Chitosan preventive effects

Fig. 8. The preventive effects of chitosan on doxorubicin-induced gastrointestinal toxicity in sarcoma 180-beanng mice, a) small intestine weight b) sucrase activity in small intestinal mucosa.

Recently, attention has been paid to chitosan because of its favorable biological properties, such as biodegradabihty, biocompatibility, and nmi-toxicity, as weU as its physiochemical properties [2, 3]. Moreover, it has been reported that chitosan can accelerate gastric ulcer healing [4], that pretreatment with chitosan prevents ulcerogenic effect in rats [5], and that chitosan displays antimicrobial activity [6,7]. 

Chitosan freeze-dried fleeces support chondrocyte attachment and synthesis of extracellular matrix [344]. Chitosan was used to assist the spontaneous tissue repair of the meniscus [345]. The repair of the cartilage and the prevention of its degradation in osteoarthritis is, however, possible with the association of glucosamine sulfate salt and chondroitine sulfate, the latter being particularly effective [346]. 

Gastrointestinal toxicity and myelotoxicity are caused by the 5-FU after its phosphorylation in the digestive tract and bone marrow tissue. To clarify whether chitosan enhances the antitumor activity of 5-FU and prevents the side effects induced by 5-FU, we examined the antitumor activity and side effects, such as myelotoxicity, immimocompetent organ toxicity, and gastrointestinal toxicity of combined treatment with chitosan and 5-FU in sarcoma 180-beaiing mice. 

Chitosan may be considered as a dietary supplement for reducing body weight in humans. Industrial production of chitosan tablets (Muzzarelli et al., 2000) and chitosan dietary fibers (Hughes, 2002) has occurred. Furthermore, Schiller et al. (2001) reported that a rapidly soluble chitosan (LipoSan Ultra that has a higher density and solubility than chitosan itself) facilitated weight loss and reduced body fat. This effect was due to the fact that this chitosan was able to prevent dietary fat absorption in overweight and mildly obese individuals that consumed a high-fat diet. 

It is well known that dietary fat is not absorbed from the intestine unless it has been subjected to the action of pancreatic lipase [1], Previously, we found that basic proteins such as protamines, histones and purothionine inhibited the hydrolysis of triolein emulsified with phosphatidylcholine [2], The inhibition of hydrolysis of dietary fat may cause a decrease or delay in the intestinal absorption of fat and reduce blood chylomicron levels, an excess of which is known to induce obesity [3], Therefore, there was a possibility that inhibitory substances toward pancreatic lipase activity may prevent the onset of obesity induced by feeding a high fat diet to mice. Recently, we found that natural products such as tea saponin, platycodi radix saponin, chitin-chitosan and chondroitin sulfate inhibited the pancreatic lipase activity. In the following section, the anti-obesity effects of these natural products will be described in detail. 

In addition to its use as an effective antineoplastic agent, several studies have demonstrated that Taxol is highly effective in preventing restenosis after angioplasty or vascular injury. . The encapsulation of Taxol in polylactic acid microspheres within heparin-chitosan spheres has been shown to provide controlled release of Taxol and... 

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