(-)-Alkannin (Shikonin) is a natural red naphthoquinone pigment, has antimicrobial, anti-tumor, and anti-inflammatory effects; a purified shikonin preparation is widely used for the production of medicinals, cosmetics, and some food products; shikonin also enters into the antiinflammatory ointment and cream compositions used for the treatment of burns. It can suppress the cell viability, adhesion, invasion and migratory ability of MGC-803 cells through TLR2- or NF-κB-mediated pathway.

通过细胞划痕修复实验评估细胞迁移能力，采用Transwell实验评估细胞侵袭能力。使用Western blot和实时聚合酶链式反应（PCR）分析了蛋白质和mRNA的表达情况。Shikonin对MGC-803细胞的半抑制浓度（IC50）为1.854μm。Shikonin（1μm）显著抑制了MGC-803细胞的粘附、侵袭和迁移能力。有趣的是，Shikonin在有或无抗Toll样受体2（TLR2）抗体（2μg）和核因子-κB（NF-κB）抑制剂MG-132（10μm）的情况下，均可显著减少MGC-803细胞的这些能力，以及基质金属蛋白酶（MMP）-2、MMP-7、TLR2和p65 NF-κB的表达水平。此外，Shikonin与抗TLR2/MG-132的共孵化比单独使用抗TLR2或MG-132具有显著更强的活性。

Histamine release from basophils stimulated with anti-IgE antibody was analyzed fluorimetrically. Syk and Lyn kinase activities were tested in Vitro with recombinant proteins and analyzed by off-chip mobility shift assay. Shikonin dose-dependently inhibited the histamine release from basophils induced by anti-IgE antibody (IC50 = 2.6 +/- 1.0 microM; mean +/- SEM). A search for the target(s) of Shikonin in the signal cascade of IgE-mediated activation showed that it strongly inhibits Syk (IC50 = 7.8 microM, in the recombinant kinase assay), which plays a pivotal role in the degranulation response. A less significant inhibition was found for Lyn, which phosphorylates FcepsilonRI-betagamma subunits and also Syk.