Structure, antioxidant and α-amylase inhibitory activities of longan pericarp proanthocyanidins

Effect of free and bound proanthocyanidins from Chinese quince on heterocyclic aromatic amine formation and quality in fried chicken

The abilities of Chinese quince free proanthocyanidins (FP) and bound proanthocyanidins (BP) at different levels (0.1%, 0.15%, and 0.3%) to mitigate heterocyclic aromatic amine (HAA) formation in fried chicken patties were investigated for the first time and compared with vitamin C (Vc). FP and BP reduced HAAs in a dose-dependent manner. Significantly, high concentrations of FP (0.3%) resulted in a reduction of PhIP, harman, and norharman levels by 59.84%, 22.91%, and 38.21%, respectively, in chicken patties. The addition of proanthocyanidins significantly (p < 0.05) reduced the weight loss of fried chicken patties. Furthermore, a positive correlation was observed among pH, weight loss, and total HAA formation in all three groups (FP, BP, and Vc). Multivariate analysis showed that FP had a more pronounced effect than BP from the perspective of enhancing the quality of fried chicken patties and reducing the formation of HAAs. These results indicate that proanthocyanidins, both BP and FP, but especially FP, from Chinese quince can inhibit the formation of carcinogenic HAAs when added to protein-rich foods that are subsequently fried.

Condensed tannins-Their content in plant foods, changes during processing, antioxidant and biological activities

Condensed tannins are considered nutritionally undesirable, because they precipitate proteins, inhibit digestive enzymes, and can affect the absorption of vitamins and minerals. From the consumer's point of view, they impart astringency to foods. Yet, they are viewed as a double-edged sword, since they possess antioxidant and anti-inflammatory activities. Intake of a small quantity of the right kind of tannins may in fact be beneficial to human health. This chapter reports on the chemical structure of condensed tannins, their content in plants and food of plant origin, how they are extracted, and methods for their determination. A description of the effects of processing on condensed tannins is discussed and includes soaking, dehulling, thermal processing (i.e., cooking, boiling, autoclaving, extrusion), and germination. The astringency of condensed tannins is described in relation to their interactions with proteins. Finally, details about the biological properties of condensed tannins, including their antimicrobial, anti-inflammatory, anticancer, anti-diabetic, and anti-obesity activities, are reviewed.

Potential of longan (Dimocarpus longan Lour.) in functional food: A review of molecular mechanism-directing health benefit properties

Longan (Dimocarpus longan Lour.) has received widespread attention worldwide as a therapeutic food with nutritional, economic, and medicinal value. Its fruit, seed, pericarp, and flower becoming dietary tools for health maintenance when it comes to targeting chronic diseases or sub-health conditions. In recent years, research focusing on longan and human health has intensified, and the high-value products of the whole fruit, including polyphenols, polysaccharides, angiotensin-I-converting enzyme (ACE)-inhibiting peptides, gamma-aminobutyric acid (GABA), and Maillard reaction products etc., may have beneficial effects on human health by preventing the onset of chronic diseases and cancer, maintaining intestinal homeostasis and skin health. Here, we review and summarize the new available evidence on the bioactive role of phytochemicals in longan and explore the relationship between longan bioactive compounds and health benefits, with a focus on the molecular mechanisms of the health effects.

Characterization of Băbească Neagră Grape Pomace and Incorporation into Jelly Candy: Evaluation of Phytochemical, Sensory, and Textural Properties

The influence of particle size intervals (<125 μm, ≥125-<200 μm, and ≥200-<300 μm) of grape pomace (Vitis vinifera var. Băbească Neagră) was analyzed in terms of the proximate composition, functional properties, and physicochemical parameters. The aim was to study the effect of the formulation variables (extract from grape pomace with different particle size intervals and gelatin doses-7, 8.5, and 10 g) on the mechanical properties (hardness, cohesiveness, adhesiveness, springiness, and gumminess), color, and sensorial, microbiological, and phytochemical parameters. The jelly candy formulated with grape pomace extract (<125 μm) and 7 g of gelatin showed the highest total phenolic content (156 mg GAE/g) and antioxidant activity (65.8% inhibition), while grape pomace jellies with a particle size of ≥125-<200 μm and different concentration of gelatin presented the greatest sensory acceptance in terms of sweetness, taste, odor, elasticity, color, and overall acceptability of the resulting jelly. The concluding observation was supported by the microbiological analysis, which also showed that there is no growth in jelly samples except the jelly candies prepared with a ≥200-<300 μm particle size interval of grape pomace extract.

In Vitro Anti-Diabetic, Anti-Inflammatory, Antioxidant Activities and Toxicological Study of Optimized Psychotria malayana Jack Leaves Extract

Psychotria malayana Jack (Family: Rubiaceae, local name: Salung) is a traditional herb used to treat diabetes. A previous study by our research group demonstrated that P. malayana methanolic and water extract exhibits significant potential as an effective agent for managing diabetes. Further research has been performed on the extraction optimization of this plant to enhance its inhibitory activity against α-glucosidase, a key enzyme associated with diabetes, and to reduce its toxicity. The objectives of this study are to evaluate the anti-diabetic, anti-inflammatory, and antioxidant properties of the optimized P. malayana leaf extract (OE), to evaluate its toxicity using a zebrafish embryo/larvae model, and to analyze its metabolites. The anti-diabetic effects were assessed by investigating α-glucosidase inhibition (AGI), while the inflammation inhibitory activity was performed using the soybean lipoxygenase inhibitory (SLOXI) test. The assessment of antioxidant activity was performed utilizing FRAP and DPPH assays. The toxicology study was conducted using the zebrafish embryo/larvae (Danio rerio) model. The metabolites present in the extracts were analyzed using GC-MS and LC-MS. OE demonstrated significant AGI and SLOXI activities, represented as 2.02 and 4.92 µg/mL for IC50 values, respectively. It exhibited potent antioxidant activities as determined by IC50 values of 13.08 µg/mL (using the DPPH assay) and 95.44 mmol TE/mg DW (using the FRAP assay), and also demonstrated an LC50 value of 224.29 µg/mL, which surpasses its therapeutic index of 111.03. OE exhibited a higher therapeutic index compared to that of the methanol extract (13.84) stated in the previous state of the art. This suggests that OE exhibits a lower level of toxicity, making it safer for use, and has the potential to be highly effective in its anti-diabetic activity. Liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) demonstrated the presence of several constituents in this extract. Among them, several compounds, such as propanoic acid, succinic acid, D-tagatose, myo-inositol, isorhamnetin, moracin M-3'-O-β-D-glucopyranoside, procyanidin B3, and leucopelargonidin, have been reported as possessing anti-diabetic and antioxidant activities. This finding offers great potential for future research in diabetes treatment.

Anthocyanin and proanthocyanidin from Aronia melanocarpa (Michx.) Ell.: Purification, fractionation, and enzyme inhibition

Aronia melanocarpa (Michx.) Ell. is a rich source of anthocyanins and proanthocyanidins with confirmed health benefits. Individual cyanidin glucosides (cyanidin 3-galactoside, cyanidin 3-arabinoside, cyanidin 3-xyloside, and cyanidin 3-glucoside) of anthocyanins (calculated by individual cyanin glycoside fractions was 419.9 mg/100 g FW) were isolated by Sephadex LH-20 column and different parts of proanthocyanidins with a different mean degree of polymerization (mDP) were fractionated by the solubility differences in different solvents. The composition of different mDP of proanthocyanidins was as follows: monomers (1.51%), oligomer (mDP of 4.2 ± 0.9, 20.57%), CPP-50 (mDP of 78.9 ± 4.1, 22.17%), CPP-60 (mDP of 66.1 ± 1.2, 27.94%), CPP-70 (mDP of 36.8 ± 3.9, 36.8%), CPP-75 (mDP of 25.2 ± 1.3, 6.14%), CPP-L (mDP of 10.2 ± 2.6, 6.95%), and there were recycling loss of 0.34%. Cyanidin 3-glucoside showed the strongest inhibition effects on α-amylase and lipase and cyanidin 3-arabinoside showed the strongest inhibition effect on α-glucosidase, while cyanidin 3-xyloside has no inhibition effect on the α-amylase, and cyanidin 3-galactoside, cyanidin 3-arabinoside, and cyanidin 3-xyloside have no inhibition effects on lipase. The inhibition effect of proanthocyanidins with different mDP to the enzymes all showed high negative correlations between the mDP and IC₅₀ (half-maximal inhibitory concentration). This study suggests that A. melanocarpa (Michx.) Ell. can have beneficial effects due to inhibition of the digestion enzyme.

Tackling the Future Pandemics: Broad-Spectrum Antiviral Agents (BSAAs) Based on A-Type Proanthocyanidins

A-type proanthocyanidins (PAC-As) are plant-derived natural polyphenols that occur as oligomers or polymers of flavan-3-ol monomers, such as (+)-catechin and (-)-epicatechin, connected through an unusual double A linkage. PAC-As are present in leaves, seeds, flowers, bark, and fruits of many plants, and are thought to exert protective natural roles against microbial pathogens, insects, and herbivores. Consequently, when tested in isolation, PAC-As have shown several biological effects, through antioxidant, antibacterial, immunomodulatory, and antiviral activities. PAC-As have been observed in fact to inhibit replication of many different human viruses, and both enveloped and non-enveloped DNA and RNA viruses proved sensible to their inhibitory effect. Mechanistic studies revealed that PAC-As cause reduction of infectivity of viral particles they come in contact with, as a result of their propensity to interact with virion surface capsid proteins or envelope glycoproteins essential for viral attachment and entry. As viral infections and new virus outbreaks are a major public health concern, development of effective Broad-Spectrum Antiviral Agents (BSAAs) that can be rapidly deployable even against future emerging viruses is an urgent priority. This review summarizes the antiviral activities and mechanism of action of PAC-As, and their potential to be deployed as BSAAs against present and future viral infections.

Prostatic Therapeutic Efficacy of LENILUTS®, a Novel Formulation with Multi-Active Principles

Lower Urinary Tract Symptoms (LUTs) in men are usually associated to benign prostatic hyperplasia (BPH), a non-malignant prostate enlargement. Unfortunately, BPH etiology is still unclear. Recent works highlighted a relevant inflammation role in BPH onset and development. Consequently, to complement the 5-α reductase (and α-adrenergic receptor agonists-based therapy, an anti-inflammatory therapy should be devised. To reduce potential adverse effects of multi-drug treatment, plant extract-based therapies are becoming increasingly common. Serenoa repens, the main phytotherapic treatment for BPH, is not sufficient to front the multi-faceted etiology of BPH. In response to this, a novel, multiple phytotherapic agents-based formulation, LENILUTS®, was developed. In the present work, we compared, using an in vitro approach, the prostatic safety and efficacy of LENILUTS® with a commercial formulation, based only on Serenoa repens, and a 5αR inhibitor, Dutasteride. Furthermore, preliminary in vitro experiments to investigate the active principles, bioaccessibility and bioavailability of LENILUTS® were performed. Our results showed a better prostatic safety and therapeutic efficacy of LENILUTS® compared to the commercial formulation and Dutasteride, with increased anti-inflammatory, and pro-apoptotic activity, and a stronger inhibitory effect on the release of the key enzyme 5αR and Prostatic-Specific Antigen (PSA). The limited bioaccessibility and bioavailability of the active principles of LENILUTS® were highlighted. Considering the results obtained, the LENILUTS® formulation is more promising for BPH and LUTs therapy compared to formulations based on Serenoa repens only, but further efforts should be made to improve the bioaccessibility and bioavailability of the active principles.

Highly galloylated and A-type prodelphinidins and procyanidins in persimmon (Diospyros kaki L.) peel

The structure of persimmon peel proanthocyanidins (PPPAs) was characterized. After acid catalysis of PPPAs in the presence of phloroglucinol, five reaction products such as (epi)gallocatechin-phloroglucinol ((E)GC-ph) etc. were identified by HPLC-DAD-ESI/MS. FT-IR analysis confirmed that all of the compounds exhibited a 2, 3-cis configuration. Therefore, the extension units in PPPAs were EGC, epigallocatechin gallate (EGCG), epicatechin, and epicatechin gallate and only EGCG was detected as the terminal unit. PPPAs contained 25.21% of procyanidins and 74.79% of prodelphindins and had a high degree of 3-O-galloylation (>74.79%). The mean degree of polymerization of PPPAs was calculated to be 10.18. MALDI-TOF MS analysis showed that A-type linkage and galloylation existed commonly in PPPAs.

Extraction and identification of proanthocyanidins from the leaves of persimmon and loquat

Proanthocyanidins is flavan-3-ol polymers with many activities which attracted a lot of attention. However, most of the proanthocyanidins come from fruits and seeds, resulting in higher costs. The extraction of proanthocyanidins from leaves that were trimmed as wastes from fruit trees is of good economic benefits. The proanthocyanidins in persimmon leaves and loquat leaves were extracted and purified. The purity of persimmon and loquat leaves were 85.33 ± 0.11% and 88.45 ± 0.96% with yield of 3.40% and 2.37% respectively. Detailed structure information was analyzed. Persimmon leaves proanthocyanidins mainly consist of catechin with B-type link along with a small portion of gallocatechin, catechin gallate and A-type link. Loquat leaves proanthocyanidins consist of catechin, gallocatechin, gallocatechin gallate and afzelechin with B-type link along with a small portion of A-type link. The α-amylase inhibition effect of the two leaves was analyzed. Persimmon leaves proanthocyanidins and loquat leaves proanthocyanidins were two mixed-type inhibitors to α-amylase.

Effects of superfine pulverization technology on the morphology, microstructure, and physicochemical properties of Apium graveolens L. root

In this study, the characteristics of the transverse section of Apium graveolens L. root (AR) were observed. The surface morphology, physicochemical properties, and antioxidant activity of five kinds of powders obtained by superfine pulverization (850-355, 355-180, 180-125, 125-50, and <50 μm) were evaluated. Under the microscope, the transverse section of AR had distinct identification features. Parenchyma cells, cork cells, vessels, fibers, nonglandular hair, and tubing fragments were observed via powder microscopic identification. Scanning electron microscopy (SEM) revealed that superfine pulverization evidently changed the shape and surface morphology of the AR powders. As particle size decreased, the moisture and oil-binding capacity (OBC) of AR powder decreased, whereas its total ash content, water solubility index (WSI), swelling capacity (SC), water-holding capacity (WHC), bulk densities, tapped densities, repose angles, slide angles, and crash angles increased. The AR powder with a particle size of <50 μm had the highest contents of total flavonoids (30.46 mg/g), apiin (15.29 mg/g), and 3'-methoxyapiin (6.78 mg/g). Fourier transform infrared spectroscopy (FTIR) analysis revealed that the chemical composition of the powder and its extracts did not notably change as particle size decreased. Meanwhile, the scavenging ability of DPPH and ABTS radicals increased with the decrease of particle size. Therefore, there are more obvious differences in physicochemical properties and antioxidant activity of AR powders with different particle sizes. This study provides a theoretical basis for the development and application of new AR products.

The underlying mechanism of A-type procyanidins from peanut skin on DSS-induced ulcerative colitis mice by regulating gut microbiota and metabolism

Ulcerative colitis (UC) is a kind of inflammatory bowel disease. Procyanidins have been found to prevent UC. However, most research has been focused on the alleviation effect of B-type procyanidins on UC and ignored those of A-type procyanidins. Hence, this study aims to investigate the anti-UC effect and the potential mechanism of A-type procyanidins by combining gut microbiome and metabolic profile. UC was induced by dextran sulfate sodium (DSS) in Balb/c mice, and then the mice were administrated with peanut skin procyanidins (PSP; rich in A-type procyanidins) for 9 days. Administration of PSP can ameliorate DSS-induced UC by mediating the intestinal barrier, the expression of inflammatory cytokines (TNF-α, IL-β, IL-6, and IL-10) and oxidative stress (MDA, T-SOD, NO, and iNOS) in mice. We observed that PSP affects the gut microbiota and colon metabolomic patterns of mice. The 16S rDNA sequencing showed increase in abundance of Lachnospiraceae_NK4A136_group, Oscillibacter and Roseburia and decrease of Bacteroides, Helicobacter, Parabacteroides, Escherichia-Shigella, and Enterobacter after PSP treatment. The colon tissue metabolome was significantly altered, as reflected by regulating taste transduction, mTOR signaling pathway, PI3K-Akt signaling pathway, and FoxO signaling pathway to improve the protection against UC. PRACTICAL APPLICATIONS: We investigated the anti-ulcerative colitis (UC) effect and its potential mechanism of peanut skin procyanidins (PSP). This suggests that PSP with abundant A-type procyanidins may be an effective candidate for dietary supplementation to alleviate the symptoms of UC by regulating gut microbiota and metabolism.

Composition analysis and antioxidant activity evaluation of a high purity oligomeric procyanidin prepared from sea buckthorn by a green method

Procyanidin is an important polyphenol for its health-promoting properties, however, the study of procyanidin in sea buckthorn was limited. In this paper, sea buckthorn procyanidin (SBP) was obtained through a green isolation and enrichment technique with an extraction rate and purity of 9.1% and 91.5%. The structure of SBP was analyzed using Ultraviolet–visible spectroscopy (UV–vis), Fourier-transform infrared spectroscopy (FT-IR), and liquid chromatography-mass spectrometry (LC-MS/MS). The results show that SBP is an oligomeric procyanidin, mainly composed of (−)-epicatechin gallate, procyanidin B, (+)-gallocatechin-(+)-catechin, and (+)-gallocatechin dimer. SBP showed superior scavenging capacity on free radicals. Furthermore, the cleaning rate of the ABTS radical was 4.8 times higher than vitamin C at the same concentration. Moreover, SBP combined with vitamin C presented potent synergistic antioxidants with combined index values below 0.3 with concentration rates from 5:5 to 2:8. SBP also provided significant protection against oxidative stress caused by hydrogen peroxide (H₂O₂) on RAW264.7 cells. These findings prove the potential of SBP as a natural antioxidant in food additives and support the in-depth development of sea buckthorn resources.

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A green method for the extraction of procyanidin was proposed.

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An oligomeric procyanidin in sea buckthorn was identified for the first time.

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SBP combined with VC exerted strong synergistic antioxidant.

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SBP provided protection of macrophages against oxidative damage.

Utilization of Maillard reaction in moist-dry-heating system to enhance physicochemical and antioxidative properties of dried whole longan fruit

This research aimed to enhance the physicochemical and antioxidant properties of dried whole longan fruit using Maillard reaction or non-enzymatic glycosylation (glycation) in a moist-dry-heating system at 60 °C with approximately 75% relative humidity for 5-50 days. During Maillard reaction, the browning index (BI) of the fruits increased significantly while lightless, redness and yellowness decreased. Interestingly, the rare sugars especially D-psicose and D-allose gradually increased by 2-3 folds when compared to the initial Maillard reaction. The development of D-mannose was additionally established through the glycation. The degree of glycation increased with the decrease of free amino acid, suggesting that conjugation of sugar with amino acids was involved. SDS-PAGE confirmed that the high molecular weight (HMW) of conjugated sugar-amino acid was the Maillard reaction product. The antioxidative properties including DPPH and ABTS radical scavenging activities, also ferric reducing antioxidant power (FRAP) were also increased as Maillard reaction progressed, which showed the activities in the range of 43.2-94.1 mg GAE/100 g dry basis, 0.23-3.09 g TE/100 g dry basis, and 0.35-5.95 g FeSO4/100 g dry basis, respectively. This study demonstrated a practical approach of Maillard reaction for the development of dried longan fruit with high antioxidative properties.

Antioxidant and Antidiabetic Activity of Proanthocyanidins from Fagopyrum dibotrys

Proanthocyanidins are natural glycosidase inhibitors with excellent antioxidant activity. This study aims to search for a new source of proanthocyanidins for the prevention and treatment of type 2 diabetes with higher content and better activity and get their structure elucidated. First, the total proanthocyanidins contents (TOPCs), antioxidant activity, antidiabetic activity of seven common Polygonaceae plants were analyzed and compared. Then proanthocyanidins from the rhizome of Fagopyrum dibotrys were purified, and the detailed structure was comprehensively analyzed by ultraviolet visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), ¹³C nuclear magnetic resonance spectroscopy (¹³C NMR), reversed-phase high-performance liquid chromatography-electrospray mass spectrometry (RP-HPLC-ESI-MS), and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). The rhizome of F. dibotrys showed the highest TOPCs, the strongest antioxidant, and antidiabetic activities; the TOPCs, antioxidant and antidiabetic activities were all very significantly positively correlated. Proanthocyanidins purified from the rhizome of F. dibotrys showed better antidiabetic activity than grape seed proanthocyanidins (GsPs). Seventy-two proanthocyanidins from trimer to undecamer with a mean degree of polymerization (mDP) of about 5.02 ± 0.21 were identified with catechin and epicatechin as the dominant monomers. Conclusion: Proanthocyanidins are the main antioxidant and antidiabetic active substances of F. dibotrys and are expected to be developed into potential antioxidant and hypoglycemic products.

Six new triterpenoids from the root of Potentilla reptans and their cardioprotective effects in silico

Tormentic acid ester glucosides derivatives (1, 2 and 4), 3-oxoursane ester glycoside (3) and 11-methoxy-ursane ester glycosides (5, 6) as six new triterpenoids, along with catechin were isolated from the ethyl acetate fraction of Potentilla reptans root (Et) methanolic extract. The structures of the compounds were elucidated by 1D, 2D NMR, IR and MS spectroscopy. Additionally, isolated triterpenoid compounds (1-6) and catechin were evaluated for their cardioprotective effects via glycogen synthase kinase 3β (GSK-3β) and glucocorticoid regulated kinase-1 (SGK1) protein kinase inhibition by Molecular Docking. Compound 1 and catechin (compound 7) exhibited significant inhibitory effects against GSK-3β and SGK1 protein kinases with a binding energy value -9.1 and -8.8 kcal/mol, respectively. Hence, Et can be a suitable natural candidate to protect cardiomyocytes injury.

Effects of ultrafine grinding on physicochemical, functional and surface properties of ginger stem powders

BACKGROUND

Ginger stem (GS) is a by-product of ginger processing. It is not directly edible as a feed or food, which leads to it being discarded as waste or burned. Accordingly, it is very important to develop new functional products in the food or feed industry as a result of high nutritional and medicinal values. In the present study, the structures and physicochemical properties of GS powders of different sizes were evaluated after ultrafine grinding by a vibrating mill.

RESULTS

The ultrafine powders exhibited a smaller particle size and uniform distribution. Higher values in bulk density (from 1.07 ± 0.06 to 1.62 ± 0.08 g mL-1 ), oil holding capacity (from 3.427 ± 0.04 to 4.83 ± 0.03 g mL-1 ), and repose and slide angles (from 42.33 ± 1.52 to 54.36 ± 1.15° and 33.62 ± 0.75 to 47.27 ± 1.34°, respectively) of ultrafine GS powders were exhibited compared to coarse powders. With a reduced particle size, the solubility of ultrafine powders increased significantly (P < 0.05), whereas the water holding and swelling capacities decreased with a reduced particle size and then increased. Fourier transform infrared spectroscopy analysis showed that ultrafine grinding did not damage the main cellular structure of GS powder. The reduction of fiber length and particle size in GS was observed by light microscopy and scanning electron microscopy. The X-ray diffraction patterns demonstrated the crystallinity and the intensity of the peak in superfine GS powders.

CONCLUSION

The present study suggests that ultrafine grinding treatments influence the structures and physicochemical properties of GS powders, and such changes would improve the effective utilization of GS in the food or feed industry. © 2020 Society of Chemical Industry.

Glucose-rich polysaccharide from dried 'Shixia' longan activates macrophages through Ca2+ and CR3- mediated MAPKs and PI3K-AKT pathways

A water-soluble glucose-rich polysaccharide from dried 'Shixia' longan pulp (LPsx) has been isolated for the first time, and its structure and immuno-regulatory mechanism were studied. LPsx is a hetero-polysaccharide with the average molecular weight 4102 g/mol. It was mainly consisted of glucose (95.9%), and small proportions of arabinose (2.1%), galactose (1.0%), mannose (0.6%), and xylose (0.4%). As analyzed by NMR, LPsx was mainly composed of (1 → 6)-α-d-glucose and (1 → 6)-β-d-glucose, branched with α-d-glucose-(1→. The immunomodulatory activity study showed that LPsx significantly increased the phagocytosis of macrophages, and strongly promoted the production of NO, IL-1β, IL-6 and TNF-α. Moreover, LPsx could inhibit the inflammatory response induced by lipopolysaccharide. The immuno-regulatory mechanism of LPsx was studied using RNA- sequencing and receptors activity analyses. It was found that LPsx induced macrophage activation via Ca²⁺ and CR3-mediated MAPKs and PI3K-AKT signaling pathways. The results would be helpful for revealing the health promoting mechanism of dried 'Shixia' longan in traditional Chinese medicine.

In vitro inhibitory effects of Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins on pancreatic α-amylase and their interaction

Chinese bayberry leaves proanthocyanidins (BLPs) belongs to the prodelphinidin category with potent EGCG unit, whose inhibition effect on α-amylase and their interaction were investigated by in vitro digestion and enzyme kinetic analysis, multi fluorescence spectroscopies (fluorescence quenching, synchronous fluorescence, and three-dimensional fluorescence), circular dichroism spectra, Fourier transform infrared spectroscopy and in silico modelling. The results revealed that BLPs was a mixed inhibitor to α-amylase with the IC₅₀ value of 3.075 ± 0.073 μg/mL. BLPs could lead to a static fluorescence quenching of α-amylase, mainly by means of interacting with amino acids (mainly Try and Tyr residues) in one site on α-amylase molecule under the action of hydrogen bonding and/or Van der Waals force. This interaction further induced the change of secondary conformational structure, functional group structure and hydrophobicity of α-amylase, thus resulting in lowering activity. Molecular docking simulated that this binding occurred in a cavity on the surface of the α-amylase molecule, and BLPs trimer showed a relatively high binding energy. The present study provided a new insight of BLPs as an α-amylase inhibitor, which could be considered in anti-diabetic therapy.

Characteristics of New Peptides GQLGEHGGAGMG, GEHGGAGMGGGQFQPV, EQGFLPGPEESGR, RLARAGLAQ, YGNPVGGVGH, and GNPVGGVGHGTTGT as Inhibitors of Enzymes Involved in Metabolic Syndrome and Antimicrobial Potential

The aim of this study was to determine the cytotoxic properties, influence on enzyme activity involved in metabolic syndrome, and antimicrobial activity of synthetic peptides with GQLGEHGGAGMG, GEHGGAGMGGGQFQPV, EQGFLPGPEESGR, RLARAGLAQ, YGNPVGGVGH, and GNPVGGVGHGTTGT sequences. Peptides have no cytotoxic effect on cells. The highest inhibitory effect on angiotensin converting enzyme I was noted for peptide GT-14 (IC50 = 525.63 µg/mL). None of the tested peptides had an influence on α-glucosidase. The highest α-amylase and lipase inhibitory activity was noted for GG-12 (IC50 = 56.72 and 60.62 µg/mL, respectively). The highest lipoxidase inhibitory activity was determined for peptide ER-13 (IC50 = 84.35 µg/mL). Peptide RQ-9 was characterized by the highest COX inhibitory activity (0.31 and 4.77 µg/mL for COX-1 and COX-2, respectively). Only peptide RQ-9 inhibited S. enteritidis ATCC 4931 growth (42%-48%) in all tested concentrations (15.62-250 mg/mL).

Dietary polyphenols modulate starch digestion and glycaemic level: a review

Polyphenols, as one group of secondary metabolite, are widely distributed in plants and have been reported to show various bioactivities in recent year. Starch digestion not only is related with food industrial applications such as brewing but also plays an important role in postprandial blood glucose level, and therefore insulin resistance. Many studies have shown that dietary phenolic extracts and pure polyphenols can retard starch digestion in vitro, and the retarding effect depends on the phenolic composition and molecular structure. Besides, dietary polyphenols have also been reported to alleviate elevation of blood glucose level after meal, indicating the inhibition of starch digestion in vivo. This review aims to analyze how dietary polyphenols affect starch digestion both in vitro and in vivo. We can conclude that the retarded starch digestion in vitro by polyphenols results from inhibition of key digestive enzymes, including α-amylase and α-glucosidase, as well as from interactions between polyphenols and starch. The alleviation of postprandial hyperglycemia by polyphenols might be caused by both the inhibited starch digestion in vivo and the influenced glucose transport. Therefore, phenolic extracts or pure polyphenols may be alternatives for preventing and treating type II diabetes disease.

Protective effects of polyphenolic extracts from longan seeds promote healing of deep second-degree burn in mice

The objective of this study was to evaluate the ability of a polyphenolic extract from longan seeds as a wound-healing material for deep second-degree burn wounds.

Chemical Compositions, Antiobesity, and Antioxidant Effects of Proanthocyanidins from Lotus Seed Epicarp and Lotus Seed Pot

Lotus seed epicarp (LSE) and lotus seed pot (LSP) were characterized, and a total of 5 and 7 proanthocyanidins (PAs) were identified in purified LSE and LSP extract, respectively. Purified LSE and LSP PAs significantly suppressed the body weight and weight gain of white adipose tissue (WAT) and decreased the WAT cell size in high-fat diet-induced obese mice regardless of the daily food intake. LSE or LSP administration significantly lowered the serum leptin level and improved the serum and liver lipid profiles (including total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C) levels), increased activities of antioxidant enzymes (superoxide dismutase (SOD) and glutathione transferase (GST)) and reduced glutathione (GSH) concentration, and suppressed lipid peroxidation in hepatic tissue. LSP PAs were generally more effective than LSE PAs. Both extracts ameliorated obesity, insulin resistance, and oxidative damage in obese mice, suggesting they are good candidates for value-added functional food and nutraceutical ingredients.

Anti-atherosclerosis of oligomeric proanthocyanidins from Rhodiola rosea on rat model via hypolipemic, antioxidant, anti-inflammatory activities together with regulation of endothelial function

BACKGROUND

Rhodiola rosea has been used as a traditional medicine for a long history. Previous studies on oligomeric proanthocyanidins from Rhodiola rosea (OPCRR) have showed that it exhibited significant free radical-scavenging activities, antioxidant activities in aging mice and lipid lowering effects.

HYPOTHESIS/PURPOSE

We hypothesized that OPCRR can improve the atherosclerosis pathological in rats. In the present study, we investigated the effects of OPCRR on the serum lipid profiles, oxidant stress status, inflammatory cytokines and atherosclerotic mediators, and endothelial dysfunction as well as changes in abdominal aorta of atherosclerosis rats.

METHODS

The major components of OPCRR were analyzed by using infrared spectrum and HPLC-ESI-MS. The atherosclerosis rat model was induced by high fat and vitamin D3 feeding for 9 weeks and two OPCRR doses (60 and 120 mg/kg b.w.) were orally administered daily for 9 weeks. The rats were then sacrificed and the blood was collected via abdominal aorta and serum was separated by centrifugated for biochemical analysis. Part of the aorta tissues were excised immediately for histopathological examination and western blotting.

RESULTS

Compared to model group, OPCRR treatments significantly decreased the serum lipid profiles including total cholesterol, total triglycerides, low-density lipoprotein cholesterol (LDL-C) and ox-LDL and increased the high-density lipoprotein cholesterol (HDL-C); significant increased serum antioxidant enzymes (SOD and GSH-Px) and decrease of MDA content as a product of lipid peroxidation; lowered serum levels of TNF-α, IL-1β, IL-6, ICAM-1 and VCAM-1 and enhanced IL-10 level; increased the serum release of nitric oxide and expression of iNOS in aortic, whereas decreased the expression of eNOS.

CONCLUSION

OPCRR can improve the progress of atherosclerosis by regulation of lipid metabolism, restoring of the antioxidant capacities, and attenuation of pro-inflammatory cytokines and chemcytokines release, and improving the endothelial dysfunction indicated by nitric oxide system.

Identification of Antioxidant and Anti-α-amylase Components in Lotus (Nelumbo nucifera, Gaertn.) Seed Epicarp

Lotus seed epicarp, a byproduct of lotus seed production process, is usually discarded as a waste. In this study, antioxidant and anti-α-amylase activities of freeze-dried water and various methanol extracts of lotus seed epicarp were evaluated. The extract obtained by 80% methanol exhibited the strongest DPPH and ABTS radical scavenging activity and ferric reducing power, as well as the greatest inhibitory potential on α-amylase. The excellent antioxidant and α-amylase inhibitory activities of 80% methanol extract might be attributed to its highest concentrations of total phenolics, flavonoids, and condensed tannins. The inhibition kinetic analysis revealed that the 80% methanol extract was a reversible and uncompetitive-type inhibitor of α-amylase. Furthermore, based on MALDI-TOF-MS and thiolysis-HPLC-ESI-MS, the main active components present in 80% methanol extract were identified to be B-type heteropolymeric condensed tannins built up of mixtures of propelargonidins, procyanidins, and prodelphinidins, with the predominance of procyanidins and epicatechin as the main constitutive units. The results obtained suggested that lotus seed epicarp could be exploited as a potential source of natural antioxidants and α-amylase inhibitors.

Energy Regulated Nutritive and Antioxidant Properties during the Germination and Sprouting of Broccoli Sprouts ( Brassica oleracea var. italica)

The role of energy status in germination and sprouting of broccoli seeds was investigated by exogenous ATP and DNP treatments. With the synthesis of adenylates from 38.82 to 142.69 mg·100 g^-1 DW, the nutritive components (soluble sugar, proteins, pigments, and phenolics) and AAs were increased during germination and early sprouting (day 5). Elements of the BoSnRK2 pathway were down-regulated by more than 2 fold under the energy charge feedback inhibition. At the end of sprouting (day 7), energy depletion resulted in slowdown or reduced nutritional accumulation and antioxidant capacities. Exogenous ATP depressed the BoSnRK2 pathway by maintaining the energy status at high levels and further promoted the nutrition and antioxidant levels. It also prevented the energy depletion at day 7. On the contrary, DNP reduced the ATP contents (16.10-26.86%) and activated the BoSnRK2 pathway. It also notably suppressed the energy-consuming activities including germination, sprouts growth, and secondary metabolic synthesis.

Antioxidant and α-amylase inhibitory activities of tannic acid

Tannic acid widely exists in plants, which forms a part of human diet. The antioxidant activity of tannic acid was evaluated by the chemical and cellular antioxidant assays. And its α-amylase inhibitory activity and behavior were also investigated. It was found that hydrogen- and electron donating capacities of tannic acid were higher than those of tertiary butylhydroquinone (TBHQ) based on reducing power, ABTS and DPPH radical scavenging assays. But for its low hydrophobic property, the antioxidant activity of tannic acid in linoleic acid system was inferior to that of TBHQ. In the cellular antioxidant assay, tannic acid showed the higher activity than gallic acid in the "PBS wash" protocol, which could attribute to its high binding capacity of cell membrane. Compared with acarbose, tannic acid possessed the stronger α-amylase inhibitory capacity. And the static fluorescence quenching of α-amylase in the presence of tannic acid could be also observed, which was caused by their binding interaction.

Phytochemical and physical properties of blueberries, tart cherries, strawberries, and cranberries as affected by different drying methods

The effects of hot-air drying (AD), freeze drying (FD) and Refractance Window drying (RWD) on the retention of anthocyanins, phenolics, flavonoids, vitamin C and B, and antioxidant capacity (ORAC) in blueberries, tart cherries, strawberries, and cranberries, as well as organic acids and proanthocyanins in cranberries and chlorogenic acid and catchins in blueberries were evaluated. Changes in color, glass transition, specific heat, and surface morphology of the dried fruits were also evaluated. The quality retention in the dried fruits was found to be product and drying method specific. The FD products exhibited a better retention of vitamin C, ORAC, anthocyanins, and phenolics than the AD and RWD fruits. The RWD produced samples with a less effective ORAC, anthocyanins, and phenolics retention, but a higher total vitamin B retention compared to the FD products. The AD-dried fruits displayed significantly lesser quality retention in most of the quality indexes measured in the study.

Phenolic compounds and biological effects of edible Rumex scutatus and Pseudosempervivum sempervivum: potential sources of natural agents with health benefits

The present study outlines a chemical characterization and further effects beneficial to health of edible Rumex scutatus and Pseudosempervivum sempervivum, in addition to presenting the antioxidant, enzyme inhibitory effects and antimicrobial properties of different extracts. The phenolic compounds composition of the extracts was assessed by RP-HPLC-DAD, outlining benzoic acid and rutin as major constituents in P. sempervivum and rutin and hesperidin in R. scutatus. Moreover, further biological effects were tested on key enzymes involved in diabetes mellitus, Alzheimer's disease and skin melanogenesis revealing an important tyrosinase inhibitory effect of Pseudosempervivum water extract. Moreover, both species possessed antimicrobial properties towards bacteria and fungi relevant to public health. Accordingly, we find that R. scutatus and P. sempervivum can be considered as novel functional foods because they are rich sources of biologically active compounds that provide health benefits.