Abstract: Objective To observe the acute toxicity and long-term toxicity that may occur in the body of 14-day-old SD rats after oral administration of different doses of sea-buckthorn syrup, and provide data on safety for a larger population that is eligible for sea-buckthorn syrup. Methods On the acute toxicity test, 14-day-old SD rats were given 30, 90, and 180 g·kg^-1·d^-1 sea-buckthorn syrup at a single oral dose, and the acute toxicity within 2 weeks of administration was observed. On the long-term toxicity test, 14-day-old SD rats were given 15 (low dose), 45 (medium dose), 90 (high dose)g·kg^-1·d^-1 sea-buckthorn syrup orally for 13 weeks before being allowed to recover for 4 weeks. The clinical symptoms, body weight, food intake, indicators of physiological development, indicators of FOB, learning and memory ability, organ weights and coefficients, hematology, coagulation, blood biochemistry, urine indicators, results of histopathological examinations were observed. Results On the acute toxicity test, the MTD of sea-buckthorn syrup for a single administration exceeded 180 g·kg^-1. On the long-term toxicity test, the NOAEL level of sea-buckthorn syrup was 90 g·kg^-1. Conclusion The decrease in weight and food intake of young rats is positively correlated with the dose of sea-buckthorn syrup, and large doses ( >180 g·kg^-1) should be avoided in clinical use.

Key words: sea-buckthorn syrup, acute toxicity test, long-term toxicity test, maximal tolerance dose（MTD）