Immunomodulatory Effects of Oral Administration of Chitosan Hydrolysate in BALB/c Mice

Abstract

BALB/c mice were fed with three doses of chitosan hydrolysate (50 mg, 500 mg, and 2.5 g/kg(subscript body weight)) for 4 weeks. The effects of this hydrolysate on the phagocytic activity of macrophages, lymphoproliferation, serum immunoglobulin amounts, and cytokine production by splenocytes were evaluated. The phagocytic activity of the peritoneal macrophage was significantly increased when the mouse was fed with any one of doses of chitosan hydrolysate. Chitosan hydrolysate also significantly enhanced concanavalin A (ConA)-stimulated proliferation of splenocytes and Peyer's patch lymphocytes. However, the proliferation of the lipopolysaccharide (LPS)-stimulted splenocytes and Peyer's patch lymphocytes were significantly suppressed if the mouse was fed with chitosan hydrolysate at the dose of 2.5 g/kg. After fed with chitosan hydrolysate at the dose of 2.5 g/kg body weight, serum antibodies of IgM, IgA and IgG in mice were significantly increased; while only IgM antibody was significantly increased for the 500 mg/kg -dose group. In the presence of ConA, the secretion of IFN-γ and IL-4 cytokines by spleen T cells in mice fed with chitosan hydrolysate (500 mg/kg) was significantly increased. Moreover, the IFN-γ/IL-4 ratio was also significantly increased.本研究以三種不同劑量（50mg、500mg和2.5g/kg(下標 body weight)）的幾丁聚醣水解液餵食BALB/c小鼠四週，探討其對小鼠腹腔巨噬細胞吞噬活性、淋巴細胞增生活性、血中免疫球蛋白含量和脾臟淋巴細胞分泌細胞激素的影響。攝食三種不同劑量幾丁聚醣水解液均可顯著增加小鼠腹腔巨噬細胞的吞噬活性，且顯著增加由concanavalin A(ConA)所刺激的脾臟與培耶氏囊淋巴細胞增生活性，然而，攝食2.5g/kg幾丁聚醣水解液卻會抑制由lipopolysaccharide (LPS)所刺激的脾臟與培耶氏囊淋巴細胞增生活性。餵食2.5g/kg幾丁聚醣水解液四週可明顯增加BALB/c小鼠血液中IgM、IgA和IgG抗體含量，而餵食劑量為500mg/kg時則僅IgM抗體顯著高於控制組。在ConA存在下，攝食500mg/kg幾丁聚醣明顯提升脾臟T細胞分泌細胞激素IFN-γ及IL-4，且IFN-γ/IL-4比值明顯大於控制組。