Effects of Essential Oils on Telomere Length in Human Cells
Essential oils are used for their reputed health benefits; reversal of inflammation, oxidative damage, and infection are some of the therapeutic effects that essential oils are believed to possess. In many cases, there is scientific evidence to back these claims. However, the purported anti-aging effects of essential oils are not yet supported by the literature. We set out to evaluate the effects of 31 oils on telomere length, believed to play a role in cellular senescence. Cells were subjected to oils in the presence or absence of hydrogen peroxide, and changes in telomere length were measured using a PCR-based assay. Two oils which showed telomere-protective effects were further characterized using a cytogenetic assay, staining for telomeres. Significant variability was seen among these oils with respect to their ability to induce an apparent increase or decrease in telomere length, and to protect against peroxideinduced telomere damage. Expression analysis showed that telomere-protective oils did not increase telomerase (hTERT) gene transcription, but reduced TERF-1, a suppressor of telomere length. Though this mechanism is not yet understood, these data provide a base upon which the community can build, and represent the first formal scientific foray into the study of essential oils on the telomere. Conclusion: Certain essential oils, including those from basil and rosemary, appear to have telomere-protective effects, mediated through a reduction of the TERF-1 telomere-suppressive protein.