Objective: To detect the molecular characterization of polysaccharide purified from Amusium pleuronectes, so as to investigate its role of intervention to the formation of hepatic fibrosis caused by Schistosoma japonicum infection.
Methods: The crude polysaccharide from A. pleuronectes was extracted and further purified, and the molecular weight and monosaccharide composition were determined by the high pressure size exclusion chromatography and PMP pre-column derivatization method, respectively. A total of 50 female BALB/c mice were randomly divided into five groups：A (normal group), B (experimental group), C (polysaccharide group), D (praziquantel), and E (polysaccharide + praziquantel group). The mice in B, C, D, or E groups were attacked on the abdominal skin by using the cercariae of S. japonicum (30 ± 2 for each mouse) respectively. After 8 weeks, the mice in C, D, and E groups were administrated by polysaccharide and/or praziquantel, and the mice in B group were instead of saline. All the livers and sera were collected after 16 weeks. HE staining was employed for the livers, and serum IFN-γ and IL-13 were measured by using ELISA kits.
Results: The molecular weight of purified polysaccharide from A. pleuronectes was 11.7 kDa. Compared with A and B groups, the serum levels of IFN-γ in C, D, and E groups were significantly increased (F = 63.525, P < 0.01). However, the serum levels of IL-13 in C, D, and E groups were significantly decreased (F = 99.788, P < 0.01) compared with that in B group. HE staining showed that the egg nodules and hepatic fibrosis were observed in B, C, D, and E groups. The number of egg nodules and fibrosis degree in E group were milder than those in B group (χ2 = 7.875, P < 0.05).
Conclusions: The polysaccharide from A. pleuronectes has an obvious effect in preventing hepatic fibrosis process induced by S. japonicum infection, particularly combining with the administration of praziquantel.
[摘要] 目的 检测亚洲日月蛤多糖的分子特性, 探讨其在干预小鼠日本血吸虫肝纤维化中的作用。方法 提取并纯 化亚洲日月蛤多糖, 采用凝胶排阻法对其分子量进行测定, 应用PMP柱前衍生法对其单糖组成进行检测。取50只雌性 BALB/c小鼠, 随机分成5组, 每组10只小鼠。A组给予生理盐水灌胃, B、C、D、E组小鼠分别经腹部皮肤攻击感染血吸虫 尾蚴 (30 ± 2) 条/只; 饲养第8周末, C、D、E组小鼠分别给予多糖、吡喹酮及多糖+ 吡喹酮治疗, B组小鼠给予生理盐水; 第 16周末, 收集小鼠肝脏及血清, 通过HE染色观察小鼠肝脏虫卵肉芽肿病变及肝纤维化情况, 采用ELISA法检测血清IFN-γ、 IL-13水平。结果 亚洲日月蛤多糖相对分子量为11.7 kDa, 其多糖主要由葡萄糖组成。C、D组和E组小鼠血清IFN-γ浓 度显著高于对照组 (F = 63.525, P < 0.01), C、D组和E组小鼠血清IL-13浓度显著低于B组 (F = 99.788, P < 0.01)。HE染 色显示, B、C、D、E组小鼠肝组织均见不同程度虫卵结节和纤维化改变, A组小鼠肝脏正常, E组虫卵结节较B组少 (χ2 = 7.875, P < 0.05)。结论 亚洲日月蛤多糖具有明显的抗日本血吸虫肝纤维化作用, 与吡喹酮联用效果更好。.
Keywords: Amusium pleuronectes; Liver fibrosis; Mouse; Polysaccharide; Praziquantel; Schistosoma japonicum.