Anti-inflammatory and antioxidant effects of Lavandula stoechas L. on human macrophages and in silico prediction of α7 nicotinic acetylcholine receptor interaction

Lavandula stoechas L., commonly known as lavender, has been traditionally used in various therapeutic applications, including as a smoking cessation aid. The aim of this study was to investigate the anti-inflammatory and antioxidant activity of Lavandula stoechas extract and essential oil in an in vitro inflammation model using THP-1 human macrophages. We further performed an in silico analysis to predict molecular interactions between the active ingredients of the plant and α7 nicotinic acetylcholine receptors (α7nAChRs). Varenicline, a well-known smoking cessation aid, was used as a positive control due to its established role in modulating α7nAChRs as well as its proven anti-inflammatory effects in vitro. This comparison allowed us to evaluate whether Lavandula stoechas exhibits similar or complementary biological activity to varenicline in suppressing inflammatory cytokine production in vitro. THP-1 macrophages were treated with increasing concentrations of Lavandula extract or its essential oil to determine non-toxic concentrations. Next, the cells were exposed to a bacterial endotoxin, lipopolysaccharide (LPS) in the presence and absence of the plant’s products for 24 h after which the levels of reactive oxygen species (ROS), proinflammatory cytokines (TNFα and IL-6) and macrophage markers (CD80 and CD86) were measured. Molecular docking analysis was performed on essential compounds of L. stoechas to predict their binding affinities to the α7nAChRs using AutoDock Vina in the open access PyRx Docking-based virtual screening (DBVS) tool. ADMET (Absorption, Distribution, Metabolism, Excretion and Toxicity) profiles were also predicted. Lavandula extract and its essential oil suppressed ROS levels, inflammatory cytokines, and the early macrophage polarization marker CD86 elevated by LPS in macrophage culture. In addition, DBVS analysis revealed possible significant binding affinities of several L. stoechas compounds for α7nAChRs. Predicted ADMET profiles of compounds with the highest binding affinities appeared to be comparable to varenicline in silico, without implying superior pharmacodynamic safety. The anti-inflammatory and antioxidant properties as well as the favorable ADMET profiles of the phytochemicals found in L. stoechas provide preliminary in vitro and in silico evidence supporting further investigation of the therapeutic potential of Lavandula stoechas as a smoking cessation aid.