Most of the plants used in traditional medicine have solid scientific support with regard to their efficacy.
There is little information available on the possible risks that the natural products may pose to health (Dias and Takahashi, 1994).
Based on their long-term exploit by humans one might expect plants used in traditional medicine to have low toxicity. However, recent investigations have revealed that many plants used as food or in traditional medicine showed mutagenic effects in in vitro assays (Higashimoto et al.,1993; Schimmer et al., 1994; Kassie et al., 1996).
This raises concern about the potential mutagenic hazards resulting from the short-term and long-term use of such plants.