Polysaccharides from Plantaginaceae and Brassicaceae: effects on innate immunity

Many pathological states are characterized by a decrease in innate immunity [1]. In this respect, five raw water-soluble polysaccharides were investigated for the effects on innate immunity: PM, Pm and Pl – polysaccharides isolated from leaves of Plantago major L., Plantago media L. and Plantago lanceolata L., respectively, PB and PR – polysaccharides isolated from fresh pressed juice obtained from leaves of Brassica oleracea L. convar. capitata (L.) Alef. var. alba DC and roots of Raphanus sativus L. var. niger. The raw polysaccharides were administrated orally to normal mice in a dose of 50mg/kg (PM, PM, Pl, PR) and 100mg/kg (PB) for a seven day period. Levamisole (10mg/kg) was used as positive control. The effects on innate immunity were assessed by evaluating serum opsonic capacity, phagocytic and bactericide activities of peritoneal macrophages, phagocytic activity of neutrophil granulocytes and hemolytic activity of seric complement [2]. PR was found to be the most active polysaccharide; its immunostimulating effects were comparable with those of levamisole. PR increased serum opsonic capacity by 20%, phagocytic and bactericide activities of peritoneal macrophages by 33.3% and 80.9%, respectively, phagocytic activity of neutrophils by 44.3% and decreased hemolytic activity of seric complement by 30.4%. The immunostimulating effects of tested polysaccharides partially justify therapeutical uses of plantain leaves, white cabbage leaves and black radish roots in traditional medicine. Besides, these polysaccharides could be used as complementary therapy in many diseases in which innate immunity is significantly decreased.

References: [1] Romagne, F. (2007) Drug Discov. Today 12: 80–87. [2] Ghiciuc, C.M. et al. (2004) Ann. Pharm. Fr. 62: 43–48.