries. Deltamethrin also caused cell necrosis, nuclear pycnosis, decreasing number of spermatogenic cells, decreasing spermatozoa within the lumen of tubule, decreasing number of spermatocyte cells, hypertrophy and degeneration of spermatogonia cells, and increasing number of macrophages in testis. Vitamin E decreased some histopathological changes induced by deltamethrin, but did not confer complete protection.