Investigation of cytotoxic and apoptotic effects of carvacrol on ras transformed 5RP7 and normal F2408 embryonic fibroblast cells and U-2 OS osteosarcoma cells in vitro

In this study, the cytotoxic and apoptotic effects of carvacrol, a herbal monoterpene, were investigated on F2408, 5RP7 and U-2 OS cells. The cytotoxic effect was determined by MTT and neutral red uptake and the apoptotic effect was morphologically by AO/EB staining, respectively. In addition, the expression levels of 84 genes after carvacrol treatment of U-2 OS were studied using RT2-PCR array. IC50 values for F2408, 5RP7 and U-2 OS treated with carvacrol for 48 hours were detected as 300 µM, 300 µM and 250 µM, respectively. The characteristics of apoptotic morphology such as membrane blebbing, chromatin condensation and fragmantation were observed under a flouresans microscope. Incubation of U-2 OS with carvacrol caused a diminution in the expression level of 56 genes and an elevation of two genes related with apoptosis and MAPK pathway. Thirteen genes of them showed two fold or more reduction in the expression levels. Because of these genes are related with ERK1/2, JNK, p38 MAPK signaling pathways, mechanism of cell death was cleared. Sisplatin as a chemothrepeutic agent caused changes in the expression of 8 genes in the same cells and was effective less than carvacrol. In conclusion, carvacrol showed significantly cytotoxic and apoptotic effects on F2408, 5RP7 and U-2 OS cells. Furthermore, inhibition of ERK1/2, JNK, p38 MAPK and cell cycle pathways on an osteosarcoma cell, U-2 OS, indicate that carvacrol might be an efficient therapeutic agent for various cancers at least osteosarcomas.