Lavandin cell extract enriched in rosmarinic acid attenuates inflammation via AMPK/Nrf2/HO-1 activation and IKK/IκB/NF-κB inhibition

Lavandula species are rich in bioactive compounds, among which rosmarinic acid (RA) is a major phenolic known for potent antioxidant and anti-inflammatory activities. In this study, Lavandin ( Lavandula × intermedia ), a sterile hybrid widely cultivated for essential oil production, was used to develop RA-enriched cell extracts through plant cell culture technology combined with methyl jasmonate (MJ) elicitation. Lavandin cell suspension cultures accumulated higher levels of RA compared to those of L. angustifolia , and MJ treatment further enhanced RA biosynthesis, as confirmed by the upregulation of RA biosynthetic genes. Extracts derived from untreated and MJ-treated lavandin cell suspension cultures were assessed in LPS-stimulated RAW 264.7 macrophages. Both extracts were non-cytotoxic and significantly suppressed nitric oxide production, pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and the expression of iNOS and COX-2. Notably, the MJ-treated lavandin cell extract exhibited superior anti-inflammatory efficacy. Mechanistic analyses revealed that lavandin cell extract selectively inhibited the IKK/IκB/NF-κB pathway with minimal influence on MAPK pathways, while concurrently activating the AMPK/Nrf2/HO-1 axis. These findings demonstrate that MJ-elicited lavandin cell extract enriched in RA possesses strong anti-inflammatory activity and highlight its potential as a functional biomaterial for mitigating oxidative stress–related and inflammatory conditions.