Chlorogenic acid reduces the plasma glucose peak in the oral glucose tolerance test: effects on hepatic glucose release and glycaemia

Variability in the Qualitative and Quantitative Composition of Phenolic Compounds and the In Vitro Antioxidant Activity of Sour Cherry (Prunus cerasus L.) Leaves

Sour cherry (Prunus cerasus L.) is a deciduous tree belonging to the Rosaceae Juss. family. Cherry leaves are an underutilized source of biologically active compounds. The aim of this study was to determine the composition of the phenolic compounds, as well as the total antioxidant activity, in leaf samples of P. cerasus cultivars and to elucidate the cultivars with particular phytochemical compositions. The phytochemical profiles of P. cerasus leaves vary significantly in a cultivar-dependent manner. The total content of identified phenolic compounds varied from 8.254 to 16.199 mg/g in the cherry leaves. Chlorogenic acid ranged between 1413.3 µg/g ('North Star') and 8028.0 µg/g ('Note'). The total content of flavonols varied from 4172.5 µg/g ('Vytenu zvaigzde') to 9030.7 µg/g ('Tikhonovskaya'). The total content of identified proanthocyanidins varied from 122.3 µg/g ('Note') to 684.8 µg/g ('Kelleris'). The highest levels of phloridzin (38.1 ± 0.9 µg/g) were found in samples of 'Molodezhnaya', while the lowest level of this compound was determined in the leaf samples of 'Turgenevka' (6.7 ± 0.2). The strongest antiradical (138.0 ± 4.0 µmol TE/g, p < 0.05) and reducing (364.9 ± 10.5 µmol TE/g, p < 0.05) activity in vitro was exhibited by the cultivar 'Vytenu zvaigzde' cherry leaf sample extracts. 'Kelleris', 'Note', and 'Tikhonovskaya' distinguish themselves with peculiar phytochemical compositions.

Functional Food Based on Potato

Potato (Solanum tuberosum L.) has gradually become a stable food worldwide since it can be a practical nutritional supplement and antioxidant as well as an energy provider for human beings. Financially and nutritionally, the cultivation and utility of potatoes is worthy of attention from the world. Exploring the functionality and maximizing the utilization of its component parts as well as developing new products based on the potato is still an ongoing issue. To maximize the benefits of potato and induce new high-value products while avoiding unfavorable properties of the crop has been a growing trend in food and medical areas. This review intends to summarize the factors that influence changes in the key functional components of potatoes and to discuss the focus of referenced literature which may require further research efforts. Next, it summarizes the application of the latest commercial products and potential value of components existing in potato. In particular, there are several main tasks for future potato research: preparing starchy foods for special groups of people and developing fiber-rich products to supply dietary fiber intake, manufacturing bio-friendly and specific design films/coatings in the packaging industry, extracting bioactive proteins and potato protease inhibitors with high biological activity, and continuing to build and examine the health benefits of new commercial products based on potato protein. Notably, preservation methods play a key role in the phytochemical content left in foods, and potato performs superiorly to many common vegetables when meeting the demands of daily mineral intake and alleviating mineral deficiencies.

Health-Promoting compounds in Potatoes: Tuber exhibiting great potential for human health

Potatoes are consumed worldwide because of their high accessibility, low cost, taste, and diversity of cooking methods. The high carbohydrate content of potatoes masks the presence of -vitamins, polyphenols, minerals, amino acids, lectins and protein inhibitors in the minds of consumers. The consumption of potatoes faces challenges among health-conscious people. This review paper attempted to provide up-to-date information on new metabolites reported in potatoes that play role in disease prevention and overall human well-being. We tried to compile information on antidiabetic, antihypertensive, anticancer, antiobesity, antihyperlipidemic, and anti-inflammatory potential of potato along with role in improving gut health and satiety. In-vitro studies, human cell culture, and experimental animal and human clinical studies showed potatoes to exhibit a variety of health-enhancing properties. This article will not only popularize potato as a healthy food, but will also improve its use as a staple for the foreseeable future.

Food Polyphenols and Type II Diabetes Mellitus: Pharmacology and Mechanisms

Type II diabetes mellitus and its related complications are growing public health problems. Many natural products present in our diet, including polyphenols, can be used in treating and managing type II diabetes mellitus and different diseases, owing to their numerous biological properties. Anthocyanins, flavonols, stilbenes, curcuminoids, hesperidin, hesperetin, naringenin, and phenolic acids are common polyphenols found in blueberries, chokeberries, sea-buckthorn, mulberries, turmeric, citrus fruits, and cereals. These compounds exhibit antidiabetic effects through different pathways. Accordingly, this review presents an overview of the most recent developments in using food polyphenols for managing and treating type II diabetes mellitus, along with various mechanisms. In addition, the present work summarizes the literature about the anti-diabetic effect of food polyphenols and evaluates their potential as complementary or alternative medicines to treat type II diabetes mellitus. Results obtained from this survey show that anthocyanins, flavonols, stilbenes, curcuminoids, and phenolic acids can manage diabetes mellitus by protecting pancreatic β-cells against glucose toxicity, promoting β-cell proliferation, reducing β-cell apoptosis, and inhibiting α-glucosidases or α-amylase. In addition, these phenolic compounds exhibit antioxidant anti-inflammatory activities, modulate carbohydrate and lipid metabolism, optimize oxidative stress, reduce insulin resistance, and stimulate the pancreas to secrete insulin. They also activate insulin signaling and inhibit digestive enzymes, regulate intestinal microbiota, improve adipose tissue metabolism, inhibit glucose absorption, and inhibit the formation of advanced glycation end products. However, insufficient data are available on the effective mechanisms necessary to manage diabetes.

Limosilactobacillus reuteri and caffeoylquinic acid synergistically promote adipose browning and ameliorate obesity-associated disorders

OBJECTIVE

High intake of caffeoylquinic acid (CQA)-rich dietary supplements, such as green coffee bean extracts, offers health-promoting effects on maintaining metabolic homeostasis. Similar to many active herbal ingredients with high pharmacological activities but low bioavailability, CQA has been reported as a promising thermogenic agent with anti-obesity properties, which contrasts with its poor oral absorption. Intestinal tract is the first site of CQA exposure and gut microbes might react quickly to CQA. Thus, it is of interest to explore the role of gut microbiome and microbial metabolites in the beneficial effects of CQA on obesity-related disorders.

RESULTS

Oral CQA supplementation effectively enhanced energy expenditure by activating browning of adipose and thus ameliorated obesity-related metabolic dysfunctions in high fat diet-induced obese (DIO) mice. Here, 16S rRNA gene amplicon sequencing revealed that CQA treatment remodeled the gut microbiota to promote its anti-obesity actions, as confirmed by antibiotic treatment and fecal microbiota transplantation. CQA enriched the gut commensal species Limosilactobacillus reuteri (L. reuteri) and stimulated the production of short-chain fatty acids, especially propionate. Mono-colonization of L. reuteri or low-dose CQA treatment did not reduce adiposity in DIO mice, while their combination elicited an enhanced thermogenic response, indicating the synergistic effects of CQA and L. reuteri on obesity. Exogenous propionate supplementation mimicked the anti-obesity effects of CQA alone or when combined with L. reuteri, which was ablated by the monocarboxylate transporter (MCT) inhibitor 7ACC1 or MCT1 disruption in inguinal white adipose tissues to block propionate transport.

CONCLUSIONS

Our data demonstrate a functional axis among L. reuteri, propionate, and beige fat tissue in the anti-obesity action of CQA through the regulation of thermogenesis. These findings provide mechanistic insights into the therapeutic use of herbal ingredients with poor bioavailability via their interaction with the gut microbiota. Video Abstract.

Green/Roasted Coffee and Silverskin Extracts Inhibit Sugar Absorption by Human Intestinal Epithelial (Caco-2) Cells by Decreasing GLUT2 Gene Expression

Moderate coffee ingestion has been associated with a decrease in type 2 diabetes risk, mainly due to its richness in chlorogenic acids (CGA). To explore this, extracts of green beans, roasted beans, and silverskin were prepared by aqueous ultrasound-assisted extraction and characterized by a reversed-phase high-performance liquid chromatography-photodiode array detector (RP-HPLC-DAD). The effects on the uptake of glucose and fructose by human intestinal epithelial (Caco-2) cells and the influence on the expression of sugar transporter genes (by RT-qPCR) were investigated and compared. The uptake of ³H-deoxy-D-glucose and ¹⁴C-fructose by Caco-2 cells was significantly reduced by all the extracts, with green coffee (which also contained higher amounts of CGA) achieving the highest efficiency. Although silverskin presented the lowest amounts of CGA and caffeine, it promoted an inhibitory effect similar to the effects of green/roasted beans. In the case of glucose uptake, the effect was even higher than for roasted coffee. This activity is explained by the ability of the extracts to markedly decrease GLUT2, but not GLUT5 gene expression. In addition, a decrease in SGLT1 gene expression was also found for all extracts, although not at a statistically significant rate for silverskin. This study also revealed a synergistic inhibitory effect of caffeine and 5-CQA on the uptake of sugars. Thus, silverskin appears as an interesting alternative to coffee, since the valorization of this by-product also contributes to the sustainability of the coffee chain.

Baccharis trimera Infusion Reduces Macrophages Activation and High-Fat Diet-Induced Metabolic Disorders in Mice

The aim of this study is to evaluate the efficacy of Baccharis trimera infusion on high-fat diet-induced metabolic disorders in mice and macrophages activation. This study evaluated obesity, insulin resistance, dyslipidemia and hepatic steatosis induced by a high-fat diet in Swiss mice. Cellular parameters in macrophages, such as cell viability (MTT), the production and release of nitric oxide (NO) and hydrogen peroxide (H₂O₂), cell spreading, cell adhesion and phagocytosis were determined. Our results showed that treatment with B. trimera prevented the mentioned conditions, except for the production of hydrogen peroxide. B. trimera prevented the development of obesity and associated comorbidities, as well as activation of macrophages. In conclusion, B. trimera is able to prevent obesity and metabolic disorders and macrophages activation, minimizing inflammation and validating the popular use of this plant tea.

Effects of decaffeinated green coffee extract supplementation on anthropometric indices, blood glucose, leptin, adiponectin and neuropeptide Y (NPY) in breast cancer survivors: a randomized clinical trial

Objective: This study aimed to evaluate the effects of decaffeinated green coffee extract (DGCE) supplementation on anthropometric indices, blood glucose, leptin, adiponectin, and neuropeptide Y (NPY) in breast cancer survivors with obesity. Method: A total of 44 breast cancer survivors with obesity aged between 18 and 70 years and with a mean body mass index (BMI) of 31.62 ± 4.97 kg m^-2 participated in this double-blind randomized clinical trial. Eligible patients were randomized to the intervention (n = 22) and control (n = 22) groups. They received two 400 mg capsules of DGCE or two identical placebos daily for 12 weeks. Serum concentrations of leptin, adiponectin, NPY, fasting blood sugar, insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were measured at the baseline and after completion of the intervention. Also, weight, waist circumference, fat percentage, muscle percentage, and visceral fat were measured. Results: There were no significant differences in terms of changes of anthropometric indices and concentrations of leptin, adiponectin, NPY, and blood sugar between the two studied groups. Conclusion: Supplementation with DGCE in breast cancer survivors with obesity had no significant effect on anthropometric indices and blood glucose, leptin, adiponectin, and NPY levels.

Analysis of Chlorogenic Acid in Sweet Potato Leaf Extracts

Sweet potato (Ipomoea batatas L.) is one of the most important food crops worldwide, with leaves of different varieties showing purple, green and yellow, and these leaves provide a dietary source of nutrients and various bioactive compounds. The objective of this study was to identify the active constituents of chlorogenic acids (CGAs) in different methanolic extract of leaves of three varieties of sweet potato (purple CYY 98-59, green Taoyuan 2, and yellow CN 1927-16) using liquid chromatography–tandem mass spectrometry. Genotype-specific metabolite variations were observed; CGAs and three isomeric peaks were detected in sweet potato leaf extracts (SPLEs). Among them, the yellow SPLE contained the highest contents of 3,5-dicaffeoylquinic acid (3,5-di-CQA) and 3,4-dicaffeoylquinic acid (3,4-di-CQA), followed by the green SPLE, whereas the purple SPLE retained lower 3,5-di-CQA content compared to yellow and green SPLEs. All three SPLEs contained lower 4,5-dicaffeoylquinic acid (4,5-di-CQA) and CGA contents compared to 3,5-di-CQA and 3,4-di-CQA, although CGA constituents were not significantly different in genotypes, whereas purple SPLE contained higher 4,5-di-CQA content compared to yellow and green SPLEs. This study indicates that SPLs marketed in Taiwan vary widely in their biological potentials and may impart different health benefits to consumers.

Metabolomic Characterization of Pigmented and Non-Pigmented Potato Cultivars Using a Joint and Individual Variation Explained (JIVE)

Potatoes (Solanum tuberosum L.) are one of the most valuable agricultural crops, and the flesh of these tubers provides various classes of healthy compounds important for human nutrition. This work presents the results of a joint analysis of different chemical classes of compounds which provided insights on the metabolic characterization of pigmented and non-pigmented potato varieties collected from Italy. The identification of common or individual metabolic characteristics across the omic datasets (antioxidants, total polyphenolic content, polyphenols, and sugars) is conducted by Joint and Individual Variation Explained (JIVE), a data fusion multivariate approach. The common part of the multivariate model allowed the separation between non-pigmented and pigmented samples. Polyphenolic compounds were mainly responsible for the separation between purple-fleshed and red-skinned potatoes. An additional detailed analysis of the anthocyanin composition, including the acylated anthocyanins, allowed to pinpoint the diversities between the pigmented potato groups. Furthermore, the presence of an appreciable amount of hydroxycinnamic acids and anthocyanins in the purple-fleshed varieties, which are also characterized by a lower content of sugars, is found. Our results provide scientific evidence for the promotion of promising potato cultivars, which are characterized by a remarkable amount of various health benefit compounds.

Drug Discovery of Plausible Lead Natural Compounds That Target the Insulin Signaling Pathway: Bioinformatics Approaches

The growing smooth talk in the field of natural compounds is due to the ancient and current interest in herbal medicine and their potentially positive effects on health. Dozens of antidiabetic natural compounds were reported and tested in vivo, in silico, and in vitro. The role of these natural compounds, their actions on the insulin signaling pathway, and the stimulation of the glucose transporter-4 (GLUT4) insulin-responsive translocation to the plasma membrane (PM) are all crucial in the treatment of diabetes and insulin resistance. In this review, we collected and summarized a group of available in vivo and in vitro studies which targeted isolated phytochemicals with possible antidiabetic activity. Moreover, the in silico docking of natural compounds with some of the insulin signaling cascade key proteins is also summarized based on the current literature. In this review, hundreds of recent studies on pure natural compounds that alleviate type II diabetes mellitus (type II DM) were revised. We focused on natural compounds that could potentially regulate blood glucose and stimulate GLUT4 translocation through the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway. On attempt to point out potential new natural antidiabetic compounds, this review also focuses on natural ingredients that were shown to interact with proteins in the insulin signaling pathway in silico, regardless of their in vitro/in vivo antidiabetic activity. We invite interested researchers to test these compounds as potential novel type II DM drugs and explore their therapeutic mechanisms.

Effects of Dietary Chlorogenic Acid Supplementation Derived from Lonicera macranthoides Hand-Mazz on Growth Performance, Free Amino Acid Profile, and Muscle Protein Synthesis in a Finishing Pig Model

Chlorogenic acid (CGA), as one of the richest polyphenol compounds in nature, has broad applications in many fields due to its various biological properties. However, initial data on the effects of dietary CGA on protein synthesis and related basal metabolic activity has rarely been reported. The current study is aimed at (1) determining whether dietary CGA supplementation improves the growth performance and carcass traits, (2) assessing whether dietary CGA alters the free amino acid profile, and (3) verifying whether dietary CGA promotes muscle protein synthesis in finishing pigs. Thirty-two (Large × White × Landrace) finishing barrows with an average initial body weight of $71.89\pm 0.92$  kg were randomly allotted to 4 groups and fed diets supplemented with 0, 0.02%, 0.04%, and 0.08% CGA, respectively. The results indicated that, compared with the control group, dietary supplementation with 0.04% CGA slightly stimulated the growth performance of pigs, whereas no significant correlation was noted between the dietary CGA levels and animal growth ( $P>0.05$ ). Furthermore, the carcass traits of pigs were improved by 0.04% dietary CGA ( $P<0.01$ ). In addition, dietary CGA significantly improved the serum free amino acid profiles of pigs ( $P<0.01$ ), while 0.04% dietary CGA promoted more amino acids to translocate to skeletal muscles ( $P<0.05$ ). The relative mRNA expression levels of SNAT2 in both longissimus dorsi (LD) and biceps femoris (BF) muscles were augmented in the 0.02% and 0.04% groups ( $P<0.05$ ), and the LAT1 mRNA expression in the BF muscle was elevated in the 0.02% group ( $P<0.05$ ). We also found that dietary CGA supplementation at the levels of 0.04% or 0.08% promoted the expression of p-Akt and activated the mTOR-S6K1-4EBP1 axis in the LD muscle ( $P<0.05$ ). Besides, the MAFbx mRNA abundance in the 0.02% and 0.04% groups was significantly lower ( $P<0.05$ ). Our results revealed that dietary supplementation with CGA of 0.04% improved the free amino acid profile and enhanced muscle protein biosynthesis in the LD muscle in finishing pigs.

Comparative transcriptome analysis reveals variations of bioactive constituents in Lonicera japonica flowers under salt stress

Lonicera japonica flowers (LJF) is a traditional Chinese medicine packed with phenols constituents and widely used in the treatments of various diseases throughout the world. However, there is still very little known on how LJF identifies and resists salt stress. Here in, we systematically investigated the effect of salt on the phenotypic, metabolite, and transcriptomic in LJF. During long term stress (35 days), 1055 differential expression genes (DEGs) involved in the biosynthesis of secondary metabolites were screened through transcriptome analysis, among which the candidate genes and pathways involved in phenols biosynthesis were highlighted; and performed by phylogenetic tree analysis and multiple nucleotide sequence alignment. Ninety compounds were identified and their relative levels were compared between the control and stressed groups based on the LC-MS analysis, Putative biosynthesis networks of phenolic acid and flavonoid were con-structed with structural DEGs. Strikingly, the expression patterns of structural DEGs were mostly consistent with the variations of phenols under salt stress. Notably, the upregulation of UDP-glycosyl transferases under salt stress indicated post-modification of glycosyl transferases may participate in downstream flavonoids synthesis. This study reveals the relationships of the gene regulation and the phenols biosynthesis in LJF under salt stress, paving the way for the use of gene-specific expression to improve the yield of biocomponent.

Synthesis and in vitro evaluation of chlorogenic acid amides as potential hypoglycemic agents and their synergistic effect with acarbose

Type 2 Diabetes mellitus is a chronic disease considered one of the most severe global health emergencies. Chlorogenic acid (1) has been shown to delay intestinal glucose absorption by inhibiting the activity of α-glucosidase (α-Glu) and α-amylase (α-Amy). In the present work, eleven chlorogenic acid amides have been synthesized and evaluated for their antioxidant properties (as DPPH and ORAC) and inhibition activity towards the two enzymes and, with the aim to obtain dual-action antidiabetic agents. The two most promising hypoglycemic compounds, bearing a tertiary amine function on an alkyl chain (8) and a benzothiazole scaffold (11), showed IC₅₀ values lower than that of (1) (45.5 µM α-Glu; 105.2 µM α-Amy). Amides 8 and 11 were by far more potent α-Glu inhibitors than the antidiabetic drug acarbose (IC₅₀ = 268.4 µM) and about twice less active toward α-Amy than acarbose (IC₅₀ = 34.4 µM). Kinetics experiments on amides 8 and 11 indicated these compounds as mixed-type inhibitors of α-Glu with K'_i values of 13.3 and 6.3 µM, respectively. The amylase inhibition occurred with a competitive mechanism in the presence of 8 (K_i = 79.7 µM) and with a mixed-type mechanism with 11 (K_i = 19.1 µM; K'_i = 93.6 µM). Molecular docking analyses supported these results, highlighting the presence of additional binding sites in both enzymes. Fluorescence experiments confirmed the grater affinity of amides 8 and 11 towards the two enzymes respect to (1). Moreover, a significant enhancement in acarbose efficacy was observed when inhibition assays were performed adding acarbose and amide 11. The above outcomes pinpointed the benzothiazole-based amide 11 as a promising candidate for further studies on type 2 diabetes treatment, both alone or combined with acarbose.

Cabbage (Brassica oleracea var. capitata): A food with functional properties aimed to type 2 diabetes prevention and management

Type 2 diabetes mellitus (T2DM) is increasing the prevalence worldwide at an alarming rate, becoming a serious public health problem that mainly affects developing countries. Functional food research is currently of great interest because it contributes to developing nutritional therapy strategies for T2DM prevention and treatment. Bioactive compounds identified in some plant foods contribute to human health by mechanisms of action that exert biological effects on metabolic pathways involved in the development of T2DM. Hence, vegetables with high bioactive compounds content may be a source of functional value for the control of T2DM. Cabbages varieties (Brassica oleracea var. capitata) such as green (GCB), white (WCB), and red (RCB) are foods consumed (raw or cooked) and cultivated in different regions of the world. Scientific evidence shows that cabbage has multi-target effects on glucose homeostatic regulation due to its high content of bioactive compounds. It has also been shown to decrease damage to organs affected by T2DM complications, such as the liver and kidney. Additionally, it could contribute as a preventive by attenuating problems underlying the development of T2DM as oxidative stress and obesity. This review highlights the functional properties of cabbage varieties involved in glucose regulation and the main mechanisms of the action exerted by their bioactive compounds. In conclusion, cabbage is a valuable food that can be employed as part of nutritional therapy or functional ingredient aimed at the prevention and treatment of T2DM.

Controlled Release of Chlorogenic Acid from Polyvinyl Alcohol/Poly(γ-Glutamic Acid) Blended Electrospun Nanofiber Mats with Potential Applications in Diabetic Foot Treatment

This work biosynthesized poly(γ-glutamic acid) (γ-PGA) produced by Bacillus licheniformis ATCC-9945a. This material was utilized to prepare electrospun nanofibers with solutions of 10% polyvinyl alcohol (PVA) (w/v) mixed with γ-PGA at 5 and 10% w/v, intended as a wound dressing for diabetic foot treatment. These solutions were loaded with chlorogenic acid (CGA), an active hypoglycemic agent. Morphological analysis showed a decrease in size of the fibers with the combination of PVA/γ-PGA compared to pure PVA nanofibers, which was attributed to the hydrogen bonding interactions between the glutaraldehyde vapors, γ-PGA, and PVA that permitted nanofiber cross-linking and allowed CGA release. The in vitro release analysis showed that the PVA membranes reached 28% delivery after the first 24 h. Notably, the nanofiber mat with PVA blended with 5% γ-PGA reached 57% delivery, and the PVA nanofiber with 10% γ-PGA reached 66% release after the same amount of time. The rate constant for the release kinetics showed that PVA with 5% γ-PGA had a higher value than that of the other samples, reaching saturation first.

Physicochemical Properties and Effects of Fruit Pulps from the Amazon Biome on Physiological Parameters in Rats

This study aimed to analyze the physicochemical characteristics and the effects of Amazonian pulp fruits consumption, such as araçá-boi (Eugenia stipitata), abiu grande (Pouteria caimito), araticum (Annona crassiflora), biri-biri (Averrhoa bilimbi L.), and yellow mangosteen (Garcinia xanthochymus), on hematologic, metabolic, renal, and hepatic function parameters in Wistar rats (n = 10 rats/group). The pulp of abiu had the highest levels of soluble solids, sugars, and pH. Biri-biri pulp had the highest levels of ascorbic acid and total titratable acidity, and a low pH. The araticum pulp had higher (p ≤ 0.05) ash content, total phenolic compounds, and antioxidant activity than the pulp of other analyzed fruits. No significant increase in hematocrit, nor reduction of blood glucose, plasma cholesterol, and serum levels of glutamic-pyruvic transaminase (TGP), creatinine, and urea was observed in experimental groups relative to the control group of rats after the consumption of fruits pulp. The intake of abiu and araticum pulps promoted a significant reduction (p ≤ 0.05) in total leukocytes of the experimental groups as compared to the control group and only the intake of araticum significantly increased (p ≤ 0.05) triglyceride blood levels in rats (99.50 mg/dL). The regular consumption of biri-biri pulp for 30 days significantly (p ≤ 0.05) increased serum glutamic-oxaloacetic transaminase (TGO) levels in rats (116.83 U/L) compared to the control group (98.00 U/L). More researches are needed to generate knowledge about these promising Amazonian fruits, supporting the native fruit production, in addition to promoting health in the population and sustainability in the Amazon region.

Antioxidants in Potatoes: A Functional View on One of the Major Food Crops Worldwide

With a growing world population, accelerating climate changes, and limited arable land, it is critical to focus on plant-based resources for sustainable food production. In addition, plants are a cornucopia for secondary metabolites, of which many have robust antioxidative capacities and are beneficial for human health. Potato is one of the major food crops worldwide, and is recognized by the United Nations as an excellent food source for an increasing world population. Potato tubers are rich in a plethora of antioxidants with an array of health-promoting effects. This review article provides a detailed overview about the biosynthesis, chemical and health-promoting properties of the most abundant antioxidants in potato tubers, including several vitamins, carotenoids and phenylpropanoids. The dietary contribution of diverse commercial and primitive cultivars are detailed and document that potato contributes much more than just complex carbohydrates to the diet. Finally, the review provides insights into the current and future potential of potato-based systems as tools and resources for healthy and sustainable food production.

Dietary Supplementation With Chlorogenic Acid Derived From Lonicera macranthoides Hand-Mazz Improves Meat Quality and Muscle Fiber Characteristics of Finishing Pigs via Enhancement of Antioxidant Capacity

Chlorogenic acid (CGA), one of the most abundant polyphenol compounds in nature, is regarded as a potential feed additive to promote animal health and enhance the meat products’ quality via its various biological properties. The current study aims: (1) to determine whether dietary CGA supplementation improves meat quality and muscle fiber characteristics, and (2) to ascertain whether the corresponding improvement is associated with enhancing the antioxidant capacity of the finishing pigs. Thirty-two (Large × White × Landrace) finishing pigs with an average initial body weight of 71.89 ± 0.92 kg were allotted to 4 groups, and each was fed diets supplemented with 0, 0.02, 0.04, or 0.08% (weight/weight) of CGA. The meat quality traits, muscle fiber characteristics, and the serum and muscle antioxidant capacity were assessed. Results suggested that, compared with the control group, dietary CGA supplementation at a level of 0.04% significantly decreased the b^∗ value and distinctly increased the inosinic acid content of longissimus dorsi (LD) and biceps femoris (BF) muscles (P < 0.01). Moreover, dietary supplementation with 0.04% of CGA markedly improved the amino acid composition of LD and BF muscles, as well as augmented the mRNA abundance of Nrf-2, GPX-1, MyoD, MyoG, and oxidative muscle fiber (I and IIa) in LD muscle (P < 0.05). This result indicates that a diet supplemented with 0.04% of CGA promotes myogenesis and induces a transformation toward more oxidative muscle fibers in LD muscle, subsequently improving meat quality. Besides, dietary supplementation with 0.02% and 0.04% of CGA notably enhanced the serum GSH-PX level (P < 0.01). Considering all these effects are closely related to the alteration of antioxidant activities of the finishing pigs, the underlying metabolism is likely connected to the boosting of their antioxidant capacity induced by dietary CGA.

Bioactive Compounds, Antioxidants, and Health Benefits of Sweet Potato Leaves

Sweet potato (Ipomoea batatas) is one of the most important food crops worldwide and its leaves provide a dietary source of nutrients and various bioactive compounds. These constituents of sweet potato leaves (SPL) vary among varieties and play important roles in treating and preventing various diseases. Recently, more attentions in health-promoting benefits have led to several in vitro and in vivo investigations, as well as the identification and quantification of bioactive compounds in SPL. Among them, many new compounds have been reported as the first identified compounds from SPL with their dominant bioactivities. This review summarizes the current knowledge of the bioactive compositions of SPL and their health benefits. Since SPL serve as a potential source of micronutrients and functional compounds, they can be further developed as a sustainable crop for food and medicinal industries.

Gynura divaricata Water Extract Presented the Possibility to Enhance Neuronal Regeneration

Gynura divaricata (GD) is an Asian herb widely used as an alternative medicine and functional food for type 2 diabetes. Diabetic neuropathy is considered as an important complication of diabetic patients. This study focused on neuroregenerative effects of GD for use in the prevention of diabetic neuropathy. GD leaves were cut and boiled in water to mimic real-life cooking. The boiled content was filtered through white gauze and lyophilized to preserve as dried powder. Antioxidant assay was performed using DPPH assays. UHPLC-QTOF-MS/MS was employed to test for important compounds in the extract of these herbs. MTT assay was used to test for cell viability. The extracts at concentration of 250 μg/mL were tested with human gingival cell to observe the change of gene expression. The DPPH assay showed that GD water extract at the concentration of 5000 μg/mL could inhibit DPPH radical for 39.2%. The results showed that 5000 µg of GD water extract contained total phenolic content equivalent to 310.9 µg standard gallic acid. UHPLC-QTOF-MS/MS result found phenolic acids and flavonoids as the main components. Human gingival cells treated with 250 μg/mL of GD water extract for 10 days showed upregulation of some neuronal differentiation markers. Staining with Cdr3 dye confirmed the presentation of neuronal progenitors. The extract at the concentration of 250 μg/mL was also tested with apical papilla cells to screen for change of gene expression by RNA sequencing. The result also showed significant upregulation of alpha-internexin (INA). These results indicated that GD water extract might have an inductive effect for neural regeneration and could be used as functional food and supplementation for the prevention or treatment of diabetic neuropathy. This work provided the basic knowledge for further investigations into the benefits of GD for diabetic neuropathy.

Combined LC-MS/MS and 16S rDNA analysis on mice under high temperature and humidity and Herb Yinchen protection mechanism

With increased global warming, the impact of high temperature and humidity (HTH) on human health is increasing. Traditional Chinese medicine describes the Herb Yinchen as a remedy for reducing heat and eliminating dampness. This study focused on the impact of HTH conditions on mice and the potential protective effect of Herb Yinchen. Five male Balb/c mouse groups included two normal control groups, two HTH-exposed groups, and one Yinchen-treated group. For either three or ten days, normal and HTH-exposed mice were housed under normal or HTH (33 ± 2 °C,85% relative humidity) conditions, respectively. Yinchen-treated mice, housed under HTH conditions, received the Herb Yinchen decoction for three days. Metabolite profiles of plasma and liver samples from each group were analyzed using LC–MS/MS. Fecal DNA was extracted for 16S rDNA analysis to evaluate the intestinal microbiome. Spearman correlation analysis was performed on metabolites, bacteria, and bile acids that differed between the groups. We found that HTH altered the host metabolite profiles and reduced microbial diversity, causing intestinal microbiome imbalance. Interestingly, Herb Yinchen treatment improved HTH-mediated changes of the metabolite profiles and the intestinal microbiome, restoring them to values observed in normal controls. In conclusion, our study reveals that HTH causes intestinal bacterial disturbances and metabolic disorders in normal mice, while Herb Yinchen could afford protection against such changes.

Acute and sub-chronic toxicity evaluation of a standardized green coffee bean extract (CGA-7™) in Wistar albino rats

OBJECTIVE

Despite having numerous physiological benefits, toxicological assessment of green coffee beans is sparce. Here, we document the oral acute and sub-chronic toxicity of a standardized decaffeinated green coffee bean extract containing 50% chlorogenic acids (CGA-7™) in rats.

METHODS

We have performed a limit test at single oral dose of 2000 mg/kg to evaluate the acute toxicity in female Wistar rats. Furthermore, repeated dose 90-day toxicity study was conducted to assess the risk of long-term use of CGA-7.

RESULT

A 14-day observation revealed no clinical signs of toxicity or mortality in animals at 2000 mg/kg acute oral dose of CGA-7. The administration of 250, 500, and 1000 mg/kg CGA-7 showed significant alterations in some parameters such as food consumption, relative organ weights of brain and spleen, haematological and biochemical parameters compared to control. These changes were not consistent and dose-dependent throughout the study. Furthermore, the changes were within the physiological range and toxicologically insignificant. CGA-7 did not affect the normal metabolism and physiology of the animals up to 1000 mg/kg dose. Macroscopic and histological examination of organs did not reveal any organ toxicity.

CONCLUSION

Finally, the findings from this study suggest the safety of green coffee bean extract.

Chlorogenic acid ameliorates obesity by preventing energy balance shift in high-fat diet induced obese mice

BACKGROUND

Chlorogenic acid is a type of phenolic acid found in many plants. Chlorogenic acid has an anti-obesity effect with an unclear mechanism. The present study aimed to investigate the regulatory effect of chlorogenic acid on energy balance in high-fat diet (HFD) induced obese C57BL/6J mice administrated 100 mg kg^-1 chlorogenic acid for 13 weeks.

RESULTS

The consumption of chlorogenic acid ameliorated HFD induced obesity. Chlorogenic acid did not change the physical activity but significantly decreased food intake and increased body temperature, thermal dissipation and brown adipose tissue activity. Moreover, chlorogenic acid improved glucose tolerance but had a moderate impact on other blood indices. Additionally, chlorogenic acid failed to restore the microbiota change associated with HFD induced obesity, but modified the gut bacterial composition in a unique way.

CONCLUSION

Supplementation with chlorogenic acid can improve HFD induced obesity and associated glucose intolerance mainly via regulating food intake and energy expenditure. © 2020 Society of Chemical Industry.

The effect of black coffee on fasting metabolic markers and an abbreviated fat tolerance test

BACKGROUND & AIMS

Coffee is typically prohibited prior to metabolic assessment in clinical and research settings. However, whether coffee meaningfully alters fasted metabolic testing or the results of a fat tolerance test is unclear. We investigated whether allowing black coffee intake within a fast prior to blood work affected fasting triglycerides (TG) and glucose, as well as the postprandial lipemic and glycemic response following an abbreviated fat tolerance test (AFTT).

METHODS

Participants completed two randomized AFTTs separated by at least 1 week. For each AFTT, participants arrived into the laboratory following a 10 h overnight fast and consumed either 8 oz of water or black coffee. Thirty minutes later, a baseline blood draw was collected. Immediately following, participants consumed a standardized high-fat shake (70% fat; 9 kcal/kg body mass), vacated the laboratory, and returned 4 h later for a follow-up blood draw.

RESULTS

Ten healthy individuals (5M, 5F; age: 22.9 ± 3.8 years; BMI: 24.3 ± 2.6 kg/m²) completed the study. There was no difference between trials with regard to baseline TG (MD = 1.7 mg/dL; p = 0.74), 4 h TG (MD = 2.7 mg/dL; p = 0.75), Δ TG (MD = 4.4 mg/dL; p = 0.52), or % change TG (MD = 7.7%; p = 0.99). Similarly, following coffee consumption, baseline glucose was unchanged relative to water (MD = 0.4 mg/dL; p = 0.84) and there were no differences in postprandial glucose measures, including 4 h (MD = 0.9 mg/dL; p = 0.58), Δ (MD = 1.3 mg/dL; p = 0.31), and % change in glucose (MD = 1.6%; p = 0.29).

CONCLUSION

In our small study sample, coffee intake prior to an AFTT did not affect baseline or postprandial TG and glucose. Therefore, coffee intake prior to an AFTT may not affect its validity.

Phytochemical and Nutritional Quality Changes During Irrigation and Postharvest Processing of the Underutilized Vegetable African Nightshade

Underutilized or traditional leafy vegetables are grown in the wild and cultivated. They are consumed as nutritional accompaniments to staples, either raw (fresh), cooked, or in a dried form, through custom, habit, and tradition. These traditional leafy vegetables are natural rich sources of phytochemicals and nutritional compounds. Over time, the keenness for consumption of traditional vegetables has become less popular. Poor nutrient diets are the main cause of mortality and morbidity, especially in developing countries, where the problem is predominant due to poverty. Consumption of traditional vegetables can assist in the prevention of chronic disease development, as they contain various bioactive compounds that exhibit multiple health benefits. Traditional leafy vegetables play a vital role in combatting hunger, food insecurity, and malnutrition, and most are suitable for food intervention programs. African nightshade (Solanum family) is one such commonly consumed traditional leafy vegetable. During dry seasons, communities often face shortages of vegetables; thus, the preservation of edible leaves is one strategy to help overcome this problem. The adoption of solar drying and fermentation are traditional methods to extend the availability of African nightshade vegetables. Additionally, the agronomy practices and postharvest processing methods affect the phytochemicals and nutritional compounds of African nightshade accessions. This mini-review provides information on changes in phytochemicals, nutrition, and antinutritive compounds with different postharvest processing methods and irrigation. The review provides the justification to promote the cultivation for consumption, by identifying the potential African nightshade accessions that are rich in phytonutritional compounds. This mini-review summarizes and discusses the major information on (i) the micro- and macronutrients present in Solanum retroflexum, the most commonly consumed nightshade species compared with other traditional vegetables in Southern Africa, (ii) the composition of phytochemical compounds present in different nightshade accessions, (iii) the impact of irrigation on phytochemical composition in different nightshade species, and (iv) the impact of postharvest processing on phytochemicals and antinutritive compounds in S. retroflexum. Inclusion of African nightshade, especially S. retroflexum, with the main staple foods can improve protein, iron, and calcium levels in daily diets, which will help to improve people's health and well-being.

The gut microbiome drives inter- and intra-individual differences in metabolism of bioactive small molecules

The origin of inter-individual variability in the action of bioactive small molecules from the diet is poorly understood and poses a substantial obstacle to harnessing their potential for attenuating disease risk. Epidemiological studies show that coffee lowers the risk of developing type 2 diabetes, independently of caffeine, but since coffee is a complex matrix, consumption gives rise to different classes of metabolites in vivo which in turn can affect multiple related pathways in disease development. We quantified key urinary coffee phenolic acid metabolites repeated three times in 36 volunteers, and observed the highest inter- and intra-individual variation for metabolites produced by the colonic microbiome. Notably, a urinary phenolic metabolite not requiring the action of the microbiota was positively correlated with fasting plasma insulin. These data highlight the role of the gut microbiota as the main driver of both intra- and inter-individual variation in metabolism of dietary bioactive small molecules.

Transformed Shoots of Dracocephalum forrestii W.W. Smith from Different Bioreactor Systems as a Rich Source of Natural Phenolic Compounds

Transformed shoots of the Tibetan medicinal plant Dracocephalum forrestii were cultured in temporary immersion bioreactors (RITA and Plantform) and in nutrient sprinkle bioreactor (NSB) for 3 weeks in MS (Murashige and Skoog) liquid medium with 0.5 mg/L BPA (N-benzyl-9-(2-tetrahydropyranyl)-adenine) and 0.2 mg/L IAA (indole-3-acetic acid). The greatest biomass growth index (GI = 52.06 fresh weight (FW) and 55.67 dry weight (DW)) was observed for shoots in the RITA bioreactor, while the highest multiplication rate was found in the NSB (838 shoots per bioreactor). The levels of three phenolic acids and five flavonoid derivatives in the shoot hydromethanolic extract were evaluated using UHPLC (ultra-high performance liquid chromatography). The predominant metabolite was rosmarinic acid (RA)—the highest RA level (18.35 mg/g DW) and total evaluated phenol content (24.15 mg/g DW) were observed in shoots grown in NSB. The NSB culture, i.e., the most productive one, was evaluated for its antioxidant activity on the basis of reduction of ferric ions (ferric reducing antioxidant power, FRAP) and two scavenging radical (O₂^•– and DPPH, 1,1-diphenyl-2-picrylhydrazyl radical) assays; its antibacterial, antifungal, and antiproliative potential against L929 cells was also tested (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test). The plant material revealed moderate antioxidant and antimicrobial activities and demonstrated high safety in the MTT test—no cytotoxicity at concentrations up to 50 mg/mL was found, and less than a 20% decrease in L929 cell viability was observed at this concentration.

Characterization of Local Products for Their Industrial Use: The Case of Italian Potato Cultivars Analyzed by Untargeted and Targeted Methodologies

The chemical characterization of local Italian potato cultivars is reported to promote their preservation and use as high quality raw material in food industries. Twenty potato (Solanum tuberosum L.) cultivars from Piedmont and Liguria Italian regions were investigated using NMR (Nuclear Magnetic Resonance) and RP-HPLC-PDA-ESI-MSn (Reversed Phase High-Performance Liquid Chromatography with Photodiode Array Detector and Electrospray Ionization Mass Detector) methodologies. Water soluble and lipophilic metabolites were identified and quantified. With respect to literature data, a more complete ¹H (protonic) spectral assignment of the aqueous potato extracts was reported, whereas the ¹H NMR assignment of potato organic extracts was reported here for the first time. Phenolics resulted to be in high concentrations in the purple–blue colored Rouge des Flandres, Bergerac, Fleur Bleu, and Blue Star cultivars. Servane, Piatlina, and Malou showed the highest amount of galacturonic acid, a marker of pectin presence, whereas Jelly cultivar was characterized by high levels of monosaccharides. Roseval and Rubra Spes contained high levels of citric acid involved in the inhibition of the enzymatic browning in fresh-cut potato. High levels of the amino acids involved in the formation of pleasant-smell volatile compounds during potato cooking were detected in Rouge des Flandres, Blue Star, Bergerac, Roseval, and Ratte cultivars. These results suggest that each local cultivar is characterized by a proper chemical profile related to specific proprieties that can be useful to obtain high quality industrial products.

Decaffeinated coffee and its benefits on health: focus on systemic disorders

The current literature has mainly focused on benefits and risks deriving from the consumption of caffeinated coffee and its implications for inflammation, cardiovascular diseases, neurodegenerative disorders, and cancer. Today, data about the role of caffeine in many disorders are controversial and the attention has increasingly focused on decaffeinated coffee and its non-caffeine compounds, which could have mainly beneficial effects. In fact, coffee phenolic compounds not only exhibit well-known antioxidant properties, but they can also antagonize some negative effects of caffeine, for example in inflammatory pathway and in glucose metabolism and homeostasis. In this review, we consider the literature of the last two decades and critically discuss the effects of decaffeinated coffee compounds on systemic disorders, mainly inflammation, cardiovascular diseases, hepatic dysfunctions, and cancer.

Anthocyanin-rich extract from purple potatoes decreases postprandial glycemic response and affects inflammation markers in healthy men

Our recent clinical study suggested that polyphenol-rich purple potatoes lowered postprandial glycemia and insulinemia compared to yellow potatoes. Here, 17 healthy male volunteers consumed yellow potatoes with or without purple potato extract (PPE, extracted with water/ethanol/acetic acid) rich in acylated anthocyanins (152 mg) and other phenolics (140 mg) in a randomized cross-over trial. Ethanol-free PPE decreased the incremental area under the curve for glucose (p = 0.019) and insulin (p = 0.015) until 120 min after the meal, glucose at 20 min (p = 0.015) and 40 min (p = 0.004), and insulin at 20 min (p = 0.003), 40 min (p = 0.004) and 60 min (p = 0.005) after the meal. PPE affected some of the studied 90 inflammation markers after meal; for example insulin-like hormone FGF-19 levels were elevated at 240 min (p = 0.001). These results indicate that PPE alleviates postprandial glycemia and insulinemia, and affects postprandial inflammation.

Formulation of a Mixture of Plant Extracts for Attenuating Postprandial Glycemia and Diet-Induced Disorders in Rats

The aim of this study was to design a mixture consisting of plant-derived preparations containing inhibitors of carbohydrate digestion and/or glucose absorption that could lower postprandial glycemia and attenuate dietary-induced disorders. The following standardized preparations were tested: white mulberry leaf extract, green coffee bean extract, white kidney bean extract, pomelo fruit extract, bitter melon fruit extract, and purified l-arabinose. The study design was composed of oral sucrose and starch tolerance tests in Wistar rats preceded by a single ingestion of the preparations or their mixtures. Then, a 20 week-long experiment was conducted on rats that were fed a high-fat diet and supplemented with the most effective mixture. Based on the results of the oral sucrose and starch tolerance tests, the mulberry leaf extract, l-arabinose, kidney bean extract, and coffee bean extract were selected for composing three mixtures. The most effective inhibition of postprandial glycemia in the oral tolerance tests was observed after the ingestion of a mixture of mulberry leaf, kidney bean, and coffee bean extract. The glucose-lowering effect of the mixture and its effective dosage was confirmed in the feeding experiment.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

Potatoes and risk of chronic disease: a systematic review and dose-response meta-analysis

PURPOSE

We aimed to synthesize the evidence on the relation between different types of potato consumption with risk of all-cause mortality, coronary heart disease (CHD), stroke, type 2 diabetes (T2D), colorectal cancer (CRC), and hypertension.

METHODS

Systematic searches until May 2018 were conducted in PubMed, Scopus, and Web of Science. Random effects meta-analyses comparing extreme categories, linear and non-linear dose-response analyses were conducted.

RESULTS

Twenty-eight reports were identified. Only total potato consumption was available for some endpoints which showed no associations with all-cause mortality (RR: 0.88, 95% CI 0.69-1.12), CHD (RR: 1.03, 95% CI 0.96-1.09), stroke (RR: 0.98, 95% CI 0.93-1.03), and CRC (RR: 1.05, 95% CI 0.92-1.20) per one daily/serving (150 g/day) increase. Consumption of one daily serving of boiled/baked/mashed-potatoes was not associated with risk of hypertension (RR: 1.08, 95% CI 0.96-1.21), but slightly with the risk of T2D (RR: 1.09, 95% 1.01-1.18). Positive associations for the risk of T2D (RR: 1.66, 95% CI 1.43-1.94) and hypertension (RR: 1.37, 95% CI 1.15-1.63) were observed for each 150 g/day increase in French-fries consumption. The quality of evidence was rated mostly low (moderate quality of evidence for the risk-associations of French-fries).

CONCLUSION

Total potato consumption is not related to risk for many chronic diseases but could pose a small increase in risk for T2D if consumed boiled. A clear risk relation was found between French-fries consumption and risk of T2D and hypertension. For several outcomes, the impact of different preparation procedures could not be assessed.

Reversing ROS-mediated neurotoxicity by chlorogenic acid involves its direct antioxidant activity and activation of Nrf2-ARE signaling pathway

Chlorogenic acid (CA), the ester of caffeic acid and quinic acid, is one of the most abundant polyphenols in coffee, and has multiple pharmacological functions. The present study is designed to explore the protection provided by CA against hydrogen peroxide (H₂ O₂ )-induced oxidative damages in the rat pheochromocytoma cells, and the underlying mechanisms engaged in this process. CA displays robust free radical-scavenging activity in vitro. More importantly, CA strikingly rescues the cells from the H₂ O₂ -mediated oxidative insults. Mechanistic studies revealed that CA upregulates a panel of phase II cytoprotective species, such as heme oxygenase-1, NAD(P)H: quinone oxidoreductase 1, glutathione, thioredoxin reductase 1, and thioredoxin 1. This neuroprotection is dependent on the activation of the transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2), as knockdown of Nrf2 abolishes such effect. Our results demonstrate that CA provides dual neuroprotection via directly neutralizing free radicals and indirectly inducing expression of Nrf2-driven cytoprotective enzymes, and suggest a potential therapeutic usage of CA as a neuroprotective agent. Coffee is one of the most popular drinks in the world, and our discovery may also contribute to understanding the beneficial effects of regular coffee consumption. © 2019 BioFactors, 45 (4):616-626, 2019.

Aster koraiensis extract lowers postprandial glucose in normoglycemic and high-fat-diet-induced obese mice

The Aster koraiensis extract (ASKO) is a newly developed dietary herbal supplement. In this study, the potent blood glucose-lowering activity of ASKO in vitro and in vivo was investigated. In an in vitro glucose uptake assay, ASKO was found to enhance glucose transport in 3T3-L1 adipocytes. Oral administration of ASKO significantly reduced glucose levels in normoglycemic mice during oral glucose tolerance tests (OGTTs). In a long-term efficacy study, 4 weeks of oral ASKO treatment significantly attenuated blood glucose levels during OGTTs in diet-induced obese (DIO) mice. ASKO also enhanced plasma insulin levels after glucose loading, leading to a reduction in blood glucose levels. In addition, ASKO normalized glucose transporter-4 mRNA expression in the muscles of DIO mice. These results indicate that ASKO has postprandial glucose-lowering effects and could be beneficial in the management of prediabetes or type 2 diabetes mellitus.

A lignin polymer nanocomposite based electrochemical sensor for the sensitive detection of chlorogenic acid in coffee samples

In this study, an innovative nanocomposite of multiwalled carbon nanotubes (MWCNTs), copper oxide nanoparticles (CuONPs) and lignin (LGN) polymer were successfully synthesized and used to modify the glassy carbon electrode for the determination of chlorogenic acid (CGA). Cyclic voltammetry (CV) emphasised a quasi-reversible, adsorption controlled and pH dependent electrode procedure. In cyclic voltammetry a pair of well distinct redox peaks of CGA were observed at the LGN-MWCNTs-CuONPs-GCE in 0.1 M phosphate buffer solution (PBS), at pH 2. The synthesized nanoparticles and nanocomposites were characterized by Fourier transformation infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and x-ray diffraction (XRD) analyses. Differential pulse voltammetry (DPV) was applied to the anodic peak and used for the quantitative detection of CGA. Under optimal conditions, the proposed sensor showed linear responses from 5 μM to 50 μM, the linear regression equation I_pa (μA) = 2.6074 C-5.1027 (R² = 0.995), whilst the limit of detection (LOD) and limit of quantifications (LOQ) were found to be 0.0125 μM and 0.2631 μM respectively. The LGN-MWCNTs-CuONPs-GCE were applied to detect the CGA in real coffee samples with the recovery ranging from 97 to 106 %. The developed sensor was successfully applied for the analysis of CGA content in the coffee samples. In addition, electrophilic, nucleophilic reactions and chlorogenic acid docking studies were carried out to better understand the redox mechanisms and were supported by density functional theory calculations.

Effect of Decaffeinated Coffee-enriched Chlorogenic Acid on Blood Glucose Levels in Healthy Controls: A Systematic Review

As an important group of health problems, glucose metabolism disorders are associated with a number of diseases as well as mortality rate. Recently, studies have demonstrated that the consumption of decaffeinated coffee-enriched chlorogenic acid (CGA) can reduce the risk of diabetes and blood glucose rise, while the results of some previous studies have shown an opposite effect. Hence, a systematic search was conducted based on literature search and appropriate keywords through PubMed, Google Scholar, Web of Knowledge, Science direct, Medline, Cochrane, and Scopus databases from 2003 to 2018. After searching, 1593 articles were found. Then, we excluded papers based on the duplication and relevant for title and abstract, whereas 25 relevant articles remained for checking eligibility criteria. Since only randomized clinical trials studies (RCTs) could be included in the current study, six RCTs remained in end-stage for qualitative synthesis. The results of reviewed studies showed no significant effect of decaffeinated coffee-enriched CGA on blood glucose concentration. Although recent studies have suggested the effectiveness of decaffeinated coffee-enriched CGA on blood glucose in animals, and there are various mechanisms for this effect, and the result of our review showed that there is not sufficient evidence for this claim in healthy humans. Hence, further research in this area seems necessary.

Metabolic syndrome, Mediterranean diet, and polyphenols: Evidence and perspectives

Metabolic syndrome (MetS) is defined as the co-occurrence of metabolic risk factors that includes insulin resistance, hyperinsulinemia, impaired glucose tolerance, type 2 diabetes mellitus, dyslipidemia, and visceral obesity. The clinical significance of MetS consists of identifying a subgroup of patients sharing a common physiopathological state predisposing to chronic diseases. Clinical and scientific studies pinpoint lifestyle modification as an effective strategy aiming to reduce several features accountable for the risk of MetS onset. Among the healthy dietary patterns, the Mediterranean diet (MedDiet) emerges in terms of beneficial properties associated with longevity. Current evidence highlights the protective effect exerted by MedDiet on the different components of MetS. Interestingly, the effect exerted by polyphenols contained within the representative MedDiet components (i.e., olive oil, red wine, and nuts) seems to be accountable for the beneficial properties associated to this dietary pattern. In this review, we aim to summarize the principal evidence regarding the effectiveness of MedDiet-polyphenols in preventing or delaying the physiopathological components accountable for MetS onset. These findings may provide useful insights concerning the health properties of MedDiet-polyphenols as well as the novel targets destined to a tailored approach to MetS.

Carcinogenic and neurotoxic risks of acrylamide consumed through caffeinated beverages among the lebanese population

The present study aims to quantify acrylamide in caffeinated beverages including American coffee, Lebanese coffee, espresso, instant coffee and hot chocolate, and to determine their carcinogenic and neurotoxic risks. A survey was carried for this purpose whereby 78% of the Lebanese population was found to consume at least one type of caffeinated beverages. Gas Chromatography Mass Spectrometry analysis revealed that the average acrylamide level in caffeinated beverages is 29,176 μg/kg sample. The daily consumption of acrylamide from Lebanese coffee (10.9 μg/kg-bw/day), hot chocolate (1.2 μg/kg-bw/day) and Espresso (7.4 μg/kg-bw/day) was found to be higher than the risk intake for carcinogenicity and neurotoxicity as set by World Health Organization (WHO; 0.3-2 μg/kg-bw/day) at both the mean (average consumers) and high (high consumers) dietary exposures. On the other hand, American coffee (0.37 μg/kg-bw/day) was shown to pose no carcinogenic or neurotoxic risks among the Lebanese community for consumers with a mean dietary exposure. The study shows alarming results that call for regulating the caffeinated product industry by setting legislations and standard protocols for product preparation in order to limit the acrylamide content and protect consumers. In order to avoid carcinogenic and neurotoxic risks, we propose that WHO/FAO set acrylamide levels in caffeinated beverages to 7000 μg acrylamide/kg sample, a value which is 4-folds lower than the average acrylamide levels of 29,176 μg/kg sample found in caffeinated beverages sold in the Lebanese market. Alternatively, consumers of caffeinated products, especially Lebanese coffee and espresso, would have to lower their daily consumption to 0.3-0.4 cups/day.

Effects of Coffee Components on Muscle Glycogen Recovery: A Systematic Review

Coffee is one of the most consumed beverages in the world, and it can improve insulin sensitivity, stimulating glucose uptake in skeletal muscle when adequate carbohydrate intake is observed. The aim of this review is to analyze the effects of coffee and coffee components on muscle glycogen metabolism. A literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis, and seven studies were included, that explored the effects of coffee components on various substances and signaling proteins. In one of the studies with humans, caffeine was shown to increase glucose levels, Ca²⁺/calmodulin-dependent protein kinase phosphorylation, glycogen resynthesis rates, and glycogen accumulation after exercise. After intravenous injection of caffeine in rats, caffeine increased adenosine monophosphate-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) phosphorylation, and glucose transport. In in vitro studies, caffeine raised AMPK and ACC phosphorylation, increasing glucose transport activity and reducing energy status in rat muscle cells. Cafestol and caffeic acid increased insulin secretion in rat beta cells and glucose uptake into human muscle cells. Caffeic acid also increased AMPK and ACC phosphorylation, reducing the energy status and increasing glucose uptake in rat muscle cells. Chlorogenic acid did not show any positive or negative effect. The findings from this review must be taken with caution due to the limited number of studies on the subject. In conclusion, various coffee components had a neutral or positive role in the metabolism of glucose and muscle glycogen, whereas no detrimental effect was described. Coffee beverages should be tested as an option for athletes' glycogen recovery.

Effect of Green Coffee Consumption on Resting Energy Expenditure, Blood Pressure, and Body Temperature in Healthy Women: A Pilot Study

KEY TEACHING POINTS

• There are several findings, and chlorogenic acid may have antihypertensive effects. • There is a significant correlation between green coffee chlorogenic acid amount and REE. • Intracellular and extracellular liquid amounts decrease following green coffee consumption (215-280 mg caffeine), and these changes are observed in individuals whose usual dietary caffeine intake is relatively both low and high. • The body temperature values of individuals whose usual dietary caffeine intake was in the 50th percentile or greater (relatively high) increased after green coffee consumption.