The discovery of anthranilic acid-based MMP inhibitors. Part 2: SAR of the 5-position and P1(1) groups

A novel series of anthranilic acid-based inhibitors of MMP-1, MMP-9, MMP-13, and TACE was prepared and evaluated. Selective inhibitors of MMP-9, MMP-13, and TACE were identified, including the potent, orally active MMP-13 inhibitor 4p.

Rapid induction of early osteoarthritic-like lesions in the rabbit knee by continuous intra-articular infusion of mammalian collagenase or interleukin-1

Aminophenyl mercuric acetate (APMA)-activated collagenase (C) (60 U/ml) obtained from in vitro cultures of human skin fibroblasts or recombinant interleukin-1 beta (IL-1 beta) (200 U/ml) was infused continuously for 7 days into the rabbit knee synovial space by means of an implanted Alzet osmotic pump. In stability studies in vitro, activated C or IL-1 incubated for 7 days at 37 degrees C, showed no significant loss of biological activity. Alterations in knee cartilage morphology and proteoglycan (PG) content were determined histologically, and the incidence of cartilage damage calculated. C or IL-1 vehicles infused for 7 days, caused no damage. Incidences of damage for C or IL-1 (n = 8-9), respectively, were as follows: loss PG: 88% and 100%; chondrocyte disorganization and loss, 50% and 78%, fissures and or fraying, 25% and 78%; and convergence of inflammatory cells, 25% and 66%. These results confirm the important role of C and IL-1 in cartilage damage.