Sinomenine, an alkaloid extracted from Sinomenium acutum, is a blocker of the NF-κB activation^[1]. Sinomenine also is an activator of μ-opioid receptor^[2]. IC50 & Target: NF-κB^[1], μ-opioid receptor^[2] In Vitro: Cell viability gradually decreased with increasing Sinomenine concentration. The migration ability of MDA-MB-231 cells is significantly weakened by 0.25, 0.5, and 1 mM of Sinomenine treatment. The wound-healing assay reveals that 0.25 and 0.5 mM Sinomenine significantly suppress the healing of the wound. When the MDA-MB-231 cells are treated with 0.5 mM Sinomenine, the healing progress is about 50%, but in the group treated with 0.25 mM Sinomenine and the untreated control, the healing is about 80% and nearly 95%, respectively. The IB assay following inhibitor of NF-κB (IκB) antibody IP shows that the binding of NF-κB to IκB is inhibited by Sinomenine treatment in a dose-dependent manne^[1]. In Vivo: Sinomenine (i.p.) produces antinociception in the hot plate and tail flick tests in male rats at 40 mg/kg, but not at lower doses (10 or 20 mg/kg). At 10 to 40 mg/kg Sinomenine does not produce any observable side effect such as sedation, allergy or motor impairments. At 80 mg/kg, Sinomenine is mildly sedative in rats. Antinociception is also seen mice at 60 min following 80 mg/kg i.p. Sinomenine, but not at lower doses (20 or 40 mg/kg), in the tail flick test. Sinomenine at 80 mg/kg i.p. does not produce any observable side effects in mice. I.p or p.o. Sinomenine at 40 or 80 mg/kg dose-dependently reduces mechanical hypersensitivity in nerve injured mice. I.p. Sinomenine at 40 mg/kg, but not lower doses or vehicle, significantly decreases mechanical and cold allodynia for up to 240 min without producing motor deficits or sedation^[3]. At doses of 10 to 40 mg/kg, Sinomenine dose-dependently increases the paw withdrawal threshold. In non-chronic constriction injury (CCI) healthy rats, Sinomenine at the dose range of 10 to 40 mg/kg does not change the immobility behavior in the forced swimming test^[4].