Background: Medicinal plants are primery source of many drugs to cure different diseases. The genus Prangos, (Umbelliferae family) consists of several medicinal plants that their desirable dffects have been approved. The aim of this study is to investigate the effectiveness of methanol extract in different parts of prangos ferulacea and prangos acaualis on human lymphocytes proliferation and their mutagenicity in salmonella typhimurium TA98.

 Materials and Methods: In this experimental study, the plants were collected from different areas of Kurdistan. Then, samples were air dried and powdered and methanol material of plants was extracted. The extracts were diluted to give concentrations of 10, 100, 500, 1000, 1500, 2000, 2500 &mug/ml. Finally, the effects of these extracts on human lymphocytes proliferation and their mutagenecity have been investigated by the MTT and Ames test.

 Results: The results showed that different organs extract from both tested plants caused a significant increase in lymphocytes proliferation, specially in concentrations of 500 to 2500 &mug/ml. Of studied excrtacts, the highest and lowest effect on lymphocytes proliferation was obtained in presence of flower and seed, respectively. In total, the levels of proliferation resulted of prangos ferulacea as compared with prangos acaulis were higher. Also, the results of study showed no mutagenicity of studied plant exctracts with considered concentrations.

 Conclusion: The findings revealed that both species of prangos can increase immune system function and were used as an safe medicinal plant to cure patients with immune deficiencies and microbial infections.