Acemannan stimulates GFs proliferation, KGF-1, VEGF expressions and wound healing

Gingival fibroblasts (GFs) play important role in wound healing. They proliferate and secrete several growth factors, such as KGF-1 and VEGF, to generate new tissue. Objectives: To investigate effects of acemannan, the polysaccharide extracted from Aloe vera gel, on GFs proliferation, KGF-1, VEGF expression, as well as, acemannan's effect on oral wound healing in rats. Methods: Cells were treated with different concentrations of acemannan (0.25, 0.5, 1, 2, 4, 8 and 16 mg/ml) for 24 hours. After that, [3H]-thymidine incorporation assay was performed to determine cell proliferation. KGF-1 and VEGF expressions were detected by ELISA. Punch biopsy wounds at hard palate of Sprague Dawley rats were evaluated for the effect of acemannan on oral wound healing. All treatments (normal saline, 0.1% triamcinolone acetonide, plain 1% Carbopol^®, Carbopol^® containing acemannan 0.5%, 1% and 2% (w/w)) were applied daily. Wounded areas and histological features were observed at day 7. Results: Acemannan at concentrations 2, 4, 8 and 16 mg/ml significantly induced cell proliferation (p<0.05). Acemannan at concentration 2-16 mg/ml and 8-16 mg/ml significantly stimulated KGF-1 and VEGF expressions, respectively (p<0.05). Wound healing of animals receiving Carbopol^® containing acemannan 0.5% (w/w) was significantly better than that of the animals receiving 0.1% triamcinolone acetonide, plain 1% Carbopol^® or normal saline (p<0.05). Conclusion: These findings suggest that acemannan plays significant roles in the oral wound healing process, at least, via the induction of fibroblast proliferation and stimulation of KGF-1 and VEGF expressions. This study was supported by Thai Government Research Fund 2005-2008 and the 90th Anniversary of Chulalongkorn University Fund (Ratchadaphiseksomphot Endownment Fund) 2007-2008.