| ABSTRACT: Objective To evaluate the acute toxicity and genotoxicity of γ-polyglutamic acid(γ-PGA). Methods Acute toxicity was evaluated by oral gavage of γ-PGA at 10,000 mg/(kg·bw) to rats and mice using the limit test method, with observations of toxic signs and mortality; the 30-hour double gavage method followed by microscopic examination to quantify the frequency of micronucleated polychromatic erythrocytes in mouse bone marrow was employed to detect the micronucleus induction of γ-PGA; the plate incorporation method was utilized to enumerate revertant colonies of Salmonella typhimurium strains(TA97a, TA98, TA100, TA102 and TA1535) to assess the mutagenic potential of γ-PGA; a continuous 5-day gavage followed by microscopic analysis was conducted to analyze the number and frequency of chromosomal structural aberrations in mouse spermatocytes to evaluate the chromosomal aberration induction of γ-PGA. Results The maximum tolerated dose(MTD) of γ-PGA via acute oral administration to both male and female mice and rats was greater than 10,000 mg/(kg?bw). At a dose of 5,000 mg/(kg?bw), γ-PGA did not significantly increase micronucleated polychromatic erythrocytes in the bone marrow of either male or female mice（P>0.05）, nor did it induce chromosomal aberrations in primary spermatocytes of mice（P>0.05）. Additionally, at a dose of 5,000 μg per plate, no significant mutagenic activity was detected in the standard tested strains(TA97a, TA98, TA100, TA102, and TA1535), regardless of S9 activation. Conclusion Under the experimental conditions of this study, γ-PGA is classified as practically non-toxic and non-genotoxic, providing a toxicological basis for its development and application in the food industry. |
