Aqueous and Alcoholic Extracts of Triphala and Their Active Compounds Chebulagic Acid and Chebulinic Acid Prevented Epithelial to Mesenchymal Transition in Retinal Pigment Epithelial Cells, by Inhibiting SMAD-3 Phosphorylation

作者：Sivasankar, Shanmuganathan; Lavanya, Ramu; Brindha, Pemaiah; Angayarkanni, Narayanasamy^*

来源：PLos One, 2015, 10(3): e0120512.

DOI：10.1371/journal.pone.0120512

• PROLIFERATIVE VITREORETINOPATHY
• MATRIX-METALLOPROTEINASE
• DIABETIC-RETINOPATHY
• RISK-FACTORS
• EXPRESSION
• GROWTH
• RPE
• ANTIOXIDANTS
• FORMULATION
• DETACHMENT

Epithelial to Mesenchymal Transition (EMT) of the retinal pigment epitheliumis involved in the pathogenesis of proliferative vitreoretinopathy (PVR) that often leads to retinal detachment. In this study, Triphala, an ayurvedic formulation and two of its active ingredients, namely chebulagic acid and chebulinic acid were evaluated for anti-EMT properties based on in vitro experiments in human retinal pigment epithelial cell line (ARPE-19) under TGF beta 1 induced conditions. ARPE-19 cells were treated with TGF beta 1 alone or co-treated with various concentrations of aqueous extract (AqE) (30 - 300 mu g/ml); alcoholic extract (AlE) (50 -500 mu g/ml) of triphala and the active principles chebulagic acid (CA) and chebulinic acid (CI) (CA, CI: 50 -200 mu M). The expression of EMT markers namely MMP-2, alpha SMA, vimentin and the tight junction protein ZO-1 were evaluated by qPCR, western blot and immunofluorescence. The functional implications of EMT, namelymigration and proliferation of cells were assessed by proliferation assay, scratch assay and transwell migration assay. AqE, AlE, CA and CI reduced the expression and activity of MMP-2 at an ED50 value of 100 mu g/ml, 50 mu g/ml, 100 mu M and 100 mu M, respectively. At these concentrations, a significant down-regulation of the expression of alpha SMA, vimentin and up-regulation of the expression of ZO-1 altered by TGF beta 1 were observed. These concentrations also inhibited proliferation and migration of ARPE-19 cells induced by TGF beta 1. EMT was found to be induced in ARPE-19 cells, through SMAD-3 phosphorylation and it was inhibited by AqE, AlE, CA and CI. Further studies in experimental animals are required to attribute therapeutic potential of these extracts and their active compounds, as an adjuvant therapy in the disease management of PVR.

• 出版日期2015-3-20