A Daegu Lab Traces Rooibos's Signature Compound to Calmer Skin in an Eczema Model
South Korean researchers found aspalathin, the flavonoid unique to rooibos, eased eczema-like skin inflammation in mice by blocking a specific immune signal. The work is a mouse study, not a human result.
Aspalathin, the flavonoid unique to rooibos among food plants, eased eczema-like skin inflammation in mice by blocking a specific immune signal, researchers at Kyungpook National University in South Korea reported.
The team, led by Sang-Hyun Kim of the university's pharmacology department, applied aspalathin to the skin of mice with induced atopic dermatitis. Treated mice showed less redness, less scaling, and thinner, less inflamed skin than untreated mice, the researchers said in Biomedicine and Pharmacotherapy.
Aspalathin makes up more than 40 percent of the flavonoid content in green, unfermented rooibos. The Daegu-based team traced its effect to a specific mechanism: aspalathin blocked activation of STAT6 and NFAT1, two proteins that drive the immune overreaction behind atopic dermatitis, in the mice's skin tissue and in isolated T cells, basophils, and keratinocytes. Treated mice also had lower blood levels of the antibodies IgE and IgG2a, both markers of the allergic response the condition involves.
The study is a mouse model, not a clinical trial in people, and topical aspalathin is not an available treatment. Whether the same mechanism holds in human skin, and at what dose, is not something a mouse study can settle.
A topical dose measured on a mouse's shaved skin is not a cup, and the Ministry keeps the two apart. What is established is narrower and older than this study: rooibos is caffeine-free and rich in antioxidants, aspalathin among them.
Sources: Yang et al., "Aspalathin, a key flavonoid in rooibos, restores STAT6-mediated immune dysregulation in atopic dermatitis," Biomedicine and Pharmacotherapy, vol. 184 (2025), DOI: 10.1016/j.biopha.2025.117926; PubMed record, PMID 39970731.