The effect of the oil of Agastache rugosa O. Kuntze and three of its components on human cancer cell lines

The reduction of tumor cell proliferation and antimutaginicity of the essen tial oil from Agastache rugosa O. Kuntze and its major components such as m ethyl chavicol (82.8%), limonene (3.9%) and anisaldehyde (2.6%) were invest igated by using four human carcinoma cell Lines. Both the oil and its three major components were shown to possess low cytotoxicity on normal human li ver cells, WRL68 by only inhibiting less than 12% of normal cell growth. It s inhibition percentage was much less than those from other medicinal herb extracts. The oil had relatively strong antimutaginicity when screened agai nst a genetically engineered Chinese Hamster Ovary(CHO AS-52) cell line, an d the results of antimutaginicity were shown to be closely related to the e ffect of inhibiting cancer cell growth. In general, the oil had better inhi bition effect on cancer cells than individual components: 63% for crude oil vs. 49% for anisaldehyde at 1 g/L of the treatment. It was found that the oil could effectively inhibit the growth of human lung cancer cell up to 82 %, having 0.09 of IC50. The proliferation of other human cancer cell lines have also been retarded in the range of 40-80% by addition of the oil. This was well matched, with the result of antimutaginicity as follows: 75% for the oil and 38-63% for individual oil components at 1 gn, respectively. The functions of antimutaginicity and inhibiting cancer cell growth of the com ponents were also confirmed by the kinetic analysis of human immune cell gr owth. The growth of both B and T cell lines was enhanced up to about 200% b y adding the oil, but the oil components could not improve the human T cell s. The results of a kinetic analysis using a microphysiometer revealed that the oil could affect human B cell growth rapidly within 10 min of the trea tment showing up to 180% enhancement of the growth. While the individual co mponents only reacted after 20 min. This may be interpreted that the oil ( mixture of components) can have a synergistic effect on the growth of human T cells and better inhibition of cancer cell growth. These results also im ply that the oil could selectively inhibit the proliferation of human cance r cells (>1.5 of the selectivity) better than the individual oil components , possibly due to the synergistic effect of the three major components and/ or the combined effects by other unknown minor components in the oil.