COVID-19 studies are our top priority.

For new and updated trial submissions, we are processing trials as quickly as possible and appreciate your patience. We recommend submitting your trial for registration at the same time as ethics submission.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Can taking a plant extract improve blood glucose in adult men with pre-diabetes? First in human study
Scientific title
A first in human (FIH) clinical study to assess the effect of different doses of Dahlia spp. extract on glucose metabolism.
Secondary ID [1] 293154 0
Universal Trial Number (UTN)
UTN: U111112016917
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Pre-Diabetes 305130 0
Diabetes 305131 0
Condition category
Condition code
Metabolic and Endocrine 304453 304453 0 0
Alternative and Complementary Medicine 304519 304519 0 0
Herbal remedies

Study type
Description of intervention(s) / exposure
An extract of Dahlia spp. will be given at 3 different dosages on one occasion per dose, and an oral glucose tolerance test performed with each dosage. The doses will be 0.5, 1 and 2 mg/m2 given as capsules. All participants will receive all three doses with a one week washout period. The doses will be administered by a research nurse.
Intervention code [1] 299404 0
Treatment: Other
Comparator / control treatment
Each patient will act as their own control, as this is a first in human trial, with an OGTT first with no intervention administered.
Control group
Dose comparison

Primary outcome [1] 303695 0
Area under the curve glucose
Timepoint [1] 303695 0
Baseline, visits 1, 2 and 3. Blood samples will be collected at 30 minute intervals during the oral glucose tolerance test for 3 hours.
Primary outcome [2] 303696 0
Area under the curve insulin
Timepoint [2] 303696 0
Baseline, visits 1, 2 and 3. Blood samples will be collected at 30 minute intervals during the oral glucose tolerance test for 3 hours.
Secondary outcome [1] 339881 0
Safety measures - liver function, full blood count and kidney function as a composite outcome
Timepoint [1] 339881 0
Blood tests will be done the day before and day after the intervention to check liver function and full blood count and kidney function.
Secondary outcome [2] 340093 0
Timepoint [2] 340093 0
Baseline, Visits 1, 2 and 3
Secondary outcome [3] 340094 0
Blood pressure, heart rate, saturations, respiratory rate, temperature as a composite outcome reported as acute adverse events.
Timepoint [3] 340094 0
Observations done every 30 mins for 5 hours following administration of dose 1, 2 and 3 but not at baseline.

Key inclusion criteria
Males aged 18-65 years with pre-diabetes (HbA1c 41-49 mmol/mol)
Minimum age
18 Years
Maximum age
65 Years
Can healthy volunteers participate?
Key exclusion criteria
Any prior history of diabetes or taking glucose lowering medication
Previous bariatric surgery
Liver disease or AST/ ALT >3x ULN, Renal disease or eGFR <60.
Known cardiac disease

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Three doses are being tested, the order of dose administration will be randomised. The number of capsules will be consistent each time, with the rest of the dose being made up with dummy capsules.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The generation of dose randomisation will be computer generated.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 1
Type of endpoint(s)
Statistical methods / analysis
The main outcomes are area under the curve (AUC) for glucose and insulin during the OGTT, using the trapezoidal method, and insulin sensitivity using the Matsuda index. The pre-specified contrasts are between baseline and dose 1, baseline and dose 2, baseline and dose 3 as well as dose 1 and dose 2, dose 2 and dose 3 and dose 1 and dose3. Other outcomes are change in glucose, insulin and insulin sensitivity measured by the homeostasis model assessment (HOMA) between T0 and 60 mins following each dose.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 9295 0
New Zealand
State/province [1] 9295 0

Funding & Sponsors
Funding source category [1] 297781 0
Name [1] 297781 0
University of Otago
Address [1] 297781 0
PO Box 56
Country [1] 297781 0
New Zealand
Funding source category [2] 297782 0
Name [2] 297782 0
New Zealand Society for the Study of Diabetes
Address [2] 297782 0
New Zealand Society for the Study of Diabetes (NZSSD)
c/o Edgar National Centre for Diabetes Research
Department of Medicine
University of Otago
PO Box 56
Country [2] 297782 0
New Zealand
Primary sponsor type
University of Otago
Department of Physiology
Centre for Neuroendocrinology,
University of Otago
PO Box 56
New Zealand
Secondary sponsor category [1] 296817 0
Name [1] 296817 0
Centre for Endocrine, Diabetes and Obesity Research
Address [1] 296817 0
Capital and Coast DHB
Wellington Hospital
Private Bag 7902
Country [1] 296817 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 298840 0
NZ Health and Disability Ethics Committee
Ethics committee address [1] 298840 0
Ministry of Health
Health and Disability Ethics Committees
PO Box 5013
Wellington 6140
Ethics committee country [1] 298840 0
New Zealand
Date submitted for ethics approval [1] 298840 0
Approval date [1] 298840 0
Ethics approval number [1] 298840 0

Brief summary
Type 2 Diabetes (T2DM) affects around 7% of the adult NZ population. 25% have prediabetes. Obesity is a risk factor for T2DM. One potential mechanism is due to the proinflammatory cytokines released from adipose tissue. In mice high fat diets result in obesity and loss of sensitivity to insulin. It has been demonstrated that purified plant
metabolites from Dahlia spp. as well as the plant extract significantly improve glucose homeostasis in high fat diet diabetic mice. This study is a First in Human study of the effect of these compounds on humans.
Twenty male participants aged 18-65 with prediabetes (HbA1c 4149
mmol/mol) will be recruited for this study.
Each participant will receive three different doses (0.5, 1 and 2 mg/m2) of a Dahlia spp. extract.
The study will look at glucose handling following the ingestion of the extract and compare this to glucose handling without exposure to these using an oral glucose tolerance test.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 78406 0
Dr Jeremy Krebs
Address 78406 0
Wellington Hospital Riddiford St Wellington 6021
Country 78406 0
New Zealand
Phone 78406 0
+64 4 8062458
Fax 78406 0
Email 78406 0
Contact person for public queries
Name 78407 0
Dr Amber Parry Strong
Address 78407 0
Wellington Hospital Riddiford St Wellington 6021
Country 78407 0
New Zealand
Phone 78407 0
+64 4 8062458
Fax 78407 0
Email 78407 0
Contact person for scientific queries
Name 78408 0
Dr Charles Barter
Address 78408 0
Wellington Hospital Riddiford St Wellington 6021
Country 78408 0
New Zealand
Phone 78408 0
+64 4 8062458
Fax 78408 0
Email 78408 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
This data is commercially sensitive and so is unable to be shared at this time.
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary