Pharmacological Effects of Kava Extracts in Cancer and Anxiety Disorders

Kava (Piper methysticum) root extracts contain two principal classes of bioactive compounds—kavalactones and flavokawains—that exert a spectrum of pharmacological effects relevant to oncology and neuropsychiatry. In cancer models, kavalactones have demonstrated anti-proliferative, pro-apoptotic and anti-migratory properties in lung, bladder and prostate malignancies, acting through pathways such as mTOR inhibition, androgen receptor down-regulation and epigenetic modification of histone methylation. Flavokawains further enhance these effects by targeting oxidative stress and TGF-β-mediated fibrotic programmes. In parallel, kavalactones modulate central nervous system activity by positive allosteric enhancement of GABAA receptors, reducing neuronal excitability and alleviating symptoms of anxiety. Clinical investigations have explored standardised kava extracts in generalised anxiety disorder, while preclinical work continues to refine mechanisms of action, bioavailability and safety profiles. Together, these findings highlight kava’s dual potential as a chemopreventive agent and an anxiolytic, underscoring the need for standardisation, mechanistic biomarkers and rigorous clinical trials.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Pharmacological Effects of Kava Extracts in Cancer and Anxiety Disorders publication trend

The graph below shows the total number of articles in pharmacological effects of kava extracts in cancer and anxiety disorders across all publications each year (not limited to Nature Index journals).

Technical terms

Kavalactones: Lipophilic lactone compounds in kava root responsible for anxiolytic and anticancer activities.

Flavokawains: Chalcone-based phenolic constituents of kava with anti-oxidative and anti-fibrotic properties.

GABAA receptor: Ligand-gated chloride channel mediating inhibitory neurotransmission in the brain.

Histone methylation: Post-translational addition of methyl groups to histone proteins that regulates chromatin structure and gene expression.

Chemoprevention: Use of natural or synthetic agents to prevent, inhibit or reverse the development of cancer.

References

1. Opportunities and Challenges of Kava in Lung Cancer Prevention. International Journal of Molecular Sciences (2023).
2. Kawain Inhibits Urinary Bladder Carcinogenesis through Epigenetic Inhibition of LSD1 and Upregulation of H3K4 Methylation. Biomolecules (2023).
3. Kavalactone Kawain Impedes Urothelial Tumorigenesis in UPII-Mutant Ha-Ras Mice via Inhibition of mTOR Signaling and Alteration of Cancer Metabolism. Molecules (2023).
4. Kavain, the Major Constituent of the Anxiolytic Kava Extract, Potentiates GABAA Receptors: Functional Characteristics and Molecular Mechanism. PLOS ONE (2016).
5. Kava Components Down-Regulate Expression of AR and AR Splice Variants and Reduce Growth in Patient-Derived Prostate Cancer Xenografts in Mice. PLOS ONE (2012).
6. Kava for the treatment of generalised anxiety disorder (K-GAD): study protocol for a randomised controlled trial. Trials (2015).
7. Chalcone flavokawain A attenuates TGF‐β1‐induced fibrotic pathology via inhibition of ROS/Smad3 signaling pathways and induction of Nrf2/ARE‐mediated antioxidant genes in vascular smooth muscle cells. Journal of Cellular and Molecular Medicine (2018).