RESUMO
OBJECTIVE: In this study, chitosan/alginate-ellagic acid sustained-release microspheres were prepared, and the effect of sustained-release microspheres on preadipocyte adipogenic differentiation was analyzed. METHODS: Chitosan/alginate-ellagic acid microspheres were prepared and identified by scanning electron microscopy (SEM) and infrared spectroscopy (IR). The drug release rates were measured at pH 6.8, 7.0, 7.2, 7.4 to determine sustained release of ellagic acid from microspheres. The effects of 0.1, 1, 10 mg/L chitosan/alginate-ellagic acid microsphere on 3T3-F442A preadipocyte proliferation were determined by Methyl thiazolyl tetrazolium assay (MTT), and cell morphology was checked by hematoxylin/ eosin staining (HE staining). The effect of chitosan/alginate-ellagic acid microspheres on preadipocyte adipogenic differentiation was also determined by Oil red O staining, and lipogenesis was measured by isopropanol extraction. The molecular mechanism was investigated by detecting the mRNA expression of CCAAT/enhancer binding protein alpha (C/EBPα) and peroxisome proliferatorsactivated receptor gamma (PPARγ). RESULTS: Chitosan/alginate-ellagic acid sustained-release microspheres were successfully prepared, and the inhibition of proliferation and adipogenic differentiation of preadipocytes was found to be dosedependent. The mechanism of differentiation inhibition was found to be closely related to the expression of transcription factor C/EBPα and PPARγ. CONCLUSION: Chitosan/alginate can be used as a good material to prepare ellagic acid sustained-release microspheres, and these microspheres can be used for treating the obesity.
Assuntos
Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Alginatos/química , Diferenciação Celular/efeitos dos fármacos , Quitosana/química , Portadores de Fármacos/química , Ácido Elágico/farmacologia , Células 3T3 , Animais , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Ácido Elágico/administração & dosagem , Camundongos , Microesferas , PPAR gama/genética , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
OBJECTIVE: The optimum extraction of ursolic acid from Punica granatum peel by SFE-CO2 was investigated. METHODS: Based on the design of Plackett-Burman(PB), significant factors influencing the yield of ursolic acid in the operation process were filtered, with the extraction rate of ursolic acid as the index. The results obtained by steepest ascent method approximated the maximum area of ursolic acid yield. Then the Central Composite Design(CCD) design was used to carry on the response surface optimization of significant factors, getting a two order mathematical model affecting the ursolic acid yield, as well as the optimum process conditions. RESULTS: The best technological conditions of the extraction of ursolic acid from Punica granatum peel by SFE-CO2 were that the extraction temperature was 46. 29 °C, extraction time was 91. 6 min and the extraction pressure was 34. 49 MPa. Under the optimal conditions, verification test of ursolic acid yield was 12. 508 mg/g, approximating to the predicted value of 12. 645 mg/g. CONCLUSION: The PB test and CCD test design are combined to optimize the extraction process of ursolic acid from Punica granatum peel by SFE-CO2. The screening results are statistically significant and the process operation is feasible.