Abstract

Background/objectivesType 2 diabetes (T2D) is a global pandemic, and contributes significantly to the increasing incidence of conditions such as cardiovascular disease (CVD). Postprandial plasma glucose measured 2-h after the start of a meal is a good indicator of the overall status of glucose homeostasis. Clove (Syzygium aromaticum L.) and its essential oils (eugenol and acetyl eugenol) have been shown in preclinical studies to modulate pathways involved in glucose homeostasis. In addition, a water-soluble polyphenolic extract of unopened clove buds was recently shown to benefit liver function and redox status. Therefore, we conducted an open-label pilot study to test whether this polyphenolic clove extract (PCE) could influence glucose metabolism.MethodsWe evaluated the effect of PCE supplementation (250 mg once daily for 30 days) on preprandial glucose levels and 2-h postprandial glucose levels in 13 otherwise healthy volunteers who were stratified into two groups according to their initial preprandial glucose levels: Group I (n = 7) ≤100 mg/dL, Group II (n = 6) – between 101 and 125 mg/dL. In an effort to elucidate the molecular mechanisms of PCE action, we tested in vitro the effects of PCE on glucose uptake, hepatocyte glucose production, and carbohydrate hydrolyzing enzymes.ResultsAt day 12 of supplementation, we observed statistically significant reductions in mean postprandial glucose levels in both groups [(Group I: Initial - Day 12 PPG = 13.29 mg/dL, 95% CI: 3.329–23.24) (Group II: Initial – Day 12 PPG = 16.67 mg/dL, 95% CI: 4.687–28.65, P = 0.0159)], which continued through study completion at day 30. PCE supplementation significantly decreased mean preprandial glucose levels only in Group II at Days 24 (Initial – Day 24 = 13.00 mg/dL, 95% CI: 1.407–24.59, P = 0.0345) and 30 (Initial – Day 30 = 13.67 mg/dL, 95% CI: 5.766–21.57, P = 0.0067). In cell-based assays, PCE enhanced glucose uptake in L6 myocytes and inhibited hepatocyte glucose production HepG2 cells. In cell-free assays, PCE inhibited α-amylase activity and α-glucosidase activity.ConclusionsThese findings underscore the therapeutic utility of PCE for maintaining healthy glucose metabolism and warrant further larger-scale clinical trials.Trial registrationThis trial was retrospectively registered in the ISRCTN registry on September 29, 2018 (ISRCTN15680985).

Highlights

  • Type 2 diabetes is a tremendous public health issue

  • At day 12 of supplementation, we observed statistically significant reductions in mean postprandial glucose levels in both groups [(Group I: Initial - Day 12 Postprandial glucose (PPG) = 13.29 mg/dL, 95% CI: 3.329–23.24) (Group II: Initial – Day 12 PPG = 16.67 mg/dL, 95% CI: 4.687–28.65, P = 0.0159)], which continued through study completion at day 30

  • In cell-free assays, polyphenolic clove extract (PCE) inhibited α-amylase activity and α-glucosidase activity. These findings underscore the therapeutic utility of PCE for maintaining healthy glucose metabolism and warrant further larger-scale clinical trials

Read more

Summary

Introduction

Type 2 diabetes is a tremendous public health issue. More than 75% of the US population over 65 years of age has some degree glucose homeostasis dysfunction [1]. In 2014, adults 25 to 44 years of age were more than twice as likely to have diabetes and be overweight or obese than in 1989 [2]. Factors driving this metabolic syndrome pandemic include alterations in diet and reduced physical activity [3]. Numerous population studies across the globe have demonstrated that polyphenol intake has an inverse relationship with disease incidence [5,6,7]. Diets low in polyphenols are associated with an increase in T2DM incidence [8,9,10]. HPLC analysis of PCE revealed the presence of gallic acid, ellagic acid, catechin, quercetin, chlorogenic acid, and eugenol [12]

Methods
Results
Conclusion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.