In murine models of arthritis, inhibition of PARP withnicotinamide delayed the onset of the disease and reduced the progress of establishedcollagen-induced arthritis [127].5-iodo-6-amino-1,2-benzopyrone and PJ34, two novel PARP inhibitors, werebeneficial in a mouse model of collagen-induced arthritis by reducing both theincidence of arthritis and the severity of the disease [128,129].Similarly, GPI 6150 was found to be highly effective in a rodent model ofadjuvant-induced arthritis [130]. Here, PARP1 is linked to arthritic joint disease.