Tracheloside, a natural product isolated and purified from the herbs of Trachelospermum jasminoides (Lindl.) Lem., significantly decreases the activity of alkaline phosphatase (AP), an estrogen-inducible marker enzyme, with an IC50 value of 0.31 mg/mL, a level of inhibition comparable to that of tamoxifen (IC50 = 0.43 mg/mL).