Antiinflammatory and antinociceptive activities of gossypin and procumbentin--cyclooxygenase-2 (COX-2) inhibition studies.

In the present study the antiinflammatory and antinociceptive activities of a few selected flavonoids were investigated. Procumbentin, gossypin, chrysin and methylhespiridin were studied for antiinflammatory and antinociceptive activities using in vitro enzymatic assays and in animal models utilizing acetic acid-induced writhing in mice and hind paw edema in rats. In vitro studies were performed using TMPD (NNN'N'-tetramethyl-p-phenylene diamine) and oxygraphic methods for COX-1 (cyclooxygenase-1), COX-2, 5-LOX (5-lipoxygenase) and 15-LOX. Gossypin and procumbentin showed COX-2 inhibitory activity and exhibited IC(50) (COX-2/COX-1) ratios of 0.14 and 0.11, respectively. None of the flavonoids tested in this study showed LOX inhibitory activity. Four groups were studied for each test compound following intraperitoneal (i.p.) administration of doses of 10, 30 and 100 mg/kg. Antiinflammatory activity was measured by the carrageenin-induced rat hind paw edema model and antinociceptive activity by acetic acid-induced writhing. Procumbentin and gossypin showed antinociceptive activity at the 100 mg/kg dose. Gossypin showed antiinflammatory activity at doses of 10, 30, 100 mg/kg. Procumbentin and gossypin exhibited COX-2 inhibitory activity when tested by in vitro methods. Procumbentin and gossypin showed antinociceptive, and gossypin showed antiinflammatory, activities.