Effect of hexane fraction of leaves of Cinnamomum tamala Linn on macrophage functions.

The leaves of Cinnamomum tamala Linn (Lauraceae), component of Indian spices are associated with hypoglycemic property in Ayurveda; however, no report is available towards its immunomodulation property, which has been explored here. The dried powder of CT leaves was extracted with hexane and solvent free extract (CTH) was given orally to rats for 10 days, in various doses. Its effect was studied on peritoneal macrophage functions, and was compared with ascorbic acid (1,000 mg/kg, immune-stimulant) and cyclophosphamide (10 mg/kg, immune-suppressant). CTH significantly suppressed phagocytosis activity (EC(50) 2,355 +/- 52.45 mg/kg), reduced production of superoxide (EC(50) 275.91 +/- 10.21 microg/ml) and cellular NADPH (EC(50) 384.959 +/- 4.85 microg/ml) content in concentration dependent manner. It also inhibited LPS induced production of nitric oxide (EC(50) 143.75 +/- 3.40 microg/ml) and iNOS protein expression (EC(50) 183.132 microg/ml). Thus, it could be suggested that non-polar hexane fraction of leaves of C. tamala possesses immunosuppressive property, which is mediated through modulation of innate immunity.