Antimutagenic effects of ethanolic extracts from three Palestinian medicinal plants

Eryngium creticum, Nigella sativa, and Teucrium polium have been traditionally used for the treatment of inflammations, liver disorders, and arthritis. Several studies on N. sativa revealed antioxidant, anti-inflammatory, hepatoprotective and antimutagenic activities. T. polium is reported to have antioxidant, anti-inflammatory, and antiulcerogenic activities, while Eryngium species are considered to have antioxidant and anti-inflammatory properties. In this study the antimutagenic activity of these plant species was tested in rat hepatocyte primary cultures by treatment with N-methyl-N’-nitro-N-nitrosoguanidine (MNNG), a directly acting mutagen, which methylates DNA and was shown to induce massive chromosomal damage in hepatocytes (1). Since it cannot be excluded that the active constituents of the plant extracts require biotransformation or induce metabolic enzymes, causing antimutagenic or detoxifying effects, the present investigation was carried out with metabolically competent primary cultures of rat hepatocytes Rat hepatocytes were isolated as described by Michalopoulos et al. (2). Establishment of primary cultures and cytogenetic studies were performed according to Eckl et al. (1). plant Ethanolic extracts were dissolved in dimethyl sulfoxide (DMSO). Antimutagenicity testing was done in three modes: pre-treatment, combined treatment and post-treatment of the primary cultures with plant extracts and MNNG. Therefore, both the induction of metabolizing enzymes, direct interaction of plant constituents with the mutagen and increased recovery, i.e. enhanced repair of induced DNA damage can be evaluated. Student’s double sided t-test for independent samples was used to evaluate the levels of significance. The results of our investigation clearly indicate an inhibitory effect on MNNG mutagenicity by the three plant extracts, and this effect can be attributed to a direct antimutagenic activity and an increased recovery. Acknowledgments: This investigation was supported by a stipend of the Austrian Exchange Service (OEAD)