Role of protease and self-digestion in the pathogenesis of inflammatory bowel disease / 医学研究生学报

Inflammatory bowel diseases (IBD) are non-specific inflammatory diseases of unknown cause, mainly including ulcerative colitis and Crohn’s disease. IBDs have some similarities to peptic ulcer diseases (PUD) in clinical manifestations, histopathological changes and treatment strategies, and therefore pepsin might have a similar effect on both PUD and IBD. Recent studies show that “self-digestion” induced by digestive enzymes, especially trypsin, may play an important role in the development and progression of IBD. This article focuses on the role of mucosal barrier injury induced by trypsin and self-digestion in the formation of digestive ulcer in IBD.

Preparation and quality evaluation of levocarnitine thermosensitive in situ gel / 药学学报

In this paper, a new type of preparation for treatment of initial dry eye disease, thermosensitive in situ gel, was prepared using levocarnitine as a model drug. Poloxamer 407 and poloxamer 188 were used as the gel matrix, and sodium hyaluronate and sodium carboxymethylcellulose were used as bioadhesive materials. Gelation temperature was determined by a rotor method and the prescription was optimized by central composite design-response surface methodology. The pH value, viscosity value and gelation temperature of the optimal prescription were measured. The release of the drug in vitro was examined by dialysis membrane permeation, and retention time of the thermosensitive in situ gel preparation on the rabbit's ocular surface was observed by a slit lamp microscope. The results showed that the dosage of the poloxamer 407 and poloxamer 188 were 20.81% and 3.46%, respectively, and sodium hyaluronate was 0.02%, sodium carboxymethyl cellulose was 0.10% of the optimal formulation of levocarnitine thermosensitive in situ gel. The pH value was 6.90 ± 0.06 at room temperature and the viscosity value started to rise sharply at 27 ℃ of the optimal formulation. The gelation temperature of the optimal preparation before and after dilution by simulated tear fluid were (26.37 ± 0.06) ℃ and (33.57 ± 0.21) ℃, respectively. In the first 240 min, in vitro release rate per unit area of levocarnitine thermosensitive in situ gel was lower than that of solution (P<0.05), and after 600 min, the cumulative release rate of levocarnitine thermosensitive in situ gel could reach more than 80%. The retention time of the thermosensitive in situ gel preparation on rabbit's ocular surface reached about 25 min, at least 5 times as much as that of the solution. The animal experiment was conducted following the National Institutes of Health Guidelines for the use of experimental animals, and approved by the Ethics Committee of the Experimental Animal Center of Beijing University of Chinese Medicine. The levocarnitine thermosensitive in situ gel showed good characteristics and sustained release property and significantly improved the retention time of the drug on the rabbit's ocular surface.

Research progress in drugs for anti-hepatic fibrosis / 药学学报

Hepatic fibrosis is an important pathological process in the development of liver cirrhosis and liver cancer from chronic liver damage. So far there is no effective chemical drug in clinic for treatment of hepatic fibrosis. Therefore, the research in anti-hepatic fibrosis drugs is a hot topic. For drugs currently under research and development, most of the mechanisms of action are related to inhibition of factors that could cause or deteriorate liver fibrosis, including activation and proliferation of hepatic stellate cells, inflammation, oxidative stress and production of extracellular matrix, et al. In this review, we briefly analyze targets and drugs related to the mechanisms mentioned above in order to provide a reference to the future research and development of anti-hepatic fibrosis drugs.