Non-cytotoxic doses of shikonin inhibit lipopolysaccharide-induced TNF-α expression via activation of the AMP-activated protein kinase signaling pathway.
Exp Ther Med. 2020 Nov ;20(5):45. Epub 2020 Sep 3. PMID: 32952636
Shikonin has been reported to exhibit a wide variety of medical functions. However, the strong non-selective cytotoxicity of shikonin can restrict its clinical application. The aim of the present study was to investigate the effects of shikonin at non-cytotoxic doses on the pro-inflammation functions of monocytes and macrophages. The present results suggested that the non-cytotoxic doses of shikonin effectively inhibited lipopolysaccharide (LPS)-induced reactive oxygen species production, NF-κB activation and TNF-α expression in RAW 264.7 mouse macrophages via AMP-activated protein kinase (AMPK) signaling pathway. In addition, the non-cytotoxic doses of shikonin downregulated LPS-induced TNF-α expression via AMPK signaling activation in primary murine bone marrow-derived macrophages,and also in monocytes culturedfrom patients with chronic obstructive pulmonary disease (COPD). The presentresults indicated that the low-toxic dose of shikonin suppressed LPS-induced endotoxin shock and TNF-α expression in mice. Collectively, the present results may provide clinical and translational relevance for treating COPD and other TNF-α-related inflammatory disorders.