Protecting effect of chitin and chitosan on experimentally induced murine candidiasis

Chitin and chitosan were found to exhibit a protective effect on mice administered these polysaccharides intraperitoneally against infection of the viable cells of Candida albicans NIH A-207 strain. A significant difference was observed between the protective effects of chitin and chitosan, i.e., chitin was much more effective than chitosan when the C. albicans cells were challenged via the intravenous route. In intraperitoneal inoculations of C. albicans cells, however, chitosan provided stronger resistance for mice than chitin. It has also been revealed that the number of polymorphonuclear leukocytes from circulating blood of chitin-administered mice increased remarkably compared with that of untreated and chitosan-treated mice, and that the increase of active oxygen-generating phagocytic cells was significant. On the other hand, the number of peritoneal exudate cells (PEC) and the amounts of active oxygen generated from these cells in chitosan-treated mice were larger than those of chitin-treated mice. However, candidacidal activities of PEC per fixed cell number in mice treated with chitin or with chitosan were almost the same and greater than those of untreated mice.