Novel chondrogenic and chondroprotective effects of the natural compound harmine

► Harmine was identified to be an inducer of CCN2 that promotes cartilage generation. ► Harmine increased the expression of aggrecan, collagen type II and SOX-9 genes. ► Harmine induced chondrogenesis of ATDC5 cells in micromass cultures. ► Harmine rescued TNFα-induced decrease in expression of CCN2 and cartilage markers.