Dietary n-3 fatty acids, curcumin and capsaicin lower the release of lysosomal enzymes and eicosanoids in rat peritoneal macrophages

Male Wistar rats (12 rats/group) were fed a diet containing 8 wt % coconut oil or groundnut oil or cod-liver oil for a total period of 8 weeks. The di ets were also supplemented with 2 wt % groundnut oil for providing essentia l fatty acids. During the last 2 weeks, 6 rats form each group were additio nally given curcumin (30 mg/kg body wt/day) or capsaicin (5 mg/kg body wt/d ay) in 1 ml groundnut oil. The peritoneal macrophages from rats fed cod-liv er oil diet secreted lower levels of lysosomal enzymes collagenase, elastas e and hyaluronidase as compared to those from rats fed coconut oil or groun dnut oil diets. Curcumin and capsaicin significantly lowered the secretion of these lysosomal enzymes from macrophages in animals given coconut oil or groundnut oil diet. Macrophages from rats fed cod-liver oil secreted lower amounts of prostaglandin E-2, 6-keto PGF(1 alpha), leukotrienes B-4 and C- 4 and also incorporated lesser amounts of [H-3]-arachidonic acid as compare d to those given coconut oil or groundnut oil diets. Curcumin and capsaicin lowered the secretion of these eicosanoids and decreased the incorporation of [H-3]-arachidonic acid in macrophage lipids. However curcumin and capsa icin significantly increased the secretion of 6-keto PGF(1 alpha) in all th e groups of animals. These studies indicated that dietary cod-liver oil (ri ch in n-3 fatty acids), and spice principles curcumin and capsaicin can low er the secretory functions of macrophages in a beneficial manner.