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.