Ferulic Acid Groups Research Articles

Influence of interfacial properties on Ostwald ripening in crosslinked multilayered oil-in-water emulsions

The influence of interfacial crosslinking, layer thickness and layer density on the kinetics of Ostwald ripening in multilayered emulsions at different temperatures was investigated. Growth rates of droplets were measured by monitoring changes in the droplet size distributions of 0.5% (w/w) n-octane, n-decane, and n-dodecane oil-in-water emulsions using static light scattering. Lifshitz–Slyozov–Wagner theory was used to calculate Ostwald ripening rates. A sequential two step process, based on electrostatic deposition of sugar beet pectin onto fish gelatin or whey protein isolate (WPI) interfacial membranes, was used to manipulate the interfacial properties of the oil droplets. Laccase was added to the fish gelatin–beet pectin emulsions to promote crosslinking of adsorbed pectin molecules via ferulic acid groups, whereas heat was induced to promote crosslinking of WPI and helix coil transitions of fish gelatin. Ripening rates of single-layered, double-layered and crosslinked emulsions increased as the chain length of the n-alkanes decreased. Emulsions containing crosslinked fish gelatin–beet pectin coated droplets had lower droplet growth rates (3.1±0.3×10−26m3/s) than fish gelatin-stabilized droplets (7.3±0.2×10−26m3/s), which was attributed to the formation of a protective network. Results suggest that physical or enzymatic biopolymer-crosslinking of interfaces may reduce the molecular transport of alkanes between the droplets in the continuous phase.

Effects of Ferulic Acid Supplementation on Lipid Profiles, Oxidative Stress and Inflammatory Status in Hypercholesterolemic Subjects

Ferulic acid is the most abundant phenolic compound found in vegetables and cereal grains. In vitro and animal studies have shown that ferulic acid has anti‐hyperlipidemic, anti‐oxidative and anti‐inflammatory effects. The objective of this study was to investigate the effects of ferulic acid supplementation on lipid profiles, oxidative stress, LDL‐C oxidation and inflammatory status in hypercholesterolemia subjects. The study design was a randomized, double‐blind, placebo‐controlled trial. Volunteers with hypercholesterolemic were randomly divided into 2 groups. The treatment group (n = 24) was given ferulic acid and the control group (n = 24) was provided placebo 500 mg twice a day for 6 weeks. Ferulic acid supplementation demonstrated a statistically significant decrease of total cholesterol (8.1%), LDL‐C (9.3%), triglyceride (12.1%) and increase of HDL‐C (4.3%) compared with the placebo group. Ferulic acid also significantly decreased d‐ROMs (11.7%), MDA (24.5%) and increased BAP (11.8%), biomarkers of oxidative stress. Moreover, oxidized LDL‐C was significantly decreased in the ferulic acid group (7.1%) compared with the placebo group. In addition, ferulic acid supplementation demonstrated a statistically significant reduction of the inflammatory markers, hs‐CRP (32.66%) and TNF‐alpha (13.06%). These data suggest that ferulic acid supplementation could decrease the risk factors of cardiovascular disease. (Supported by National Research Council of Thailand)

Kinetics of Enzyme-Catalyzed Cross-Linking of Feruloylated Arabinan from Sugar Beet

Ferulic acid (FA) groups esterified to the arabinan side chains of pectic polysaccharides can be oxidatively cross-linked in vitro by horseradish peroxidase (HRP) catalysis in the presence of hydrogen peroxide (H(2)O(2)) to form ferulic acid dehydrodimers (diFAs). The present work investigated whether the kinetics of HRP catalyzed cross-linking of FA esterified to α-(1,5)-linked arabinans are affected by the length of the arabinan chains carrying the feruloyl substitutions. The kinetics of the HRP-catalyzed cross-linking of four sets of arabinan samples from sugar beet pulp, having different molecular weights and hence different degrees of polymerization, were monitored by the disappearance of FA absorbance at 316 nm. MALDI-TOF/TOF-MS analysis confirmed that the sugar beet arabinans were feruloyl-substituted, and HPLC analysis verified that the amounts of diFAs increased when FA levels decreased as a result of the enzymatic oxidation treatment with HRP and H(2)O(2). At equimolar levels of FA (0.0025-0.05 mM) in the arabinan samples, the initial rates of the HRP-catalyzed cross-linking of the longer chain arabinans were slower than those of the shorter chain arabinans. The lower initial rates may be the result of the slower movement of larger molecules coupled with steric phenomena, making the required initial reaction of two FAs on longer chain arabinans slower than on shorter arabinans.

Cross-Linking of Interfacial Layers Affects the Salt and Temperature Stability of Multilayered Emulsions Consisting of Fish Gelatin and Sugar Beet Pectin

This study assessed the stabilizing effect of enzymatic cross-linking on double-coated emulsions (beet pectin-fish gelatin). The beet pectin layer was cross-linked via ferulic acid groups using laccase (an enzyme that is known to catalyze the oxidation of phenolic groups). Fish gelatin-coated oil droplets (primary emulsion) were mixed at pH 3.5 to promote electrostatic deposition of the beet pectin molecules onto the surfaces of the oil droplets (secondary emulsion). Laccase was then added to promote cross-linking of the adsorbed beet pectin layer. Cross-linked pectin-coated oil droplets had similar or significantly better stability (p < 0.05) than oil droplets of primary or secondary emulsions to NaCl addition (0-500 mM), CaCl(2) addition (0-250 mM), and thermal processing (30-90 °C for 30 min). Freeze-thaw stability and creaming behavior of enzyme-treated, secondary emulsions after two cycles (-8 °C for 22 h; 25 °C for 2 h) were significantly improved (p < 0.05). These results may have important implications for food manufacturers that are in need of emulsions with improved physical stability, for example, emulsions used in frozen foods for sauces or dips.

2-deoxy-D-glucose combined with ferulic acid enhances radiation response in non-small cell lung carcinoma cells

Abstract The present study was undertaken to investigate the radiosensitizing effects of 2-deoxy-D-glucose (2DG), a glycolytic inhibitor, and ferulic acid (FA), a phenolic prooxidant, in relatively radioresistant human non-small cell lung carcinoma cells (NCI-H460). NCI-H460 cells were treated with 4 mM 2DG and/or 53.8 µM FA for 24 h and then exposed to 2 Gy irradiation. Compared to cells that were 2 Gy-irradiated alone (50%), FA and 2DG with radiation (FA+2DG+IR) showed additional decrease in cell viability (15%). This has been further validated by decreased (86%) colony formation in 2DG+FA+IR group compared to 2DG (29%), FA (24%) and IR (37%) group alone. Increased apoptotic cells (84%) in 2DG+FA+IR group further confirm the radiosensitizing property of 2DG or FA. In NCI-H460 cells 2DG decreased NADPH levels (10%) and FA increased ROS levels leading to enhanced oxidative damage in the 2DG+FA+IR group. This was reflected as altered mitochondrial membrane potential, increased lipid peroxidative markers (TBARS), DNA damage and decreased intracellular glutathione (GSH) levels in combined treatment groups when compared to radiation or 2DG or FA treatment alone. The present study suggests that FA and 2DG act by increasing oxidative damage in NCI-H460 cells.

Biochemical Characterization and Relative Expression Levels of Multiple Carbohydrate Esterases of the Xylanolytic Rumen Bacterium Prevotella ruminicola 23 Grown on an Ester-Enriched Substrate

We measured expression and used biochemical characterization of multiple carbohydrate esterases by the xylanolytic rumen bacterium Prevotella ruminicola 23 grown on an ester-enriched substrate to gain insight into the carbohydrate esterase activities of this hemicellulolytic rumen bacterium. The P. ruminicola 23 genome contains 16 genes predicted to encode carbohydrate esterase activity, and based on microarray data, four of these were upregulated >2-fold at the transcriptional level during growth on an ester-enriched oligosaccharide (XOS(FA,Ac)) from corn relative to a nonesterified fraction of corn oligosaccharides (AXOS). Four of the 16 esterases (Xyn10D-Fae1A, Axe1-6A, AxeA1, and Axe7A), including the two most highly induced esterases (Xyn10D-Fae1A and Axe1-6A), were heterologously expressed in Escherichia coli, purified, and biochemically characterized. All four enzymes showed the highest activity at physiologically relevant pH (6 to 7) and temperature (30 to 40°C) ranges. The P. ruminicola 23 Xyn10D-Fae1A (a carbohydrate esterase [CE] family 1 enzyme) released ferulic acid from methylferulate, wheat bran, corn fiber, and XOS(FA,Ac), a corn fiber-derived substrate enriched in O-acetyl and ferulic acid esters, but exhibited negligible activity on sugar acetates. As expected, the P. ruminicola Axe1-6A enzyme, which was predicted to possess two distinct esterase family domains (CE1 and CE6), released ferulic acid from the same substrates as Xyn10D-Fae1 and was also able to cleave O-acetyl ester bonds from various acetylated oligosaccharides (AcXOS). The P. ruminicola 23 AxeA1, which is not assigned to a CE family, and Axe7A (CE7) were found to be acetyl esterases that had activity toward a broad range of mostly nonpolymeric acetylated substrates along with AcXOS. All enzymes were inhibited by the proximal location of other side groups like 4-O-methylglucuronic acid, ferulic acid, or acetyl groups. The unique diversity of carbohydrate esterases in P. ruminicola 23 likely gives it the ability to hydrolyze substituents on the xylan backbone and enhances its capacity to efficiently degrade hemicellulose.

Stabilization of Soybean Oil Bodies by Enzyme (Laccase) Cross-Linking of Adsorbed Beet Pectin Coatings

Soybean oil bodies are naturally coated by a layer of phospholipids and oleosin proteins, which protect them from in vivo environmental stresses. When oil bodies are incorporated into food products, they encounter new environmental stresses such as changes in pH, ionic strength, and temperature. Consequently, additional protection mechanisms are often needed to stabilize them. The purpose of this study was to determine whether soybean oil bodies could be stabilized by coating them with a layer of cross-linked anionic polysaccharide (beet pectin). The beet pectin layer was cross-linked via its ferulic acid groups using laccase (an enzyme that catalyzes the oxidation of phenolic groups). Oil body suspensions were prepared that contained 1 wt % oil and 0.06 wt % beet pectin at pH 7 and were then adjusted to pH 4.5 to promote electrostatic deposition of the beet pectin molecules onto the surfaces of the oil bodies. Laccase was then added to promote cross-linking of the adsorbed beet pectin layer. Cross-linked pectin-coated oil bodies had similar or better stability than uncoated oil bodies to pH changes (3 to 7), NaCl addition (0 to 500 mM), and freeze-thaw cycling (-20 °C for 22 h; +40 °C for 2 h). These pectin-coated oil bodies may provide a convenient means of incorporating soybean oil into food and other products.

Anti-atherogenic property of ferulic acid in apolipoprotein E-deficient mice fed Western diet: Comparison with clofibrate

Anti-atherogenic effect of ferulic acid (0.02%, w/w) was investigated in comparison with the clofibrate (0.02%, w/w) in apolipoprotein E-deficient (apo E −/−) mice fed Western diet. Concentrations of total cholesterol (total-C), apolipoprotein B (apo B) in the plasma and epididymal adipose tissue weight were significantly lower in the ferulic acid and clofibrate supplemented groups compared to the control group. The ratio of apo B to apo A-I was also significantly lower in those groups than in the control group. Activities of hepatic ACAT and HMG-CoA reductase were only significantly lower in the ferulic acid and clofibrate groups, respectively than in the control group. The numbers of mice that exhibited aortic fatty plaque were 8/10 in control groups vs. 0/10 in the ferulic acid or clofibrate group. The activities of anti-oxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and paraoxonase) in the hepatocyte and erythrocyte were significantly higher in the ferulic acid group than in the control group. In contrast, hepatic TBARS level was only markedly lower in the ferulic acid group. These results provide a new insight into the anti-atherogenic property of ferulic acid in the apo E −/− mice fed a Western diet.

Novel Effects of a Single Administration of Ferulic Acid on the Regulation of Blood Pressure and the Hepatic Lipid Metabolic Profile in Stroke-Prone Spontaneously Hypertensive Rats

We studied the effects of a single oral administration of ferulic acid (FA) on the blood pressure (BP) and lipid profile in stroke-prone spontaneously hypertensive rats (SHRSP). Male 12-week-old SHRSP were administered FA (9.5 mg/kg of body weight) and distilled water as the control (C) (1 mL) via a gastric tube. The hypotensive effect of FA was observed at the lowest value after 2 h administration. A decrease in the angiotensin-1-converting enzyme (ACE) activity in the plasma corresponded well with the reduction of BP. Plasma total cholesterol and triglyceride levels were lower after 2 h administration. The mRNA expression of genes involved in lipid and drug metabolism was downregulated in the FA group. These results suggest that oral administration of FA appears beneficial in improving hypertension and hyperlipidemia.

Hypoglycemic Effects of a Phenolic Acid Fraction of Rice Bran and Ferulic Acid in C57BL/KsJ-db/dbMice

Rice bran contains many phenolic acids, the most abundant of which is the antioxidant, ferulic acid (FA). We evaluated the hypoglycemic effects of a phenolic acid fraction (the ethyl acetate fraction, EAE) of rice bran and of FA in C57BL/KsJ db/db mice. Type 2 diabetic mice were allocated to a control group, an EAE group, or an FA group. Animals were fed a modified AIN-76 diet, and EAE or FA was administered orally for 17 days. There was no significant difference in body weight gain between groups. Administration of EAE and FA significantly decreased blood glucose levels and increased plasma insulin levels. EAE or FA groups had significantly elevated hepatic glycogen synthesis and glucokinase activity compared with the control group. Plasma total cholesterol and low density lipoprotein (LDL) cholesterol concentrations were significantly decreased by EAE and FA administration. These findings suggest that EAE and FA may be beneficial for treatment of type 2 diabetes because they regulate blood glucose levels by elevating glucokinase activity and production of glycogen in the liver.

Bio-mimetic approach to improving emulsion stability: Cross-linking adsorbed beet pectin layers using laccase

The purpose of this study was to prepare and characterize stable oil-in-water emulsions containing oil droplets coated by multilayered biopolymer interfaces that were cross-linked by the enzyme laccase. Laccase is an enzyme that can cross-link ferulic acid groups present in beet pectin. Emulsions were prepared that contained 0.1 wt% corn oil, 0.05 wt% β-lactoglobulin, and 0.02 wt% beet pectin at pH 7. The emulsions were then adjusted to pH 4.5 to promote electrostatic deposition of the beet pectin molecules onto the surfaces of the protein-coated droplets. Laccase was then added to the emulsions to promote cross-linking of the adsorbed beet pectin molecules. We have shown that stable emulsions can be formed that are coated by cross-linked β-lactoglobulin–beet pectin interfaces, and that these emulsions have improved stability to NaCl addition over conventional one-layer or non-cross-linked two-layer emulsions.

Protective effect of ferulic acid on nicotine-induced DNA damage and cellular changes in cultured rat peripheral blood lymphocytes: A comparison with N-acetylcysteine

Nicotine is the major pharmacologically active substance in cigarette smoke and plays an important etiological role in the development of lung cancer. Incidence of cancer may be related to oxidative damage to host genome by nicotine. These oxidative actions may be modified by the phytochemicals present in food. The present study describes the protective effect of ferulic acid (FA), a naturally occurring nutritional compound on nicotine-induced DNA damage and cellular changes in cultured rat peripheral blood lymphocytes in comparison with N-acetylcysteine (NAC), a well-known antioxidant. One-hour exposure of lymphocytes to nicotine at the doses of 0.125, 0.25, 0.5, 1, 2, 3 and 4 mM induced a statistically significant dose-dependent increase in the levels of thiobarbituric acid reactive substances (TBARS), a lipid peroxidative marker and decrease in the levels of reduced glutathione (GSH), an important endogenous antioxidant. The lowest concentration eliciting significant damage was 1 mM nicotine and maximum damage was observed with 3 mM concentration. Hence, the test concentration was fixed at 3 mM nicotine. We have used 5 different doses of FA (10, 50, 100, 150 and 300 μM) and NAC (0.25, 0.5, 1, 2 and 4 mM) to test their protective effects. In all the groups, FA and NAC showed a dose-dependent inhibitory effect. Maximum protection was observed at the dose of 150 μM FA and 1 mM NAC. So, 150 μM FA and 1 mM NAC were used for further studies. There was a significant increase in the levels of lipid peroxidative index (TBARS and hydroperoxides (HP)), severity of DNA damage (evaluated by comet assay) in nicotine-treated group, which were significantly decreased in FA and NAC-treated groups. Nicotine treatment significantly decreased the endogenous antioxidant status viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), GSH, vitamin A, E and C. Co-administration of FA and NAC to nicotine-treated lymphocytes showed a significant increase in the antioxidant status. The protective effect of FA was merely equal to that of NAC effect. FA and NAC treatment alone did not produce any toxicity to the normal lymphocytes at their effective doses. On the whole, there is overwhelming evidence that FA has the ability to modulate DNA damage and a variety of cellular changes that occur during nicotine-induced toxicity in rat peripheral blood lymphocytes.

Elucidation of the Emulsification Properties of Sugar Beet Pectin

A protocol has been developed to fractionate sugar beet pectin using hydrophobic affinity chromatography. Three samples eluted from the column using 4 M NaCl as solvent (fractions 1A, 1B, and 1C), two fractions eluted using 2 M NaCl (fractions 2A and 2B), and one fraction eluted using water (fraction 3). The fractions were shown to be very polydisperse, and differences between the GPC refractive index and UV absorbance (214 nm) elution profiles demonstrated chemical heterogeneity. They were found to contain significantly different proportions of protein (1A, 2.79%; 1B, 0.97%; 1C, 0.77%; 2A, 1.41%; 2B, 5.09%; and 3, 5.89%) and ferulic acid (approximately 1A, 0.5%; 1B, 0.5%; 1C, 0.9%; 2B, 1.5%; and 3, 2%). The weight-average molecular mass, M(w), of the fractions also varied (1A, 153 kDa; 1B, 155 kDa; 1C, 306 kDa; 2A, 562 kDa; 2B, 470 kDa; 3, 282 kDa). Three fractions, that is, 1A, 1B, and 3, produced orange oil emulsions with a relatively small droplet size that were stable over a period of weeks. The other three fractions (1C, 2A, and 2B with higher M(w) values) produced emulsions with an initially larger droplet size, and the droplet size increased considerably over time. The increased droplet size may be influenced by the viscosity of the aqueous continuous phase. There was no simple relationship between protein or ferulic acid content and emulsification ability. For example, fraction 1B, which contained the lowest proportion of both protein and ferulic acid, produced stable emulsions of similar droplet size to fraction 3, which contained the largest proportion of protein and ferulic acid. The role of protein in the emulsification process was investigated by measuring the amount of protein in the aqueous phase before and after emulsification. It was clearly demonstrated that proteinaceous material adsorbed at the oil-water interface. It is evident that the emulsification properties of sugar beet pectin are influenced by the accessibility of the protein and ferulic acid groups to the surface of the oil droplets, the proportion of ester groups, and the molecular mass distribution of the fractions.

Goitrogenic activity of p-coumaric acid in rats.

The effects of three natural phenolic acids (caffeic, ferulic, and p-coumaric) on the rat thyroid gland were examined in a 3-week oral-treatment study. Forty male Wistar albino rats, divided into groups of 10 rats each and fed iodine-rich diet, were administered by gastrointestinal tube saline (control), caffeic acid, ferulic acid, or p-coumaric acid at a dose level of 0.25 micromol/kg/day for 3 weeks. The mean absolute and relative thyroid weights in caffeic, ferulic, or p-coumaric acid groups were significantly increased to 127 and 132%, 146 and 153%, or 189 and 201% compared to control value, respectively. Histological examination of the thyroids of p-coumaric acid group revealed marked hypertrophy and/or hyperplasia of the follicles. Caffeic or ferulic groups showed slight to moderate thyroid gland enlargement. Thyroid lesions in p-coumaric acid group were associated with significant increases in cellular proliferation as indicated by [(3)H]thymidine incorporation. In addition, the goitrogenic effect of p-coumaric acid was further confirmed by significant decreases (50%) in serum tri-iodothyronine (T(3)) and thyroxine (T(4)), and a parallel increase (90%) in serum thyroid stimulating hormone (TSH) compared to control group. These results indicate that administration of p-coumaric acid at relatively high doses induces goiter in rats.

Ferulic acid and diferulic acids as components of sugar-beet pectins and maize bran heteroxylans

Enzymatic hydrolysis of sugar-beet pulp, and subsequent isolation of feruloylated oligosaccharides, has shown that ferulic acid groups are ester-linked mainly on O-2 of arabinose residues and on O-6 of galactose residues in the pectin side-chains. After saponification of sugar-beet pulp enzymatic digests, dehydrodiferulic acids (0.14%, w/w) have also been identified and characterised as 8-5', 5-5', 8-8' and 8-O-4' isomers, suggesting that covalent cross-linking of pectic polysaccharides through diferulic bridges occurs in sugar-beet pulp. Feruloylated oligosaccharides from the side-chains of heteroxylans have been isolated from maize bran by acid hydrolysis. Ferulic acid is esterified on O-5 of arabinofuranose residues. 8-8', 8-5', 8-O-4' and 5-5' coupled dimers, which represent 2.5% (w/w) of the bran, have also been detected. It has been calculated that, in the cell wall, each heteroxylan macromolecule bore ∼ 75 esterified ferulic acid groups and could be cross-linked through ∼ 30 diferulic bridges. This result suggests a high degree of cross-linking of heteroxylans chains through ferulic acid in maize bran cell walls.