Figure 1.

Cytotoxic profile of shikonin in RAW 264.7 mouse macrophages. (A) Chemical structure of shikonin. RAW 264.7 cells were treated with the indicated doses of shikonin for 24 h, the survival rates of cells were evaluated by (B) MTT assay and the death rates of cells were assessed using a (C) trypan blue exclusion assay. Cell apoptosis was assessed by (D) flow cytometry analysis and (E) TUNEL staining. Magnification, x100. (F) Contents of TNF-α in culture medium were examined by ELISA assay. ^*P<0.05 vs. control group. C, control; TNF-α, tumor necrosis factor α.