Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12624000491561
Ethics application status
Approved
Date submitted
8/04/2024
Date registered
22/04/2024
Date last updated
22/04/2024
Date data sharing statement initially provided
22/04/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
Impact of the New Zealand pine bark extract (Enzogenol®) on sucrose metabolism and glycaemic responses in healthy adults – a single-blind, randomised, placebo-controlled, crossover trial
Scientific title
Impact of the New Zealand pine bark extract (Enzogenol®) on sucrose metabolism and glycaemic responses in healthy adults – a single-blind, randomised, placebo-controlled, crossover trial
Secondary ID [1] 311398 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record
Yes, this new study is related to the previous study (ACTRN12619001571167), which has been completed. This new study aims to further understand the underlying mechanism of hypoglycaemic action of Enzogenol(R) in inhibiting sucrose (sugar) metabolism in humans.

Health condition
Health condition(s) or problem(s) studied:
Dysglycaemia 332672 0
Diabetes 332673 0
Glycaemic control 332674 0
Condition category
Condition code
Diet and Nutrition 329378 329378 0 0
Other diet and nutrition disorders
Metabolic and Endocrine 329379 329379 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is an acute, randomised, single-blind, crossover, placebo-controlled study. The study aims to determine the effects of the New Zealand pine bark extract (Enzogenol®) in two effective doses (50 and 400 mg) in improving glycaemic and insulinaemic postprandial responses in healthy participants when co-administered with 75 g of sucrose solution. There will be a total of four visits involving the following intervention arms: placebo (only 75 g of sucrose powder), 250 mg of Reducose®, 50 mg of Enzogenol®, and 400 mg of Enzogenol®. Each intervention extract will be added with 75 g of sucrose powder, well mixed with 250 mL of water in an opaque vessel (to conceal contents) given to participants on separate occasion during the study visits. All intervention arms will be of similar taste and odour. Enzogenol® will be compared with Reducose® regarding its efficacy and impact on glycaemia. Briefly, Reducose® (Phynova Group, Ltd.) is a commercially available water extract of white mulberry (Morus alba Linn) leaf extract (standardised to 4.5-5.5% 1- deoxynojirimycin, DNJ, a type of iminosugar). DNJ has been demonstrated in research to inhibit carbohydrate-digesting enzymes such as alpha-glucosidase and amylase due to its structure similarity to carbohydrate monosaccharides. They potentially compete with carbohydrates for the enzyme receptors that may lead to the delay or reduction in carbohydrate digestion.

At each study visit, all eligible participants will be checked for dietary and lifestyle compliance, such as having fasted at least 10-12 hours prior to the visit, keeping their diet constant, no strenuous physical activity, no alcohol, no caffeinated tea or coffee formulations, no health supplements 24 hours to visit, and no consumption of pine bark or mulberry leaf extract throughout the duration of the study. A baseline sample will be taken at 10 min and at 0 min prior to consuming the treatment at each visit. The participants will be required to consume the treatment within 5 minutes. Further blood samples will be taken at time points 15, 30, 45, 60, 90 and 120 min. Blood samples are obtained via the finger prick test using a single use disposable lancet (Accu-Chek Safe T-Pro Plus) and 300 uL blood collected into chilled microvette capillary blood collection tubes treated with heparin (Sarstedt Microvette CB300 Lithium Heparin) for plasma insulin analysis. Samples are centrifuged to obtain 200 uL supernatent for plasma insulin analysis. Plasma glucose levels obtained from the finger prick test are immediately measured using a glucose meter (MediSense, Optium, Abbott, 2.7-4.0% CV). There is a washout period of at least a week between study visits.
Intervention code [1] 327839 0
Prevention
Comparator / control treatment
A placebo treatment is included in one of the four study visits. The placebo comprises only 75 g of sucrose mixed with 250 mL of water and does not contain any pine bark extract (Enzogenol®) nor Reducose®
Control group
Placebo

Outcomes
Primary outcome [1] 337201 0
Plasma glucose
Timepoint [1] 337201 0
Blood samples will be obtained from the participant for glucose measurement at -10, 0, 15, 30, 45, 60, 90, and 120 min following consumption of the treatment
Primary outcome [2] 337202 0
Plasma insulin
Timepoint [2] 337202 0
Blood samples will be obtained from the participant for insulin analysis at -10, 0, 15, 30, 45, 60, 90, and 120 min following consumption of the treatment
Secondary outcome [1] 431045 0
Peak glucose
Timepoint [1] 431045 0
Blood samples will be obtained from the participant at -10, 0, 15, 30, 45, 60, 90, and 120 min following consumption of the treatment and the highest glucose reading will be considered as the peak glucose concentration.
Secondary outcome [2] 434098 0
Peak insulin
Timepoint [2] 434098 0
Blood samples will be obtained from the participant at -10, 0, 15, 30, 45, 60, 90, and 120 min following consumption of the treatment and the highest insulin reading will be considered as the peak insulin concentration.
Secondary outcome [3] 434099 0
Time to peak glucose
Timepoint [3] 434099 0
Blood samples will be obtained from the participant at -10, 0, 15, 30, 45, 60, 90, and 120 min following consumption of the treatment and the time to reach the highest glucose reading will be considered as time to peak glucose.
Secondary outcome [4] 434100 0
Time to peak insulin
Timepoint [4] 434100 0
Blood samples will be obtained from the participant at -10, 0, 15, 30, 45, 60, 90, and 120 min following consumption of the treatment and the time to reach the highest insulin reading will be considered as time to peak insulin.

Eligibility
Key inclusion criteria
The inclusion criteria will be:
• Healthy participants (males and females)
• Aged between 18-60 years old
• Body Mass Index (BMI) of 18.5-29.9kg/m2 (Healthy and overweight)
• Glycated haemoglobin A1c (HbA1c) <39 mmol/mol (ADA guidelines)
• Fasting blood glucose (FBG) <5.6 mmol/L (ADA guidelines)
• Able to communicate well in English
Minimum age
18 Years
Maximum age
60 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
The exclusion criteria will be:
• Body Mass Index (BMI) >29.9kg/m2 (obese)
• Glycated haemoglobin A1c (HbA1c) >39 mmol/mol (ADA guidelines)
• Fasting blood glucose (FBG) >5.6 mmol/L (ADA guidelines)
• Known food allergies or intolerance to pine bark extract or mulberry leaf extract
• Having dietary restrictions or dietary disorders
• Pre-existing medical conditions (cardiovascular disease, hypertension, diabetes etc.) or taking medications including anti-hyperglycaemic drugs and insulin known to affect glucose metabolism or regulation
• Use of steroids, protease inhibitors or antipsychotics medicines known to influence glucose metabolism and body fat distribution
• Pregnant or breastfeeding
• Smoking

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation concealment will be applied to the study. Each of the treatment arm will be allocated a random number and sequence generated by the computer, and concealed in an opaque envelope till the day of assignment for each participant. Each participant will not know in which order or what type of intervention treatment they will be provided at each visit.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation of participants to each of the intervention treatment will be performed using a randomisation table created by computer software (www.randomization.com).
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Statistical analyses will be performed using the latest IBM SPSS statistics version 29 (IBM corporation, New York, US). Prior to statistical analysis, data normality will be tested using the Shapiro-Wilks statistic. A linear mixed model for repeated-measures using the repeated covariance compound symmetry with estimation employing restricted maximum likelihood (REML) will be used. A p value of equal or less than 0.05 is considered to be significant (95% confidence level), based on 80% power with alpha=0.05 and beta=0.10. The data will be expressed as model-adjusted mean +/- standard error of the mean (SEM).

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
22/04/2024
Actual
Date of last participant enrolment
Anticipated
30/11/2024
Actual
Date of last data collection
Anticipated
31/12/2024
Actual
Sample size
Target
40
Accrual to date
Final
Recruitment outside Australia
Country [1] 26099 0
New Zealand
State/province [1] 26099 0
Auckland

Funding & Sponsors
Funding source category [1] 315657 0
Commercial sector/Industry
Name [1] 315657 0
ENZO Nutraceutical Limited
Country [1] 315657 0
New Zealand
Primary sponsor type
University
Name
Riddet Institute, Massey University
Address
Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442
Country
New Zealand
Secondary sponsor category [1] 317763 0
None
Name [1] 317763 0
Address [1] 317763 0
Country [1] 317763 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 314541 0
Central Health and Disability Ethics Committee
Ethics committee address [1] 314541 0
https://ethics.health.govt.nz/about/central-health-and-disability-ethics-committee/
Ethics committee country [1] 314541 0
New Zealand
Date submitted for ethics approval [1] 314541 0
21/03/2024
Approval date [1] 314541 0
28/03/2024
Ethics approval number [1] 314541 0
2024 EXP 19678

Summary
Brief summary
Obesity and diabetes are epidemic in New Zealand (and in other Western countries), and many individuals now have problems controlling their blood glucose levels within normal levels. More alarmingly, epidemiological studies have shown that approximately 40% of individuals with normal glucose tolerance (NGT) may still eventually develop type 2 diabetes. Research has also revealed that 20% of NGT individuals already have a certain degree of insulin resistance. According to prior knowledge, Enzogenol® contains a high level of proanthocyanidins that is responsible for the inhibition of digestion enzymes including alpha-amylase, alpha-glucosidase and DPP-4 enzymes. It is hypothesised that Enzogenol® will be able to inhibit the enzymes involved in sucrose digestion such as sucrase that metabolises sucrose (found in most processed foods). The enzyme inhibition will reduce or delay the digestion of sucrose into glucose and fructose for subsequent absorption and may aid in improving glycaemic control in humans. This study aims to determine if Enzogenol® of two effective doses (50 and 400 mg) is able to improve glycaemic and insulinaemic postprandial responses in healthy participants when co-administered with 75 g of sucrose solution.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 131950 0
Dr Wen Xin Janice Lim
Address 131950 0
Riddet Institute, Massey University, Auckland (East Precinct), Albany 0632
Country 131950 0
New Zealand
Phone 131950 0
+64 02108903957
Fax 131950 0
Email 131950 0
[email protected]
Contact person for public queries
Name 131951 0
Dr Wen Xin Janice Lim
Address 131951 0
Riddet Institute, Massey University, Auckland (East Precinct), Albany 0632
Country 131951 0
New Zealand
Phone 131951 0
+64 02108903957
Fax 131951 0
Email 131951 0
[email protected]
Contact person for scientific queries
Name 131952 0
Dr Wen Xin Janice Lim
Address 131952 0
Riddet Institute, Massey University, Auckland (East Precinct), Albany 0632
Country 131952 0
New Zealand
Phone 131952 0
+64 02108903957
Fax 131952 0
Email 131952 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Only de-identified participant data underlying published results will be shared
When will data be available (start and end dates)?
Immediately following publication, no end date
Available to whom?
Case-by-case basis at the discretion of Primary Sponsor
Available for what types of analyses?
Only to achieve the aims in the approved proposal, for IPD meta-analyses
How or where can data be obtained?
Access subject to approvals by Principal Investigator. The Principal Investigator can be contacted at [email protected]


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.