ABSTRACT
OBJECTIVE@#To investigate the effect of ferulic acid, a natural compound, on pancreatic beta cell viability, Ca2+ channels, and insulin secretion.@*METHODS@#We studied the effects of ferulic acid on rat insulinoma cell line viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability assay. The whole-cell patch-clamp technique and enzyme-linked immunosorbent assay were also used to examine the action of ferulic acid on Ca2+ channels and insulin secretion, respectively.@*RESULTS@#Ferulic acid did not affect cell viability during exposures up to 72 h. The electrophysiological study demonstrated that ferulic acid rapidly and concentration-dependently increased L-type Ca2+ channel current, shifting its activation curve in the hyperpolarizing direction with a decreased slope factor, while the voltage dependence of inactivation was not affected. On the other hand, ferulic acid have no effect on T-type Ca2+ channels. Furthermore, ferulic acid significantly increased insulin secretion, an effect inhibited by nifedipine and Ca2+-free extracellular fluid, confirming that ferulic acid-induced insulin secretion in these cells was mediated by augmenting Ca2+ influx through L-type Ca2+ channel. Our data also suggest that this may be a direct, nongenomic action.@*CONCLUSION@#This is the first electrophysiological demonstration that acute ferulic acid treatment could increase L-type Ca2+ channel current in pancreatic β cells by enhancing its voltage dependence of activation, leading to insulin secretion.
Subject(s)
Rats , Animals , Insulin Secretion , Insulin/pharmacology , Insulin-Secreting Cells/metabolism , Coumaric Acids/metabolism , Calcium/metabolismABSTRACT
Background: Brettanomyces bruxellensis is an important spoilage yeast in the winemaking process. The capacity of this yeast to generate an undesired off-flavor constitutes a significant loss in the Chilean wine industry. Results: The proteomic profile of B. bruxellensis in the presence of p-coumaric acid was determined by 2D gel electrophoresis, gel image analysis and differential spot selection. A set of 41 proteins showed a differential accumulation of ±2 and a p-value <0.0001. The homology sequence analysis was performed using the databases available. Differential proteins belonged to the categories of 'energy production and conversion' and 'amino acid transport and metabolism'. Conclusions: The proteomic profile of B. bruxellensis cultivated in the presence of p-coumaric acid in synthetic wine, agrees with the hypothesis of metabolic flux regulation, allowing a better conditioning to an adverse environment. This study involved the translational level of B. bruxellensis in the production of ethylphenols and corroborated that this yeast presented an advantage in these stress conditions. Thus, this work will allow an understanding of the regulation and processes involved in the production of ethyl-derivate compounds by B. bruxellensis. Furthermore, it allows the development of newer and better techniques for spoilage yeast control.
Subject(s)
Wine , Coumaric Acids/metabolism , Proteome , Brettanomyces/metabolism , Phenols , Yeasts , Electrophoresis, Gel, Two-Dimensional , Electrophoresis , Wine IndustryABSTRACT
Two mesophilic streptomycetes (S. violaceoruber and S. spiroverticillatus) were selected to study their Poly R-478 decolorization ability and lignocellulose solubilizing activity. Both strains were able to degrade Poly R-478 dye and ferulic acid during growth on a minimal salts medium. The Poly R-478 decolorizing activities of both strains were induced by adding different carbon sources to the culture media. S. violaceoruber could decolorize 63% of Poly R-478 after 24 h. Both strains could solubilize straw and produce acid-precipitable polymeric lignin (APPL) with different efficiency. From the major extracellular enzymes recovery of both strains on rice and wheat straw, we can predicate that the biodegradation process was partial indicating a possible utilization in biological delignification.