An enzymatic clinical chemistry laboratory experiment incorporating an introduction to mathematical method comparison techniques

Effect of a 12-Week Polyphenol Rutin Intervention on Markers of Pancreatic β-Cell Function and Gut Microbiota in Adults with Overweight without Diabetes

Supplementation with prebiotic polyphenol rutin is a potential dietary therapy for type 2 diabetes prevention in adults with obesity, based on previous glycaemic improvement in transgenic mouse models. Gut microbiota are hypothesised to underpin these effects. We investigated the effect of rutin supplementation on pancreatic β-cell function measured as C-peptide/glucose ratio, and 16S rRNA gene-based gut microbiota profiles, in a cohort of individuals with overweight plus normoglycaemia or prediabetes. Eighty-seven participants were enrolled, aged 18-65 years with BMI of 23-35 kg/m2. This was a 12-week double-blind randomised controlled trial (RCT), with 3 treatments comprising (i) placebo control, (ii) 500 mg/day encapsulated rutin, and (iii) 500 mg/day rutin-supplemented yoghurt. A 2-h oral glucose tolerance test (OGTT) was performed at baseline and at the end of the trial, with faecal samples also collected. Compliance with treatment was high (~90%), but rutin in both capsule and dietary format did not alter pancreatic β-cell response to OGTT over 12 weeks. Gut bacterial community composition also did not significantly change, with Firmicutes dominating irrespective of treatment. Fasting plasma glucose negatively correlated with the abundance of the butyrate producer Roseburia inulinivorans, known for its anti-inflammatory capacity. This is the first RCT to investigate postprandial pancreatic β-cell function in response to rutin supplementation.

Shared-cathode closed bipolar electrochemiluminescence cloth-based chip for multiplex detection

Electrochemiluminescence (ECL) chips have been widely used in the field of medical diagnosis. However, most of these chips currently in use are costly and require high amounts of sample. In this work, we present, for the first time, a shared-cathode closed bipolar electrochemiluminescence (SC-CBP-ECL) cloth-based chip, which can be used for multiplex detection. The SC-CBP-ECL chips ($0.03-0.05 for each chip) are manufactured using carbon ink- and wax-based screen-printing techniques, without the need for expensive and complex fabrication equipment. Under optimised conditions, the SC-CBP-ECL chips were successfully used for coinstantaneous detection of glucose in double ECL systems (i.e., Ru(bpy)₃²⁺ and luminol), with corresponding linear ranges of 0.05-1 mM and 0.05-10 mM, and detection limits of 0.0382 mM and 0.0422 mM. To our knowledge, this is the first report on the application of fibre material-based closed bipolar electrodes (C-BPE) combined with double ECL systems. Furthermore, the SC-CBP-ECL chips exhibit an acceptable specificity and good reproducibility and stability and can be used for glucose detection in human serum samples with a good agreement compared with the clinical method. Finally, the SC-CBP-ECL chips could be successfully used for simultaneous detection of seven glucose samples and also show potential for simultaneous detection of three different targets (hydrogen peroxide [H₂O₂], glucose, and uric acid [UA]). Therefore, we believe that the chip described in this study has broad potential application in the field of cost-effective multiplex detection.

Efficacy and Safety of Nutraceutical on Menopausal Symptoms in Post-Menopausal Women: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

BACKGROUND

Menopausal symptoms severely reduce the quality of life of post-menopausal women worldwide. Nutraceuticals are widely prescribed as a viable and safer alternative and complementary approach to standard therapies. The aim of this study was to evaluate the clinical efficacy and safety of a nutraceutical in post-menopausal women.

METHODS

The study was designed as a randomized, double-blinded, placebo-controlled clinical trial. Post-menopausal women aged 45-60 years old were enrolled and randomly assigned to either treatment (n = 50) or placebo group (n = 51). The intervention, a proprietary combination of soy isoflavone, black cohosh, chasteberry and evening primrose oil extracts, and the placebo, were administered to each group for total of 12 weeks. Menopausal symptoms, endocrine profiles, and blood chemistry were evaluated at baseline, 6 weeks, and 12 weeks of the study.

RESULTS

Nutraceutical supplementation demonstrated a statistically significant reduction in hot flushes and sweating (p < 0.0001), sleep problems (p < 0.0005), depressed mood (p = 0.0004) and irritability symptoms (p < 0.0003) compared with the placebo group. There were no significant differences in hormonal levels between the test and placebo groups, however levels of C-reactive protein were significantly decreased. Moreover, serum LDL-C and triglyceride levels were significantly lower than baseline levels in the treatment group at 6- and 12-week timepoints. No adverse effects were reported during the treatment.

CONCLUSION

These data indicate that a nutraceutical containing a combination of four medicinal herbs effectively and safely improved menopausal symptoms, as well as general health indicators, in post-menopausal women.

Nutraceutical Improves Glycemic Control, Insulin Sensitivity, and Oxidative Stress in Hyperglycemic Subjects: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

The aim of this research was to investigate the effects of nutraceuticals including bitter melon, fenugreek, cinnamon, alpha-lipoic acid, zinc, biotin, chromium, and cholecalciferol on glycemic control, insulin sensitivity, lipid profiles, oxidative stress, and inflammatory markers in hyperglycemia. The study design was a randomized, double-blind, placebo-controlled trial. Subjects with hyperglycemia were randomly divided into 2 groups. The treatment group ( n = 52) was given a nutraceutical and the control group ( n = 50) was provided with a placebo for 12 weeks. Fasting blood glucose (FBG), hemoglobin A1c (HbA1C), homeostatic model assessment of insulin resistance (HOMA-IR), lipid profiles, biomarkers of oxidative stress, and inflammation were assessed before and after the intervention at 6 weeks and 12 weeks. Nutraceutical supplementation demonstrated a statistically significant decrease in FBG (13.4% and 18.9%), HbA1C (6.5% and 11.3%), and HOMA-IR (28.9% and 35.2%) compared with the placebo. Moreover, low-density lipoprotein-cholesterol (LDL-C) level was significantly reduced in the nutraceutical group (7.1% and 9.3%). Furthermore, the nutraceutical significantly decreased oxidative stress markers, oxidized LDL-C (14.8% and 18.9%) and malondialdehyde (16.6% and 26.2%) compared with the placebo. In conclusion, this nutraceutical can improve glycemic control, insulin resistance, lipid profiles, and oxidative stress markers in hyperglycemic subjects. Therefore, it has the potential to decrease cardiovascular disease risk factors. Clinical trial registration: TCTR20180907001, www.clinicaltrials.in.th.

Not all has been said about glucose oxidase/peroxidase: New pedagogical uses for a classical and robust undergraduate laboratory experiment

The enzymatic determination of glucose in soft drinks, based on the glucose concentration measurement by means of the coupled reactions of glucose oxidase and peroxidase, has been implemented at the University of Malaga and optimized according to the Biochemistry and Chemistry undergraduate students' results and feedback throughout the last few years. This traditional and robust laboratory practical has been reformed, in the light of inquiry-based and interdisciplinary learning approaches, in order to optimize the students' formative achievements that now are not restricted to the learning of enzymology, but also integrates cross-curricular knowledge from chemistry and mathematics. In this experiment, inexpensive and feasible to be carried out in a single laboratory session, students have to make the decision of what method is the most suitable for a given analytical problem, anticipating situations that they will probably face throughout their professional careers. It not only illustrates basic issues related to the use of enzymes as reagents for enzymatic analyses and its application to food chemistry, but it is also used to put into practice some principles of statistical analysis and analytical methods evaluation. This can be achieved because students get results from two different enzymatic analysis protocols (kinetic and end-point methods) using a single reaction mixture. The measurement of glucose concentration in four carbonated soft-drinks, regular or sugar-free colas and tonic waters makes students deal with the presence of color interferences that should be either avoided or eliminated. Undergraduate students, having performed this experiment, have found it formative, interesting, and challenging. © 2019 International Union of Biochemistry and Molecular Biology, 47(3):341-347, 2019.

Ferulic Acid Supplementation Improves Lipid Profiles, Oxidative Stress, and Inflammatory Status in Hyperlipidemic Subjects: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Ferulic acid is the most abundant phenolic compound found in vegetables and cereal grains. In vitro and animal studies have shown ferulic acid has anti-hyperlipidemic, anti-oxidative, and anti-inflammatory effects. The objective of this study is to investigate the effects of ferulic acid supplementation on lipid profiles, oxidative stress, and inflammatory status in hyperlipidemia. The study design is a randomized, double-blind, placebo-controlled trial. Subjects with hyperlipidemia were randomly divided into two groups. The treatment group (n = 24) was given ferulic acid (1000 mg daily) and the control group (n = 24) was provided with a placebo for six weeks. Lipid profiles, biomarkers of oxidative stress and inflammation were assessed before and after the intervention. Ferulic acid supplementation demonstrated a statistically significant decrease in total cholesterol (8.1%; p = 0.001), LDL-C (9.3%; p < 0.001), triglyceride (12.1%; p = 0.049), and increased HDL-C (4.3%; p = 0.045) compared with the placebo. Ferulic acid also significantly decreased the oxidative stress biomarker, MDA (24.5%; p < 0.001). Moreover, oxidized LDL-C was significantly decreased in the ferulic acid group (7.1%; p = 0.002) compared with the placebo group. In addition, ferulic acid supplementation demonstrated a statistically significant reduction in the inflammatory markers hs-CRP (32.66%; p < 0.001) and TNF-α (13.06%; p < 0.001). These data indicate ferulic acid supplementation can improve lipid profiles and oxidative stress, oxidized LDL-C, and inflammation in hyperlipidemic subjects. Therefore, ferulic acid has the potential to reduce cardiovascular disease risk factors.

Diet with high content of advanced glycation end products induces systemic inflammation and weight gain in experimental mice: Protective role of curcumin and gallic acid

The present study was aimed to investigate the effect of diet derived AGEs (dAGEs) on the circulatory levels of pro-inflammatory cytokines, chemokines and to evaluate the protective efficacy of natural anti-oxidants curcumin (CU) and gallic acid (GA) respectively against the dAGEs-induced systemic inflammation in experimental Swiss albino mice. The experimental mice were fed with dAGEs in the presence and absence of CU and GA for 6 months. The levels of 40 circulatory pro-inflammatory cytokines and chemokines were evaluated using Proteome-Cytokine Array kit. In addition, serum levels of N-ɛCML, CRP and HbA1c were estimated by ELISA method. Among the sixteen pro- and anti-inflammatory cytokines analysed, five (IL-16, IL-1α, ICAM, TIMP-1 and C5a) were found to be highly expressed (3.5-fold) and eleven cytokines were moderately expressed (2-fold) in dAGEs fed mice. In case of chemokines, three (BLC, SDF-1 and MCP-1) were found to be highly expressed (4-fold) and ten showed moderate expression (2-fold) as compared with basal diet fed mice. Interestingly, CU or GA co-treatment normalized the levels of circulatory pro- and anti-inflammatory cytokines, chemokines, N-ɛCML, CRP and HbA1c levels. Together, the present study suggests that dAGEs are positively associated with the development of systemic inflammation in experimental mice.