Tanshinone IIA attenuates LPS-induced HUVECs injury by inhibiting the NF-κB signaling pathway

Background: Currently, atherosclerosis (AS) is generally considered to be a chronic inflammatory response. Tanshinone IIA (TSIIA) is the most important bioactive lipophilic isolated from danshen, and its pharmacological effects have been generally recognized, including its anti-atherosclerosis effects. However, the mechanism of action of TSIIA in the amelioration of AS has not yet been identified. Methods: First, LPS was used to build a human umbilical vein endothelial cell (HUVECs) inflammatory model. Cultured HUVECs were seeded and preincubated with 2.5 mu M TSIIA for 2 h followed by stimulation with 2.0 mu g/mL LPS at 37 degrees C for 12 h. With that, the MTT method was used to determine the effects of LPS and TSIIA on cell cytotoxicity. The protein levels of cytokine TNF-alpha, IL-1 beta, IL-6, and IL-8 in were determined by ELISA. The total NO production in the supernatants was estimated by using a nitric oxide (NO) assay kit. The adhesive ability of HUVECs to monocytes (THP-1 cells) was analyzed using a cell adhesion assay. RT-qPCR, Western blot and flow cytometry were used to determine the expressions of the different levels of VCAM-1 and ICAM-1 in HUVECs. Western blot was used to analyze the activity of the NF-kappa B transcription factor. Results: In this study, a significant inhibition of HUVECs viability exposed to 2.0 mu g/mL LPS and an obvious relief after the use of 2.5 mu M TSIIA were emphasized. Furthermore, TSIIA inhibited the expressions of the inflammatory factors (TNF-alpha, IL-1 beta, IL-6), chemokine (IL-8) and adhesion molecules (VCAM-1 and ICAM-1) and suppressed the adhesion of monocytes (THP-1 cells) to HUVECs in LPS-stimulated HUVECs. Remarkably, like the NF-kappa B inhibitor PDTC, TSIIA also attenuates the activity of the NF-kappa B signaling pathway effectively, as mainly reflected in the decreased expression of phosphorylated p65 and IKB alpha. Conclusion: The protective effects of TSIIA on LPS-stimulated HUVECs injury, including promoting viability, anti-inflammation, and anti-adhesion, are likely mediated through the suppression of the NF-kappa B pathway.