Tetrandrine

Tetrandrine (NSC-77037; d-Tetrandrine) is a bis-benzyl-isoquinoline alkaloid, which inhibits voltage-gated Ca²⁺ current (ICa) and Ca²⁺-activated K⁺ current. IC50 & Target:Ca²⁺ current^[1]
K⁺ current^[1] In Vitro: The effects of Tetrandrine (NSC-77037), a bis-benzyl-isoquinoline alkaloid, on voltage-gated Ca²⁺ currents (ICa) and on Ca²⁺-activated K⁺ current (IK(Ca)) and channels in isolated nerve terminals of the rat neurohypophysis are investigated using patch-clamp techniques. The non-inactivating component of ICa is inhibited by external Tetrandrine (NSC-77037) in a voltage- and dose-dependent manner, with an IC₅₀=10.1μM. Tetrandrine (NSC-77037) decreases the channel-open probability, within bursts, with an IC₅₀=0.21 μM^[1]. To evaluate the effects of Tetrandrine on HCC cells, Huh7, HCCLM9 and Hep3B cells are treated with 0 (DMSO), 0.5, 1, 2 or 4 μM of Tetrandrine for 24 h. The cell proliferation assay indicates that Tetrandrine exhibits almost no effect on the inhibition of HCC cell proliferation at 0.5-2 μM. However, Tetrandrine (NSC-77037) inhibits HCC cell migration in a dose-dependent manner. Furthermore, a wound-healing and transwell assay shows that 2 μM Tetrandrine significantly inhibits HCC cell migration and invasion^[2]. In Vivo: To evaluate the effect of Tetrandrine (NSC-77037) on the inhibition of tumor metastasis in vivo, HCCLM9 subcutaneous tumor xenograft models is established with athymic nude mice. When the tumor volume reach approximately 50 mm³, nude mice are orally administered vehicle or Tetrandrine (NSC-77037) (30 mg/kg) every other day for 37 days. Tetrandrine (NSC-77037) treatment inhibits tumor growth by reducing the tumor volume and weight^[2].