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Completed

NCT Number: NCT07196059

Assessment of Delphinol® Dose on Vascular Function

Maqui berry standardized extract (e.g. Delphinol®) has been used with success to modulate blood glucose and associated variables at a dosage of 450mg daily. Lower dosages have also been used with favorable effects. However, it is unknown what dosage is optimal for positively impacting vascular function. The purpose of this study is to determine the impact of Maqui berry standardized extract (e.g. Delphinol®) at varying dosages on vascular function assessed using the perfusion index, Vendys, and blood nitrate/nitrite concentrations.

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Key information

Conditions

Age range

18 year–35 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Center for Nutraceutical and Dietary Supplement Research

Memphis, Tennessee, 38152, United States

About this study

Antioxidant compounds have been well-studied in relation to surrogate measures of overall health, with a particular impact on the function of blood vessels. Delphinol® is a botanical agent (an extract of maqui berries) with antioxidant properties primarily owing to its high anthocyanin content. Delphinol® has excellent bioavailability, as demonstrated recently. Acute and chronic anthocyanin consumption has demonstrated the ability to improve vascular reactivity assessed via flow-mediated dilation and pulse wave velocity across a range of dosages . Antioxidant compounds have also been reported to favorably impact nitric oxide, often estimated using the surrogate measure of blood nitrate/nitrite.

In a previous study using Delphinol® at various dosages, Delphinol® significantly and dose-dependently improved glucose homeostasis acutely, with noted lowering of blood glucose and lipids. The mechanism of action for this effect appears related to a novel sodium glucose cotransporter inhibition . This favorable effect on glucose and lipid metabolism is an effect that some have suggested may be associated with the protection of vascular function. A dosage of 450mg of Delphinol® daily has resulted in improvements in oxidative stress markers, another factor that can potentially contribute to vascular homeostasis. Together, these studies suggest Delphinol® may influence vascular function; however, no studies have directly determined this in human subjects.

Though similar studies exist demonstrating anthocyanin consumption resulting in improvements in vascular function, none to date have investigated different doses of a maqui extract on vascular function as assessed using the digital thermal monitoring of reperfusion. Digital thermal monitoring is suggested to be a more reliable measure of vascular function because it removes the sonographer variability; that is, accurately capturing the brachial artery with an ultrasound transducer can be very challenging.

The aim of the present study is to determine the impact of Delphinol® at varying dosages on vascular function assessed using the perfusion index, Vendys II (a tool to measure endothelial vascular function via digital thermal monitoring), and blood nitrate/nitrite concentrations in men and women. While it may be logical to assume that the higher dosage may provide a more robust overall effect with regards to our outcome measures, we will maintain a conservative non-directional hypothesis related to dose. That said, we do hypothesize that all doses of the ingredient will result in small improvements in the measured vascular indices.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

  • age 18-35 years
  • male or female
  • body mass index (BMI) between 18-29.9 kg/m2 (not obese)
  • non-smoker
  • no diagnosed history of diabetes
  • no diagnosed history of cardiovascular disease including any vascular disease
  • no diagnosed history of neurological disease
  • no consumption of alcohol or fruit within 48 hours of testing
  • no consumption of caffeine-containing beverages within at least 48 hours of testing
  • 12-lead ECG without significant heart rate and rhythm abnormalities and blood glucose within normal limits (as reviewed by Tara Hunter, BSN and confirmed by Dr. John Hyden, MD as needed)
  • if female, not be pregnant

Treatment and study plan

Delphinol

Dietary Supplement

Contains maqui berry powder

Placebo

Dietary Supplement

Contains cellulose

Primary outcomes

  1. Baseline Perfusion Index

    Time frame: On day 1

    Perfusion index will be measured using a fingertip pulse oximeter prior to first arm of study.

  2. Perfusion Index after 60 mg Delphinol treatment

    Time frame: 90 min post supplement ingestion on day 8 of treatment

    Perfusion index will be measured using a fingertip pulse oximeter on the 8th day of 60 mg Delphinol treatment.

  3. Perfusion Index after 120 mg Delphinol treatment

    Time frame: 90 min post supplement ingestion on day 8 of treatment

    Perfusion index will be measured using a fingertip pulse oximeter on the 8th day of 120 mg Delphinol treatment.

  4. Perfusion Index after 180 mg Delphinol treatment

    Time frame: 90 min post supplement ingestion on day 8 of treatment

    Perfusion index will be measured using a fingertip pulse oximeter on the 8th day of 180 mg Delphinol treatment.

  5. Perfusion Index after placebo treatment

    Time frame: 90 min post supplement ingestion on day 8 of treatment

    Perfusion index will be measured using a fingertip pulse oximeter on the 8th day of placebo treatment.

  6. baseline Vendys II endothelial measure

    Time frame: On day 1

    Endothelial measure will be determined using Vendys II (a tool to measure endothelial vascular function via digital thermal monitoring) prior to first arm of study

  7. Vendys II endothelial measure after 60 mg Delphinol treatment

    Time frame: 90 min post treatment ingestion on day 8 of treatment

    Endothelial measure will be determined using Vendys II (a tool to measure endothelial vascular function via digital thermal monitoring) 90 min post 60 mg Delphinol treatment ingestion

  8. Vendys II endothelial measure after 120 mg Delphinol treatment

    Time frame: 90 min post treatment ingestion on day 8 of treatment

    Endothelial measure will be determined using Vendys II (a tool to measure endothelial vascular function via digital thermal monitoring) 90 min post 120 mg Delphinol treatment ingestion

  9. Vendys II endothelial measure after 180 mg Delphinol treatment

    Time frame: 90 min post treatment ingestion on day 8 of treatment

    Endothelial measure will be determined using Vendys II (a tool to measure endothelial vascular function via digital thermal monitoring) 90 min post 180 mg Delphinol treatment ingestion

  10. Vendys II endothelial measure after placebo treatment

    Time frame: 90 min post supplement ingestion on day 8 of treatment

    Endothelial measure will be determined using Vendys II (a tool to measure endothelial vascular function via digital thermal monitoring) 90 min post placebo treatment ingestion

  11. Baseline Blood nitrate/nitrite

    Time frame: On day 1

    Baseline blood nitrate/nitrite will be determined prior to first arm of study

  12. Blood nitrate/nitrite after 60 mg Delphinol treatment

    Time frame: 90 min post treatment ingestion on day 8 of treatment

    Blood nitrate/nitrite will be determined on 8th day of treatment, 90 min post 60 mg Delphinol treatment ingestion

  13. Blood nitrate/nitrite after 120 mg Delphinol treatment

    Time frame: 90 min post treatment ingestion on day 8 of treatment

    Blood nitrate/nitrite will be determined on 8th day of treatment, 90 min post 120 mg Delphinol treatment ingestion

  14. Blood nitrate/nitrite after 180 mg Delphinol treatment

    Time frame: 90 min post treatment ingestion on day 8 of treatment

    Blood nitrate/nitrite will be determined on 8th day of treatment, 90 min post 180 mg Delphinol treatment ingestion

  15. Blood nitrate/nitrite after placebo treatment

    Time frame: 90 min post treatment ingestion on day 8 of treatment

    Blood nitrate/nitrite will be determined on 8th day of treatment, 90 min post placebo treatment ingestion

Secondary outcomes

  1. Blood pressure

    Time frame: At baseline and on day 8 of each treatment, prior to treatment ingestion

    Resting blood pressure will be measured

  2. Heart rate

    Time frame: At baseline and on day 8 of each treatment, prior to treatment ingestion

    Resting heart rate will be measured

Sponsors and collaborators

Lead sponsor

University of Memphis

Other

Collaborators

  • Anklam-Extrakt GmbH

Registry information

Important dates

Study start
2020
Primary completion
2020
Study completion
2020
First posted
Sep 29, 2025
Registry last updated
Sep 29, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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