Dietary-Nutraceutical Properties of Oat Protein and Peptides.

Oats are considered the healthiest grain due to their high content of phytochemicals, dietary fibers, and protein. In recent years, oat protein and peptides have gained popularity as possible therapeutic or nutraceutical candidates. Generally, oat peptides with bioactive properties can be obtained by the enzymatic hydrolysis of proteins and are known to have a variety of regulatory functions. This review article focused on the nutraceutical worth of oat proteins and peptides and also describes the application of oat protein as a functional ingredient. Outcomes of this study indicated that oat protein and peptides present various therapeutical properties, including antidiabetic, antioxidant, antihypoxic, antihypertensive, antithrombotic, antifatigue, immunomodulatory, and hypocholestrolaemic. However, most of the conducted studies are limited to in vitro conditions and less data is available on assessing the effectiveness of the oat peptides in vivo. Future efforts should be directed at performing systematic animal studies; in addition, clinical trials also need to be conducted to fully support the development of functional food products, nutraceutical, and therapeutical applications.

Consumption of two whole kiwifruit (Actinide chinensis) per day improves lipid homeostasis, fatty acid metabolism and gut microbiota in healthy rats.

Golden kiwifruit (Actinidia chinensis) peel is a by-product enriched with polyphenols. The effects of fleshes of two Actinidia chinensis fruits (ACF) and fleshes with peels of two Actinidia chinensis fruits (ACFP) on lipid homeostasis, fatty acid metabolism and gut microbiota was investigated in healthy rats. Intervention of ACF and ACFP for 4 weeks significantly reduced total cholesterol, total triglycerides, and increased the high-density lipoprotein levels in rats. ACF and ACFP ameliorated lipid peroxidation in rats, by the lowering hepatic MDA level and enhancing GSH-Px and SOD activities. In addition, ACFP significantly decreased the saturated fatty acids in serum and increased the polyunsaturated fatty acids in hepatic and serum of rats. Analysis of gut microbiota revealed that ACF and ACFP evidently increased the microbial richness and diversity of gut microbiota. The Firmicutes/Bacteroidetes ratio was significantly reduced from 3.04 in ND group to 1.34 and 2.12 in ACF and ACFP groups, respectively. Moreover, ACF and ACFP significantly increased the abundance of beneficial bacteria (Lactobacillus and Barnesiella) and reduced harmful bacteria (Enterococcus, Escherichia, and Staphylococcus). Overall, ACFP exerts more potent health-improving effects than ACF. Our study provides a scientific basis for the development of kiwifruit (including pericarp)-based novel natural products with significant health benefits.

Regulatory Effects of Stachyose on Colonic and Hepatic Inflammation, Gut Microbiota Dysbiosis, and Peripheral CD4+ T Cell Distribution Abnormality in High-Fat Diet-Fed Mice.

A long-term high-fat diet (HFD) can cause a range of health problems. Gut microbiota plays a decisive role in the development of HFD-associated inflammation, involved in function of T cells. This study was designed to probe the regulative effects of dietary stachyose, a functional oligosaccharide, on HFD-induced weight gain, inflammation, gut microbiota dysbiosis, and T cell abnormality in C57Bl/6 mice. Mice were divided into three groups which received normal chow, HFD and HFD plus stachyose (400 mg/kg), respectively. Results showed that administration of stachyose diminished the HFD-induced upregulation of serum TNF-α level and elevation of peripheral blood leukocyte populations to alleviate the HFD-caused colonic and hepatic inflammation in mice. Analysis of gut microbiota revealed that stachyose improved the intestinal homeostasis of HFD-fed mice by improving the bacterial diversity with the increases in the relative abundances of the Prevotellaceae_NK3B31_group, Parasutterella, Christensenellaceae_R-7_group, and Anaerovorax, as well as the fecal level of butanoic acid, while decreasing the ratio of Firmicutes-to-Bacteroidetes and the abundances of the Lachnospiraceae_NK4A136_group, Desulfovibrio, Anaerotruncus, Mucispirillum, Roseburia, and Odoribacter. Flow cytometric analysis showed that stachyose antagonized the HFD-induced decrease of peripheral CD4+ T cell population in mice. Conclusively, these findings suggest that long-term consumption of stachyose can ameliorate the HFD-associated colonic and hepatic inflammation and its complications by modulating gut microbiota.

Antioxidant, antimicrobial, and antiproliferative activity-based comparative study of peel and flesh polyphenols from Actinidia chinensis.

BACKGROUND: Kiwifruit (Actinidia chinensis) peel has been always considered as useless because of the harsh taste. To promote the full utilization of kiwifruit resources it is essential to explore the nutritional benefits of kiwifruit peel. OBJECTIVE: Our studies explored the difference in polyphenolic composition and biological activity including antioxidant, antimicrobial, and antiproliferative activity of the flesh and peel of kiwifruit. DESIGN: Antioxidant activity of the extracted polyphenols of the peel and flesh of A. chinensis was checked by 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis3-ethylbenzothiazoline-6-sulphonic acid (ABTS), hydroxyl ion reduction, and ion chelating ability. Antibacterial activity against Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus and antiproliferative activity against HepG2 was tested in a dose- and time-dependent manner. Liquid chromatography/mass spectrometry (LC/MS) chromatogram of the peel and flesh further differentiated the phenolic acid profile. RESULTS: The pericarp of kiwifruit was found to be more abundant in polyphenols and flavonoids than the flesh, with contents of 12.8 mg/g and 2.7 mg/g, respectively. LC/MS analysis revealed that the catachin, quercetin and epigallocatechin content (the main polyphenols in kiwifruit) in the peel was significantly higher than in the flesh (P < 0.05). The antioxidant and antibacterial activity of the peel was significantly higher when compared to the flesh. Moreover, the proliferation of HepG2 cells was time- and dose-dependently inhibited by kiwifruit polyphenols, with IC50 values of 170 µg/mL and 291 µg/mL for peel and flesh polyphenols after 72 h of treatment time, respectively. CONCLUSION: Kiwifruit peel, with higher content of phenolics and flavonoids, exerts more potent antioxidant, antibacterial, and anticancer activity than the flesh. Our study provides scientific evidence for the development of kiwifruit, especially peel-based, novel natural products with excellent bioactivity.

Immunomodulatory effects of an acidic polysaccharide fraction from herbal Gynostemma pentaphyllum tea in RAW264.7 cells.

A new acidic polysaccharide (GPTP-3) with a molecular weight of 2.49 × 106 Da was extracted and purified from Gynostemma pentaphyllum tea. Monosaccharide analysis revealed that GPTP-3 mainly comprised mannose (20.4%), glucuronic acid (17.4%), glucose (33.4%), and galactose (21.4%) (parentheses indicate the molar percentages). Immunostimulating assays indicated that GPTP-3 could markedly promote the secretion of NO, TNF-α, IL-1ß, and IL-6 in murine macrophage RAW264.7. TLR4 was found to be a recognized target of GPTP-3. Moreover, TLR4-related mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt, including ERK, JNK, p38, and Akt, were rapidly activated by GPTP-3 in RAW264.7 cells. Furthermore, GPTP-3 was found to induce the nuclear translocation of NF-κB subunit p65. All these findings suggest that MAPK, PI3K/Akt, and NF-κB pathways are involved in GPTP-3-induced macrophage activations, and GPTP-3 has the potential to be developed as a functional food with immunomodulatory functions.

Physicochemical responses and microbiological changes of bream (Megalobrama ambycephala) to pectin based coatings enriched with clove essential oil during refrigeration.

The effectiveness of pectin coatings enriched with clove essential oil (CEO), as new edible coatings were investigated to preserve bream (Megalobrama ambycephala) fillets during refrigeration over a period of 15 days. All samples were analyzed for physicochemical (pH, PV, TBA and TVB-N), microbiological (Total viable count, Psychrophilic bacteria, Lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp., H2S producing bacteria) and organoleptic attributes. The results revealed that the CEO incorporation reduced the extent of lipid oxidation, as judged by PV, TBA and TVB-N, thus extending the shelf life of bream fillets by at least 15 days. Moreover, the application of pectin coatings with CEO improved the weight loss, water holding capacity, textural and color attributes of the bream samples significantly compared to untreated sample. Pectin coating along with CEO was effective in inhibiting bacterial growth especially in gram-negative bacteria, while the growth of lactic acid bacteria remained constant for most of the storage period. The effect on the microorganisms during storage was in accordance with biochemical indexes of the quality, representing the viability of these coatings for bream preservation. Thus, the coatings developed in present study could inhibit the development of lipid oxidation during cold storage, representing an option as a seafood preservative.

Chemical characteristics, antioxidant capacities and hepatoprotection of polysaccharides from pomegranate peel.

This proposed work aimed to investigate the chemical characteristic, antioxidant capacities and hepatoprotection effect of pomegranate peel polysaccharides (PPP) on CCl4-induced oxidative damage in mice. PPP was identified as the acidic heteropolysaccharides by HPLC methods. In vitro test showed that PPP had excellent reducing power and scavenging effects against free radicals. Administration of PPP (50, 100 and 200 mg/kg·bw) in mice before the injection of CCl4 could observably antagonize the increased serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and hepatic malonaldehyde level in CCl4-induced mice, especially administrated with 200 mg/kg·bw of PPP. Hepatic enzymatic activities of total superoxide dismutase, glutathione peroxidase, catalase and non-enzymatic activity of glutathione were markedly increased at high dosage of PPP, respectively. In addition, histopathological observation of liver further proved these biochemical characteristics. Therefore, it can be concluded that PPP exhibits strong protective effects against CCl4-induced liver injury in mice.

Chemical characterization of a novel polysaccharide ASKP-1 from Artemisia sphaerocephala Krasch seed and its macrophage activation via MAPK, PI3k/Akt and NF-κB signaling pathways in RAW264.7 cells.

The aim of this study was to investigate the molecular mechanism underlying the immunomodulatory effect of the purified Artemisia sphaerocephala Krasch seed polysaccharide (ASKP-1) in RAW264.7 macrophages. Chemical characteristic analysis revealed that ASKP-1 consisted of 14.1% mannose, 56.9% glucose and 19.6% galactose with the average molecular weight of 9.08 × 105 Da and the mixed glycan backbone structure containing 1→4)-Glcp (39.8%), 1→6)-Galp (18.8%), 1→3,6)-Manp (19.6%), 1→)-Glcp (10.8%), 2→6)-Manp (4.0%) and 2→3,5)-Araf (7.0%). In vitro studies showed that ASKP-1 markedly induced the release of cytotoxic molecules (NO and ROS) and secretion of the cytokines (TNF-α, INF-ß, and IL-6) and significantly enhanced the phagocytosis of RAW264.7 macrophages. Furthermore, TLR4 was found to be a recognized target of ASKP-1 and its related mitogen-activated protein (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt, including phosphorylated ERK, JNK, p38 and Akt, were rapidly activated by ASKP-1 in RAW264.7 macrophages. Moreover, ASKP-1 was found to cause the nuclear translocation of the nuclear factor NF-κB subunit p65 and the degradation of IκB-α in RAW264.7 macrophages. All these findings suggest that MAPK, PI3K/Akt and NF-κB pathways are involved in ASKP-1-induced macrophage activation, and ASKP-1 is a potential immunomodulating function food.