Cytogerontological studies of biological activity of oregano essential oil

In order to clarify possible cytological mechanisms that underlie the beneficial effects of carvacrol-bearing essential oils on health and mental abilities, we studied one of them (oregano essential oil) in experiments on transformed cultured Chinese hamster cells. Possible cytotoxic or mitogenic effects of the preparation at various concentrations were preliminarily estimated by analyzing the cell culture density after 4 days of cultivation. The preparation concentration in the growth medium (on carvacrol basis) varied from 1 × 10−15 up to 5 × 10−4 M (on carvacrol basis). As a result, two concentrations were selected for further experiments, including 2.5 × 10−5 M as the maximal absolutely non-toxic concentration and 2.5 × 10−4 M as the concentration at which the oregano essential oil decreased approximately 2-fold the final cell density of the grown culture. It was found that the preparation at 2.5 × 10−5 M had no effect on either the colony-forming ability of the cells or the saturation density of the culture (which is a marker of its “biological age”) or kinetics of its “stationary phase aging” (degradation of cultured cells in the stationary phase of growth, similar to age-related changes of the cells in aging organism). On the contrary, the oregano essential oil at 2.5 × 10−4 M abruptly diminished colony-forming ability of the cells and influenced as a “pro-aging” factor on the saturation density of the cell culture and kinetics of the cell death induced by “stationary phase aging.” Based on our own concept of aging and the data obtained, we assumed that detected increase in the life span of mice under the influence of the oregano essential oil could be determined by certain functional changes at the organismal level only, but is not associated with any geroprotective (anti-aging) activity of the preparation, which is manifested at the cellular level and improves the cell viability.