In vitro genotoxicity assessment and 28-day repeated dose oral toxicity study of steady-calcium formula in rats.

Steady-calcium formula (SCF), a functional food mixture with potential of joint care, contains five major ingredients. However, the uncertain cross-reactivity among these included ingredients cannot be excluded. Hence, it is important to ensure the safety of this mixture. In this study, the safety of SCF was evaluated through in vitro genotoxicity assessment and 28-day oral toxicity study in rats. The bacterial reverse mutation test and mammalian chromosome aberration test displayed that SCF did not induce mutagenicity and clastogenicity. The 28-day repeated dose assessment of SCF in rats revealed no mortality and adverse effects in clinical signs, body weight, urinalysis, hematology, organ weight, and histopathology at all treated groups. Although some significant changes were observed in food intake and parameters of serum biochemistry at the highest dose in males, they were not dose-related and considered to be within normal range. These findings indicate that SCF does not possess genotoxic potential and no obvious evidence of subacute toxicity. These results demonstrate for the first time that the genotoxicity and subacute toxicity for SCF are negative under our experimental conditions and the no observed adverse effect level (NOAEL) of SCF may be defined as at least 5470 mg/kg/day.