# A phased clinical trial of a dietary supplement kava: biomarker changes and anxiolytic effects

> **NIH NIH R61** · UNIVERSITY OF FLORIDA · 2020 · $375,597

## Abstract

ABSTRACT
Generalized anxiety disorder (GAD) affects more than 16 million American adults annually, and is primarily
treated with antidepressants or benzodiazepines (BZDs). Unfortunately, many GAD patients report only a partial
response or cannot tolerate the side effects of these medications. BZD-based anxiolytics are of particular
concern because of the risk for chemical dependence, addiction, cognitive impairment, and even death. There
is thus an unmet clinical need for new anxiolytics free of BZD adverse effects. However, our limited
understanding of the neurobiology of anxiety has impeded the discovery of novel pharmacotherapies for GAD.
Kava, prepared from the root of Piper methysticum, is consumed in many parts of the world as a daily beverage
to help people relax, socialize and improve sleep. Clinical trials in Europe and elsewhere also indicate that it is
an effective anxiolytic. In these studies, kava usage showed no signs of addiction or withdrawal, indicating that
its mechanism of action differs from that of BZD, which is mediated through GABAA. Although the mechanisms
behind kava's anxiolytic activity are not yet established, in vivo studies indicate that it is not mediated through
GABAA. Kava thus is a promising source to search for novel anxiolytics with unique mechanism(s) of action to
help manage GAD.
In a pilot study of daily dietary kava use among general smokers, we found that a one-week kava ingestion
reduced smoking dependence, supporting kava's anxiolytic activity. More interestingly, this treatment regimen
significantly and consistently reduced the plasma levels of protein kinase A catalytic subunit alpha (PRKACA)
and plasma cortisol among the general smokers. Given the well-established role of PRKACA and cortisol in
anxiety and stress, kava may induce its anxiolytic activity via a novel PRKACA-dependent mechanism. Thus,
plasma levels of PRKACA, and potentially plasma cortisol and cyclic AMP and urinary N-acetyl serotonin may
serve as biomarkers to monitor kava's anxiolytic efficacy. Thus, the R61 phase of this phased clinical trial aims
1) to validate the changes of plasma PRKACA, cortisol, c-AMP and urinary NA-5HT in GAD patients upon kava
ingestion and 2) to characterize the safety, compliance, bioavailability and pharmacokinetics of kava. The R33
phase will build on the R61 to 1) explore the potential of the identified biomarkers in predicting kava's anxiolytic
efficacy and 2) identify the specific subgroup of GAD patients that are most likely to benefit from kava treatment.
Safety Measures: Built upon our understanding of kava's hepatotoxic risk, a flavokavain A/B-free kava dietary
supplement will be used in this trial, which is expected to reduce/eliminate kava's potential hepatotoxic risk. We
will exclude individuals with elevated risk for hepatotoxicity, and will closely monitor liver function and other
potential adverse events during and for 12 weeks following treatment.

## Key facts

- **NIH application ID:** 10005997
- **Project number:** 5R61AT009988-02
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **Principal Investigator:** Carol A Mathews
- **Activity code:** R61 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $375,597
- **Award type:** 5
- **Project period:** 2019-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10005997

## Citation

> US National Institutes of Health, RePORTER application 10005997, A phased clinical trial of a dietary supplement kava: biomarker changes and anxiolytic effects (5R61AT009988-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10005997. Licensed CC0.

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