Shikonin is a
naphthoquinone pigment isolated from the root of Lithospermum erythrorhizon, which has displayed potent anti-
tumor properties. However, the effects of
shikonin in
colorectal cancer cells have not been yet fully investigated. In this study, we demonstrated that
shikonin significantly inhibited the activity of
colorectal cancer cells in a time- and dose-dependent manner. The flow cytometry and western blot results indicated that
shikonin induced cell apoptosis by down-regulating BCL-2 and activating
caspase-3/9 and the cleavage of PARP. The expression of BiP and the PERK/elF2α/ATF4/CHOP and IRE1α /JNK signaling pathways were upregulated after
shikonin treatment. The pre-treatment with N-acetyl
cysteine significantly reduced the cytotoxicity of
shikonin. Taken together,
shikonin could inhibit proliferation of the
colorectal cancer cell through the activation of ROS mediated-ER stress. The in vivo results showed that
shikonin effectively inhibited
tumor growth in the HCT-116 and HCT-15 xenograft models. In conclusion,
shikonin inhibited the proliferation of
colorectal cancer cells in vitro and in vivo and warrants future investigation.