Pharmacokinetics and safety evaluation of anemoside B4 in healthy Beagle dogs.

Background: Anemoside B4 (AB4), a pentacyclic triterpenoid saponin extracted from the traditional Chinese medicinal herb Methods: In the single-dose pharmacokinetic study, 40 dogs received subcutaneous AB4 at 10, 20, or 40 mg/kg, or an intravenous bolus at 20 mg/kg. Plasma concentrations were measured using a validated HPLC-MS/MS method to determine pharmacokinetic parameters, bioavailability, dose proportionality, and sex-related differences. In the repeated-dose study, 10 dogs received 20 mg/kg subcutaneously once daily for 7 consecutive days to evaluate drug accumulation and fluctuation. In the target animal safety study, 32 dogs were randomly assigned to receive 1× (20 mg/kg), 3× (60 mg/kg), or 5× (100 mg/kg) doses of AB4, and saline as a control, via daily subcutaneous injection for 7 days. Routine clinical examinations, hematology, serum biochemistry, gross necropsy, and histopathology were assessed. Result: AB4 exhibited rapid elimination, high absolute bioavailability, and dose-proportional pharmacokinetics in the 10-40 mg/kg range. No evidence of accumulation after repeated dosing. Within the dose range of 20-100 mg/kg, AB4 demonstrated good safety, with no observable toxicity or adverse effects. No significant effects were observed on physiological parameters. Histopathological analysis revealed no consistent or target-organ specific lesions. Discussion: These findings provide fundamental pharmacokinetic and safety data to support the rational clinical use of AB4 in veterinary medicine and lay the groundwork for future clinical applications.