FURTHER-STUDIES ON ANTIINFLAMMATORY ACTIVITY OF PHYCOCYANIN IN SOME ANIMAL-MODELS OF INFLAMMATION

Objective: To examine the effects of C-phycocyanin, a pigment found in blue-green algae which acts as an antioxidant in vitro and in vivo, i n different animal models of inflammation. Material: Male Sprague Dawl ey rats and OF1 mice were used. Treatments: Oedema was induced by: a) AA (0.5 mg/ear) or TPA (4 mu g/ear) in the mouse ear b) carrageenan in jection (0.1 mL of 1% suspension) in the rat paw (+/- adrenalectomy) a nd c) cotton pellet implantation in the rat axilla. Phycocyanin (50-30 0 mg/kg, p.o.) or indomethacin (1 mg/ear or 3-10 mg/kg, p.o.) as contr ol were tested in the four animal models. Methods: Measurement of the increase in the weight (mg) of 6 mm ear punch biopsies from treated ea rs were made in comparison to control ears, together with myeloperoxid ase (MPO) activity as an index of neutrophil infiltration. The increas e in the paw thickness (mm) was measured with a dial caliper. Cotton p ellet was implanted and seven days afterwards the granuloma was remove d and the dry weight was determined. Acute toxicity was studied in mic e and rats. Statistics were performed using one-way analysis of varian ce with the Duncan Multirange test. Results: Phycocyanin reduced signi ficantly (p < 0.05) and in a dose-dependent manner ear oedema induced by AA and TPA in mice as well as carrageenan-induced rat paw oedema (b oth in intact and adrenalectomized animals). In the TPA test, phycocya nin also reduced MPO content. Phycocyanin also exerted an inhibitory e ffect in the cotton pellet granuloma test. In the acute toxicity test in rats and mice, even at the highest dose tested (3 000 mg/kg, p.o.), no toxicity was found. Conclusions: Phycocyanin shows anti-inflammato ry activity in four experimental models of inflammation. Its antioxida tive and oxygen free radical scavenging properties may contribute, at least in part, to its anti-inflammatory activity.