Abstract
Objective: The aim of the present study is to investigate the cytotoxic and apoptotic effects of oregano oil from Origanum minutiflorum, which is an endemic medicinal plant in Turkey, on NB2a neuroblastoma cells.
Material and Method: Cell proliferation, apoptosis, and expression of inducible and endothelial nitric oxide synthase have been determined by MTT, TUNEL, and immunohistochemistry, respectively.
Result and Discussion: The cell viability was significantly decreased gradually in NB2a cells when the concentrations of both oregano oil and doxorubicin were increased. IC50 doses were found to be10.75 µl/ml for oregano oil and 5µM for doxorubicin. Furthermore, expression of inducible and endothelial nitric oxide synthase, also the number of apoptotic cells was significantly enhanced in NB2a cells after treatment with oregano oil and doxorubicin. There was a remarkable increase in inducible and endothelial nitric oxide synthase expression levels and in the number of apoptotic cells by the dual application of these agents. In addition, oregano oil enhanced the apoptotic effect of doxorubicin. In conclusion, our results indicated that oregano oil of O. minutiflorum has a cytotoxic and apoptotic effect on NB2a cells and these effects may be related to its enhancing effects on inducible and endothelial nitric oxide synthase levels.
Thanks
The authors wish to thank Associate Prof. Dr. Sabri Erbaş, Agriculture Faculty, Suleyman Demirel University, Isparta, Turkey, for providing the plant material. The abstract of this work has been previously presented at the 2nd International Conference on Natural Products for Cancer Prevention and Therapy and published in the Multidisciplinary Digital Publishing Institute Proceedings Journal, vol.1 number 10 (https://www.mdpi.com/2504-3900/1/10/1026).