当归多糖对镉染毒大鼠肝损伤及免疫损伤的影响

Effects of Angelica Sinensis Polysaccharide on Liver Damage and Immunocyte Injury Caused by Cadmium in Rats

目的观察当归多糖对镉染毒大鼠肝功能和免疫功能的影响,分析中药对镉染毒大鼠的保护作用和可能机制。方法采用腹腔注射氯化镉(1.5mg·kg^(-1),每周5次,连续5周)建立大鼠镉染毒模型,同时模型大鼠灌胃给予当归多糖(20mg·kg^(-1)),每天1次,连续5周;末次给药24h后处死大鼠,计算胸、脾、肝指数。脾淋巴细胞的转化功能和NK细胞的杀伤活性检测采用MTT法,血清AST、ALT、LDH活性检测采用分光光度法,血清IL-2和TGF-β1含量测定采用ELISA法,肝组织镉含量采用火焰原子吸收光谱法、Bcl-2和Bax的蛋白表达采用免疫组化法。结果当归多糖可以增加胸脾指数(P<0.05);明显增强脾淋巴细胞转化能力和NK细胞杀伤能力(P<0.01);明显增加血清IL-2含量、明显降低血清TGF-β1含量(P<0.01);明显降低血清AST、ALT、LDH活性(P<0.05或P<0.01);明显降低肝组织镉含量(P<0.01);明显增强肝组织Bcl-2蛋白表达,降低Bax的蛋白表达(P<0.05或P<0.01)。结论当归多糖对镉染毒大鼠的免疫损伤和肝损伤具有明显的保护作用,其机制可能与增强免疫功能、调节酶活性和细胞凋亡相关蛋白有关。

Objective To investigate the protective effects of angelica sinensis polysaccharide on the immune function and liver function in cadmium exposed rats and its possible mechanisms.Methods The rats were treated with 1.5 mg·kg^-1 cadmium by intraperitoneal injection and ig given angelica sinensis polysaccharide（20 mg·kg^-1）once a day for 5 weeks.These rats were sacrificed at 24 hafter the last administration.The indexes of the thymus,spleen and liver were calculated with weighing method.The transformation ability of T lymphocytes and the killing activity of NK cells were detected with MTT method.The activities of AST,ALT and LDH were tested with a spectrophotometer.The contents of IL-2 and TGF-β1 were analyzed with ELISA.Cadmium content was detected with oxygen-enriched shield flame atomic absorption spectrometry.The protein expressions of Bcl-2 and Bax were measured via immunohistochemistry.Results Compared with the exposed cadmium chloride model group,the indexes of the spleen and thymus were increased in angelica sinensis polysaccharide treated group（P〈0.05）.Meanwhile,the T lymphocyte stimulation indexs and the NK killing activity were increased significantly in angelica sinensis polysaccharide treated group（P〈0.01）.The serum level of IL-2 and the expression of Bcl-2 in liver tissue were augmented evidently in angelica sinensis polysaccharide treated group（P〈0.05 or P〈0.01）,but the serum level of TGF-β1 was decreased significantly（P〈0.01）.Furthermore,the serum levels of AST,ALT and LDH were decreased distinctly in angelica sinensis polysaccharide treated group（P〈0.05 or P〈0.01）,while the Bax expression and cadmium contents in liver tissue were depressed（P〈0.05 or P〈0.01）.Conclusion Angelica sinensis polysaccharide can enhance immune function,improve enzymatic activity,regulate apoptosis protein,which may be one of the important mechanisms for the treatment of damage to immunity and liver injury caused by by cadmium chloride.