Absorption Rates and Mechanisms of Avenanthramides in a Caco-2 Cell Model and Their Antioxidant Activity during Absorption

Development and characterization of avenanthramide-loaded bilosomes: Bile salt-incorporated liposomes as a cholesterol substitute for enhanced oral delivery

Avenanthramide (AVN), a phenolamide unique to oats, offers health benefits but is limited in application due to poor solubility, instability, and low bioavailability. This study developed bilosomes (AOE-BL) by incorporating bile salts into liposomes (AOE-LP) as a cholesterol substitute to enhance the oral delivery of AVN-enriched oat extract (AOE). AOE-BL exhibited smaller particle sizes and higher encapsulation efficiency than AOE-LP. Both formulations significantly increased AVN solubility by 2.74-fold and 2.71-fold, respectively, compared to free AOE while preventing heat-induced degradation. AOE-BL demonstrated superior stability under acidic conditions, with less pronounced changes in particle size and zeta potential than AOE-LP. After in vitro digestion, AOE-BL achieved significantly higher bioaccessibility (77.31 ± 3.31 %) than AOE-LP (67.21 ± 2.37 %) and free AOE (55.69 ± 3.43 %). Cellular uptake studies in Caco-2 enterocytes revealed that bile salts enhanced intracellular uptake compared to cholesterol. These findings highlight the potential of AOE-BL as an effective oral delivery system for AVN.

Formation of polyphenol-based nanoparticles in dried hawthorn with enhanced cellular absorption over free polyphenols

Plant-derived nanoparticles are gaining attention for enhancing the delivery and bioavailability of bioactive compounds, though the mechanisms remain unclear. This study aims to investigate dried hawthorn-derived nanoparticles (DHNPs), focusing on their composition, molecular interactions and impact on polyphenol absorption. The results showed that DHNPs, averaging 275.7 nm, were primarily composed of polysaccharides and high content of polyphenolic compounds (∼25%), with covalent and non-covalent interactions forming between them. Saponification increased the polyphenol release, and metabolomics identified 252 polyphenolic compounds, with 195 showing a relative increase post-treatment, including caffeic acid and (-)-catechin. An in vitro intestinal absorption test using Caco-2 cell monolayer model demonstrated that DHNPs-bound polyphenols exhibited significantly higher permeability (27.90%) compared to free polyphenols (12.38%), indicating that endocytosis may serve as a potential pathway through which DHNPs enhance polyphenol absorption. This study provides new insights into the role of plant-derived nanoparticles contributing to bioactive compound delivery and bioavailability.

Antioxidant Properties of Postbiotics: An Overview on the Analysis and Evaluation Methods

Antioxidants found naturally in foods have a significant effect on preventing several human diseases. However, the use of synthetic antioxidants in studies has raised concerns about their potential link to liver disease and cancer. The findings show that postbiotics have the potential to act as a suitable alternative to chemical antioxidants in the food and pharmaceutical sectors. Postbiotics are bioactive compounds generated by probiotic bacteria as they ferment prebiotic fibers in the gut. These compounds can also be produced from a variety of substrates, including non-prebiotic carbohydrates such as starches and sugars, as well as proteins and organic acids, all of which probiotics utilize during the fermentation process. These are known for their antioxidant, antibacterial, anti-inflammatory, and anti-cancer properties that help improve human health. Various methodologies have been suggested to assess the antioxidant characteristics of postbiotics. While there are several techniques to evaluate the antioxidant properties of foods and their bioactive compounds, the absence of a convenient and uncomplicated method is remarkable. However, cell-based assays have become increasingly important as an intermediate method that bridges the gap between chemical experiments and in vivo research due to the limitations of in vitro and in vivo assays. This review highlights the necessity of transitioning towards more biologically relevant cell-based assays to effectively evaluate the antioxidant activity of postbiotics. These experiments are crucial for assessing the biological efficacy of dietary antioxidants. This review focuses on the latest applications of the Caco-2 cell line in the assessment of cellular antioxidant activity (CAA) and bioavailability. Understanding the impact of processing processes on the biological properties of postbiotic antioxidants can facilitate the development of new food and pharmaceutical products.

The transport of polyphenols from Camellia fascicularis in Caco-2 cells based on UPLC-ESI-MS/MS

Camellia fascicularis, as a food and medicinal plant, is rich in polyphenols. Herein, digestion samples (DS) of C. fascicularis polyphenols (CFPs) were metabolically analyzed based on their bidirectional translocation in Caco-2 cells using ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry. The results indicated that after DS transported via Caco-2 cell monolayer models nine polyphenol compounds in transit solution (TSB) from apical (AP) to basolateral (BL) side were upregulated, whereas seven in the transit solution (TSA) from BL to AP side were upregulated. In addition, 53 significantly different polyphenol compounds dominated by flavonoids were identified in the TSA vs. TSB groups, with a dominantly moderate degree of uptake. Among them, 40 polyphenol compounds were upregulated including eupatorin, 5,7,4'-trihydroxy-3,6,3',5'-tetramethoxyflavone, and jaceosidin-7-O-glucoside, which might exhibit active transport, whereas the remaining 13 were downregulated and might exhibit passive diffusive transport. This study offers a rationale that further explored the bioactive mechanisms of CFPs.

Novel Insight into the Composition Differences Between Buffalo and Holstein Milk and Potential Anti-Inflammation and Antioxidant Effect on Caco-2 Cells

Milk is one of the most common sources of nutrients in humans, however, the composition and healthy value of the milk derived from different animals are very different. Here, we systemically compared the protein and lipid profiles and evaluated the anti-inflammation and antioxidant effect of buffalo and Holstein-derived milk on Caco-2 cells. Results showed that 906 proteins and 1899 lipids were identified in the buffalo milk and Holstein milk samples including 161 significantly different proteins (DEPs) and 49 significantly different lipids. The DEPs were mainly enriched in defense response-related terms, while the differential lipids were mainly included in fat digestion and absorption and cholesterol metabolism pathways. In addition, the Caco-2 cells co-cultured with buffalo and Holstein milk components showed significant benefits in being resistant to LPS-induced inflammation stress and H2O2-induced ROS stress. The qRT-PCR and ELISA results showed that the expression of TNF-α, IL-1β, and IL-6 was significantly lower (p < 0.05) in the cells co-cultured with milk components. Further analysis showed that, after H2O2 treatment, the expression of keap1 and Nrf-2 in the Caco-2 cells co-cultured with milk components was significantly lower (p < 0.05). In addition, being co-cultured with milk components significantly decreased the SOD, MDA, CAT, and GSH-Px content (p < 0.05) in the Caco-2 cells induced by H2O2. This study provides a novel insight into the differences in proteins and lipids between buffalo milk and Holstein milk, and a reference understanding of the anti-inflammation and antioxidant effect of the consumption of milk on the intestines.

Oral sericin ameliorates type 2 diabetes through passive intestinal and bypass transport into the systemic circulation

ETHNOPHARMACOLOGICAL RELEVANCE

Boiled silkworm cocoons have been used to treat 'Xiaoke disease' (diabetes mellitus) recorded in Chinese medicine for over 800 years. In recent years, it has been found that the active substance silk sericin (SS) has therapeutic benefits in treating type 2 diabetes mellitus (T2DM). SS promotes pancreatic islet signalling, the proliferation of pancreatic islet cells, and insulin secretion. It is inferred that SS enters the bloodstream after oral administration and plays a role in the body's circulation. As a natural protein, SS needs to resist digestion by proteases in the gastrointestinal tract and cross the gastrointestinal barrier after oral administration. It is currently unclear how SS crosses the gastrointestinal barrier and whether it exerts therapeutic effects on T2DM by entering the circulation.

AIM OF THE STUDY

To study how SS crosses the gastrointestinal barrier and whether it enters the body circulation to exert a therapeutic effect on T2DM.

MATERIALS AND METHODS

SS was extracted from silkworm cocoons using an alkaline method with sodium carbonate. The antidigestive capacity of SS was detected using SDS-PAGE gel electrophoresis experiments. The mode of uptake and translocation of orally consumed SS in vivo was analysed using the AP-side to BL-side and BL-side-AP-side translocations, apparent Permeability coefficient (Papp), and Exocytosis rates (ER). The study compared the differences between the adSS group and the adSS + EDTA group by using Ethylenediaminetetraacetic acid (EDTA) to separate the tight junctions between Caco-2 cells. The aim was to analyze whether the transport mode of oral filaggrin proteins in vivo could be absorbed by bypass transport. By administering SS through oral and intraperitoneal injection to type 2 diabetic mice, we measured its concentration in the blood, as well as blood glucose and insulin levels, to determine its effectiveness in treating diabetes and its ability to enter the body's circulation for treatment.

RESULTS

The molecular weight of SS decreased from 10k∼25 kDa to 10k∼15 kDa after in vitro simulated gastrointestinal fluid digestion, indicating its good antidigestive properties. The apparent Papp was greater than 1 × 10-6 cm·s-1, and the ER was between 0.5 and 1.5, indicating that adSS was well-absorbed and mainly passively transported. The Caco-2 cell model showed that the addition of EDTA promoted the transport of adSS, resulting in significantly larger Papp and ER values, indicating that adSS was absorbed by bypass transport. After oral administration of SS, the concentration of SS in the blood was lower than after intraperitoneal injection, which is 60% of intraperitoneal administration. Mice with a T2DM model who were administered SS for 5 weeks showed significant improvement in insulin resistance and glucose tolerance. Additionally, the pancreatic tissue appeared more regular. In the treatment of T2DM, injections of SS have been shown to be more effective than oral administration. Both oral and intraperitoneal injections have been partially involved in the circulation.

CONCLUSIONS

SS is enzymatically cleaved by proteolytic enzymes in the gastrointestinal tract. The smaller molecules are partially absorbed into the body's circulation through passive and paracrine transport, exerting a therapeutic effect on T2DM.

Catechins and caffeine absorption, and antioxidant activity of tea-macerated wine in a Caco-2 intestinal cell culture model

A novel style of flavored wine was developed via infusion of either black tea or green tea into Chardonnay wine. The bioaccessibility and bioavailability of phenolic substances in green/black tea-infused Chardonnay wine were investigated. Catechin, caffeine, and epicatechin gallate, originating from the tea, displayed high absorption rates with apparent permeability coefficient values above 10 × 10-6 cm/s in a human Caco-2 intestinal cell model. A paracellular pathway was proposed to drive the transport of catechin and epicatechin gallate, while the possible transport pathway of caffeine is passive transcellular diffusion route. Co-supplementation of flavonoids of quercetin or naringenin (20 µM) could further enhance the uptake of catechin and epicatechin gallate, but reduce the absorption of caffeine. Great in vitro and cellular antioxidant capacities were witnessed in the tea-macerated wine samples. The wine samples also neutralized the negative impact of tert-butyl hydroperoxide (25 µM) on glutathione S-transferase and glutathione levels, apoptosis induction, and intracellular malondialdehyde levels. RNA sequencing with limma method revealed a total of 1473 and 406 differentially expressed genes in the 21-day-old Caco-2 intestinal cells treated with the green and black tea-macerated wines for 5 h respectively, indicating metabolic changes in the cells from the different wines.

The Bioaccessibility and Bioavailability of Pentachlorophenol in Five Animal-Derived Foods Measured by Simulated Gastrointestinal Digestion

Pentachlorophenol (PCP) is a ubiquitous emerging persistent organic pollutant detected in the environment and foodstuffs. Despite the dietary intake of PCP being performed using surveillance data, the assessment does not consider the bioaccessibility and bioavailability of PCP. Pork, beef, pork liver, chicken and freshwater fish Ctenopharyngodon Idella-fortified by three levels of PCP were processed by RIVM and the Caco-2 cell model after steaming, boiling and pan-frying, and PCP in foods and digestive juices were detected using isotope dilution-UPLC-MS/MS. The culinary treatment and food matrix were significantly influenced (p < 0.05) in terms of the bioaccessibility and bioavailability of PCP. Pan-frying was a significant factor (p < 0.05) influencing the digestion and absorption of PCP in foods, with the following bioaccessibility: pork (81.37-90.36%), beef (72.09-83.63%), pork liver (69.11-78.07%), chicken (63.43-75.52%) and freshwater fish (60.27-72.14%). The bioavailability was as follows: pork (49.39-63.41%), beef (40.32-53.43%), pork liver (33.63-47.11%), chicken (30.63-40.83%) and freshwater fish (17.14-27.09%). Pork and beef with higher fat content were a key factor in facilitating the notable PCP bioaccessibility and bioavailability (p < 0.05). Further, the exposure of PCP to the population was significantly reduced by 42.70-98.46% after the consideration of bioaccessibility and bioavailability, with no potential health risk. It can improve the accuracy of risk assessment for PCP.

Solubility-permeability interplay of a supersaturated lutein delivery system constructed by glycosylated stevioside and hydroxypropyl-methylcellulose

This study investigated the solubilizing capacity of glycosylated stevioside/hydroxypropyl-methylcellulose (stevia-G-HPMC) complexes with varying mass ratios on lutein. The impact on the steady-state flux and permeability coefficient of intracellular lutein was also explored through the construction of a Caco-2 cellular transport model. The results indicated that the equilibrium solubility of lutein linearly increased with an increase in stevia-G amount. The stability constants of the ternary system surpassed those of the binary system. Molecular dynamics simulation revealed a tight and stable structure in lutein supersaturated complexes. Meanwhile, lutein-stevia-G-HPMC complexes demonstrated superior cumulative penetrations, with the peak Papp (AP → BL) value being (3.24 ± 0.89) × 10-5 cm·s-1. There was a slight decrease in Papp (BL → AP), which improved the forward transport of lutein. Highly soluble lutein in aqueous environments saturated the extracellular transport proteins on the AP side of cell membranes, thereby maintaining the high permeability transport. Notably, the permeability trend of lutein in Caco-2 cells negatively correlated with the equilibrium solubility and matched the single exponential growth model. When the mass ratio of lutein, stevia-G and HPMC was 1:21:5, the solubility-permeability trade-off of lutein was effectively maintained.

Hypoglycemic effect and intestinal transport of phenolics-rich extract from digested mulberry leaves in Caco-2/insulin-resistant HepG2 co-culture model

Phenolics of mulberry (Morus alba L.) leaves (MLs) have potential anti-diabetic effects, but they may be chemically modified during gastrointestinal digestion so affect their biological activity. In this study, an in vitro digestion model coupled with Caco-2 monolayer and Caco-2/insulin-resistant HepG2 coculture model were used to study the transport and hypoglycemic effects of phenolics in raw MLs (U-MLs) and solid-fermented MLs (F-MLs). The results of LC-MS/MS analysis showed that the Papp (apparent permeability coefficient, 10-6cm/s) of phenolics in digested MLs ranged from 0.002 ± 0.00 (quercetin 3-O-glucoside) to 60.19 ± 0.67 (ferulic acid), indicating higher phenolic acids absorbability and poor flavonoids absorbability. The Papp values of phenolic extracts of F-MLs in Caco-2 monolayer were significantly higher (p > 0.05) than that of U-MLs. Digested phenolic extracts inhibited the activities of sucrase (60.13 ± 2.03 %) and maltase (82.35 ± 0.78 %) and decreased 9.28 ± 0.84 % of glucose uptake in Caco-2 monolayer. Furthermore, a decrease in the mRNA expression of glucose transporters SGLT1 (0.64 ± 0.18), GLUT2 (0.14 ± 0.02) and the sucrase-isomaltase (0.59 ± 0.00) was observed. In Caco-2/insulin-resistant HepG2 co-culture model, phenolic extracts regulated glucose metabolism by up-regulating the mRNA expressions of IRS1 (9.32-fold), Akt (17.07-fold) and GYS2 (1.5-fold), and down-regulating the GSK-3β (0.22-fold), PEPCK (0.49-fold) and FOXO1 (0.10-fold) mRNA levels. Both U-MLs and F-MLs could improve glucose metabolism, and the partial least squares (PLS) analysis showed that luteoforol and p-coumaric acid were the primary phenolics that strongly correlated with the hypoglycemic ability of MLs. Results suggested that phenolics of MLs can be used as dietary supplements to regulate glucose metabolism.

Formulation, Preparation, and Evaluation of Bifunctional Micelle with Glycyrrhizic Acid Containing Emodin for Toxicity Attenuation Application

OBJECTIVE

To prepare GA-Emo micelles and investigate the feasibility of using GA as both a bifunctional drug and carrier.

METHODS

The preparation of GA-Emo micelles was accomplished via the thin-film dispersion method with GA as the carrier. Size distribution, entrapment efficiency, and drug loading were used to evaluate the characteristics of micelles. The absorption and transport properties of the micelles in Caco-2 cells were investigated, while their pharmacodynamics in mice were preliminarily studied.

RESULTS

The optimal formulation featured a GA/Emo in weight ratio of 2:1 and an encapsulation efficiency of 23.68%. The optimized GA/Emo was characterized as small uniform spheres with an average micellar size of 168.64 ± 5.69 nm, a polydispersity index of 0.17 ± 0.01, and an electrically negative surface (-35.33 ± 0.94 mV). Absorption and transport experiments with Caco-2 cells showed that the absorption of GA-Emo micelles in small intestines was mainly passive transport, amid their transport volume being significantly higher than that of Emo monomer. The intestinal wall thickness of the GAEmo micelles group was significantly lower than that of the Emo group, which meant that the colonic toxicity of the micelles was lower than unincorporated Emo.

CONCLUSION

The advantages of GA as a bifunctional micelle carrier in formulation characters, drug release, and toxicity attenuation provide a new idea for the application of the GA of natural medicine in drug delivery for toxicity reduction.

Polyphenols in edible herbal medicine: targeting gut-brain interactions in depression-associated neuroinflammation

Supplementing with edible herbal medicine is an important strategy because of its role in nutrition. Many polyphenols, which are universal components in edible herbal medicines, have low bioavailability. Therefore, gut microbiota is a key determinant of polyphenol bioactivity. Polyphenols can alter the abundance of flora associated with neuroinflammation by reversing intestinal microbiota dysbiosis. Intestinal flora-mediated chemical modification of polyphenols can result in their conversion into active secondary metabolites. The current review summarizes the main edible medicines used in anti-depression and details the interactions between polyphenols and gut microbiota; in addition, it provides insights into the mechanisms underlying the possible suppression of neuroinflammation associated with depression, by polyphenols in edible herbal medicine. A better understanding of polyphenols with bioactivities that are crucial in edible herbal medicine may facilitate their use in the prevention and treatment of neuroinflammation associated with depression.

Cellular uptake, transport mechanism and anti-inflammatory effect of cyanidin-3-glucoside nanoliposomes in Caco-2/RAW 264.7 co-culture model

Cyanidin-3-glucoside (C3G), which is the widest and richest anthocyanin (ACN) found in the edible fruit and vegetables, has been illustrated to perform a wide range of bioactivities. Nanoliposomes can inhibit C3G degradation and enhance the absorption rate of C3G as tools for conveying materials to particular locations. This experiment aims to study the absorption, transport and anti-inflammatory effects of C3G nanoliposomes in Caco-2/RAW 264.7 co-culture model, which symbolizes an intestinal inflammation system. The results indicated that the uptake and transport of C3G nanoliposomes by Caco-2/RAW 264.7 co-culture model were concentration-dependent as well as affected by temperature (37 and 4°C) and endocytic inhibitors, which revealed C3G nanoliposomes penetrate cells via endocytosis. Moreover, compared with C3G, C3G nanoliposomes significantly decreased pro-inflammatory cytokine expression (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8), suggesting a stronger anti-inflammatory potential. Conclusively, the uptake of C3G nanoliposomes by Caco-2/RAW 264.7 co-culture model is mainly involved in macropinocytosis and endocytosis mediated by carrier protein (clathrin). C3G nanoliposomes may play a better role in the treatment of LPS-induced intestinal inflammation diseases.

The intestinal absorption mechanism of chicoric acid and its bioavailability improvement with chitosan

Chicoric acid (CA), an active phenolic acid of Echinacea purpurea (Linn.) Moench, has been demonstrated to exhibit antioxidative, antiviral and immunological activities. A prior study showed that CA is a water-soluble compound with low bioavailability. The current study was performed to study the intestinal absorption mechanism of CA and improve its bioavailability using natural biodegradable chitosan. A Caco-2 monolayer cell model was established to characterise the mechanisms involved in the intestinal absorption of CA. The bioavailability improvement of CA was studied in Sprague–Dawley rats after oral (20 mg/kg) administration of 0.5% chitosan. In vitro, the results showed that the absorption transport of CA was fairly poor, with Papp values of 8.2 × 10⁻⁸ to 2.1 × 10⁻⁷ cm/s in the absorption direction and 1.5 × 10⁻⁷ to 2.6 × 10⁻⁷ cm/s in the secretory direction. The permeability was increased by EDTA and chitosan in both directions. Moreover, the transport through the intestinal monolayer was H⁺ dependent, and P-glycoprotein and OATP2B1 transporters were involved in the intestinal transport of CA. In vivo, the absorption of CA was increased and accelerated with chitosan in rats because the bioavailability was 1.74-fold that of the prototype drug. The above mentioned results indicated that CA was a poor absorption drug and that paracellular and carrier-mediated trancellular transport both participated in its transport route. Chitosan is an excellent absorption enhancer for CA. The transport characteristics uncovered in this study lay the groundwork for further studies directed toward the development and utilisation of its new formulations.

Study on the intestinal permeability of lamivudine using Caco-2 cells monolayer and Single-pass intestinal perfusion

Background

The aim of this work is to investigate the intestinal permeability of lamivudine and explore its absorption mechanism.

Method

Caco-2 cells monolayer and single-pass intestinal perfusion (SPIP) were selected for the investigation of lamivudine under different conditions, such as different concentration, absorption time, bidirectional transportation, and transportation with efflux transporters inhibitor. The concentration of lamivudine both in Caco-2 cells monolayer samples and SPIP samples was detected by HPLC-UV. Then the permeability parameters were calculated.

Results

The established HPLC-UV method reach the requirements for detection. There is no statistically difference between absorption parameters of lamivudine both in Caco-2 cells monolayer and SPIP (P > 0.05) under different dose groups. After transportation with efflux transporters inhibitor, the efflux rate of lamivudine in three dose groups was significantly decreased from 2.67, 2.59 and 2.59 to 1.78, 1.61, and 1.81 respectively. Lamivudine exhibits an absorption mechanism of passive diffusion.

Conclusion

The absorption of lamivudine may be related to efflux transporters. In addition, lamivudine is a moderate-permeability drug in Biopharmaceutics Classification System.

Recent advance of <i>in vitro</i> models in natural phytochemicals absorption and metabolism

Natural phytochemicals absorption and metabolic process are mainly in the human gut. Simulating the absorption and metabolism of natural phytochemicals in vitro to predict the rate and degree of absorption of natural phytochemicals provides convenience for many researchers. However, in this process, many physiological factors <i>in vitro</i> are affected, such as stomach and intestinal juice composition, pH, intestinal transmission rate and so on. In recent years, the research methods have gradually improved to make these models more suitable for the natural phytochemicals absorption process, <i>in vitro</i> simulation models have become an essential means to study natural phytochemicals absorption. Therefore, this paper introduces the advantages and disadvantages of commonly used <i>in vitro</i> simulation models of natural phytochemicals absorption and metabolism, as well as briefly introduces the working principle of each model. To provide a theoretical basis for simulating natural phytochemicals absorption <i>in vitro</i> and development and utilization of natural phytochemicals.

Enhanced Lignanamide Absorption and Antioxidative Effect of Extruded Hempseed (Cannabis sativa L.) Hull in Caco-2 Intestinal Cell Culture

Despite the latest pursuit to discover novel phenolic compounds in hempseed and its biological properties, it remains a mystery whether they can be absorbed in the human body. Extrusion treatment and extraction of the free phenolic fraction significantly (p < 0.05) improved human Caco-2 intestinal cell absorption for hempseed hull lignanamides including cannabisin B (P_app value of 1.35 × 10^-5 ± 1.0 × 10^-6) as compared to the bound fraction of raw hull (P_app value of 2.82 × 10^-6 ± 5.2 × 10^-7). Co-supplementation of the flavonoid naringenin (20 μM) further improved these absorption rates. Higher cellular antioxidant activity was observed in the free extraction fractions. Treatment with the free phenolic fraction of extruded hempseed hull (100 mg/mL) alleviated tert-butyl hydroperoxide's (25 μM) negative effects on cell viability, intracellular malondialdehyde levels, apoptosis induction, glutathione S-transferase, and glutathione levels. RNA-sequencing with the limma method unveiled a total of 2795 differentially expressed genes in 21 day-old Caco-2 intestinal cells, suggesting the changes in cell metabolism after exposure to extruded hempseed hull extract. This study could promote the utilization of extrusion technology to improve the absorption and antioxidant capacities of bioactive phenolics in plant food processing byproducts.

Effect of extract from common oat on the antioxidant activity and fatty acid composition of the muscular tissues of geese

Among natural antioxidants, increasing attention is being drawn to avenanthramides - phenolic compounds of the common oat Avena sativa (Linnaeus, 1753). Research has shown that avenanthramides have much higher antioxidant activity than well-known bioflavanoids. Currently, a great deal of work is being conducted on the structure of these compounds and mechanisms of their effect on the organism of humans and animals. We explored the specifics of the influence of aqueous extract from A. satíva on the antioxidant activity and fatty acid composition of lipids of histologically similar tissues of geese with different levels of aerobicity (muscles of the stomach and cardiac muscle), dynamics of the birds’ live weight and pterylographic parameters under physiological loading by the development of contour and juvenile feathers. The addition of extract of oat to the diet of geese during growth of feathers was observed to increase the antioxidant activity of their tissues. Physiological loading related to the development of contour feathers in the examined tissues of geese significantly weakens as a result of selective inhibition of synthesis of unsaturated fatty acids, especially oleic acid, the content of which in 28-day old geese of the experimental group decreased by 31.7 in the cardiac muscle and 46.8 times in the stomach, compared with the control. Further changes in fatty acid composition were characterized by lower number of differences between the control and experimental groups. Increase in antioxidant activity in these tissues during development of juvenile feathers (day 49) occurs as a result of activation of alternative mechanisms of antioxidative protection, which take place with no significant changes in fatty acid composition. Furthermore, we determined that in the stomach and cardiac muscles of geese, the action of extract from common oat activated mechanisms of antioxidative protection, which increased the level of correlation between the changes in fatty acid composition. The study confirmed that the extract caused not only significant increase in the weight of geese at the end of the experiment, but also improved their pterylographic parameters. Therefore, it is practical to conduct similar studies on wild species of birds grown for hunting, because this process of development of feathers, particularly for such species of birds, is essential.

Characterization of DPP-IV Inhibitory Peptides Using an In Vitro Cell Culture Model of the Intestine

Here, we characterize the activities of two depeptidyl peptidase-IV (DPP-IV) inhibitory peptides, VLATSGPG and LDKVFER, using the Caco-2 monolayer model for the intestine. VLATSGPG and LDKVFR inhibited the DPP-IV in the cells via a mixed-type inhibition mode, with in situ IC₅₀ values of 207.3 and 148.5 μM, respectively. Furthermore, VLATSGPG and LDKVFR were transported intact across the cells, with P_app values of 2.41 ± 0.16 and 4.23 ± 0.29 × 10^-7 cm/s, respectively. Fragmented peptides were identified in the basolateral side of the membrane. Two of these, GPG and VLA, exhibited high inhibitory activities of 83.6 ± 3.3 and 58.5 ± 2.5%, respectively, at 100 μM concentration. Although 3 mM VLATSGPG and LDKVFR were transported across the epithelium in a concentration-dependent manner, their transport did not damage the tight junction proteins, ZO-1 and occludin. This study demonstrates that the two peptides potentially regulate DPP-IV activity in the intestine.

A systematic review of phytochemicals in oat and buckwheat

Consumption of oat and buckwheat have been associated with various health benefits that may be attributed to their nutritional composition. We performed a systematic review to evaluate the profile and quantity of bioactive compounds present in oat and buckwheat. Among 154 studies included in final analysis, 113 and 178 bioactive compounds were reported in oat and buckwheat, respectively. Total phytosterols, tocols, flavonoids and rutin content were generally higher in buckwheat, β-glucans were significantly higher in oat, while avenanthramides and saponins were characteristically present in oat. The majority of studies included in current review were published before 2010s. The heterogeneous methodological procedures used across the studies precluded our possibility to meta-analyse the evidence and raises the need for harmonization of separation and extraction methods in future studies. Our findings should further stimulate the exploration of metabolites related to identified phytochemicals and their roles in human health.