Abstract

Many types of naturally growing plants are used traditionally for the treatment of different types of cancers and infectious diseases. In this report, the cytotoxic activity of 30 medicinal plants, commonly used in folk medicine in Saudi Arabia and Indonesia, was evaluated in vitro using Vero and HEp-2 cell lines. Plants were randomly chosen and harvested from different districts of both countries based on ethnobotanical information and subsequently extracted by methanol. Serial two-fold dilutions of each extract, starting from the concentration of 1000 µg/ml, were incubated with Vero and HEp-2 cells for 72 h. The cytotoxic effect of different extracts was in vitro characterized by identification of cellular alterations microscopically and cellular viability colormetrically. The plant extracts were classified according to the minimal toxic concentration and 50% cytotoxicity concentration indexes into three groups: highly cytotoxic (8 to 31 µg/ml), moderately cyototoxic (32 to 499 µg/ml) and low cyototoxic (500 to 1000 µg/ml). The results showed that the extracts of Juniperus phoenicea and Calotropis procera were highly cytotoxic on both cell lines to the minimal concentration of 1 µg/ml and may be well-considered as potential candidates for anticancer research. Two more extracts (Datura inoxia and Citrullus colocynthis) produced significant cytotoxicity to the minimum concentration of 16 µg/ml, with selective powerful activity of C. colocynthis on HEp-2 cells. The other extracts showed lower degrees of cytotoxicity and may be utilized for testing as antiviral agents using cell culture models.

Key words: Calotropis procera, cell titer blue assay, cytotoxic activity, Juniperus phoenicea, medicinal plants, methanolic extracts.