Biochemical and Histopathological Alterations in Different Tissues of Rats Due to Repeated Oral Dose Toxicity of Cymoxanil.

Evaluating potential adverse health impacts caused by pesticides is an important parameter in human toxicity. This study focuses on the importance of subchronic toxicity assessment of cymoxanil fungicide in rats with special reference to target biochemical enzymes and histopathological changes in different tissues. In this regard, a 21-day toxicity study with repeated cymoxanil oral doses was conducted. It has been shown that low doses (0.5 mg/kg) were less effective than medium (1 mg/kg) and high (2 mg/kg) doses. Moreover, high dose dose-treated rats showed piecemeal necrosis in the liver, interstitial nephritis and tubular degeneration in the kidneys, interstitial pneumonia and type II pneumocyte hyperplasia in the lungs, gliosis, spongiosis, and malacia in the brain, and testicular edema and degeneration in the testes. Cymoxanil significantly increased AST, ALT, and ALP in serum and liver, indicating tissue necrosis and possible leakage of these enzymes into the bloodstream. Creatinine levels increased, indicating renal damage. Similarly, significant inhibition was recorded in brain acetylcholinesterase, indicating that both synaptic transmission and nerve conduction were affected. Importantly, these histopathological and biochemical alterations were dose-dependent. Taken together, our study reported interesting biochemical and histopathological alterations in different rat tissues following repeated toxicity with oral doses of cymoxanil. Our study suggests future studies on different pesticides at different concentrations that would help urge governments to create more restrictive regulations concerning these compounds' levels.

Microbial detoxification of metalaxyl in aquatic system.

Four microorganisms, Pseudomonas sp. (ER2), Aspergillus niger (ER6), Cladosporium herbarum (ER4) and Penicilluim sp. (ER3), were isolated from cucumber leaves previously treated with metalaxyl using enrichment technique. These isolates were evaluated for detoxification of metalaxyl at the recommended dose level in aquatic system. The effect of pH and temperature on the growth ability of the tested isolates was also investigated by measuring the intracellular protein and mycelia dry weight for bacterial and fungal isolates, respectively. Moreover, the toxicity of metalaxyl after 28 d of treatment with the tested isolates was evaluated to confirm the complete removal of any toxic materials (metalaxyl and its metabolites). The results showed that the optimum degree pH for the growth of metalaxyl degrading isolates (bacterial and fungal isolates) was 7. The temperature 30 degrees C appeared to be the optimum degree for the growth of either fungal or bacterial isolates. The results showed that Pseudomonas sp. (ER2) was the most effective isolate in metalaxyl degradation followed by Aspergillus niger (ER6), Cladosporium herbarum (ER4) and Penicilluim sp. (ER3), respectively. There is no toxicity of metalaxyl detected in the supernatant after 28 d of treatment with Pseudomonas sp. (ER2). The results suggest that bioremediation by Pseudomonas sp. (ER2) isolate was considered to be effective method for detoxification of metalaxyl in aqueous media.