Effects of allicin on the proliferation and cell cycle of chondrocytes.

The present study demonstrates the effect of allicin on the proliferation and the cell cycle distribution of the chondrocytes. MTT assay and flow cytometry were used for the evaluation of the effect of allicin on cell proliferative and the cell cycle distribution, respectively of the chondrocytes. The reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis were respectively used for the analysis of mRNA and protein expression levels of cyclin D1, CDK4 and CDK6. The results revealed that exposure of the chondrocytes to allicin at a concentration of 40 µM significantly promoted the cell viability. Treatment of the cells with 10, 20, 30, 40, and 50 μg/mL of allicin enhanced the cell viability by 2.5.47 ± 0.86, 5.43 ± 0.66, 10.74 ± 1.48, 35.89 ± 3.78, and 32.21 ± 2.92%, respectively after 36 h compared to control cells. Allicin exposure caused a marked decrease in the percentage of cells in G0/G1 phase with a subsequent increase in the S phase population. Furthermore, allicin treatment enhanced the expression of cyclin D1, CDK4 and CDK6. Therefore, allicin treatment enhances the proliferation of chondrocytes by promoting the transition from G1 to S phase of the cell cycle through increase in the expression of cyclin D1, CDK4 and CDK6 levels.