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

Gingival fibroblasts play an important role in the 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 proliferation, KGF-1, VEGF expressions in gingival fibroblasts and its 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 enzyme-linked immunosorbent assay (ELISA). Punch biopsy wounds at hard palate of Sprague Dawley rats were used to evaluated effect of acemannan on oral wound healing. Animals were divided into 6 groups of 5 animals each. In group 1, animals were topically treated with normal saline as negative control and group 2 were treated with Kenalog^® as reference treatment. In group 3, animals were treated with plain 1% Carbopol^®, mucoadhesive polymer. In group 4, 5 and 6, animals were received Carbopol^® containing acemannan 0.5%, 1% and 2% (w/w), respectively. All vehicles were applied daily and wound areas were observed at day 7. Results: From [³H]-thymidine incorporation assay, acemannan at concentrations 4, 8 and 16 mg/ml significantly induced cell proliferation (p<0.05). ELISA revealed acemannan at concentration 8 mg/ml significantly stimulated KGF-1 and VEGF expressions (p<0.05). The wound healing of animals received Carbopol^® containing acemannan 0.5% (w/w) were significantly better than the animals received Kenalog^® and plain 1% Carbopol^®(p<0.05). Conclusion: These findings suggest that acemannan plays a role 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 2004-2006.