In vitro cytotoxicity of P. vulgaris on EPC and CHSE-214 fish cell lines. The cells (1 × 106) from each cell line were incubated with P. vulgaris ranging from 10 ng to 100 μg/ml and incubated at 24°C for 3 days. Formazan development was read at 595 nm using ELISA reader (ASYS HITECH, Austria). Error bars represent SD from the mean of triplicate wells. The result is a representative of three experiments.