Zhao Linjing, Wu Hongbing, Zhao Aihua, Lu Huili, Sun Wei, Ma Chungwah, Yang Yiting, Xin Xue, Zou Haimiao, Qiu Mingfeng, Jia Wei
School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China; College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China.
J Ethnopharmacol. 2014 Apr 11;153(1):151-9. doi: 10.1016/j.jep.2014.02.008. Epub 2014 Feb 16.
Lycium barbarum and Astragalus membranaceus are two traditional medicinal herbs widely used in China for nourishing Yin and reinforcing Qi. The purpose of the study was to investigate the prophylactic and curative effects of crude polysaccharides (QHPS) extracted from a two-herb formula composed of Lycium barbarum and Astragalus membranaceus at a ratio of 2:3 in colitis rats, and to further elucidate the potential mechanism of action in epithelial cell proliferation in vitro.
An acetic acid (AA)-induced ulcerative colitis rat model was applied in the study. Two independent protocols were used to assess the prophylactic and curative effects of QHPS, respectively, in which rats were either pre-treated with QHPS (0.18g/kg) for 14 days prior to AA induction, or post-treated with QHPS for 7 days after AA induction. The stool consistency and weight loss were used to evaluate disease activity. The morphological changes in intestinal mucosa at the end of the experiments were observed. The serum levels of endotoxin (EDT), diamine oxidase (DAO) and d-lactate (DLA), important biochemical markers for evaluating intestinal mucosal structure and function, were measured. In the in vitro mechanistic studies, rat intestinal epithelial cells (IEC-6) were used to access for epithelium regeneration.
The intra-colonic instillation of AA induced ulcerative colitis in rat, as indicated by diarrhea, weight loss, and colonic mucosal damage. Both prophylactic and curative treatments effectively reduced the weight loss and diarrhea and attenuated the colonic mucosal damage associated with inducible colitis. The significant increase in serum levels of DAO, DLA and EDT was induced by AA and inhibited by QHPS treatment. Moreover, QHPS could significantly stimulate IEC-6 proliferation in a dose-dependent manner (p<0.05).
The present study indicated for the first time that polysaccharides extracted from this two-herb formula can protect against experimental ulcerative colitis, presumably by promoting the recovery of the intestinal barrier.
枸杞和黄芪是中国广泛用于滋阴补气的两种传统草药。本研究的目的是探讨从由枸杞和黄芪按2:3比例组成的两味药配方中提取的粗多糖（QHPS）对结肠炎大鼠的预防和治疗作用，并进一步阐明其体外上皮细胞增殖的潜在作用机制。
本研究采用乙酸（AA）诱导的溃疡性结肠炎大鼠模型。分别用两个独立的方案评估QHPS的预防和治疗作用，其中一组大鼠在AA诱导前用QHPS（0.18g/kg）预处理14天，另一组大鼠在AA诱导后用QHPS治疗7天。用粪便稠度和体重减轻来评估疾病活动度。观察实验结束时肠黏膜的形态变化。检测血清中内毒素（EDT）水平、二胺氧化酶（DAO）和D-乳酸（DLA）水平，这些是评估肠黏膜结构和功能的重要生化指标。在体外机制研究中，使用大鼠肠上皮细胞（IEC-6）来研究上皮再生。
结肠内注入AA可诱导大鼠发生溃疡性结肠炎，表现为腹泻、体重减轻和结肠黏膜损伤。预防和治疗性处理均有效减轻了体重减轻和腹泻，并减轻了与诱导性结肠炎相关的结肠黏膜损伤。AA诱导血清中DAO、DLA和EDT水平显著升高，而QHPS治疗可抑制这种升高。此外，QHPS能以剂量依赖的方式显著刺激IEC-6增殖（p<0.05）。
本研究首次表明，从该两味药配方中提取的多糖可预防实验性溃疡性结肠炎，可能是通过促进肠屏障的恢复来实现的。
