Abstract
INTRODUCTION: Stevia rebaudiana extract (SREC), primarily composed of chlorogenic acid and its analogues, is a promising feed additive with potential benefits for livestock performance, gut health, and antioxidant capacity. However, its safety evaluation has not been comprehensively studied. METHODS: The safety of SREC was assessed through a series of tests, including acute oral toxicity in mice and rats, a 90-day subchronic toxicity test in rats, genotoxicity assays (Ames test, mouse bone marrow micronucleus test, and mouse sperm abnormality test), and teratogenicity evaluation in pregnant rats. RESULTS: The acute oral toxicity test indicated that the LD₅₀ of SREC in mice and rats was greater than 5,000 mg/kg body weight. In the 90-day subchronic toxicity test, SREC was non-toxic at doses up to 50,000 mg/kg in feed. The Ames test showed no mutagenic effects on Salmonella typhimurium strains TA(97), TA(98), TA(100), and TA(102). No genotoxicity was observed in the mouse bone marrow micronucleus test or the sperm abnormality test, with no significant differences compared to controls (p > 0.05). Similarly, no teratogenic effects were found in pregnant rats, with normal embryonic development across treatment and control groups. DISCUSSION: SREC exhibited low toxicity in both acute and subchronic tests, and no evidence of genotoxicity or teratogenicity was observed. These findings suggest that SREC is safe as a potential feed additive and provide valuable reference data for its safety evaluation.