140 Alpha-Mangostin Inhibits Proliferation, Promotes Apoptosis, and Modulates Fibrotic Gene Expression in Normal and Keloid Fibroblasts In Vitro

Abstract

Abstract Introduction Keloids are disfiguring lesions that result from an abnormal wound healing process. Despite the availability of numerous therapeutic options, keloids remain challenging to treat and often recur after therapy. α-Mangostin, a natural xanthone isolated from the fruit of the Mangosteen tree, has been used for centuries in many Southeast Asian nations for medicinal purposes, and has gained attention more recently due to its anti-inflammatory, antimicrobial, and antioxidant properties, with numerous studies suggesting possible anticarcinogenic activities. Hypothetically, α-mangostin may have therapeutic value for keloid suppression. To investigate this hypothesis, the effects of α-mangostin on fibroblast proliferation, apoptosis, and gene expression in vitro were analyzed. Methods Dermal fibroblasts were isolated and cultured from normal human skin and excised keloid lesions (3 donors each), and were treated with multiple doses (0–10 µm) of α-mangostin in vitro. Proliferation was measured using an MTT assay, gene expression was measured using quantitative real-time PCR (qPCR), and protein levels in culture media were measured by enzyme-linked immunosorbent assay (ELISA). Apoptosis was assessed by measuring expression of C/EBP homologous protein (CHOP), which mediates endoplasmic reticulum stress-induced apoptosis, by qPCR. Results Dose-dependent decreases in proliferation of keloid and normal fibroblasts were observed following treatment with α-mangostin. The α-mangostin treated fibroblasts displayed significantly increased expression of CHOP, indicating increased apoptosis. In addition, numerous changes in gene expression were observed in α-mangostin-treated keloid fibroblasts, including decreased expression of collagen type I alpha 1 chain (COL1A1) and increased expression of matrix metalloproteinase 1 (MMP1), MMP3, and MMP13. Secretion of pro-collagen I was decreased, and secretion of MMP1 and MMP3 proteins were increased, in α-mangostin-treated fibroblasts. Conclusions The results suggest that α-mangostin may exhibit antiproliferative, proapoptotic, and antifibrotic activities in keloid and normal fibroblasts.