龙眼肉多糖LPII的体外免疫调节活性评价

In vitro Evaluation of Immunomodulatory Activity for Polysaccharide LPII from Arillus longanae

摘要:

LPII是龙眼肉多糖的主要级分之一，本文研究了其体外免疫调节活性及酶降解作用对活性的影响。采用尼龙毛柱分离脾淋巴T/B细胞，在25~400 μg/mL剂量范围内体外评价LPII对脾淋巴细胞的刺激作用发现，LPII能刺激脾淋巴细胞及B细胞增殖，并促进B细胞抗体生成，但对T细胞激活作用不明显（P>0.05）。此外，LPII还能有效刺激巨噬细胞增殖，并增强其吞噬功能和NO生成量。LPII的高分子量组分在木瓜蛋白酶、链酶蛋白酶和胰蛋白酶的作用下均发生明显降解，且200 μg/mL剂量下对刀豆蛋白A诱导的脾淋巴细胞增殖的刺激作用显著降低（P<0.05），但对脂多糖诱导的脾淋巴细胞增殖和巨噬细胞吞噬的刺激作用却显著增强（P<0.05）。LPII具有显著的体外免疫调节活性，是龙眼肉“滋补”的重要功能成分，而适度降解有利于增强活性。

Abstract:

LPII is one of the main fractions of polysaccharides from Arillus longanae. The immunomodulatory activities of LPII, and the effect of enzymolysis on its activity were investigated in vitro. Splenic lymphocytes were injected into a nylon fiber column to separate T cells and B cells. The stimulating effects of LPII on lymphocytes in the dose range of 25~400 μg/mL indicated that LPII could stimulate the proliferations of splenic lymphocyte and B cell and promote the antibody production of B cell. However, its activation on T cells was not significant. In addition, LPII could effectively enhance the proliferation, phagocytosis and NO production of macrophage in the dose range. The fraction of LPII with higher molecule weight obviously degraded by papain, pronase or trypsin, following with the weakened effect on ConA-induced splenic lymphocyte proliferation (P < 0.05) and the strengthened effects on LPS-induced splenic lymphocyte proliferation and macrophage phagocytosis (P < 0.05). LPII has the significant immunomodulatory activity in vitro, and the activity can be enhanced with appropriate degradation, which is confirmed as the most important functional component in Arillus longanae.