In vitro evaluation of the effects of capsaicin on normal and cancerous cells of human cartilage

Chondrosarcoma is a common form of bone cancer which effects the fibrous connective tissue around a joint. It most commonly develops in legs, arms, shoulder blades, rib cage, and pelvis. Capsaicin is an active bitter compound found in red pepper, the fruit of the species Capsicum annuum, and it has been shown to have a lethal effect on different types of cancer. However, to date, investigation of its effect on human chondrosarcoma cells has remained limited. In the study presented here, we determined IC(50) values of capsaicin for chondrosarcoma and chondrocyte cells in both fetal bovine serum (FBS)-containing and FBS-deprived media, and no statistically significant difference was found between the cell types. Besides, when the cells were cultured with capsaicin at their determined IC(50) value for 24 h and their caspase-3 gene expression levels were detected by real-time polymerase chain reaction (RTPCR) and western blotting, it was demonstrated that the caspase-3 protein and mRNA levels were not altered in any cells upon capsaicin exposure, suggesting a caspase-independent pathway for cell death. Migration and invasion abilities of the cancerous cells, on the other hand, were observed to decrease dramatically when the cells were exposed to capsaicin (P < 0.05).