Microcystin-LR oral prolonged exposure at low doses induced hepatic and intestinal alteration in mice.

SEDAN D., LAGUENS M., COPPARONI G., ARANDA J. O., GIANNUZZI L., AND ANDRINOLO D.

Buenos Aires

Congreso; 52th Annual Meeting International Association of Forensic Toxicologis (TIAFT).; 2014

TIAT

Aims: Injury caused by Microcystin-LR (MC-LR)prolonged intraperitoneal administration in animals was widely reported; however there are few studies on the effects of prolonged oral exposure to these toxins. Since the most important form of exposure to MC-LR is orally at low doses and for long periods, it is important to assess the real impact of MC-LR on health in these exposure conditions. The aim of this work was to study the toxic effects of MC-LR in a prolonged oral exposure to low doses in N: NIH-Swiss mice. Methods: MCLR was purified from natural blooms of Microcystis aeruginosa and quantified by HPLC-DAD. Two groups of 6 mice were treated with 100 μgMC-LR/kg and 50 μgMC-LR/kg body weight by gavage every 48 h during 1 month. At the end of the study,liver, kidney, intestine, lung and heart histological studies (Hematoxylin & Eosin, Red Oil, PAS and Thrichrome stain) and toxin determination (phosphatase kit) was carried out. Alkaline phosphatase (ALP), Aspartate transaminase (AST), Alanine transaminase (ALT) were determinate on blood samples. Results: Dose dependent cytoplasmatic microvacuolation with 15.3 ± 1.6 % and 3.6 ± 0.6 % of hepatic steatosis were observed in centrolobulillar zone of mice treated with 100 μgMC-LR/kg and 50 μgMC-LR/kg respectively. However, no changes were observed in ALT, AST and FAL plasma levels. Intestine samples have shown a significant dose-dependent decrease of intraepithelial lymphocytes: 28.7 ± 5.0% and 44.2 ± 8.7% for 50- and 100- μg MC-LR/kg treated animals, respectively. These results are consistent with tissues toxin levels. Conclusions: Oral exposures to low doses of MC-LR, even when go unnoticed, generate damage not only in liver but also in intestine.