Effects of Tilianin on Proliferation, Migration and TGF-β/Smad Signaling in Rat Vascular Smooth Muscle Cells Induced with Angiotensin II.

Flavonoid Tilianin was isolated from Dracocephalum moldavica, and its pharmacological mechanism on proliferation, migration and the TGF-β/Smad signaling pathway in rat vascular smooth muscle cells (VSMCs) induced with Angiotensin II (Ang II) was systematically evaluated. Primary rat VSMCs were stimulated with Ang II to induce proliferation. The cells were then treated with Tilianin for 24 or 48 h. MTT assay and Transwell assays were used to evaluate the effects of Tilianin on proliferation and migration. The expression of intracellular proliferating cell nuclear antigen (PCNA), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were measured by immunohistochemistry as verification of effects on proliferation and migration. The expression of TGF-β1, Smad2 and Smad3 mRNA was measured by qRT-PCR, and the expression of TGF-β1 and P-Smad2/3 protein was measured by Western blotting. The results show that Tilianin can inhibit proliferation and expression of intracellular PCNA in VSMCs induced with Ang II, in a dose-dependent manner. Tilianin also mediates a dose-dependent inhibition of migration and the expression of intracellular ICAM-1, VCAM-1, MMP-2 and MMP-9. Furthermore, TGF-β1, Smad2, Smad3, Smad2/3 and P-Smad2/3 in Ang II-induced VSMCs are suppressed by Tilianin. The inhibitory effects of Tilianin support its use in the suppression and treatment of atherosclerosis.