| Low molecular weight heparin (LMWH) and Unfractioned heparin (UFH) possess anti-inflammatory properties which have been demonstrated both in animal models of inflammation and in human diseases, apart from their known anticoagulant and antithrombotic activities. Based on this feature, they have been proposed for the treatment of inflammatory bowel disease (IBD). IBD encompasses ulcerative colitis (UC) and Crohn's disease (CD), both of which are chronic, recurrent, nonspecific intestinal inflammatory processes of unknown aetiology.LMWH's clinical application limites to anticoagulation and antithrombosis and limits to parenteral route administration at present, thus we prepared the LMWH rectal suppository and oral colon-specific delivery capsule with an endeaver to make its anti-inflammation applicable to UC. In the present study, the mechanism of LMWH on the treatment of UC was also investigated. This is the focus of our project listed as follows.1. Preparation of LMWH rectal suppositoryLMWH rectal suppository was prepared using polyethylene glycol (PEG) 6000 and PEG 400 (7:3) as the suppository base. The results showed that the drug release rate is slow and sustained, consistent with the characteristics of local medication. The appearance characters, melt time, weight variation, content determination and dissolution experiment in vitro were determined according to Chinese pharmacopoeia (2005). The results were all in accordance with the 2005 edition of Chinese pharmacopoeia. LMWH rectal suppository efficacy was studied by macroscopical and histological scoring systems as well as myeloperoxidase activity. The present study demonstrated that the rectal suppository of LMWH could attenuate macroscopic and histological features of colitis.2. Preparation of LMWH oral colon-specific delivery capsuleLMWH oral colon-specific delivery capsule was prepared with sugar and dextrin (3:1) as the excipients. The appearance characters, content uniformity, content determination were determined according to Chinese pharmacopoeia (2005), and the in vitro and in vivo drug release behavior was investigated. The results were all in accordance with the 2005 edition of Chinese pharmacopoeia. The in vitro and in vivo drug release studies clearly indicated that the specific coated capsule was capable of protecting LMWH from releasing in stomach and small intestine, while specifically delivering at colon. The macroscopical and histological scoring systems, wet colon mass index and myeloperoxidase activity were assessed to evaluate the efficacy of the capsule after administered orally to experimental colitis mice. The oral colon-specific delivery capsule of LMWH could attenuate macroscopic and histological features of colitis.3. Preparation of LMWH compound oral colon-specific delivery capsuleLMWH has anti-thrombosis, anti-inflammatory. Xylo-oligosaccharides plays an important role in promoting the growth of intestinal probiotics. This study intends to combine heparin with xylo-oligosaccharides to explore the efficacy of UC treatment by oral colon targetting drug delivery system. LMWH compound oral colon-specific delivery capsule was prepared with sugar and dextrin and xylo-oligosaccharides (1: 1.5:1.5). The appearance characters, content uniformity, content determination and dissolution experiment in vitro were determined according to Chinese pharmacopoeia (2005). The results were all in accordance with the 2005 edition of Chinese pharmacopoeia. The macroscopical and histological scoring systems, myeloperoxidase activity and the intestinal flora of bacteria were assessed to evaluate the efficacy of the capsule after administered orally to experimental colitis rats. The LMWH compound oral colon-specific delivery capsule could attenuate macroscopic and histological features of colitis. 4. The mechanism of LMWH on treating ulcerative colitisWith the efficacy test of LMWH, serum levels, including tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6) and a link factor of blood coagulation and inflammation factor Xa (FXa) were asssayed by enzyme-linked immunosorbent assay, and the expression of Musashi-1(as an intestinal stem cell marker) in the colons was assessed by immunohistochemical analysis. The results showed that LMWH significantly decreased serum levels of TNF-a, IL-6 as well as FXa, while increased the expression of Musashi-1 in colon compared with acetic acid induced UC model group. All these preliminary results indicate LMWH is promising for treatment of UC. The study of anti-inflammatory mechanism of LMWH is still at the early stage at present, but LMWH is expected to become a novel anti-inflammatory drug with better efficacy and fewer side effects for its unique properties.The main achievements obtained in the study are as follows:1. LMWH rectal suppository was prepared, its quality evaluation and efficacy evaluation of LMWH rectal suppository were investigated. The results show that the suppository meets the requirement of Chinese Pharmacopeia (2005) for suppositiory, and can attenuate macroscopic and histological features of colitis.2. LMWH oral colon-specific delivery capsule was prepared, and the quality evaluation and efficacy evaluation of LMWH oral colon-specific delivery capsule were investigated. The results show that the capsule meets the requirement of Chinese Pharmacopeia (2005) for capsule, and can attenuate macroscopic and histological features of colitis.3. LMWH compound oral colon-specific delivery capsule was prepared, and the quality evaluation and efficacy evaluation of LMWH compound oral colon-specific delivery capsule were investigated. The results show that the capsule meets the requirement of Chinese Pharmacopeia (2005) for capsule, and can attenuate macroscopic and histological features of colitis.4. The results showed that LMWH rectal suppository significantly decreased serum levels of TNF-a, IL-6 as well as FXa, while increased the expression of Musashi-1 in colon compared with acetic acid induced ulcerative colitis model group. All these preliminary results indicate LMWH is promising for treatment of ulcerative colitis. |
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