Cytotoxic effect of some indigenous Iranian plants

Abstract

Cancer is a general term applied to some malignant diseases that may affect different parts of the body. Recently there has been a great effort in finding and synthesizing effective anticancer drugs. Effective compounds from plants such as periwinkle and taxus, give us a bright view of the future of plants and their anticancer agents. The alkaloids vincristine and vinblastine which were discovered in the late 1950s and the diterpenoid taxol, which belongs to a new class of agents, the taxanes, are of the most important classes of antineoplastic drugs derived from these plants. The epipodophyllotoxins, etoposide (VP-16) and teniposide (VM-26), are semisynthetic compounds derived from podophyllotoxin, a plant product. Yet another group of plant-derived agents includes camptothecin (CPT) and its derivative, topotecan and irinotecan (CPT-11). In evaluating extracts and pure compounds and generally all the compounds which are of interest for their anticancer effect, the first step is evaluating cytotoxicity. If the results are interesting, then other experiments will be carried out and the evaluation will be continued. Several approaches have been used in the past, to measure cell viability and growth. Many of these methods are limited by the impracticality of processing large numbers of samples, or by the requirement for handling hazardous materials. The MTT Assay, in contrast, provides a rapid and versatile method for assessing cell viability. MTT assay offers a quantitative, convenient method for evaluating a cell population's response to external factors, whether it is an increase in cell growth, no effect, or a decrease in growth due to necrosis or apoptosis. The spectrophotometric procedure can detect slight changes in cell metabolism, making it much more sensitive than trypan blue staining. There is no need to store or manipulate radioactive substances, the procedure is relatively simple and uses equipments already available in most labs. Assays are run in a 96-well plate and read with a microtitre plate reader, allowing high-throughput handling of samples. Screening the Iranian medicinal plants for their cytotoxic activity is one of the fields of interests of TMRC, the work began with screening plants from solanaceae, and some considerable cytotoxic effect was seen in one species of the family, which raised the hopes to continue the subject. Based on the previous reports of cytotoxic activity about some genera of Compositae, some other species growing in Iran were selected, and these plants will be checked for their cytotoxic activity. The research will be continued and TMRC has planed to cover most of the existing families growing in Iran, hope that this research will give good results for those suffering from cancer.