ABSTRACT
Licorice (Glycyrrhiza) species have been widely used as a traditional medicine and a natural sweetener in foods. The 18ß-glycyrrhetinic acid (18ß-GA) is a bioactive compound in licorice that exhibits potential anti-cancer, anti-inflammatory, and anti-microbial activities. Many synthesized derivatives of 18ß-GA have been reported to be cytotoxic and suggested for the treatment of malignant diseases. In this study, we explored the possible pharmacological roles of an 18ß-GA derivative in skin biology using primary human dermal fibroblasts and HaCaT keratinocytes as cell models. We found that this 18ß-GA derivative did not cause cell death, but significantly enhanced the proliferation of dermal fibroblasts and HaCaT keratinocytes. A scratch wound healing assay revealed that the 18ß-GA derivative promoted the migration of fibroblasts. Due to the important role of aquaporin-3 in cell migration and proliferation, we also investigated the expression of aquaporin-3 and found this compound up-regulated the expression of aquaporin-3 in dermal fibroblasts and HaCaT keratinocytes. In dermal fibroblasts, the 18ß-GA derivative induced the phosphorylation of Akt, ERK, and p38. The inhibitor of Akt predominantly suppressed the 18ß-GA derivative-induced expression of aquaporin-3. Collectively, this compound had a positive effect on the proliferation, migration, and aquaporin-3 expression of skin cells, implying its potential role in the treatment of skin diseases characterized by impaired wound healing or dermal defects.
Subject(s)
Aquaporin 3/genetics , Dermis/cytology , Dermis/metabolism , Fibroblasts/drug effects , Fibroblasts/metabolism , Gene Expression Regulation/drug effects , Glycyrrhetinic Acid/analogs & derivatives , Aquaporin 3/metabolism , Cell Line, Tumor , Cell Movement/drug effects , Cell Movement/genetics , Cell Proliferation/drug effects , Cell Survival/drug effects , Glycyrrhetinic Acid/chemistry , Glycyrrhetinic Acid/pharmacology , Humans , Keratinocytes/drug effects , Keratinocytes/metabolism , Signal Transduction/drug effectsABSTRACT
The production of fatty acid methyl esters (FAMEs) by a two-step in-situ transesterification from two kinds of rice bran was investigated in this study. The method included an in-situ acid-catalyzed esterification followed by an in-situ base-catalyzed transesterification. Free fatty acids (FFAs) level was reduced to less than 1% for both rice bran A (initial FFAs content=3%) and rice bran B (initial FFAs content=30%) in the first step under the following conditions: 10 g rice bran, methanol to rice bran ratio 15 mL/g, H(2)SO(4) to rice bran mass ratio 0.18, 60 degrees C reaction temperature, 600 rpm stirring rate, 15 min reaction time. The organic phase of the first step product was collected and subjected to a second step reaction by adding 8 mL of 5N NaOH solution and allowing to react for 60 and 30 min for rice bran A and rice bran B, respectively. FAMEs yields of 96.8% and 97.4% were obtained for rice bran A and rice bran B, respectively, after this two-step in-situ reaction.
