Investigation of Mutagenic Activity of Helicteres isora L. Extract

Abstract

Helicteres isora L. (porbid, in Thai) is one of the medicinal plants that has gained special attention from researchers and the public regarding its preventive and therapeutic properties for some diseases. More interestingly, the products of this herb have been launched and consumed widely by the people, but their toxicity and safety data are still limited. This study aimed to investigate the mutagenic activity of two forms of H. isora L.’s extract based on the OECD GLP test guideline 471. Four strains of Salmonella typhimurium (TA98, TA100, TA1535, TA1537) and Escherichia coli (WP2) were treated with five different concentrations of the extract (625, 1,250, 2,500, 5,000 and 10,000 µg/ml) without any metabolic activation enzyme. The results showed that the aqueous extract did not produce revertant colonies and showed a normal background lawn compared to the control in all extract concentrations and all bacterial strains. However, the 95% ethanol extract did not produce revertant colonies compared to the control in all concentrations and all strains, but the background lawn of TA100 exhibited the killing effect at 10,000 µg/ml; and also in TA1537, the killing effect was found at concentrations higher than 2,500 µg/ml. In conclusion, the compound did not cause mutagenicity. This preliminary study indicated that the aqueous compound may be safe for using as a product component at the treated doses. It was noted that the 95% ethanol compound should not be used at the extract concentration of more than 2,500 µg/ml. The data from this research can be used as safety data and for public warning of this herbal product.