Antitumor activity of trewiasine in vitro and in vivo

Trewiasine (TWS) is a maytansinoid isolated from Trewia nudiflora seeds, a natural product from the Xishuangbanna area of China. This study demonstrates that TWS possesses a significant anti-tumor activity in vitro and in vivo. TWS 2.5-10 vg/(kg-d) x7 d ip prolonged the life-span of Ehrlich carcinoma and leukemia P388-bearing mice by 100-183% and 58-81%, respectively. The cure rate of TWS for leukemia P388-bearing mice was 56-75%. TWS lO-8-10-2 vg/ml inhibited the growth rate of P388 cultured cells remarkably. TWS inhibited the incorporation of [3H] leucine into cell protein with T/C% by 19-24%, but it had no significant effect on the incorporation of [3H]thymidine into DNA in cell culture.