Assessment of the Phenolic Profiles, Hypoglycemic Activity, and Molecular Mechanism of Different Highland Barley (Hordeum vulgare L.) Varieties

Comparative Analysis of Hulless Barley Transcriptomes to Regulatory Effects of Phosphorous Deficiency

Hulless barley is a cold-resistant crop widely planted in the northwest plateau of China. It is also the main food crop in this region. Phosphorus (P), as one of the important essential nutrient elements, regulates plant growth and defense. This study aimed to analyze the development and related molecular mechanisms of hulless barley under P deficiency and explore the regulatory genes so as to provide a basis for subsequent molecular breeding research. Transcriptome analysis was performed on the root and leaf samples of hulless barley cultured with different concentrations of KH2PO4 (1 mM and 10 μM) Hoagland solution. A total of 46,439 genes were finally obtained by the combined analysis of leaf and root samples. Among them, 325 and 453 genes had more than twofold differences in expression. These differentially expressed genes (DEGs) mainly participated in the abiotic stress biosynthetic process through Gene Ontology prediction. Moreover, the Kyoto Encyclopedia of Genes and Genomes showed that DEGs were mainly involved in photosynthesis, plant hormone signal transduction, glycolysis, phenylpropanoid biosynthesis, and synthesis of metabolites. These pathways also appeared in other abiotic stresses. Plants initiated multiple hormone synergistic regulatory mechanisms to maintain growth under P-deficient conditions. Transcription factors (TFs) also proved these predictions. The enrichment of ARR-B TFs, which positively regulated the phosphorelay-mediated cytokinin signal transduction, and some other TFs (AP2, GRAS, and ARF) was related to plant hormone regulation. Some DEGs showed different values in their FPKM (fragment per kilobase of transcript per million mapped reads), but the expression trends of genes responding to stress and phosphorylation remained highly consistent. Therefore, in the case of P deficiency, the first response of plants was the expression of stress-related genes. The effects of this stress on plant metabolites need to be further studied to improve the relevant regulatory mechanisms so as to further understand the importance of P in the development and stress resistance of hulless barley.

Developments in the study of Chinese herbal medicine's assessment index and action mechanism for diabetes mellitus

In traditional Chinese medicine (TCM), based on various pathogenic symptoms and the 'golden chamber' medical text, Huangdi Neijing, diabetes mellitus falls under the category 'collateral disease'. TCM, with its wealth of experience, has been treating diabetes for over two millennia. Different antidiabetic Chinese herbal medicines reduce blood sugar, with their effective ingredients exerting unique advantages. As well as a glucose lowering effect, TCM also regulates bodily functions to prevent diabetes associated complications, with reduced side effects compared to western synthetic drugs. Chinese herbal medicine is usually composed of polysaccharides, saponins, alkaloids, flavonoids, and terpenoids. These active ingredients reduce blood sugar via various mechanism of actions that include boosting endogenous insulin secretion, enhancing insulin sensitivity and adjusting key enzyme activity and scavenging free radicals. These actions regulate glycolipid metabolism in the body, eventually achieving the goal of normalizing blood glucose. Using different animal models, a number of molecular markers are available for the detection of diabetes induction and the molecular pathology of the disease is becoming clearer. Nonetheless, there is a dearth of scientific data about the pharmacology, dose-effect relationship, and structure-activity relationship of TCM and its constituents. Further research into the efficacy, toxicity and mode of action of TCM, using different metabolic and molecular markers, is key to developing novel TCM antidiabetic formulations.

Chemical Basis for Determining the Allelopathic Potential of Invasive Plant Wall Barley (Hordeum murinum L. subsp. murinum)

The study investigated compounds present in the invasive grass Hordeum murinum L. subsp. murinum and tested the allelopathic potential of this plant against common meadow species Festuca rubra L. and Trifolium repens L. Gas chromatography-mass spectrometry (GC-MS) performed separately on the ears and stalks with leaves of wall barley revealed 32 compounds, including secondary metabolites, that may play an important role in allelopathy. Two compounds, N-butylbenzenesulfonamide (NBBS) and diphenylsulfone (DDS), were described for the first time for wall barley and the Poaceae family. The presence of 6,10,14-trimethylpentadecan-2-one (TMP) has also been documented. Aqueous extracts of H. murinum organs (ears and stalks with leaves) at concentrations of 2.5%, 5%, and 7.5% were used to evaluate its allelopathic potential. Compared to the control, all extracts inhibited germination and early growth stages of meadow species. The inhibitory effect was strongest at the highest concentration for both the underground and aboveground parts of the seedlings of the meadow species tested. Comparing the allelopathic effect, Trifolium repens proved to be more sensitive. In light of the results of the study, the removal of wall barley biomass appears to be important for the restoration of habitats where this species occurs due to its allelopathic potential.

Molecular mechanism of microRNA-mediated hypoglycemic effect of whole grain highland barley

As a non-coding RNA, microRNA (miRNA) has been proven to play an important role in the development and progression of type 2 diabetes mellitus (T2DM). Highland barley is a whole grain from the Tibetan areas of China. Our previous studies have demonstrated its hypoglycemic effect. To further explore the underlining molecular mechanism, we investigated the effect of highland barley intervention on liver miRNA expression profiles in diabetic mice. Our results showed that ten differentially expressed miRNA among different groups were identified and their target genes were predicted. Remarkably, many glycometabolism-associated genes, including Foxo3, Nras, Rptor, Igf1r, Tsc2 and Braf, were negatively regulated by miR-122-5p, miR-503-5p, miR-455-5p and miR-210-3p, respectively. Pathway enrichment analysis revealed these target genes were mainly involved in AMPK, MAPK and FOXO signaling pathways. Thereby, these miRNA and mRNA were validated using qRT-PCR, and the results were consistent with the small RNA-seq and expectations. Highland barley could regulate the MAPK, AMPK, and FOXO signaling pathways by regulating critical miRNA-mRNA pairs, e.x. miR-210-3p-Tsc2/Braf, miR-122-5p-Foxo3, and miR-455-5p-Igf1r, thereby improving blood glucose metabolism in diabetic mice. The present study preliminarily explored the hypoglycaemic effects of highland barley based on transcriptomics, and more detailed and in-depth studies on this topic are needed in the future.

Evaluation of Olive Leaf Phenolic Compounds' Gastrointestinal Stability Based on Co-Administration and Microencapsulation with Non-Digestible Carbohydrates

The large generation of olive by-products has motivated their revalorization into high-added-value products. In this regard, olive leaves pose as an interesting source of bioactive compounds, due to their phenolic content with commonly known antioxidant, anti-inflammatory, and immunomodulatory properties, with potential application in non-communicable diseases. However, their effectiveness and applicability into functional foods is limited by their instability under gastrointestinal conditions. Thus, the development of protective formulations is essential. In this study, the spray-drying encapsulation of a phenolic-rich olive leaf extract with inulin as the encapsulating agent was optimized. Then, the behavior of the free extract under gastrointestinal conditions, its co-administration with the encapsulating agent, and the optimized microencapsulated formulation were studied through an in vitro gastrointestinal digestion process following the INFOGEST protocol. Digestion of the free extract resulted in the degradation of most compounds, whereas this was minimized in the co-administration of the non-encapsulated extract with the encapsulating agent. This protective effect, related to its interaction with inulin, was similar to the microencapsulated formulation. Thus, both approaches, co-administration and microencapsulation with inulin, could be promising strategies for the improvement of the stability of these anti-inflammatory and immunomodulatory compounds under gastrointestinal conditions, enhancing their beneficial effect.

Exploration of the molecular mechanism of insulin resistance in adipose tissue of patients with type 2 diabetes mellitus through a bioinformatic analysis

BACKGROUND

We aimed to determine the cis-expression Quantitative Trait Loci (cis-eQTL) and trans-eQTL of differentially expressed genes (DEGs) in insulin resistance (IR) related pathways.

METHODS

The expression profile data for insulin sensitivity (IS) and IR in the adipose tissue of patients with type 2 diabetes mellitus (T2DM) were acquired from the Gene Expression Omnibus databases. Then, the Gene set enrichment analysis (GSEA) and Gene set variation analysis (GSVA) methods were performed to identify the significant enrichment of potential Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways between IS and IR groups, and the Wilcoxon rank sum test was carried out to identify the DEGs related to KEGG pathways. Finally, the cis-eQTLs and trans-eQTLs that can affect the expression of DEGs were screened from the eQTLGen database.

RESULTS

The GSEA and GSVA analysis indicated that the mTOR signaling pathway, insulin signaling pathway and T2DM had a strong correlation with the pathological process of T2DM. Furthermore, six genes (ACACA, GYS2, PCK1, PRKAR1A, SLC2A4, and VEGFA) were found to be significantly differentially expressed in IR-related pathways. Finally, we have identified a total of 1073 cis-eQTLs and 24 trans-eQTLs.

CONCLUSIONS

We screened out six genes that were significantly differentially expressed in IR-related pathways, including ACACA, GYS2, PCK1, PRKAR1A, SLC2A4, and VEGFA. Moreover, we discovered that these six genes were affected by 1073 cis-eQTLs and 24 trans-eQTLs.

A comparative metabolomics study of polyphenols in highland barley (Hordeum vulgare L.) grains with different colors

Highland barley (HB) grains are gaining increasing popularity owing to their high nutritional merits. However, only limited information is available on the metabolic profiles of HB grains polyphenols, especially the difference of polyphenols in different colors of HB. In this study, we determined the metabolic profiles of black, blue, and white HB grains via an ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS)-based metabolomics. A total of 402 metabolites were identified, among which 198, 62, and 189 metabolites displayed different accumulation patterns in the three comparison groups (WHB vs. BKHB, WHB vs. BEHB, BEHB vs. BKHB), respectively. In particular, flavonoids and phenolic acids contents displayed considerable differences among the three HB cultivars. The phenolics content of black HB was relatively high. Additionally, "Flavonoid biosynthesis" and "flavone and flavonol biosynthesis" were the significantly enriched pathways. In conclusion, this study provides comprehensive insights into the adequate utilization and development of novel HB-based functional foods.

Chemical characterization, antioxidant and antidiabetic activities of a novel polyherbal formulation comprising of Hordeum vulgare, Elettaria cardamomum and Cicer arietinum extracts

Diabetes mellitus (DM) is the most prevalent endocrine disorder. Numerous individual herbs possess anti-diabetic activity. The seeds of Hordeum vulgare, Elettaria cardamomum and Cicer arietinum are traditionally used to manage DM. The ambition of this work was to formulate the poly-herbal granules (PHGs) comprising of these three functional foods and evaluate their in-vitro antioxidant and antidiabetic potential. The dried seed extracts of Hordeum vulgare, Elettaria cardamomum and Cicer arietinum were used in a ratio of 2.5:1:1 to formulate PHGs by wet granulation method. The ratio of extracts was selected on the basis of traditional phytotherapies popularly used by local Hakeems of Pakistan to achieve glycemic control in diabetic patients resistant to traditional allopathic regime of medicine. The flow properties of developed PHGs were evaluated. The UV-Visible spectroscopic, Fourier Transform Infrared (FTIR) and HPLC-DAD of all seed extracts and PHGs were performed. The in-vitro antioxidant DPPH, FRAP, total antioxidant capacity (TAC) and Nitric Oxide (NO) scavenging assays were carried out on PHGs. The in-vitro antidiabetic activity of PHGs was investigated by alpha-amylase and alpha-glucosidase enzyme inhibition activity. The developed PHGs exhibited excellent flow properties. The UV-Vis spectra of all seed extracts and PHGs demonstrated peak at 278 nm showing the presence of flavonoids and phenols. The FTIR spectra confirmed the existence of flavonoids, and phenols along with amines in seed extracts as well as PHGs. The HPLC-DAD test revealed the existence of gallic acid, ascorbic acid, Quercetin-3-(caffeoyldiglucoside)-7-glucoside, Rosmarinic acid, delphinidin-3,5-diglucosides, Kaempferol-3-feruloylsophoroside-7-glucoside and Phloroglucinol in PHGs. The PHGs exhibited IC50 of 51.23, 58.57, 55.41 and 53.13 μg/mL in DPPH assay, FRAP assay, TAC, Nitric oxide scavenging assays respectively. The PHGs also demonstrated IC50 of 49.97 and 36.16 μg/mL in alpha-amylase and in alpha-glucosidase inhibition assays respectively in dose dependent manner. The developed PHGs exhibited an excellent flow property. These exhibit significant in-vitro antioxidant and antidiabetic profile by virtue of flavonoid and phenolic acid derivatives.

Structural and physicochemical properties of the different ultrasound frequency modified Qingke protein

There is a burgeoning demand for modified plant-based proteins with desirable physicochemical and functional properties. The cereal Qingke is a promising alternative protein source, but its use has been limited by its imperfect functional characteristics. To investigate the effect of ultrasound treatment on Qingke protein, we applied single- (40 kHz), dual- (28/40 kHz), and tri- (28/40/50 kHz) frequency ultrasound on the isolated protein and measured subsequent physicochemical and structural changes. The results showed that the physicochemical properties of proteins were modified following ultrasound treatment, and many of these changes significantly increased with increasing frequency. Compared with the native Qingke protein (control), the solubility, foaming activity, stability, and water or oil holding capacity of tri-frequency ultrasound modified Qingke protein increased by 43.54%, 20.83%, 20.51%, 28.9%, and 45.2%, respectively. Furthermore, ultrasound treatment altered the secondary and tertiary structures of the protein resulting in more exposed chromophoric groups and inner hydrophobic groups, as well as reduced β-sheets and increasedrandom coils, relative to the control. Rheological and texture characterization indicated that the values of G' and G'', hardness, gumminess, and chewiness decreased after ultrasound treatment. This study could provide a theoretical basis for the application of multi-frequency ultrasonic technology for modification of Qingke protein to expand its potential use as an alternative protein source.

Polyphenol Profile and In Vitro Antioxidant and Enzyme Inhibitory Activities of Different Solvent Extracts of Highland Barley Bran

Five different solvent extracts of highland barley bran were analyzed and compared for their polyphenol profile, antioxidant activity, and α-glucosidase and α-amylase inhibitory activities. The highland barley bran acetone extract had the highest total phenolic content, total flavonoid content, and antioxidant capacity. It was followed by the methanol and ethanol extracts, while n-butanol and ethyl acetate extracts exhibited lower measured values. Diosmetin, luteolin, protocatechuic acid, vanillic acid, ferulic acid, phlorogucinol, diosmin, isoquercitrin, catechin, and isovitexin were among the most abundant phenolic compounds identified in different solvent extracts, and their concentrations varied according to the solvent used. The highest α-glucosidase and α-amylase inhibitory activity were observed in the ethyl acetate extract of highland barley bran, followed by the acetone and methanol extracts. In contrast, n-butanol and ethanol extracts exhibited lower measured values. The different solvent extracts were effective inhibitors for α-glucosidase and α-amylase with activity reaching to 34.45-94.32% and 22.08-35.92% of that of positive control acarbose, respectively. There were obvious correlations between the phenolic content and composition of different solvent extracts and their in vitro antioxidant activity, α-glucosidase inhibition activity and α-amylase inhibition activity. Black barley bran is an excellent natural raw material for developing polyphenol-rich functional foods and shows good antioxidant and hypoglycemic potential to benefit human health.

A comparison between partially peeled hulless barley and whole grain hulless barley: beneficial effects on the regulation of serum glucose and the gut microbiota in high-fat diet-induced obese mice

Though the hypoglycemic effect of whole grain hulless barley (Hordeum vulgare L.) has been documented, whether glucose metabolism would be improved by hulless barley with moderate peeling is still unclear. The purpose of this study was to compare the differences in glucose metabolism and gut microbiota between partially (10%) peeled hulless barley (PHB) and whole grain hulless barley (WHB) intervention in obese mice induced by a high-fat diet. The results showed that both PHB and WHB interventions significantly improved the impaired glucose tolerance, fat accumulation in fat and liver tissues, and the impaired intestinal barrier in mice. The dysbiosis of gut microbiota was improved and the relative abundance of some beneficial bacteria such as genera Lactobacillus, Bifidobacterium, Ileibacterium, and norank_f__Mutibaculaceae was increased by both, PHB and WHB, interventions. Spearman correlation analysis revealed that the abundance of Bifidobacterium was negatively correlated with the area under the blood glucose curve. In conclusion, our results provide evidence that hulless barley improved the gut microbiota and impaired glucose tolerance in mice, and also showed that there was little loss of hypoglycemic effect even when hulless barley was moderately peeled.

Ferulic Acid Mediates Metabolic Syndrome via the Regulation of Hepatic Glucose and Lipid Metabolisms and the Insulin/IGF-1 Receptor/PI3K/AKT Pathway in Palmitate-Treated HepG2 Cells

Ferulic acid (FA) is one of the most abundant bound phenolics in whole grains, partly contributing to its preventive effects on metabolic syndrome (MetS). The study aims to investigate if FA mediates MetS through the regulation of hepatic metabolisms and the insulin receptor related pathways in the palmitate-treated HepG2 cells (MetS model). We found that FA (50, 100, and 200 μM) dramatically ameliorated the lipid accumulation in the MetS model. FA significantly decreased the activities of the gluconeogenic enzymes, G6Pase and PEPCK, downregulated the lipogenic enzyme FAS-1, and upregulated the lipolytic enzyme CPT-1 by regulating a series of transcriptional factors including HNF4α, FOXO-1, SREBP-1c, and PPAR-γ. Notably, we found that FA's ability to alleviate MetS is achieved by activating the insulin receptor/PI3K/AKT pathway. Our results validated the effects of FA on mediating the metabolic disorders of lipid and glucose pathways and unveiled its potential intracellular mechanisms for the prevention of MetS.

Common Ayurvedic, Chinese traditional and Unani antidiabetic formulations- a review

Diabetes mellitus is the most widely recognized endocrine disorder which is influencing a bigger populace on the planet. There are various causes of diabetes, such as physical inactivity, obesity, family history, race, and age. Diabetes mellitus is associated with some life-threatening complications, such as neuropathy, nephropathy, various eye diseases or retinopathy, and cardiovascular disorders. Many synthetic antihyperglycemic agents are available in the market for the treatment of diabetes and its complications. But, due to some serious side effects of these synthetic agents, people are opting for herbal remedies and, therefore, they are now becoming popular. Herbal remedies have lesser side effects and higher affordability and therefore can be preferably used over synthetic agents for a long-term disorder like diabetes mellitus. In the present study, scientific research and review studies on the topic were collected from Science Direct, Scopus, PubMed, Google Scholar, and other relevant sources. The references of all the articles were screened manually for any additional information on popular polyherbal formulations in traditional Ayurvedic, Chinese, and Unani medicinal systems. It is found that these polyherbal formulations are studied for anti-diabetic potential. Furthermore, some are also investigated for mechanism of action of anti-diabetic effects. This review highlights various Ayurvedic, Chinese, and Unani polyherbal formulations commonly utilized in the management of diabetes mellitus along with their pre-clinical and clinical investigations, which will enhance the existing knowledge of the researchers.

In Vitro and In Vivo Digestive Fate and Antioxidant Activities of Polyphenols from Hulless Barley: Impact of Various Thermal Processing Methods and β-Glucan

The unfavorable bioaccessibility of polyphenols in cereal-based food limits their physiological functions as most polyphenols bind spontaneously to the cell-wall polysaccharides. Effects of β-glucan and various thermal processing methods including flaking and roasting, stir-frying, steam-flash explosion, and popping expansion on the bioaccessibility and antioxidant properties of polyphenols from hulless barley in vitro and in vivo were investigated in this study. The bioaccessibility and antioxidant capacity (via DPPH, ·OH, and ·O₂^- free radical scavenging, TAC, and FRAP assays) of polyphenol extracts from hulless barley treated by steam-flash explosion and popping expansion increased significantly before and after in vitro digestion compared to those from raw and other processed hulless barley. Further, the total polyphenol content of hulless barley elevated dramatically following hydrolyzing with β-glucanase, which was positively correlated with the antioxidant activity. Additionally, the hulless barley treated with steam-flash explosion exhibited potent antidiabetic effects and antioxidant capacity (via TAC, SOD, GSH-Px, CAT, and MDA assays) in type 2 diabetic rats. The absorption of individual phenolic compounds in the alimentary canal of rats was impacted obviously by thermal processing. This study provides new insights into enhancing the bioaccessibility of the polyphenols and suggests that β-glucans interact with polyphenols and proteins in the hulless barley matrix.

Genome-Wide Identification of Genes Related to Biosynthesis of Phenolic Acid Derivatives in Bletilla striata at Different Suspension Culture Stages

To screen the genes regulating the biosynthesis of phenolic acid derivatives from the genome of Bletilla striata, we designed a suspension culture system to sample the cells for the following experiments. The contents of four phenolic acid derivatives were determined by high-performance liquid chromatography, and several full-length transcriptome sequencings of RNA samples at 10 time points were performed for bioinformatics analysis. The correlation analysis was used to identify and verify the key DEGs involved in the biosynthesis of the four phenolic acid derivatives. The results showed that the contents of p-hydroxybenzylalcohol (HBA), Dactylorhin A, Militarine, and Coelonin peaked at 33 days postinoculation (Dpi), 18 Dpi, 39 Dpi, and 39 Dpi of the culture system, respectively. Based on transcriptome data, 80 DEGs involved in the biosynthesis of phenolic acid derivatives were obtained. The KEGG pathway enrichment analysis classified them mostly into five metabolic pathways: phenylpropane biosynthesis, starch and sucrose metabolic, cyanoamino acid metabolism, gluconeogenesis and glycolysis, and phenylalanine metabolism. qPCR analysis revealed that the relative gene expression levels were consistent with the overall trend of transcriptome sequencing results. Among them, 14, 18, 23, and 41 unigenes were found to be involved in the synthesis of HBA, Dactylorhin A, Coelonin, and Militarine, respectively. These unigenes laid a solid foundation for elucidating the biosynthesis mechanism of phenolic acid derivatives in suspension cells of B. striata.

Korean naked waxy barley (saechalssal) extract reduces blood glucose in diabetic mice by modulating the PI3K-Akt-GSK3β pathway

Saechalssal barley is Korea's representative naked waxy barley. This study investigated the anti-diabetic effect of the extract derived from saechalssal and its mechanism. The prethanol extract of saechalssal (SPE) showed greater α-glucosidase inhibitory activity in vitro and a more significant lowering of the postprandial blood glucose levels in normal mice compared to its water extract (SWE). When mice with type 2 diabetes (T2DM) induced by a high-fat diet and streptozotocin were fed SPE (200 mg/kg/day) for six weeks, the fasting blood glucose and serum free fatty acid levels were significantly lower than those of the control group. SPE significantly elevated the hepatic glycogen accumulation with increasing glycogen synthesis-related gene (GYS2 and UGP2) levels compared to the control group. SPE stimulated the expression of the hepatic glycolysis-related genes (GK, PFK1, and PK) and suppressed the gluconeogenesis-related genes (G6Pase, FBP1, and PEPCK). SPE up-regulated the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt), whereas it down-regulated the phosphorylation of glycogen synthase kinase 3 beta (GSK3β) compared to the control. The major flavonoids of SPE were naringin, prunin, and catechin, while its phenolic acids were ferulic acid and vanillic acid. These phytochemical compounds may contribute to the anti-hyperglycemic effects of SPE in diabetes. Overall, these results suggest that SPE has potential anti-diabetic activity through the regulating the PI3K/Akt/GSK3β pathway.

A review on the fate of phenolic compounds during malting and brewing: Technological strategies and beer styles

This review provides an overview on the influence of malting and brewing on the overall phenolic content of barley malt and beer. Beer phenolics are mainly originated from barley malt and can be found in free and bound forms, in concentrations up to 50% lower comparing to sweet wort. The use of roasted malts, in combination with proper milling and high mashing temperatures at low pH can lead to a release of bound phenolic forms and increased extraction. New technological strategies such as special yeasts, manipulation of enzymatic activity and dry-hopping may be relevant to improve the phenolic profile of beer and attain phenolic levels with benefits both for beer stability and consumer's health. As the content of free ferulic acid in beer only accounts up to approximately 15% of total content, further studies should put emphasis on its bound forms in different beer styles and non-alcoholic beers.

Beneficial Effects of Partly Milled Highland Barley on the Prevention of High-Fat Diet-Induced Glycometabolic Disorder and the Modulation of Gut Microbiota in Mice

The nutritional functions of highland barley (HB) are superior to those of regular cereals and have attracted increasing attention in recent years. The objective of this study was to investigate whether partly milled highland barley (PHB) can regulate the serum glucose and lipid disorders of mice fed a high-fat diet (HFD) and to further explore their potential gut microbiota modulatory effect. Our results showed that PHB supplementation significantly reduced fasting blood glucose (FBG) and improved oral glucose tolerance. Histological observations confirmed the ability of PHB to alleviate liver and intestine damage. Furthermore, the results of 16S amplicon sequencing revealed that PHB prevented a HFD-induced gut microbiota dysbiosis, enriching some beneficial bacteria, such as Lactobacillus, Bifidobacterium, and Ileibacterium, and reducing several HFD-dependent taxa (norank_f_Desulfovibrionaceae, Blautia, norank_f_Lachnospiraceae, unclassified_f_Lachnospiraceae, and Colidextribacter). In addition, the increase of Lactobacillus and Bifidobacterium presence has a slightly dose-dependent relationship with the amount of the added PHB. Spearman correlation analysis revealed that Lactobacillus and Bifidobacterium were negatively correlated with the blood glucose level of the oral glucose tolerance test. Overall, our results provide important information about the processing of highland barley to retain its hypoglycemic effect and improve its acceptability and biosafety.

Nano-encapsulation of polyphenols in starch nanoparticles: fabrication, characterization and evaluation

Nanoparticles are more promising than microcapsules as drug carriers because they can be absorbed directly by intestinal epithelial cells, significantly increasing the uptake and bioaccessibility of polyphenols.

Omnifarious fruit polyphenols: an omnipotent strategy to prevent and intervene diabetes and related complication?

Diabetes mellitus is a metabolic syndrome which cannot be cured. Recently, considerable interest has been focused on food ingredients to prevent and intervene in complications of diabetes. Polyphenolic compounds are one of the bioactive phytochemical constituents with various biological activities, which have drawn increasing interest in human health. Fruits are part of the polyphenol sources in daily food consumption. Fruit-derived polyphenols possess the anti-diabetic activity that has already been proved either from in vitro studies or in vivo studies. The mechanisms of fruit polyphenols in treating diabetes and related complications are under discussion. This is a comprehensive review on polyphenols from the edible parts of fruits, including those from citrus, berries, apples, cherries, mangoes, mangosteens, pomegranates, and other fruits regarding their potential benefits in preventing and treating diabetes mellitus. The signal pathways of characteristic polyphenols derived from fruits in reducing high blood glucose and intervening hyperglycemia-induced diabetic complications were summarized.

Food and Grain Consumption Per Capita in the Qinghai-Tibet Plateau and Implications for Conservation

Background: Grain security is crucial for social stability and ecosystem conservation regionally and globally, and it is particularly concerned widely in the Qinghai-Tibet Plateau (QTP) due to its high altitude and harsh climate for agriculture. Method: In this paper, we calculated and analyzed per capita food and grain consumption, including direct grain consumption, grain for fodder, industry consumption, seeds consumption, and wastage consumption and its changes in the QTP during 1995–2019. Results: The results showed that (1) in 2019, the average food consumption per capita was 333.35 kg, was stable since 1995. The dietary structure of residents was composed of direct grain consumption (44.15%), meat (10.72%), and milk (6.94%). The consumption of meat and milk was higher than the national average. (2) The average daily intake of energy and protein, animal protein, and the ratio of high-quality protein and fat energy were 2156.21 kcal·d⁻¹, 73.53 g·d⁻¹, 23.06 g·d⁻¹, 38.32%, and 27.77% in 2019. Their changes were −342.98 kcal·d⁻¹, −8.91 g·d⁻¹, 11.16 g·d⁻¹, 18.37%, and 11.08%, respectively. (3) The corresponding grain consumption per capita was 284.90 kg·a⁻¹ in 1995, 262.19 kg·a⁻¹ in 2010, and then remained stable until 2019. Conclusion: The study suggested that food consumption per capital was guaranteed at the well-off level since 2010, and food and dietary structure of residents were corresponding to physical geographic and climatic environment in the QTP. The conflict between food security and the ecosystem conservation can be managed without scarifying nature as the total grain consumption was stable since 2010, and the yield per unit area and total grain yield were both increasing since 2003 for agricultural condition improved in the QTP.

Chlorogenic acid and β-glucan from highland barley grain ameliorate β-cell dysfunction via inhibiting apoptosis and improving cell proliferation

Recent studies have reported that highland barley as a whole grain diet has anti-hyperglycemic effects, however little information is available about the active compounds that ameliorate pancreatic β-cell dysfunction and the related mechanisms. In this study, chlorogenic acid (CA) and β-glucan (BG) were identified as the active compounds that ameliorated β-cell dysfunction. CA ameliorated β-cell dysfunction by inhibiting cell apoptosis and improving glucose-stimulated insulin secretion via targeting G protein-coupled receptor 40 (GPR40) and regulating the phospholipase C β (PLCβ) pathway. BG ameliorated β-cell dysfunction by improving cell proliferation via targeting mammalian target of rapamycin (mTOR) and regulating the protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway. Furthermore, CA and BG improved β-cell sensitivity and pancreatic insulin secretion, and inhibited β-cell apoptosis in impaired glucose tolerance (IGT) mice. Notably, CA restored homeostasis model assessment (HOMA)-β values and Ca²⁺-ATP and K⁺-ATP levels back to normal levels, and BG at 300 mg per kg BW restored β-cell insulin contents back to normal levels in IGT mice. Additionally, the combination of CA and BG had an additive effect on ameliorating β-cell dysfunction. These results help develop whole highland barley grain as a functional food for preventing type 2 diabetes by ameliorating pancreatic β-cell damage.

Procyanidin B1 and p-Coumaric Acid from Highland Barley Grain Showed Synergistic Effect on Modulating Glucose Metabolism via IRS-1/PI3K/Akt Pathway

INTRODUCTION

Phenolic extract in highland barley grain has showed hypoglycemic effect, while little information is available about the active compounds and whether there exist additive or synergistic effect on modulating glucose metabolism.

METHODS AND RESULTS

Procyanidin B1 (PB) and p-coumaric acid (CA) are the active compounds in highland barley grain and show synergistic effect on improving glucose uptake and glycogen synthesis by upregulating glucose transporter (GLUT4) and downregulating glycogen synthase kinase-3β (GSK-3β) protein expression, respectively. The mechanism may be attributed to target insulin receptor (IRβ) and regulate insulin receptor substrate-1 (IRS-1)/phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (Akt) pathway. Furthermore, PB + CA exhibits synergistic effect on restoring glucose intolerance and insulin resistance, and improving hepatic glycogen synthesis in impaired glucose tolerance (IGT) mice. The postprandial blood glucose (PBG), homeostasis model assessment (HOMA)-IR values and serum insulin contents in PB + CA-treated IGT mice with dosage of 300 mg kg^-1 BW are reversed to normal levels. Additionally, PC + CA shows additive effect on inhibiting gluconeogenesis in vitro and in vivo.

CONCLUSION

PB + CA in highland barley grain synergistically modulate glucose metabolism. These results may provide evidence of whole highland barley grain diet achieve superior effect on restoring IGT than isolated components.

Highland Barley and Its By-Products Enriched with Phenolic Compounds for Inhibition of Pyrraline Formation by Scavenging α-Dicarbonyl Compounds

Pyrraline, a typical kind of advanced glycation end product, has been found to contribute to the development of pathologies associated with ageing and diabetes mellitus. In the study, phenolic compounds extracted from highland barley whole grain (HBWG) and vinasse (HBVN) were used to inhibit pyrraline formation in a simulated food. The optimal extraction condition for HBWG and HBVN was using 8 mL of 50% acetone solution at 50 °C for 60 min. The extraction and identification of phenolic compounds from HBWG and HBVN were performed by UPLC-PAD-MS/MS. The inhibitory effects of pyrraline in the simulated food were 52.03% and 49.22% by HBVN and HBWG, respectively. The diphenyl picrylhydrazyl radical- and ferric-reducing ability of plasma assays was used to evaluate the antioxidant activity of the extracts. The main inhibition pathways and molecular mechanism of phenolic compounds on pyrraline regulation were explored by scavenging α-dicarbonyl compounds. The study demonstrated that highland barley and its by-products can potentially be used as a functional food to regulate pyrraline formation during food processing.

Rhodiola extract promotes longevity and stress resistance of Caenorhabditis elegans via DAF-16 and SKN-1

The effects of Rhodiola extract (RE) on longevity and stress resistance in Caenorhabditis elegans (C. elegans), and the underlying molecular mechanisms were explored in the present study. Results showed that the lifespan of C. elegans was remarkably prolonged by 37.1% after treated with high-dose RE (480 μg mL^-1). Intervention with RE alleviated aging-related declines in the C. elegans model, and enhanced the stress resistance against heat shock, ultraviolet radiation and paraquat. Moreover, RE reduced the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and increased the activities of superoxide dismutase (SOD) and catalase (CAT). RE also upregulated the gene expression of sod-3, gst-4, daf-16, skn-1 in C. elegans, downregulated the gene expression of daf-2 and age-1, and accelerated the translocation of DAF-16 and SKN-1 into the nucleus. Furthermore, the daf-16(mu86) and skn-1(zu169) mutants reversed the extension of lifespan triggered by RE, indicating that these genes were involved in RE-regulated longevity. These results demonstrated that RE could enhance lifespan extension, healthspan and stress resistance of C. elegans via insulin/IGF signaling and SKN-1 pathways. Therefore, the present findings suggested Rhodiola as a potential candidate to ameliorate the symptoms of aging.

Diversity of Culturable Bacteria Isolated from Highland Barley Cultivation Soil in Qamdo, Tibet Autonomous Region

The soil bacterial communities have been widely investigated. However, there has been little study of the bacteria in Qinghai-Tibet Plateau, especially about the culturable bacteria in highland barley cultivation soil. Here, a total of 830 individual strains were obtained at 4°C and 25°C from a highland barley cultivation soil in Qamdo, Tibet Autonomous Region, using fifteen kinds of media. Seventy-seven species were obtained, which belonged to 42 genera and four phyla; the predominant phylum was Actinobacteria (68.82%), followed by Proteobacteria (15.59%), Firmicutes (14.29%), and Bacteroidetes (1.30%). The predominant genus was Streptomyces (22.08%, 17 species), followed by Bacillus (6.49%, five species), Micromonospora (5.19%, four species), Microbacterium (5.19%, four species), and Kribbella (3.90%, three species). The most diverse isolates belonged to a high G+C Gram-positive group; in particular, the Streptomyces genus is a dominant genus in the high G+C Gram-positive group. There were 62 species and 33 genera bacteria isolated at 25°C (80.52%), 23 species, and 18 genera bacteria isolated at 4°C (29.87%). Meanwhile, only eight species and six genera bacteria could be isolated at 25°C and 4°C. Of the 77 species, six isolates related to six genera might be novel taxa. The results showed abundant bacterial species diversity in the soil sample from the Qamdo, Tibet Autonomous Region.

Metabolite Profiling of Manilkara zapota L. Leaves by High-Resolution Mass Spectrometry Coupled with ESI and APCI and In Vitro Antioxidant Activity, α-Glucosidase, and Elastase Inhibition Assays

High-resolution mass spectrometry equipped with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) sources was used to enhance the characterization of phytochemicals of ethanol extracts of Manilkara zapota L. leaves (ZLE). Sugar compounds, dicarboxylic acids, compounds of phenolic acids and flavonoids groups, and other phytochemicals were detected from the leaves. Antioxidant activity and inhibition potentiality of ZLE against α-glucosidase enzyme, and elastase enzyme activities were evaluated in in vitro analysis. ZLE significantly inhibited activities of α-glucosidase enzyme at a lower concentration (IC50 2.51 ± 0.15 µg/mL). Glucose uptake in C2C12 cells was significantly enhanced by 42.13 ± 0.15% following the treatment with ZLE at 30 µg/mL. It also exhibited potential antioxidant activities and elastase enzyme inhibition activity (IC50 27.51 ± 1.70 µg/mL). Atmospheric pressure chemical ionization mass spectrometry (APCI-MS) detected more m/z peaks than electrospray ionization mass spectrometry (ESI-MS), and both ionization techniques illustrated the biological activities of the detected compounds more thoroughly compared to single-mode analysis. Our findings suggest that APCI along with ESI is a potential ionization technique for metabolite profiling, and ZLE has the potential in managing diabetes by inhibiting α-glucosidase activity and enhancing glucose uptake.

Highland Barley Whole Grain (Hordeum vulgare L.) Ameliorates Hyperlipidemia by Modulating Cecal Microbiota, miRNAs, and AMPK Pathways in Leptin Receptor-Deficient db/db Mice

The mechanisms of highland barley whole grain (BWG) with rich phenolics on obese db/db mice were investigated in this study. Oral consumption of BWG reduced food intake, body weight, organ/body weight indexes of liver and fat, levels of serum and hepatic lipids, liver injury, and oxidative stress. Furthermore, BWG recovered the disorder of cecal microbiota by augmenting the Bacteroidetes/Firmicutes ratio and Alistipes abundance and decreasing the abundances of Bacteroides and Desulfovibrionaceae to modulate lipid metabolism-related genes. BWG inhibited fatty acid biosynthesis via upregulating the phosphorylation of AMP-activated protein kinase α, while downregulating sterol regulatory element binding protein-1c, fatty acid synthase (FAS), and stearoyl-CoA desaturase 1 levels. BWG also significantly downregulated miRNA-122, miRNA-33, miRNA-34a, and miRNA-206 levels. Accordingly, BWG exhibited hypolipidemic potential through modulating cecal microbiota, AMPK/SREBP-1c/FAS pathway, and related miRNAs, triggering the alleviation of dyslipidemia. These findings suggested BWG as an effective candidate to ameliorate the symptoms of hyperlipidemia.

Metabonomic Responses of Grazing Yak to Different Concentrate Supplementations in Cold Season

Supplementation plays an important role in reversing the weight loss of grazing yaks during cold season. However, little is known about the effect of supplementation on the serum metabolites of grazing yaks. The objective of this study was to explore the effects of supplementary feeding on average daily gain (ADG) and serum metabolites with nuclear magnetic resonance (NMR)-based metabolomics method in growing yaks during cold season on the Qinghai-Tibetan plateau. Twenty 1.5-year-old female yaks (91.38 ± 10.43 kg LW) were evenly divided into three treatment groups and a control group (CON) (n = 5 per group). All the yaks were released to graze during daytime, whereas the yaks in the treatment groups were supplemented with highland barley (HLB), rapeseed meal (RSM), and highland barley plus rapeseed meal (HLB + RSM) at night. The whole experiment lasted for 120 days. Results indicated that the ADG of growing yak heifers was increased by concentrate supplementations, and ADG under HLB and HLB + RSM group was 37.5% higher (p < 0.05) than that with RSM supplementation. Supplementary feeding increased the plasma concentrations of total protein (TP), albumin (ALB), and blood urea nitrogen (BUN) of those in the CON group, and concentrations of BUN were higher in the RSM group than in the HLB and HLB + RSM group. Compared with the CON group, serum levels of glutamine, glycine, β-glucose were lower and that of choline was higher in the HLB group; serum levels of lactate were lower and that of choline, glutamate were higher in the HLB + RSM group. Compared with the HLB + RSM group, serum levels of glycerophosphoryl choline (GPC) and lactate were higher, and those of choline, glutamine, glutamate, leucine, N-acetyaspartate, α-glucose, and β-glucose were lower in the HLB group; serum levels of citrate, GPC and lactate were higher, and those of 3-Hydroxybutyrate, betaine, choline, glutamate, glutamine, N-acetylglycoprotein, N-acetyaspartate, α-glucose, and β-glucose were lower in the RSM group. It could be concluded that concentrate supplementations significantly improved the growth performance of growing yaks and supplementation with HBL or HLB plus RSM was better than RSM during the cold season. Supplementation with HBL or HLB plus RSM affected the serum metabolites of grazing yaks, and both treatments promoted lipid synthesis. Supplementation of yaks with HBL plus RSM could improve energy-supply efficiency, protein and lipid deposition compared with HLB and RSM.

IRS-1/PI3K/Akt pathway and miRNAs are involved in whole grain highland barley (Hordeum vulgareL.) ameliorating hyperglycemia of db/db mice

The present investigation further unravels the underlying molecular mechanism of WGH on T2DM: IRS-1/PI3K/Akt pathway and related miRNA expression.