Hydrodistillation Boosts the Yield and Bioactivity of Cineole-rich EOs † from Lavandula x allardii: An Industrially Promising Hybrid Lavender

Background Lavender essential oils (EOs) are widely valued in perfumery, cosmetics, and therapeutics due to their bioactive monoterpenes. However, both plant genotype and extraction technique critically influence oil yield, chemical composition, and biological performance, thereby determining industrial value. Comparative investigations examining hydrodistillation versus steam distillation in certain hybrid lavenders remain limited. In this study, leaf EOs from Lavandula angustifolia and the hybrid Lavandula × allardii cultivated in Lebanon were extracted via hydrodistillation and benchmarked against a commercially available EO, industrially produced via steam distillation, and sold in the European market to assess yield, composition, antioxidant potential, cytotoxicity, and anti-inflammatory activity. Results Hydrodistillation significantly enhanced EO yield, with fresh L. × allardii leaves producing  > 5% (w/w) oil, approximately eight-fold higher than L. angustifolia . GC–MS analysis revealed distinct chemotypes: hydrodistilled oils were rich in 1,8-cineole (~ 67–69%), whereas the commercial steam-distilled oil was dominated by linalool and linalyl acetate (~ 27% each) with < 3% cineole. The cineole-rich oils exhibited superior ferric reducing antioxidant power (FRAP), exceeding both the steam-distilled reference and ascorbic acid (p <z0.05). In HT-29 colon cancer cells, hydrodistilled oils demonstrated stronger cytotoxicity (IC₅₀ ≈ 0.45–0.49 µL/mL) compared to the commercial lavender oil (IC₅₀ ≈ 1.5 µL/mL). Furthermore, in LPS-stimulated rat monocytes, they significantly reduced iNOS and COX-2 protein expression, confirming enhanced anti-inflammatory activity. Conclusions The marked compositional shift toward oxygenated monoterpenes (particularly 1,8-cineole) resulting from hydrodistillation appears to underlie the improved antioxidant and biological performance. The hybrid L. × allardii when processed from fresh leaves, emerges as a high-yield , cineole-rich chemotype with strong industrial relevance. Valorization of leaf biomass, often considered a secondary plant fraction, offers a sustainable strategy for producing bioactive lavender oils tailored for cosmetic and therapeutic applications.