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Food & Function May 2024Elevated blood glucose concentration is a risk factor for developing metabolic dysfunction and insulin resistance, leading to type 2 diabetes and cardiovascular... (Review)
Review
Elevated blood glucose concentration is a risk factor for developing metabolic dysfunction and insulin resistance, leading to type 2 diabetes and cardiovascular diseases. Nuts have the potential to inhibit α-amylase activity, and so lower postprandial glucose, due to their content of polyphenols and other bioactive compounds. We conducted a systematic literature review to assess the ability of extracts from commonly consumed edible parts of nuts to inhibit α-amylase. Among the 31 included papers, only four utilised human α-amylases. These papers indicated that polyphenol-rich chestnut skin extracts exhibited strong inhibition of both human salivary and pancreatic α-amylases, and that a polyphenol-rich almond skin extract was a potent inhibitor of human salivary α-amylase. The majority of the reviewed studies utilised porcine pancreatic α-amylase, which has ∼86% sequence homology with the corresponding human enzyme but with some key amino acid variations located within the active site. Polyphenol-rich extracts from chestnut, almond, kola nut, pecan and walnut, and peptides isolated from cashew, inhibited porcine pancreatic α-amylase. Some studies used α-amylases sourced from fungi or bacteria, outcomes from which are entirely irrelevant to human health, as they have no sequence homology with the human enzyme. Given the limited research involving human α-amylases, and the differences in inhibition compared to porcine enzymes and especially enzymes from microorganisms, it is recommended that future experiments place greater emphasis on utilising enzymes sourced from humans to facilitate a reliable prediction of effects in intervention studies.
Topics: Nuts; Humans; Plant Extracts; Animals; alpha-Amylases; Swine; Enzyme Inhibitors; Polyphenols; Juglans
PubMed: 38717256
DOI: 10.1039/d4fo00414k -
Molecular Pain 2024Nociception related salivary biomolecules can be useful patients who are not able to self-report pain. We present the existing evidence on this topic using the... (Review)
Review
Nociception related salivary biomolecules can be useful patients who are not able to self-report pain. We present the existing evidence on this topic using the PRISMA-ScR guidelines and a more focused analysis of cortisol change after cold pain induction using the direction of effect analysis combined with risk of bias analysis using ROBINS-I. Five data bases were searched systematically for articles on adults with acute pain secondary to disease, injury, or experimentally induced pain. Forty three articles met the inclusion criteria for the general review and 11 of these were included in the cortisol-cold pain analysis. Salivary melatonin, kallikreins, pro-inflammatory cytokines, soluable TNF-α receptor II, secretory IgA, testosterone, salivary α-amylase (sAA) and, most commonly, cortisol have been studied in relation to acute pain. There is greatest information about cortisol and sAA which both rise after cold pain when compared with other modalities. Where participants have been subjected to both pain and stress, stress is consistently a more reliable predictor of salivary biomarker change than pain. There remain considerable challenges in identifying biomarkers that can be used in clinical practice to guide the measurement of nociception and treatment of pain. Standardization of methodology and researchers' greater awareness of the factors that affect salivary biomolecule concentrations are needed to improve our understanding of this field towards creating a clinically relevant body of evidence.
Topics: Adult; Humans; Hydrocortisone; Acute Pain; Saliva; Nociception; Salivary alpha-Amylases; Biomarkers; Stress, Psychological
PubMed: 38385158
DOI: 10.1177/17448069241237121 -
Nutrients Aug 2020Evidence synthesizing the effects of acute body water losses on various markers of glycemic regulation, appetite, metabolism, and stress is lacking. Thus, the purpose of... (Meta-Analysis)
Meta-Analysis
Evidence synthesizing the effects of acute body water losses on various markers of glycemic regulation, appetite, metabolism, and stress is lacking. Thus, the purpose of this review was to summarize the response of various hormonal changes involved in these physiologic functions to dehydration. A comprehensive literature search for peer-reviewed research in the databases PubMed, Scopus, CINAHL, and SportDiscus was conducted. Studies were included if they contained samples of adults (>18 years) and experimentally induced dehydration as measured by acute body mass loss. Twenty-one articles were eligible for inclusion. Findings suggested cortisol is significantly elevated with hypohydration (standard mean difference [SMD] = 1.12, 95% CI [0.583, 1.67], < 0.0001). Testosterone was significantly lower in studies where hypohydration was accompanied by caloric restriction (SMD= -1.04, 95% CI [-1.93, -0.14], = 0.02), however, there were no changes in testosterone in studies examining hypohydration alone (SMD = -0.17, 95% CI [-0.51 0.16], = 0.30). Insulin and ghrelin were unaffected by acute total body water losses. Acute hypohydration increases markers of catabolism but has a negligible effect on markers of glycemic regulation, appetite, anabolism and stress. Given the brevity of existing research, further research is needed to determine the impact of hydration on glucagon, leptin, peptide YY and the subsequent outcomes relevant to both health and performance.
Topics: Adolescent; Adult; Appetite; Blood Glucose; Caloric Restriction; Dehydration; Female; Ghrelin; Humans; Hydrocortisone; Leptin; Male; Peptide YY; Stress, Physiological; Testosterone; Young Adult; alpha-Amylases
PubMed: 32825404
DOI: 10.3390/nu12092526 -
Critical Reviews in Food Science and... 2021Evidence shows that polyphenols can attenuate postprandial blood glucose responses to meals containing digestible carbohydrate. Polyphenol-rich plant extracts are...
A systematic review of studies evaluating the inhibitory effects of polyphenol-rich fruit extracts on carbohydrate digestive enzymes activity: a focus on culinary fruits consumed in Europe.
Evidence shows that polyphenols can attenuate postprandial blood glucose responses to meals containing digestible carbohydrate. Polyphenol-rich plant extracts are emerging as potential ingredients in functional foods and/or beverages despite limited understanding of their physiological effects. Many studies have investigated the mechanisms of polyphenol-rich fruit extracts on inhibition of digestive enzymes. However, the evidence available has yet to be critically evaluated systematically. This report reviews the in vitro literature to quantify the effect of fruit polyphenol extracts on the activities of digestive carbohydrases. A systematic literature search was conducted using six science databases. Included studies, totaling 34 in number, were in vitro digestion models which quantified gut digestive enzyme(s) activity on starch digestion in the presence of fruit polyphenol extracts. Most studies assessed the effects of fruit extracts on either α-amylase (n = 30) or α-glucosidase (n = 30) activity. Studies were consistent overall in showing stronger inhibition of α-amylase compared to α-glucosidase by proanthocyanidin- and/or ellagitannin-rich fruit extracts. Recommendations are proposed for future reporting of this type of research to enable meaningful synthesis of the literature as a whole. Such knowledge could allow effective choices to be made for development of novel functional foods and beverages.
Topics: Fruit; Glycoside Hydrolase Inhibitors; Plant Extracts; Polyphenols; Starch; alpha-Amylases; alpha-Glucosidases
PubMed: 32838552
DOI: 10.1080/10408398.2020.1808585