Bioactivity Of Phenolic Compounds Research Articles

Extraction, Characterization, and Bioactivity of Phenolic Compounds—A Case on Hibiscus Genera

Phenolic compounds have recently gained interest, as they have been related to improvements in health and disease prevention, such as inflammatory intestinal pathologies and obesity. However, their bioactivity may be limited by their instability or low concentration in food matrices and along the gastrointestinal tract once consumed. This has led to the study of technological processing with the aim of optimizing phenolic compounds' biological properties. In this sense, different extraction systems have been applied to vegetable sources for the purpose of obtaining enriched phenolic extracts such as PLE, MAE, SFE, and UAE. In addition, many in vitro and in vivo studies evaluating the potential mechanisms of these compounds have also been published. This review includes a case study of the Hibiscus genera as an interesting source of phenolic compounds. The main goal of this work is to describe: (a) phenolic compound extraction by designs of experiments (DoEs) applied to conventional and advanced systems; (b) the influence of the extraction system on the phenolic composition and, consequently, on the bioactive properties of these extracts; and (c) bioaccessibility and bioactivity evaluation of Hibiscus phenolic extracts. The results have pointed out that the most used DoEs were based on response surface methodologies (RSM), mainly the Box-Behnken design (BBD) and central composite design (CCD). The chemical composition of the optimized enriched extracts showed an abundance of flavonoids, as well as anthocyanins and phenolic acids. In vitro and in vivo studies have highlighted their potent bioactivity, with particular emphasis on obesity and related disorders. This scientific evidence establishes the Hibiscus genera as an interesting source of phytochemicals with demonstrated bioactive potential for the development of functional foods. Nevertheless, future investigations are needed to evaluate the recovery of the phenolic compounds of the Hibiscus genera with remarkable bioaccessibility and bioactivity.

The bioaccessibility, bioavailability, bioactivity, and prebiotic effects of phenolic compounds from raw and solid-fermented mulberry leaves during in vitro digestion and colonic fermentation

The bioaccessibility and bioactivity of phenolic compounds in mulberry leaves (MLs) relate to the digestion process. This study was aimed at investigating the release of phenolic compounds, as well as the potential bioactivities of raw MLs (UF-MLs) and solid-fermented MLs (F-MLs) during in vitro digestion and colonic fermentation. Antioxidant activities and phenolic compounds released in the digested extracts are shown in decreasing order of location: intestinal > oral > gastric. The bioavailability of total phenolics and flavonoids in F-MLs were 10.14 ± 1.81 % and 6.66 ± 0.55 %, respectively. There was no significant difference in the inhibitory activity of α-glucosidase during gastrointestinal digestion. For colonic fermentation, the highest free radical-scavenging ability of DPPH and ABTS was found at 24 h and 48 h, respectively. The release of phenolic compounds was not significantly different after 48 h of colonic fermentation. LC-MS/MS showed that liquiritigenin, apigenin, chlorogenic acid, and ferulic acid were the major compounds released in the small intestine digestion, and valerenic acid was the primary colonic metabolite. 16S rDNA showed that UF-MLs promoted the growth of Bifidobacterium and F-MLs lowered the Firmicutes-to-Bacteroidetes ratio. Furthermore, F-MLs increased the concentration of acetic acids (25.75 ± 0.86 mM) after 24 h of colonic fermentation. The results of this study indicated that F-MLs exhibit relatively higher phenolic bioaccessibility, antioxidant activities, and SCFA production and are a promising candidate as a health food supplement.

Effect of de-phenolization on protein-phenolic interactions of sunflower protein isolate

Proteins and phenolic compounds are significant components of foods that can interact, and this interaction can impact the functional properties of proteins and the bioactivity of phenolic compounds. Sunflower meal, which has a high potential to be an important alternative protein source, contains phenolic compounds mostly bonded with proteins. In this study, the interaction between proteins and phenolic compounds which naturally exist in sunflower and prone to oxidation during alkaline treatment (for protein isolation) was investigated. There was a significant decrease up to 96.21% in the content of total phenolics by methanol washing. Chlorogenic acid, cryptochlorogenic acid and caffeic acid were detected in the phenolic extract obtained from sunflower protein isolate, and they exhibited different levels of reduction after methanol washing. For the total antioxidant capacity analysis, a decrease by 50% was observed after 4hwashing with methanol solution, and there was no significant decrease afterwards. In addition, the fluorescence intensity of sunflower protein was diminished with reduced washing time, which was mostly attributed to the protein–phenolic interaction. According to hydrodynamic parameters, the main force of the sunflower protein–phenolic complex formation was assumed to be hydrophobic attraction. The Stern-Volmer plot indicated that the main quenching mechanism was only static at all temperature conditions.

Analysis of Phenolic Compounds in Buckwheat (Fagopyrum esculentum Moench) Sprouts Modified with Probiotic Yeast.

Buckwheat sprouts are a source of various nutrients, e.g., antioxidant flavonoids, which have a positive effect on human health. This study analyzed the content of phenolic compounds and assessed their impact on the antioxidant and anti-inflammatory properties and dietary fiber in modified buckwheat sprouts. For this purpose, the buckwheat seeds were modified by adding Saccharomyces cerevisiae var. boulardii. The modified buckwheat sprouts showed a higher content of total phenol compounds (1526 µg/g d.w.) than the control sprouts (951 µg/g d.w.) and seeds (672 µg/g d.w.). As a consequence, a higher antioxidant activity and anti-inflammatory effect were noted. Probiotic-rich sprouts also had the highest content of total dietary fiber and its soluble fraction. A correlation between phenolic compounds and the antioxidant and anti-inflammatory effects, as well as dietary fiber, was shown. The interaction between dietary fiber and phenolic compounds affects the bioaccessibility, bioavailability, and bioactivity of phenolic compounds in food. The introduction of probiotic yeast into the sprouts had a positive effect on increasing their nutritional value, as well as their antioxidant and anti-inflammatory activity. As a consequence, the nutraceutical potential of the raw material changed, opening a new direction for the use of buckwheat sprouts, e.g., in industry.

Evaluation of the effects of simulated in vitro digestion by Gastrodia elata on biological activity and gut microflora regulation

Gastrodia elata (G. elata) is a traditional Chinese herbal medicine. In recent years, G. elata has been widely used in food and pharmaceutical industries because of its excellent health benefits. However, the stability and bioactivity of phenolic compounds from G. elata after in vitro gastrointestinal digestion remain unknown. In this study, the aqueous extract of G. elata rhizomes was used to simulate gastrointestinal digestion and colonic fermentation in vitro. This study aimed to evaluate the bioaccessibility during the simulation of gastrointestinal and colonic fermentation and to clarify the effects of different digestion stages on the anti-oxidant and enzyme inhibitory activities and intestinal health of samples in vitro. The results indicated that the total polyphenol and flavonoid contents after colonic fermentation for 72 h were 5.48- and 3.24- fold higher than those without digestion, respectively. Except for gastrodigenin and ferulic acid, the contents and bioaccessibility of the other phenols after fermentation were higher than those in the small-intestine stage. Antioxidant activity was positively correlated with the total polyphenol content. The inhibitory activities of pancrelipase and cholinesterase were enhanced by gastric digestion and colonic fermentation. The sample promoted the production of Lactobacillus and decreased the abundance of pathogenic bacteria. Moreover, the content of short-chain fatty acids also exhibited an upward trend. Therefore, G. elata has the potential to develop into a health food with anti-oxidant, anti-obesity, and intestinal health functions.

Quercus ilex leaf as a functional ingredient: Polyphenolic profile and antioxidant activity throughout simulated gastrointestinal digestion and antimicrobial activity

Quercus ilex leaf constitute a rich source of bioactive compounds, especially phenolic compounds, with health and technological properties. In this study, the influence of in vitro gastrointestinal digestion on the bioaccessibility and bioactivity of phenolic compounds from ground leaf (GL) and leaf powder extract (PE) was evaluated for the first time. The GL showed an increase in antioxidant capacity, total phenolic content and individual phenolic compounds identified in the oral and gastric phase, decreasing in the intestinal and absorption (dialysis) phases, while PE showed a slight decrease in the oral and gastric phase and a more pronounced reduction in the last phases. Although the content of phenolic compounds and the antioxidant capacity were higher in the initial PE, the bioaccessibility (55.27% in GL vs. 34.23% in PE) and the recovery in the last step of the gastrointestinal tract in the colon-available fraction (29.24% in GL vs. 27.90% in PE) were higher in GL. The PE showed high antimicrobial activity against Escherichia coli, Listeria monocytogenes, Salmonella Typhimurium, Yersinia enterocolitica and Staphylococcus aureus, showing minimum inhibitory concentration values between 1 and 5 mg/mL. These results showed the complexity and richness of Q. ilex PE and GL in phenolics with high antioxidant and antimicrobial activity, underlining their use as a source of biofunctional compounds for the development of novel food additives and nutraceuticals.

Bioaccessibility and bioactivities of phenolic compounds from roasted coffee beans during in vitro digestion and colonic fermentation

Bioaccessibility and bioactivity of phenolic compounds in coffee beans relate to roasting and digestion process. This study aimed to estimate phenolic content, antioxidant potential, bioaccessibility, and changes in short chain fatty acids (SCFAs) production during in vitro digestion and colonic fermentation of commercial roasted (light, medium and dark) coffee beans. There was no significant difference found among all three different roasting levels. TPC and DPPH were enhanced 15 mg GAE/g and 60 mg TE/g during gastrointestinal digestion, respectively. For colonic fermentation, the highest TPC and FRAP of all coffee beans was found at 2 and 4 h, respectively. The gastric bioaccessibility of most of the phenolic compounds were relatively higher due to thermal phenolic degradation. Total SCFAs production was only up to 0.02 mM because of thermal polysaccharide decomposition. Light roasted beans exhibited relatively higher phenolic bioaccessibility, antioxidant activities and SCFAs production, which would be more beneficial to gut health.

Effect of in vitro digestion on the bioaccessibility and bioactivity of phenolic compounds in fractions of Eugenia pyriformis fruit

Uvaia is a Brazilian fruit species that has great economic and nutritional potential, in addition to being a good source of compounds of biological interest. In this study, we evaluated for the first time the influence of in vitro gastrointestinal digestion on the bioaccessibility and bioactivity of phenolic compounds from two fractions of uvaia (edible and seed). It was observed that the content of total phenolic compounds was about 3 times higher in the seed (undigested extract), but reduced significantly after intestinal digestion (-50.08%). In turn, the total flavonoid content was about 5 times higher in the undigested seed extract. After intestinal digestion, the flavonoid content increased in the edible fraction (+109.49%) and decreased in the uvaia seed (-70.20%). The heatmap analysis showed that after intestinal digestion, there was an increase in the relative intensity of the flavonoids, while phenolic acids reduced their intensity. The antioxidant capacity of the undigested extract was 4–7 times greater for the seed, but decreased after intestinal digestion (-8.04–27.23%), while the antioxidant capacity of the edible fraction increased by 72.12–107.89% in this same stage of digestion. Thus, the content of phenolic compounds and antioxidant capacity were higher in the uvaia seed, and the bioaccessibility of the bioactive compounds in this fruit were dependent on the fraction and digestive phase evaluated. These results can contribute to the establishment of uvaia as a novel ingredient for preparations with functional claims.

Hydrothermal Processing and In Vitro Simulated Human Digestion Affects the Bioaccessibility and Bioactivity of Phenolic Compounds in African Pumpkin (Momordica balsamina) Leaves.

The African pumpkin (Momordica balsamina) contains bioactive phenolic compounds that may assist in reducing oxidative stress in the human body. The leaves are mainly consumed after boiling in water for a specific time; this hydrothermal process and conditions of the gastrointestinal tract may affect the presence and bioactivity of phenolics either positively or negatively. In this study, the effects of hydrothermal processing (boiling) and in vitro simulated human digestion on the phenolic composition, bioaccessibility and bioactivity in African pumpkin were investigated in comparison with those of spinach (Spinacia oleracea). A high-resolution ultra-performance liquid chromatography, coupled with diode array detection, quadrupole time-of-flight and mass spectrometer (UPLC-DAD-QTOF-MS) was used to profile phenolic metabolites. Metabolites such as 3-caffeoylquinic acid, 5-caffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid were highly concentrated in the boiled vegetable extracts compared to the raw undigested and all digested samples. The majority of African pumpkin and spinach extracts (non-digested and digested) protected Deoxyribonucleic acid (DNA), (mouse fibroblast) L929 and human epithelial colorectal adenocarcinoma (Caco-2) cells from 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidative damage. From these results, the consumption of boiled African pumpkin leaves, as well as spinach, could be encouraged, as bioactive metabolites present may reduce oxidative stress in the body.

Cooking Methods on Extractability and Bioactivity of Phenolic Compounds in Purple Potatoes

Abstract Objectives Purple-fleshed potato is a good dietary source of phenolic compounds, including anthocyanins, flavonols, and chlorogenic acids. The objective of this study is to examine impacts of cooking methods including boiling, steaming and the newly developed vacuum-sealed boiling (VSBoiling), on extractability and bioactivity of phenolic compounds in purple potato (PP). Methods Following cooking, polyphenolic compounds were extracted from raw PP or cooked PP and analyzed for total phenolic content, composition, and free radical scavenging activity. In addition, anti-oxidative and anti-inflammatory effects of extracts were tested in cultured Caco-2 cells. Results Steaming and boiling slightly reduced the extractable chlorogenic acid content, while VSBoiling increased its content. VSBoiling and steaming effectively preserved the radical scavenging activities of PP, while boiling resulted in a significant reduction compared to the extract from raw potatoes. In human colonic epithelial Caco-2 cells, all PP extracts effectively suppressed hydrogen peroxide-induced bursts of intracellular reactive oxygen species, and suppressed tumor necrosis factor-α induced inflammation in Caco-2 cells, while VSBoiling group showed the highest activity. Conclusions The contents and bioactivity of extractable polyphenols are largely retained in PP subjected to different cooking processes. VSBoiling resulted in the highest extractability of phenolic compounds and their biological function among tested cooking methods. Funding Sources USDA-NIFA and Northwest Potato Research Consortium.

The impact of boiling and in vitro human digestion of Solanum nigrum complex (Black nightshade) on phenolic compounds bioactivity and bioaccessibility

Solanum nigrum complex (Black nightshade) is a wild leafy vegetable with phenolic antioxidant compounds related to the reduction of oxidative stress. Changes in phenolics and bioactivity due to cooking and gastrointestinal digestion of black nightshade were compared to spinach. Predominant compounds of black nightshade were myricetin, quercetin-3-O-robinoside, 3,4-dicaffeoylquinic acid, 3-caffeoylquinic acid, and rutin, which were improved after boiling but reduced after in vitro digestion. Phenolics were reduced after digestion of black nightshade and spinach; however, bioactivity was still retained, especially in preventing oxidative stress in Caco-2 cells. Hence, indicating their potential to reduce oxidative stress related diseases of the digestive tract.

Bioactivity of Phenolic Compounds Extracted from Strawberry against Formation of Pseudomonas aeruginosa Biofilm

Background: Biofilm is a bacterial way of life prevalent in the world of microbes; in addition to that it is a source of alarm in the field of health concern. Pseudomonas aeruginosa is a pathogenic bacterium responsible for all opportunistic infections such as chronic and severe. Aim of this study: This paper aims to provide an overview of the promotion of isolates to produce a biofilm in vitro under special circumstances, to expose certain antibiotics to produce phenotypic evaluation of biofilm bacteria. Methods and Materials: Three diverse ways were used to inhibited biofilm formation of P.aeruginosa by effect of phenolic compounds extracts from strawberries. Isolates produced biofilm on agar MacConkey under certain circumstances. Results: The results showed that all isolates were resistant to antibiotics except sensitive to azithromycin (AZM, 15μg), and in this study was conducted on three ways to detect the biofilm produced, has been detected by the biofilm like Tissue culture plate (TCP), Tube method (TM), Congo Red Agar (CRA). These methods gave a clear result of these isolates under study. Active compounds were analyzed in both extracts by Gas Chromatography-mass Spectrometry which indicate High molecular weight compound with a long hydrocarbon chain. Conclusion: Phenolic compounds could behave as bioactive material and can be useful to be used in pharmaceutical synthesis. Phenolic contents which found in leaves and fruits extracts of strawberries shows antibacterial activity against all strains tested by the ability to reduce the production of biofilm formation rate.

Fructosylation of phenolic compounds by levansucrase from Gluconacetobacter diazotrophicus

Fructosylation can significantly improve the solubility, stability and bioactivity of phenolic compounds, increasing their health benefits. Levansucrase from Gluconacetobacter diazotrophicus (LsdA, EC 2.4.1.10) was found to transfer the fructosyl unit of sucrose to different classes of phenolic compounds. Among the various acceptors tested, the isoflavone puerarin and the phenol coniferyl alcohol were the most efficiently fructosylated compounds, with conversion rates of 93% and 25.1%, respectively. In both cases, mono-, di-, and trifructosides were synthesized at a ratio of 37:14:1 and 32:8:1, respectively. Structural characterization of the puerarin mono-fructoside revealed that the enzyme transferred the fructosyl moiety of sucrose to the O6-position of the glucosyl unit of puerarin. The water solubility of fructosyl-β-(2→6)-puerarin was increased 23-fold, up to 16.2 g L−1, while its antioxidant capacity was only decreased 1.25-fold compared with that of puerarin.

Selenium-Rich Ricegrass Juice Improves Antioxidant Properties and Nitric Oxide Inhibition in Macrophage Cells.

Ricegrass juice (Oryza sativa L.) was introduced as a functional food as the consumption of sprouts or seedlings has been claimed to provide high nutritive value. Selenium (Se) is a trace mineral that plays a key role in the human antioxidation scheme. Supplementation of Se into plants is one strategy to enhance plant bioactivities, and the consumption of Se plant foods may confer superior health benefits. In this study, ricegrass juice extract was analyzed for its major phenolic components. The effect of ricegrass juice extracts bio-fortified with 0, 10 and 40 mg Se/L named as RG0, RG10, and RG40, respectively, were investigated for a percentage of cell viability, changes of endogenous antioxidant enzymes, lipid peroxidation, and nitric oxide inhibition in RAW264.7 macrophage cells. Flavone glycosides, namely chrysoeriol arabinosyl arabinoside derivatives, were found to be the foremost bioactive components in ricegrass juice extract indicated by UHPLC-MS. The results of cell culture assessment revealed that RG40 showed an ability to promote macrophage cell proliferation at low concentration. Ricegrass juice extract in all treatments possessed the ability to reduce malondialdehyde content, which may be regarded as the bioactivity of phenolic compounds. Moreover, Se also played a role in this effect since RG40 showed the greatest ability via increasing the level of GPx enzyme. It was also discovered that phenolic compounds in the extracts played a role in inhibiting nitric oxide in LPS-induced RAW264.7 cells. Furthermore, RG40 expressed significantly higher NO inhibition properties at IC50 118.76 µg/mL compared to RG0 and RG10, at 147.02 and 147.73 µg/mL, respectively. Se bio-fortified ricegrass juice could be considered as a new potent functional food that can lower the risk of oxidative stress and chronic inflammation diseases.

ChemInform Abstract: Recent Progress in the Enzymatic Glycosylation of Phenolic Compounds

AbstractReview: 88 refs.

Onion skin — Raw material for the production of supplement that enhances the health-beneficial properties of wheat bread

Onion skin (OS) is an environmentally problematic waste that is extensively produced during onion bulb processing. Noteworthy, it contains high amounts of bioaccessible and bioavailable compounds with well documented biological activity. Here, we estimated the effect of OS-supplementation and gastrointestinal processing of wheat bread on its potential anticancer activity and ability to modify activity of lipoxygenase (LOX), xanthine oxidase (XO), catalase (CAT) and superoxide dismutase (SOD). Gastrointestinal processing releases XO and LOX inhibitors and CAT activators from supplemented bread. Most importantly, synergism between these compounds derived from bread and OS was found. Gastrointestinally adsorbed 3% OS-supplemented bread extract exerted a considerably stronger cytostatic and anti-invasive effect on gastric cancer AGS cells than its gastrointestinally digested and buffer masticated counterparts. These effects only partly correlated with the phenolic content of the extracts and their antioxidative activities. Gastrointestinal digestion and adsorption slightly influence the bioactivity of non-supplemented bread extracts. However, the activity of gastrointestinally adsorbed, OS-supplemented wheat bread extract switched from cytostatic and anti-invasive to cytoprotective upon DMSO extraction. These data directly show a complex network of synergetic and antagonistic effects of single phenolic compounds from onion skin and wheat bread. They indicate that the bioactivity of phenolic compounds and potentially beneficial effects of wheat bread fortification with onion skin may be regulated by subtle interactions between OS and bread phenolic compounds, and food matrix. They are modulated by gastrointestinal processing. These findings may open perspectives for the introduction of onion skin into wheat bread supplementation which would increase its pro-healthy properties.