Safety assessment of functional oligooctasaccharide riclinoctaose: A pilot study of genotoxicity, acute toxicity, and subchronic toxicity.

Riclinoctaose was produced by enzymatic hydrolysis of a succinoglycan-type exopolysaccharide riclin. It can be used as a prebiotic to regulate the composition of gut microbiota. Therefore, a safety evaluation is needed. Here, we reported the safety data generated on riclinoctaose. Standard in vitro genotoxicity tests such as the bacterial reverse mutation assay and in vivo micronucleus assay were performed and no mutagenic or clastogenic potential was found. In the acute toxicity study, ICR mice were administered with riclinoctaose via gavage in 14-day studies at the level corresponding to 3000 mg/kg BW/day. In the subchronic study, the diets containing 0%, 1.0%, 2.5%, and 5.0% of riclinoctaose (weight/weight) were prepared for ICR mice for 13 weeks. No test item-related adverse effects were observed in the acute and subchronic studies. No riclinoctaose-induced differences in the overall health, body weight gain, food and water consumption, hematology, blood chemistry, gross pathology, histopathology, or animal death were observed. A no-observed-adverse-effect level of 8842 mg/kg BW/day for male and 9230 mg/kg BW/day for female mice was identified for riclinoctaose when administered for 13 weeks. In conclusion, these findings demonstrated the safety of riclinoctaose and indicated the possibility that riclinoctaose may be used as a functional food. PRACTICAL APPLICATION: Functional oligosaccharide is a low-calorie sweetener, which is beneficial to human health. Dietary riclinoctaose can improve intestinal health and understanding the safety of riclinoctaose is the first step to evaluate its potential use in functional food. Therefore, genotoxicity, acute toxicity, and subchronic toxicity of riclinoctaose were studied.