Anti-inflammatory and analgesic activity of a water-soluble fraction from shark cartilage

The anti-inflammatory and analgesic activities of a water-soluble fraction (WSF), extracted with 0.1 M ammonium bicarbonate, pH 8.0, from shark cartilage were studied in several experimental models. Orally administered WSF (10 mg/kg) caused 25.7 and 23.6% inhibition of the paw edema produced in female Wistar rats (200-250 g) by carrageenan and dextran, respectively, after 3 h, as compared to controls. WSF administered orally had no effect on acetic acid-induced writhings in male Swiss mice (25-30 g) at the dose of 0.01 mg/kg but caused 52.8 and 61.4% inhibition at the doses of 0.1 and 0.5 mg/kg, respectively, compared to controls (No. of writhings/20 min, means +/- SEM: treated groups = 18.6 +/- 2.5, N = 12 and 15.2 +/- 1.4, N = 12, respectively; controls = 39.3 +/- 1.3, N = 77). In the formalin test (male Swiss mice, 25-30 g), orally administered WSF (0.5 and 1 mg/kg) caused 12.0 and 46.6% inhibition of licking time, respectively, only in the 2nd phase (inflammatory) of the test (licking time, means +/- SEM: treated group = 18.3 +/- 4.4 sec, N = 7 and 11.1 +/- 3.4 sec, N = 13; controls = 20.8 +/- 2.4 sec, N = 44). The results suggest that a molecule of a protein nature in shark cartilage is probably responsible for the effects observed.