Acute Toxicity Bioassay and Determination of LC50 of Cadmium Chloride in Trichogaster (Colisa) fasciata.

Cadmium chloride is a metal salt used in industries in a large scale. Trichogaster (Colisa) fasciata (common name banded gourami) is an air-breathing fresh water fish with both nutritional and ornamental values. In this present study, as per EPA guidelines, acute toxicity bioassay was performed in a 96-h static test method in four replicates, each replicate having one control and five concentrations (25, 50, 75, 100 and 125 mg/L, respectively) of the metal salt. A total of 192 fish was used in the study in four series with each replicate containing 8 fish per concentration. The water temperature was maintained at 20-22℃ during the study. The data observed were analysed statistically on the basis of Finney's Probit Analysis method using SPSS software. The estimated 96-h LC50 value of cadmium chloride for the fish was 49.5 mg/L.

S-allyl cysteine in combination with clotrimazole downregulates Fas induced apoptotic events in erythrocytes of mice exposed to lead.

BACKGROUND: Chronic lead (Pb(2+)) exposure leads to the reduced lifespan of erythrocytes. Oxidative stress and K(+) loss accelerate Fas translocation into lipid raft microdomains inducing Fas mediated death signaling in these erythrocytes. Pathophysiological-based therapeutic strategies to combat against erythrocyte death were evaluated using garlic-derived organosulfur compounds like diallyl disulfide (DADS), S allyl cysteine (SAC) and imidazole based Gardos channel inhibitor clotrimazole (CLT). METHODS: Morphological alterations in erythrocytes were evaluated using scanning electron microscopy. Events associated with erythrocyte death were evaluated using radio labeled probes, flow cytometry and activity gel assay. Mass spectrometry was used for detection of GSH-4-hydroxy-trans-2-nonenal (HNE) adducts. Fas redistribution into the lipid rafts was studied using immunoblotting technique and confocal microscopy. RESULTS: Combination of SAC and CLT was better than DADS and CLT combination and monotherapy with these agents in prolonging the survival of erythrocytes during chronic Pb(2+) exposure. Combination therapy with SAC and CLT prevented redistribution of Fas into the lipid rafts of the plasma membrane and downregulated Fas-dependent death events in erythrocytes of mice exposed to Pb(2+). CONCLUSION AND GENERAL SIGNIFICANCE: Ceramide generation was a critical component of Fas receptor-induced apoptosis, since inhibition of acid sphingomyelinase (aSMase) interfered with Fas-induced apoptosis during Pb(2+) exposure. Combination therapy with SAC and CLT downregulated apoptotic events in erythrocytes by antagonizing oxidative stress and Gardos channel that led to suppression of ceramide-initiated Fas aggregation in lipid rafts. Hence, combination therapy with SAC and CLT may be a potential therapeutic option for enhancing the lifespan of erythrocytes during Pb(2+) toxicity.