In vitro cytogenotoxic and mutagenic effects of Commiphora myrrha essential oil

Commiphora myrrha, located in the tropical zone, is a widely used tree for medicinal purposes in the Arabian Peninsula and a large part of Africa. In this research, cytogenotoxic effects of the commercially available Commiphora myrrha essential oil (myrrh) were studied using micronucleus (MN), comet, and total oxidant (TOS), and total antioxidant (TAS) assays on human peripheral lymphocytes under in vitro conditions. In addition, pure pBR322 plasmid DNA was used to investigate DNA damaging/protecting activity of the essential oil. Finally, a bacterial reversion (Ames) test was performed using Salmonella typhimurium mutant strains TA98 and TA100 to determine the potential effect of the agent in the induction of gene mutations. The high concentration of Commiphora myrrha (0.125 mu L/mL) induced MN formation significantly compared to the untreated control in both treatment times (24 or 48 h). Only at the highest concentration, nuclear division index (NDI) values were found lower than the controls. In the Comet test performed on healthy lymphocytes, only the highest concentration of myrrh caused significant increases in the percentage of damaged cells and genetic damage index (GDI) values. Myrrh oil showed no significant mutagenic effect on mutant Salmonella strains. In addition, the substance did not directly damage plasmid DNA but also protected DNA against damaging factors such as H2O2 and UV. Finally, in the TAS and TOS assays, no significant differences on the oxidative stress parameters were found in cell culture compared to the control. The results of this study showed that myrrh oil exerts cytogenotoxic risk only at higher concentrations.