NCT07261475

Brief 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. 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? 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.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
20

participants targeted

Target at P25-P50 for early_phase_1

Timeline
7mo left

Started Feb 2026

Shorter than P25 for early_phase_1

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress31%
Feb 2026Dec 2026

First Submitted

Initial submission to the registry

November 22, 2025

Completed
11 days until next milestone

First Posted

Study publicly available on registry

December 3, 2025

Completed
2 months until next milestone

Study Start

First participant enrolled

February 6, 2026

Completed
4 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 1, 2026

Expected
6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

December 1, 2026

Last Updated

February 4, 2026

Status Verified

February 1, 2026

Enrollment Period

4 months

First QC Date

November 22, 2025

Last Update Submit

February 3, 2026

Conditions

PrediabetesObesity & Overweight

Keywords

Crocus sativus tepalsGlycaemiaOral glucose tolerance testresting metabolismblood pressureinsulin

Outcome Measures

Primary Outcomes (1)

  • glucose levels

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

    From enrollment to the end of second measurement at 2 weeks

Secondary Outcomes (3)

  • insulin level

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

  • Resting metabolism

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

  • Blood pressure

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

Study Arms (2)

Crocus sativus

EXPERIMENTAL

Crocus sativus tepals cold aqueous extract

Biological: Crocus sativus tepals cold aqueous extract

water

SHAM COMPARATOR

cold water

Biological: cold water

Interventions

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

Crocus sativus
cold waterBIOLOGICAL

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

water

Eligibility Criteria

Age40 Years - 65 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University pf Primorska, Faculty of Health Sciences

Izola, 6310, Slovenia

RECRUITING

Related Publications (7)

  • 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.

    PMID: 39566886BACKGROUND

  • 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.

    PMID: 25386395BACKGROUND

  • 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.

    PMID: 31382514BACKGROUND

  • 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.

    PMID: 22809329BACKGROUND

  • 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.

    PMID: 29803496BACKGROUND

  • 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.

    PMID: 38318672BACKGROUND

  • 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.

    PMID: 37298165BACKGROUND

MeSH Terms

Conditions

Prediabetic StateObesityOverweightInsulin Resistance

Condition Hierarchy (Ancestors)

Diabetes MellitusGlucose Metabolism DisordersMetabolic DiseasesNutritional and Metabolic DiseasesEndocrine System DiseasesOvernutritionNutrition DisordersBody WeightSigns and SymptomsPathological Conditions, Signs and SymptomsHyperinsulinism

Study Officials

  • Nina Mohorko, PhD

    University pf Primorska, Faculty of Health Sciences

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Nina Mohorko, PhD

CONTACT

+386 5 66 35 818nina.mohorko@fvz.upr.si

Study Design

Study Type
interventional
Phase
early phase 1
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate professor

Study Record Dates

First Submitted

November 22, 2025

First Posted

December 3, 2025

Study Start

February 6, 2026

Primary Completion (Estimated)

June 1, 2026

Study Completion (Estimated)

December 1, 2026

Last Updated

February 4, 2026

Record last verified: 2026-02

Data Sharing

IPD Sharing
Will not share

Locations

SL(1)