microcystin and Kidney-Diseases

To evaluate the antagonism effects of green tea (GT) against microcystin LR (MC-LR) induced hepatotoxicity and nephrotoxicity in mice.. All 40 male mice were randomly divided into four groups. Mice in group III and IV were pretreated with green tea for free drink at doses of 2 g/L and 12 g/L prior to MC-LR intoxication, for consecutively 18 days. The toxin treatment mice were administered continually intraperitoneal injections of MC-LR at a dose of 10 microg x kg(-1) x d(-1) bw from day 6th till sacrifice, continually 13 days. Mice were sacrificed and immediately subjected to necropsy, and the body weight, relative organ weight, serum biochemical parameters, antioxidant enzyme levels (SOD and GSH), lipid peroxidation products (MDA) and histopathology were systematically evaluated.. MC-LR exposure led to increase the oxidative stress and organ injury was significantly observed through biochemical parameters and microscopic evaluation. However, high dose of GT pretreatment caused a significant elevation in serum GSH and SOD levels, and a decrease of serum MDA level as compared with MC-LR control. The mean values of GSH and SOD activities were separately 467.29 mg/L and 139.22 U/ml in group IV. Subsequently, GT pretreatment obviously diminished the serum ALT, AST and Cr activities. Those pathological damages in liver and kidney, were to a certain extent, lessened in GT pretreatment mice in correlation with the biochemical parameters.. GT might elevate antioxidant defense system, clean up free radicals, lessen oxidative damages and protect liver and kidney against MC-LR induced toxicity.

Topics: Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Free Radicals; Kidney Diseases; Liver Diseases; Male; Mice; Mice, Inbred Strains; Microcystins; Oxidative Stress; Tea

The microcystins (MCs) LR and YR are hepatotoxins produced by some species of freshwater cyanobacteria. Only a few reports on the acute nephrotoxicity of MCs have been published to date. Here we investigate the effects on rat kidneys of chronic administration of relatively low doses of MC LR and MC YR. Male Wistar rats were injected every second day for 8 months with MC LR (10 microg/kg i.p., n=5) and MC YR (10 microg/kg i.p., n=5). The control group was treated with vehicle, a mixture containing 0.8 % ethanol and 0.2 % methanol in 0.9 % saline (3.7 ml/kg i.p., n=5). We found that MCs could induce damage to the kidney cortex and medulla. The lesions mainly consisted of damaged and dilated tubuli filled with homogenous eosinophil material. We conclude that long-term exposure to relatively low doses of MCs poses a considerable risk for kidney injury.

Topics: Animals; Dose-Response Relationship, Drug; Kidney; Kidney Diseases; Male; Microcystins; Peptides, Cyclic; Rats; Rats, Wistar; Time Factors