Abstract:

Abstract:Objective To studey the acute,accumulative and genetic toxicities of carboxymethyl chitosan-Ag+（CMCT-Ag+）in mice,and provide safety guarantee for its clinical application. Methods According to the requirements of The Procedures and Methods of Food Safety Evaluation on Toxicology,ICR mice (SPF) were randomly divided into control group(H₂O),CMCT-Ag+ and SCMC (or CTX) groups.Gastric perfusion (GF) was applied once in ICR mice with the dosage of 5 g?kg-1.14 d later,the LD50 of CMTC-Ag+ in mice was measured,and the organic impairments were evaluated by mice status as well as liver,spleen,and thymus indexes.For the other 14 d,GF was applied twice a day,with 4 h interval,in mice with the dosage of 10 g/kg.The maximum tolerance dosage of CMTC-Ag+ was measured.Then,GF was applied once a day with the LD50 dosage of 5 g/kg.20 d later,the fatality of mice was counted,the accumulation coefficient was calculated,and the organic impairments were evaluated by mice status as well as liver,spleen,and thymus indexes.Finally,GF was applied once in mice for two consecutive days with the CMCT-Ag+ concentrations of 1.25,2.50 and 5.00 g?kg-1.6 h later,the number of micronucleus in  polychromatic erythrocytes (PCE) of bone marrow of mice was counted.Results The LD50 of CMCT-Ag+ in mice was over 5 g/kg;the maximum tolerance dosage was 10.00 g/kg and the accumulation coefficient was more than 5,hence,CMCT-Ag+ could not impair the visceral organs of mice.The micronucleus rates  in 1.25,2.50 and 5.00 g/kg CMCT-Ag+ groups were 3.3‰,1.8‰,and 1.3‰,respectively;there was no significant difference between experimental groups and control group (P＞0.05).Conclusion CMTC-Ag+ exhibits neither toxicity nor mutagenic reaction.It can be used in clinic.

Key words: carboxymethyl chitosan-Ag+；toxicity;accumulation coefficient;micronucleus rate