Tanshinol alleviates ulcerative colitis by promoting the expression of VLDLR

Tanshinol (TAN) is a widely used Chinese medicine ingredient with anti-inflammatory activity. The therapeutic effect of TAN in ulcerative colitis (UC) deserves further investigation. DSS induced UC model for mice, and TAN of different concentrations was used for in vivo therapy. Colons length was measured; expression of VLDLR in colonic mucosal tissue was evaluated by qRT-PCR, Western blot and histochemical staining. Besides, normal colorectal mucosal cell line (FHC) was treated with LPS to imitate the inflammatory process of UC in vitro. Different concentrations of TAN treated UC cell model. ELISA and qRT-PCR were applied to examine the concentrations of inflammatory cytokines (TNF-α, IL-6, IL-8, or IL-1β). Flow cytometry and MTT was used to identify the apoptosis and viability of FHC cells, respectively. Afterwards, Western blot was performed to detect the expressions of Bax, Bcl-2, Cleaved caspase-3, and Cleaved caspase-9 in FHC cells. VLDLR was low-expressed in UC tissues as compared to the normal tissue. TAN could alleviate DSS-induced colons length shortening, colonic tissue structure destruction, inflammatory response, and VLDLR expression decrease in vivo. Further study found that TAN could alleviate LPS-induced inflammatory response, apoptosis, and viability decrease of FHC cells, and siVLDLR could partially offset the effect of TAN. TAN alleviates LPS-induced viability decrease, apoptosis, and inflammatory response in FHC cells by promoting VLDLR expression.