Unconjugated
This study aimed to investigate the effects of paeoniflorin, the main active ingredient of the medicinal plant Paeonia lactiflora Pall., on the permeability of endothelial cells induced by lipopolysaccharide (LPS) and the underlying mechanisms. Human umbilical vein endothelial cells (HUVECs) were stimulated by LPS. Extravasated FITC-dextran reflecting permeability was assessed by multimode microplate reader, and the migration of bis-carboxyethyl-carboxyfluorescein acetoxy-methyl-labeled human acute monocytic leukemia cell line and leukemia cell line cells through HUVECs were analyzed by fluorescence microscopy. The phosphorylations of phosphatidylinositol 3-kinase (PI3K)/Akt, protein kinase C (PKC), and cofilin in HUVECs were assessed by western blotting, and the F-actin level was detected by laser scanning confocal microscopy. After LPS stimulation, inflammatory endothelial cells exhibited significantly increased permeability. Paeoniflorin (10, 30, and 100 μM) inhibited dextran extravasation and leukocyte migration through HUVECs induced by LPS in a concentration-dependent manner. Moreover, paeoniflorin was able to suppress the phosphorylations of PI3K/Akt, PKC, and cofilin, as well as F-actin reorganization in HUVECs induced by LPS. These findings revealed that paeoniflorin partly blocked LPS-induced endothelium permeability, supporting a new explanation for its anti-inflammatory effects.
Keloid is a specific skin scar that expands beyond the boundaries of the original injury as it heals. The invasive nature of keloid and notable migratory activity of fibroblasts are a hallmark, which distinguishes keloids from other common scars. Madecassoside, a triterpenoid saponin occurring in Centella asiatica herbs, possesses unique pharmacological properties to enhance wound-healing and diminish keloid formation. However, the effects of madecassoside on the formation of keloid scars have been poorly understood. Here, we focused on the potential of madecassoside on the migration of keloid-derived fibroblasts (KFs) and its mechanism. Primary KF, originating from human earlobe keloids, were purified and cultured, and then treated with madecassoside (10, 30, and 100μM). In both transwell migration assays and scratch-wound-closure assays, KF migration was considerably suppressed by madecassoside pretreatment. Furthermore, KFs treated with madecassoside showed decreased F-actin filaments, as revealed by fluorescein isothiocyanate (FITC)-phalloidin staining and confocal microscopy. By Western blot analysis, madecassoside was shown to remarkably attenuate the phosphorylation of cofilin, p38 MAPK and phosphatidylinositol-3-kinase (PI3K)/AKT signaling, but only exhibited a minor effect on MMP-13 and little effect on ERK1/2 phosphorylation. It was concluded that madecassoside could be of great use in the treatment and/or prevention of hypertrophic scars and keloids.