Immunostimulatory activity of snake fruit (Salacca edulis Reinw.) cultivar Pondoh Hitam extract on the activation of macrophages in vitro

Abstract

Snake fruit (Salacca edulis Reinw) cultivar Pondoh Hitam is a tropical fruit produced in Indonesia. It is consumed freshly or processed and believed as the most delicious snake fruit cultivar. Snake fruit flesh contains high polisaccharides such as pectin and dietary fiber. Therefore, snake fruit is a potential immunostimulator candidates but the immunological effect of snake fruit flesh has not been reported. In the present study, immunostimulatory activity of snake fruit flesh extract (SFFE) on macrophages activation was evaluated.SFFE was prepared by extracting from snake fruit flesh with water, methanol 70%, and ethanol 70% for 15 h at 4°C. Then obtained SFFE was used to stimulated cytokine production in vitro using J774.1 cell line. The extract giving strongest stimulation was sellected for in vivo assay to stimulate cytokines production and gene expression using peritoneal macrophage (P-mac) of BALB/c mice.The results showed that SFFE exhibited immunostimulatory activities. Immunostimulatory activity could be indicated by macrophages activation characteristics such as cytokines production. Water extract of SFFE gave strongest stimulation on cytokines production in vitro and sellected for in vivo assay. In vivo assay showed that SFFE stimulated cytokines production as well as their gene expression levels. The optimum stimulation was demonstrated by SFFE 16.7 mg/g. Overall findings suggest that SFFE has a potent beneficial effects to promote the body health through activating macrophages.