FRESH-WATER CYANOBACTERIUM MICROCYSTIS-AERUGINOSA (UTEX-2385) INDUCEDDNA-DAMAGE IN-VIVO AND IN-VITRO

Microcystins are a family of potent hepatotoxins and liver tumor promo ters produced by several genera of cyanobacteria including Microcystis , Nodularia, Anabena, Nostoc, etc. They are chemically very stable and represent a public health threat when they occur in water used for hu man consumption. We investigated the DNA damage effects of M. aerugino sa UTEX 2385 in mouse liver in vivo and also in mammalian cells in vit ro. The DNA damage effect is compared with purified toxin microcystin- LR (MCLR) in non-hepatic cells viz. baby hamster kidney cells (BHK-21) and mouse embryo fibroblasts primary cells (MEF). Cell-free extracts of UTEX 2385 induced significant DNA fragmentation at 0.5, 1 and 2 LD5 0 (32.7, 65.4 and 130.8 mg/kg, respectively) and it was also time depe ndent. M. aeruginosa UTEX 2385 and MCLR induced significant DNA fragme ntation in BHK-21 and MEF cells at 100 and 1.0 mu g/ml concentration. Electrophoretic analysis revealed necrotic DNA damage by UTEX 2385 in vivo. Both the toxins caused smear in agarose gel electrophoresis indi cating the necrotic DNA damage in MEF cells, whereas, multiple DNA fra gments in BHK-21 cells. The DNA damage effect of the toxin is supporte d by data on hepatotoxicity in vivo and cytotoxicity in vitro. (C) 199 8 Elsevier Science B.V.