Assessment of the immunomodulatory effect of Aloe vera polysaccharides extracts on macrophages functions

Abstract

The present study evaluates the immunomodulatory effect of high molecular weight fractions of Aloe vera polysaccharides harvested during the dry season (March-April) and the rainy season (August-September). Peritoneal macrophages (MΦs) secluded from Balb/c mice underwent treatment with A. vera leaves extract and acemannan standard (the major component found in A. vera) and stimulated with lipopolysaccharides (LPS). Macrophage cell viability was assessed by the 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. Phagocytic activity was also evaluated in peritoneal macrophages, such as the production of nitric oxide and interleukin 6 (IL-6). In the results, found that the A. vera polysaccharides harvested during the rainy season stimulated the phagocytic activity with greater intensity than dry season and improvement NO and IL-6 production. No cytotoxic effect was found on cell viability and they cause a significant proliferative effect on macrophages in a concentration-dependent manner. It can be concluded that the A. vera polysaccharides harvested during the rainy season possessed a stronger immunostimulatory effect compared to the extracts from leaves obtained during dry seasons in a concentration-dependent manner without aff at the cell viability of macrophages.