Toxicity assessment of Gryllus bimaculatus (a type of cricket) glycosaminoglycan

We performed general toxicity studies of Gryllus bimaculatus (two-spotted cricket) glycosaminoglycan (GbG), including a single, 4-week repeated oral dose toxicity test in ICR mice, and short-term genotoxicity tests. The mutagenic potential of the purified GbG was non-genotoxic when it was evaluated using short-term genotoxicity tests, namely Ames, chromosome aberration (CA), and micronuclei (MN) tests. In Salmonella typhimurium and Escherichia coli assays, GbG did not produce any mutagenic response in the absence or presence of S9 mix with five bacterial strains (TA98, TA100, TA1535, TA1537, and WP2uvrA). Chromosome aberration test showed that GbG had no significant effect on Chinese hamster ovary (CHO) cells. In mouse micronuclei tests after twice oral treatments per day for two days, no significant alteration in the occurrence of micronucleated polychromatic erythrocytes was observed in ICR male mice intraperitoneally administered with GbG at doses of 15.63, 31.25, or 62.50 mg/kg. These results indicate that GbG has no mutagenic potential in these in vitro and in vivo systems. After GbG was orally administered at doses of 20, 40, 80, and 160 mg/kg for a single oral dose toxicity study and at 0, 40, 80, and 160 mg/kg bw/day for 4-week oral dose toxicity study, there were no observed clinical signs or deaths related to treatment in any group tested. Therefore, the approximate lethal oral dose of GbG was considered to be higher than 160 mg/kg in mice. Throughout the administration period, no significant changes in diet consumption, ophthalmologic findings, organ weight, clinical pathology (hematology, clinical chemistry, coagulation, and urinalysis), or gross pathology were detected. Microscopic examination did not identify any treatment-related histopathologic changes in organs of GbG-treated mice in the high dose group. These results indicate that the no-observed adverse effect level (NOAEL) of GbG is higher than 160 mg/kg bw/day in mice.