EFFECTS OF CHITIN AND CHITOSAN PARTICLES ON BALB C MICE BY ORAL AND PARENTERAL ADMINISTRATION/

Chitin and chitosan were administered orally and parenterally into mic e and their toxicity was investigated. When 5 mg of chitin were inject ed intraperitoneally every 2 weeks over a 12-week period, the mice wer e apparently normal, but histologically, many macrophages with hyperpl asia were observed in the mesenterium and foreign-body giant-cell-type polykaryocytes were observed in the spleen. The polykaryocytes were a lso observed in the spleen of the mice injected subcutaneously with 5 mg of chitin, but no other changes were observed. When 5 mg of chitosa n were injected intraperitoneally, the body weights of the mice decrea sed significantly and inactivity was observed in the fifth week. Histo logically, many macrophages with hyperplasia were observed in the mese nterium. Subcutaneous injection of 5 mg of chitosan did not evoke the general and cellular abnormalities. Oral administration of 5% chitosan via a casein diet caused mouse body weights to decrease and also decr eased the number of Bifidobacterium and Lactobacillus in normal flora of the intestinal tract. These results indicate that special care shou ld be taken in the clinical use of chitin and chitosan over a long tim e period. (C) 1997 Elsevier Science Limited.