The Inhibitory Effect of Chitosan and SACCHACHITIN on the Growth of Propionibacterium acnes and the Activity of Lipase

• Main Authors: Wan-Ru Wang, 王婉如
• Other Authors: Ching-Hua Su Ph. D.
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/35559207284435161616

碩士 === 臺北醫學大學 === 醫學研究所 === 92 === Abstract Propionibacterium acnes ( P. acnes ) play an important role in the pathogenesis of acne vulgaris . Extracellular lipases produced by P. acnes in vivo act as key enzyme in the hydrolyzation pathway of native sebum triacylglycerols to glycerols and free fatty acids ( FFA ) The purpose of the study reported here was to investigate whether or not chitosan and SACCHACHITIN possessed the inhibitory potency on the growth of P. acnes and the activity of lipase. Putative lipase activity was detected by observation of the interactive precipitate between FFA and Victoria Blue B ( VBB ). Result of the investigation demonstrated the inhibitory effect of chitosan and SACCHACHITIN on the precipitate formation and the release of FFA. Meanwhile, the unreacted VBB in the culture broth could be a negative correlation index of lipase activity and P. acnes viability. The evaluation of minimum inhibitory concentration ( MIC ) revealed the dose-dependently inhibitory effect of chitosan on putative lipase activity, and the MIC was measured around 0.025% for chitosans of different molecular size.. Further investigation of lipase activity was detected by measuring the amount of oleic acid produced from triolein. The result suggested that all of high molecular weight chitosan, medium molecular weight chitosan, and low molecular weight chitosan possessed the potencies of significantly reducing the release of oleic acid. Among the chitosan samples tested, high molecular weight chitosan showed the most effective. Although the results showed significant inhibitory effect , there still lacked sufficient data to prove the inhibitory mechanism of chitosan on lipase activity. In addition, there was a probability that the inhibitory effect on lipase activity was based on the inhibitory effect on P. acnes viability. In order to determine whether chitosan possessed the inhibitory effect on P. acnes viability, MTT assay was performed. Results demonstrated that chitosan dose-dependently inhibited P. acnes viability. SACCHACHITIN was not suitable to evaluate its antimicrobial function by spectrophotography because of its poor solubility. However observation from the samples of 0.01% concentration and other qualitative analysis, also showed its antimicrobial potency in MTT assay. To repeat the confirmation assay system of lipase activity, we used oleic acid as a substitute for triolein and demonstrated the binding of Victoria Blue B to oleic acid, thus resulting in precipitate formation. Therefore, we proved that the unprecipitated VBB was a negative correlation index to lipase activity. For the detection of antimicrobial mechanism and pathway, the glycerol compensation assay was carried out by introducing glycerol into the culture broth containing chitosan. The result showed that glycerol was non-essential carbon/energy source in P. acnes nutrition. Altogether, these studies suggests that chitosan and SACCHACHITIN could inhibit the P.acnes viability and consequently inhibit the putative lipase activity in vitro,. therefore,chitosan or SACCHACHITIN may be a potential medicine in acne therapy