Eleven known compounds were isolated from S. miltiorrhiza var. alba roots, and the structures of all compounds were elucidated by spectroscopic analysis and comparisons with reported data. Immune anti-inflammatory activities were assessed by the ability to inhibit the production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and interleukin (IL)-8 using enzyme-linked immunosorbent assay. Quantitative real-time polymerase chain reaction (qRT-PCR) was also used to compare the inhibitory effects of the compounds on TNF-α, IL-1β, and IL-8 mRNA expression with that of tanshinone IIA in lipopolysaccharide-stimulated THP-1 macrophages.
All tanshinones, except for compound 5, significantly inhibited the mRNA and protein expression of TNF-α, IL-1β, and IL-8, and their anti-inflammatory activities were stronger than that of tanshinone IIA. Compound 9 (5 μM) showed the highest inhibitory effects for TNF-α, IL-1β, and IL-8, at 56.3%, 67.6%, and 51.7%, respectively.
Ten of the 11 tanshinones were shown to have anti-inflammatory properties superior to those of TSIIA, and which significantly inhibited the expression of TNF-α, IL-1β, and IL-8. The present results provided a referential basis for explaining the use of S. miltiorrhiza var. alba root as a Chinese folk medicine for treating cardiovascular diseases associated with inflammation, and show the importance of trace constituents of this herb.