Anti-Inflammatory Activity of Quercus infectoria, Glycyrrhiza uralensis, Kaempferia galanga and Coptis chinensis, the Main Components of Thai Herbal Remedies for Aphthous Ulcer

Abstract

Four medicinal plant powders (Quercus infectoria, Kaempferia galanga, Coptis chinensis and Glycyrrhiza uralensis) and one traditional Thai herbal recipe for aphthous ulcer were selected for the anti-inflammatory activity in vitro and skin irritation test in vivo. Among four plant powders, K. galanga, C. chinensis, and G. uralensis were inhibited IL-6 production with IC50 value of 0.04 ± 0.01, 0.07 ± 0.01 and 0.08 ± 0.01 μg/ml, respectively. Q. infectoria had lower anti-IL-6 activity with IC50 value of 0.31 ± 0.02 μg/ml. Those four plants also had anti-PGE2 activities but lower than the aphthous powder and aphthous gel. Whereas a traditional herbal recipe had significantly higher anti-inflammatory activity than each of the isolated plants by inhibit IL-6 and PGE2 production with IC50 value of 0.04 ± 0.01 and 0.08 ± 0.01 μg/ml, respectively. The anti-inflammatory activities were significantly higher than prednisolone and the COX-2 inhibitor. The plant powders and the herbal recipe had any growth inhibitory effect on the human gingival fibroblast cells even at the highest concentration. No sign of irritation was observed during the dermal irritation test with all experiments. Finally, the efficacy of anti-inflammation and safety of the medicinal plants and traditional Thai herbal remedy for aphthous ulcer treatment were evaluated by the scientific method.