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AzTrials

PrediabetesEarly Phase 1ZAFRANNCT07261475

Crocus Sativus Tepals Water Extract in Obesity and Prediabetes

A Early Phase 1 study testing Crocus sativus tepals cold aqueous extract and cold water in people with Prediabetes and Obesity & Overweight, run by University of Primorska at 1 site in Slovenia.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The goal of this clinical trial is to determine the acute effects of ingestion of a cold aqueous extract of Crocus sativus tepals on postprandial glycemia and other indicators of metabolic health in patients with obesity and/or prediabetes. Read more about this study

Who is it for?
Ages 40 to 65 years
Conditions the study is for
Prediabetes, Obesity & Overweight
What is being tested?
Crocus sativus tepals cold aqueous extract and cold water
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
20 participants
Where
1 siteSlovenia
Study dates
6 Feb 2026to Dec 2026
Phase
Early Phase 1
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 40 to 65 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Obesity type I (ITM > 30 kg/m2) and/or
  • Prediabetes (fasting glucose levels 6,1 - 6,9 mmol/L)

Who cannot join

  • Gastrointestinal diseases
  • Diabetes mellitus of any type
  • Pregnant or lactating, without contraception
  • Serious clinical conditions such as cancer, severe infections, severe psychiatric disorders, autoimmune diseases, inflammatory diseases
  • Participation in another clinical trial 3 months prior to the study
  • ITM greater than 35 kg/m2
  • Celiac disease of gluten intolerance
  • electronic implant

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Nina Mohorko, PhD contact

+386 5 66 35 818

nina.mohorko@fvz.upr.si

Slovenia1 site, 1 recruiting

  • University pf Primorska, Faculty of Health Sciences

    Izola, 6310

    Nina Mohorko, PhD, +386 5 66 35 818, nina.mohorko@fvz.upr.si

    Ana Petelin, PhD, +386 5 66 26 469, ana.petelin@fvz.upr.si

    Recruiting

Other trials in Slovenia

About this study

Official title: Acute Effects of Water Extract of Crocus Sativus Tepals on Metabolic Health Parameters in Patients With Obesity and Prediabetes

The goal of this clinical trial is to determine the acute effects of ingestion of a cold aqueous extract of Crocus sativus tepals on postprandial glycemia and other indicators of metabolic health in patients with obesity and/or prediabetes. The main questions it aims to answer are:

  • Does the ingestion of Crocus sativus tepals cold aqueous extract prior to a meal improve the glycemic response to a standard meal?
  • How does the ingestion of Crocus sativus tepals aqueous extract prior to a meal impact insulin levels and other markers of metabolic health?
  • Does the ingestion of Crocus sativus tepals cold aqueous extract prior to a meal increase the resting energy expanditure?
Read more

Researchers will compare Crocus sativus tepals cold aqueous extract to cold water.

The participants will visit the Faculty twice - on one visit they will ingest Crocus sativus tepals cold aqueous extract and on the other cold water (in random order) 5 minutes prior to a standard meal of 100 g of white bread.

On each visit, anthropometric measurements will be performed upon arrival. Blood samples will be collected 3 times, preceeded by resting metabolic rate and blood pressure measurements: at baseline in fasted conditions, and 60 minutes and 120 minutes after consuming the bread.

There will be an at least 7 days wash-out period between the two visits.

Being tested
Crocus sativus tepals cold aqueous extract, cold water
Keywords
Crocus sativus tepals, Glycaemia, Oral glucose tolerance test, resting metabolism, blood pressure, insulin
Medical subject headings
Prediabetic State, Obesity, Overweight, Insulin Resistance

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Crocus sativus tepals cold aqueous extractBiological

    2 g of Crocus sativus tepals will be infused in 200 mL of water overnight at 4 °C, resulting cold aqueous extract corresponds to 40 mg GAE of polyphenols

  • cold waterBiological

    200 mL of cold water, kept overnight at 4 °C

Study groups in NCT07261475
Study groupRoleWhat they receive
Crocus sativusExperimentalCrocus sativus tepals cold aqueous extract
Receives: Biological: Crocus sativus tepals cold aqueous extract
waterSham comparatorcold water
Receives: Biological: cold water

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. glucose levels

    Serum glucose levels will be measured from venous blood at baseline and 60 and 120 minutes after bread ingestion.

    Measured: From enrollment to the end of second measurement at 2 weeks

Secondary outcomes (3)

  1. insulin level

    Serum insulin levels will be measured from venous blood at baseline and 60 and 120 minutes after bread ingestion.

    Measured: From enrollment to the end of second measurement at 2 weeks.

  2. Resting metabolism

    Resting metabolism will be measured with indirect calorimetry at baseline in fasted state and at 40 and 100 minutes after bread ingestion.

    To determine RMR, subjects will lie relaxed on a bed in a thermoneutral room for 10 minutes to calm down, followed by a 20-minute measurement of oxygen consumption (VO2) and carbon dioxide production (VCO2). RMR and RQ will be calculated from stable values over a 15-minute period (the first 5 minutes of measurement until stabilization will not be taken into account).

    Measured: From enrollment to the end of the second measurement, at 2 weeks

  3. Blood pressure

    Measured: baseline, 60 minutes after bread ingestion, 120 minutes after bread ingestion

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted3 Dec 2025
  2. Study start6 Feb 2026 (estimated)
  3. Primary completionJun 2026 (estimated)
  4. Study completionDec 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Early Phase 1
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Crossover
Masking
None (open label)
Enrolment
20 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07261475
Sponsor's protocol ID
ZAFRAN-2025
Acronym
ZAFRAN
Status last verified
Feb 2026
First submitted
22 Nov 2025
Last updated
4 Feb 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Barik SK, Sengupta S, Arya R, Kumar S, Kim JJ, Chaurasia R. Dietary Polyphenols as Potential Therapeutic Agents in Type 2 Diabetes Management: Advances and Opportunities. Adv Nutr. 2025 Jan;16(1):100346. doi: 10.1016/j.advnut.2024.100346. Epub 2024 Nov 19.

    PubMed 39566886

  • Omidi A, Riahinia N, Montazer Torbati MB, Behdani MA. Hepatoprotective effect of Crocus sativus (saffron) petals extract against acetaminophen toxicity in male Wistar rats. Avicenna J Phytomed. 2014 Sep;4(5):330-6.

    PubMed 25386395

  • Moratalla-Lopez N, Bagur MJ, Lorenzo C, Salinas MEMR, Alonso GL. Bioactivity and Bioavailability of the Major Metabolites of Crocus sativus L. Flower. Molecules. 2019 Aug 2;24(15):2827. doi: 10.3390/molecules24152827.

    PubMed 31382514

  • Montoro P, Maldini M, Luciani L, Tuberoso CI, Congiu F, Pizza C. Radical scavenging activity and LC-MS metabolic profiling of petals, stamens, and flowers of Crocus sativus L. J Food Sci. 2012 Aug;77(8):C893-900. doi: 10.1111/j.1750-3841.2012.02803.x. Epub 2012 Jul 18.

    PubMed 22809329

  • Menghini L, Leporini L, Vecchiotti G, Locatelli M, Carradori S, Ferrante C, Zengin G, Recinella L, Chiavaroli A, Leone S, Brunetti L, Orlando G. Crocus sativus L. stigmas and byproducts: Qualitative fingerprint, antioxidant potentials and enzyme inhibitory activities. Food Res Int. 2018 Jul;109:91-98. doi: 10.1016/j.foodres.2018.04.028. Epub 2018 Apr 16.

    PubMed 29803496

  • Bursac B, Bellachioma L, Gligorovska L, Jovanovic M, Teofilovic A, Vrataric M, Vojnovic Milutinovic D, Albacete A, Martinez-Melgarejo PA, Morresi C, Damiani E, Bacchetti T, Djordjevic A. Crocus sativus tepals extract suppresses subcutaneous adipose tissue hypertrophy and improves systemic insulin sensitivity in mice on high-fat diet. Biofactors. 2024 Jul-Aug;50(4):828-844. doi: 10.1002/biof.2043. Epub 2024 Feb 6.

    PubMed 38318672

  • Bellachioma L, Morresi C, Albacete A, Martinez-Melgarejo PA, Ferretti G, Giorgini G, Galeazzi R, Damiani E, Bacchetti T. Insights on the Hypoglycemic Potential of Crocus sativus Tepal Polyphenols: An In Vitro and In Silico Study. Int J Mol Sci. 2023 May 24;24(11):9213. doi: 10.3390/ijms24119213.

    PubMed 37298165

Questions about this trial

What is this clinical trial studying?

A Early Phase 1 study testing Crocus sativus tepals cold aqueous extract and cold water in people with Prediabetes and Obesity & Overweight, run by University of Primorska at 1 site in Slovenia.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 4 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Slovenia. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Nina Mohorko, PhD (+386 5 66 35 818, nina.mohorko@fvz.upr.si), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

glucose levels (time frame: From enrollment to the end of second measurement at 2 weeks). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07261475, which also lists 7 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Feb 2026.

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