In vitro genotoxicity of extracellular extract from Nostoc piscinale

The extracellular extract obtained from 3 weeks incubation of the soil isolate cyanobacterium strain Nostoc piscinale GT-319 in BG-11 broth medium showed cytotoxic activity against Chinese Hamster Ovary (CHO) cells. Based on comet assay, a concentration of 333 µg mL^?1 (IC₅₀) produced DNA breakages in CHO cells. The concentration of 481 mg kg^?1 (LD₅₀) produced acute toxicity in mice at 48 h.