A clinical trial to investigate the effect of a proprietary mulberry leaf extract (Reducose®) on lowering blood glucose rises after consuming a drink containing sugar (sucrose)

ISRCTN ISRCTN99601810
DOI https://doi.org/10.1186/ISRCTN99601810
Secondary identifying numbers SUGERS 1.1
Submission date
12/10/2020
Registration date
23/10/2020
Last edited
13/08/2021
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Nutritional, Metabolic, Endocrine
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English Summary

Background and study aims
The glycaemic index of foods shows how quickly each food affects your blood sugar (glucose) level when that food is eaten. Maintaining healthy blood glucose levels and avoiding large blood glucose spikes has a number of positive health benefits.

Previous clinical trials have shown that Reducose, a mulberry leaf extract can lower the glycaemic index of foods and lower the total blood glucose and blood glucose spikes after eating starch. This study will build on the clinical evidence on the health benefits of Reducose by evaluating the effects of a single dose of 250 mg of Reducose in blunting the blood glucose response after eating sugar (sucrose) and compare the results to a placebo arm where subjects only consume sucrose.

Who can participate?
40 healthy adults aged 18-60 with a BMI of 20-29.9.

What does the study involve?
Participants will be recruited to attend two study visits, at least 48 h apart, in order to test either 250 mg of Reducose mixed with 75 g sucrose (test), or 75 g sucrose alone (placebo). The test meal or placebo meal are packaged in opaque containers and dissolved in 250 ml water and are consumed. In the second visit, the product that has not yet been tested by the participant in the first visit will be prepared. The products are matched for taste and smell and neither participants nor the study team will be aware of the order that the test meals are given until all of the tests have been completed. Changes in blood glucose and insulin levels will be measured over 2 h.

What are the possible benefits and risks of participating?
Mulberry extract has an excellent safety profile and is widely consumed in Asia and is available as a dietary supplement in England. Previous clinical trials have shown that Reducose does not have any reported adverse reactions, a finding mirrored in the published literature. Participants will have multiple finger pricks to test for blood glucose and insulin levels, therefore there will be a risk discomfort and bruising and a small risk of inflammation/infection at the site. Local infection control/procedures will be followed during each study visit.

Where is the study run from?
Oxford Brookes Centre for Nutrition and Health, Oxford Brookes University (UK)

When is the study starting and how long is it expected to run for?
From March 2016 to August 2016

Who is funding the study?
Phynova Group Ltd (UK)

Who is the main contact?
Andrew Gallagher
agallagher@phynova.com

Contact information

Mr Andrew Gallagher
Scientific

16 Fenlock Court
Blenheim Office Park
Long Hanborough
OX29 8LN
United Kingdom

ORCiD logoORCID ID 0000-0002-5974-4093
Phone +44 (0)1993880700
Email agallagher@phynova.com

Study information

Study designDouble-blind, randomised, repeat measure, crossover design trial
Primary study designInterventional
Secondary study designRandomised cross over trial
Study setting(s)Other
Study typeTreatment
Participant information sheet ISRCTN99601810_ PIS_v3.0_06Mar2014.pdf
Scientific titleClinical stUdy to assess the Glycaemic Effect of Reducose on a Sucrose challenge (SUGERS): a double blind, placebo controlled, crossover study
Study acronymSUGERS
Study hypothesis1. Reducose® mulberry leaf extract, when co-administered with oral sucrose will reduce the incremental area under the curve (iAUC) for plasma glucose concentration over 120 minutes in normoglycaemic adults when compared to co-administration with placebo
2. Reducose®, when co-administered with oral sucrose, will not disproportionately increase the incremental area under the curve for plasma insulin concentration over 120 minutes in normoglycaemic adults compared to co-administration with placebo
Ethics approval(s)1. Approved 07/03/2014, University Research Ethics Committee (UREC) at Oxford Brookes University (Research & Business Development Office, Directorate of Finance & Legal Services, Oxford Brookes University, Headington Campus, Gipsy Lane, Oxford, OX3 0BP, UK; +44 (0) 1865 48 4445; ethics@brookes.ac.uk), ref: 140806 (for glycaemic response),
2. Approved 24/01/2012, University Research Ethics Committee (UREC) at Oxford Brookes University (Research & Business Development Office, Directorate of Finance & Legal Services, Oxford Brookes University, Headington Campus, Gipsy Lane, Oxford, OX3 0BP, UK; +44 (0) 1865 48 4445; ethics@brookes.ac.uk), ref: 110594 (for insulinaemic response)
ConditionPostprandial glycaemic control
InterventionThe trial has a randomised crossover design and so each subject would act as their own control. Randomisation sequence was generated using www.randomization.com using the randomly permuted blocks method to assign which treatment subjects would receive first. Researchers recruiting the participants were unaware of the allocation sequence (concealed allocation). Participants were assigned to a participant number according to their chronological order of enrolment in the study. The allocated participant number was used to identify the participants and their corresponding intervention sequence.

Participants will be recruited to attend two study visits, with at least 48 h apart for washout. The study will evaluate a single dose of 250 mg mulberry leaf extract (Reducose) against matched placebo. The mulberry leaf extract is standardised to contain 5% (m/m) 1-deoxynojirimycin (DNJ). Each 250 mg dose contains 12.5 mg DNJ.

Test product contained 250 mg Reducose mulberry leaf extract directly blended into 75 g sucrose. Placebo product contained 75 g sucrose alone. Reducose has minimal impact on taste, smell, and colour of the sucrose blend. The test meal or placebo meal are packaged in opaque containers and dissolved in 250 ml water and are consumed. The participants and study team are blind to allocation.

At each study visit, plasma insulin and glucose concentrations will be measured by fingerprick blood sample at 0, 15, 30, 45, 60, 90, and 120 min.
Intervention typeSupplement
Primary outcome measureIncremental area under curve for plasma glucose concentration over 120 min, plasma glucose concentration collected by fingerprick blood sample at 0, 15, 30, 45, 60, 90, and 120 min
Secondary outcome measuresIncremental area under curve for plasma insulin concentration over 120 min, plasma insulin concentration collected by fingerprick blood sample at 0, 15, 30, 45, 60, 90, and 120 min
Overall study start date04/11/2015
Overall study end date15/08/2016

Eligibility

Participant type(s)Healthy volunteer
Age groupAdult
Lower age limit18 Years
Upper age limit60 Years
SexBoth
Target number of participants40
Total final enrolment40
Participant inclusion criteria1. Consent to study protocol
2. Aged 18-60 years
3. BMI 20-29.9 kg/m²
4. Fasting blood glucose <6.1 mmol/l
Participant exclusion criteria1. Pregnant or lactating
2. Any known food allergies or intolerance to mulberry leaf extracts
3. Presence of a medical condition, or taking medication known to affect glucose regulation and/or influence digestion and absorption of nutrients
4. History of diabetes mellitus (type I or type II), or the use of antihyperglycaemic drugs or insulin to treat diabetes or related conditions
5. Use of steroids, protease inhibitors, or antipsychotics which would affect glucose metabolism and body fat distribution
Recruitment start date21/03/2016
Recruitment end date04/08/2016

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Oxford Brookes Centre for Nutrition and Health
Oxford Brookes University
Headington Campus
Oxford
OX3 0BP
United Kingdom

Sponsor information

Phynova Group Limited
Industry

16 Fenlock Court
Blenheim Office Park
Long Hanborough
OX29 8LN
United Kingdom

Phone +44 (0) 1993880700
Email info@phynova.com
Website www.phynova.com

Funders

Funder type

Industry

Phynova Group Limited

No information available

Results and Publications

Intention to publish date01/03/2021
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot expected to be made available
Publication and dissemination planPlanned publication of the trial results. The study protocol has not been published but is adapted from the methods published in Brouns et al ( Brouns F, Bjorck I, Frayn KN, Gibbs AL, Lang V, Slama G, Wolever TMS. Glycaemic index methodology. Nutr Res Rev 2005;18:145-171) and was conducted in accordance with ISO 26642:2010. The research protocol and statistical analysis plan will be available on request from info@phynova.com.
IPD sharing planThe datasets generated and analysed during the current study will be available to researchers upon request from Phynova Group Limited. Anonymised patient level data will be available for research purposes within six months of publishing the results of the primary endpoints, key secondary endpoints and safety data in a peer-reviewed journal. As participants only consented for their data to be used to investigate a particular health benefit of the test product, access to data will only be provided for researchers that are investigating the same or an equivalent product for the same health benefit. Data will be made available on request provided Phynova has the legal authority to provide the data; for example, if Phynova has out-licensed the data to another company then it would no longer have the legal authority to provide the data. Data will only be made available if Phynova is able to anonymise the data without compromising the confidentiality and privacy of research participants. Data from clinical trials where the data labels and/or supporting documents are not in English will only be made available in their original format and no translations will be provided. The following information will be made available: raw dataset excluding any patient images, protocol with any amendments, analysis and reporting plan. Researchers requesting access to data should email their requests to info@phynova.com and should include a description of the intended research.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Participant information sheet version v3.0 06/03/2014 23/10/2020 No Yes
Results article 15/04/2021 13/08/2021 Yes No

Additional files

ISRCTN99601810_ PIS_v3.0_06Mar2014.pdf
Uploaded 23/10/2020

Editorial Notes

13/08/2021: Internal review.
19/04/2021: Publication reference added.
23/10/2020: The basic results of this trial have been uploaded as an additional file.
21/10/2020: Trial’s existence confirmed by Oxford Brookes Centre for Nutrition and Health (OxBCNH) .