Biochemical and histological hepatic changes of Nile tilapia Oreochromis niloticus exposed to carbaryl

Abstract

The purpose of this study was to evaluate biochemical and morphological responses induced by carbaryl in the liver of Nile tilapia (Oreochromis niloticus) exposed during 21 days to sublethal concentrations (0.25 and 0.5 mg L À1 ), testing also recover for 14 days in clean water, after 14 days exposure. The activities of the following enzymes were measured: superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione reductase (GR), and reduced (GSH) and oxidized glutathione (GSSG). Globally, our data showed that exposure to carbaryl decreased the SOD, CAT, GR, and GST activities, except for the SOD and GST activities after 14 days exposure to 0.25 mg L À1. In contrast, after 14 days exposure the GR activity of the hepatic tissue from carbaryl-treated fish showed significant elevation in relation to the control. When fish were left to recover, a positive response was seen in the GSH and GSSG contents. The results of the recovery group suggest that the toxicity produced by carbaryl is reversible to some extent within 15 days. The liver histological analysis showed differences between fish concerning the cellular vacuolization degree (VD) of the hepatocytes. In fish exposed to carbaryl it was observed an increasing hepatocellular basophilia. No other histological alterations were observed when fish was exposed to carbaryl, except a few necrotic foci at day 7. The sections stained with PAS reaction showed that the vacuolization was always not due to glycogen deposits, thus suggesting lipid accumulation. The combined increased basophilia and glycogen depletion is a common, although non-specific, liver response to many toxicants. In short, this work shows a relation between histological and biochemical changes in liver and carbaryl exposure. The effects of carbaryl were observed at different concentrations.

Lipotropes promote immunobiochemical plasticity and protect fish against low-dose pesticide-induced oxidative stress

“…In Fig. 8 Liver section (H&E, ×40) of L. rohita fingerlings from a group that was: a control (unexposed) and fed with control diet with normal hepatic tissue structure; b exposed to endosulfan and fed with control diet showing extensive vacuolation and marked disruption of cordal arrangements of hepatocytes; c exposed to endosulfan and fed with betaine diet showing mild disarray of hepatic cords and moderate vacuolation; d exposed to endosulfan and fed with lecithin diet showing mild disarray of hepatic cords and moderate vacuolation studies by Matos et al (2007) on carbaryl (an organochlorine pesticide) at sublethal toxicity, compared to control, liver SOD activity was decreased up to the 14th day but increased on 21st day while catalase remained significantly decreased from days 7 through 21. Studies involving propiconazole (Li et al 2010) found significantly increased activity of catalase in treated fish at the 7th day but decreased at the 20th day, and SOD was likewise decreased at the 20th day.…”

Effects of profenofos induced histopathology and recovery patterns in silver barb (Barbonymus gonionotus)

“…Dramatical changes in the physical behaviour of fish B. gonionotus were recorded in treated profenofos specimens. Histological changes associated with pesticides in fish have been studied by many authors (Wester and Canton, 1991;Bhuiyan et al, 2001;Gernhofer et al, 2001;Thophon et al, 2003;Velmurugan et al, 2007;Matos et al, 2007;Ogueji et al, 2013;Nannu et al, 2015;Mostakim et al, 2015).…”

Effects of Short or Long-Term Exposure of Dithiopyr on Certaine Blood, Growth and Tissue Biochemical Parameters in Catfish (Clarias garipinus)

“…Also, Matos et al (2007) reported that hyperglycemic was indication of a disruption in carbohydrate metabolism, possibly due to enhanced glucose 6-phosphatase activity in liver, elevated breakdown of liver glycogen, or the synthesis of glucose from extrahepatic tissue proteins and amino acids. Glucose level might elevate to cope with the increased energy demand during pesticide-induced which is important pathway for the recovery from stress (Özgür et al, 2011).…”