Anti‐inflammatory and cytotoxic properties of kānuka (
Kunzea ericoides
) subcritical water extract
Indhuja Devadass, Simon Swift, Saeid Baroutian Abstract
BACKGROUND
Kānuka ( Kunzea ericoides ) is a medicinal plant native to New Zealand with numerous therapeutic benefits due to its rich bioactive profile. Although several in vitro studies have shown promising anti‐inflammatory activity, substantial evidence elucidating its underlying inflammatory regulatory mechanism and evaluating its cytotoxic profile remains limited. This study investigated the effects of kānuka subcritical water extract on NF‐ κ B activation and its cytotoxicity using THP‐1 Dual cell lines, focusing on potential applications in pharmaceutical, cosmetic, and nutraceutical products.
RESULTS
The kānuka subcritical water extract exhibited temperature‐, time‐ and dose‐dependent cytotoxic activity in THP‐1 Dual cells. Higher extract concentrations reduced cell viability (up to 60%), whereas lower concentrations (≤ 0.17 mg/mL) were non‐cytotoxic. The extract inhibited NF‐ κ B activation in a temperature‐ and dose‐dependent manner. Optimal inhibition was observed at 160 and 170 °C at the higher concentration (1.25 mg/mL), with minimal cytotoxicity, whereas lower concentrations (0.31–0.62 mg/mL) were ineffective against NF‐ κ B activation.
CONCLUSION
The kānuka subcritical water extract showed temperature‐ and concentration‐dependent anti‐inflammatory activity with minimal cytotoxicity in THP‐1 Dual cells. However, the effect on NF‐ κ B inhibition was lower than expected given its antioxidant profile, indicating potential interactions among its bioactive constituents. These observations highlight the importance of bioactive characterization and mechanistic studies to optimize extraction parameters and improve the potential for safe anti‐inflammatory applications. © 2026 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).