Safety evaluation of nano/sub-microsized lignan glycosides from sesame meal

Nanotechnology is an emerging field in the food industry, but the potential hazards and toxicities of nano-sized food ingredients are still not clear. The aim of this study was to evaluate the mutagenicity and oral toxicity of nano/submicro-sized ingredient, lignan glycosides from sesame meal (N-LGSM), prepared by a wet-milling method to reduce the average particle size to 189 nm. Genotoxicity assays including Ames test, chromosome aberration assay, micronuclei assay and a 28-day subacute oral toxicity assay were employed to evaluate the mutagenicity and oral toxicity. Results of the Ames test showed that neither lignan glycosides from sesame meal (LGSM) nor N-LGSM increased mutagenicity toward Salmonella typhimurium strains TA97, TA98, TA100, TA102 and TA1535. Furthermore, LGSM and N-LGSM were found to have no mutagenic effects on increasing chromosome aberrations in treated Chinese Hamster Ovary (CHO) cells and the number of micronuclei in mouse erythrocytes. Most importantly, in the 28-day subacute oral toxicity trial, the "no observed adverse effect levels" (NOAELs) of LGSM and N-LGSM were determined to be 1000 and 200 mg/kg/day, respectively for both male and female mice. In conclusion, the nano/submicrosizing process did not cause the mutagenicity and oral toxicity for LGSM, and therefore it is a safe processing method for sesame lignan glycosides.