To elucidate the anti-inflammatory activity of shikonin (active compound of "Shikon"), we analyzed its effects on the gene expression of lipopolysaccharide (LPS)-induced macrophages (PMA-differentiated THP-1 cells). Briefly, DNA microarray of >2 ribosomes-bound mRNAs (translatome) and gene ontology (GO) analyses were performed with cells treated with LPS alone (LPS), shikonin alone (S), or both (LPS&S) for 3 h. Genes with inflammation-linked GOs were analyzed at 1, 2, 3 h by reverse transcription-real time-PCR (RT-qPCR). In the LPS, S and LPS&S cells, upregulated probesets outnumbered downregulated ones (fold changes >1.4/<0.71 vs. control). Among genes changed by shikonin in the comparison of LPS&S vs. LPS cells, some examples with inflammation-linked GOs were CYBA (cytochrome b-245 α subunit, NADPH oxidase), eIF4E (eukaryotic translation initiation factor 4E) and GSK3B (glycogen synthase kinase-3β). They were most lowered at 2 h in LPS&S cells as compared to LPS cells (RT-qPCR). The data suggest shikonin influences key points controlling inflammation (e.g. translation, expression of O2--generating NADPH oxidase, etc.). Expression of key genes is under analysis by immunological methods.
