Anti-inflammatory and analgesic effects of lavender are attributed to 1,8-cineole ⁽²⁾. Other major constituents include linalool and linalyl acetate, which may relax blood vessels and induce anxiolytic effects ^{(30) (40) (54)}. In a murine model, exposure to linalool odor induced anxiolytic effects without motor impairment ⁽⁷⁷⁾.

Lavender oil also has broad-spectrum antibacterial activity ⁽²²⁾. It reversed bacterial resistance to piperacillin in multi-drug-resistant E.coli via alterations of outer membrane permeability and bacterial quorum sensing inhibition ⁽²⁷⁾; and prevented immediate-type allergic reactions by inhibiting mast cell degranulation ⁽²⁵⁾. Antimicrobial activity was synergistic or additive when combined with other essential oils, with the most favorable combinations being cinnamon or sweet orange oil against C. albicans and S. aureus, respectively ⁽²⁸⁾.

In addition, lavender has CNS depressive effects ⁽³⁾. In animal models, it attenuated neuronal damage, and upregulated catalase, superoxide dismutase, glutathione peroxidase, and the glutathione/glutathione disulfide ratio ⁽²¹⁾. Activity in stroke models include increased endogenous antioxidant defense, oxidative stress inhibition, and increased VEGF expression ⁽³³⁾. In an Alzheimer’s disease model, lavender extract improved spatial performance by diminishing beta-amyloid production in the hippocampus ⁽³²⁾. In mice with anosmia, anxiolytic effects with lavender inhalation were likely due to serotonergic mechanisms rather than olfactory activation ^(30) (31). However, whether lavender alleviates or exacerbates anxiety may actually be determined by genetic influences on temperament as these behaviors were amplified after exposure to lavender inhalation in calm versus nervous sheep ⁽⁵⁶⁾. Antiepileptic effects are due to suppressed nitric oxide levels in the brain ⁽²⁶⁾. Cardioprotective effects are attributed to lavender’s antioxidant properties ⁽³⁵⁾. In wound healing models, lavender oil accelerated re-epithelialization and wound closure via enhanced epidermal growth factor secretion ⁽⁵⁵⁾.

In young women with premenstrual syndrome, lavender inhalation increased the high frequency component of heart rate variability, reflecting parasympathetic nervous system activity ⁽³⁷⁾. Although lavender reduced anxiety during urodynamic assessments by increasing gamma-aminobutyric acid inhibitory effects in the amygdala, blood pressure increases were attributed to potential diuretic activity ⁽⁴⁰⁾. A positron emission tomography study revealed anxiolytic effects may occur via reduced serotonin-1A receptor binding ⁽⁴¹⁾. Effects on preoperative anxiety were attributed to both the use of lavender aroma as well as the placebo effect of added attention to patients ⁽⁶⁸⁾.

An aqueous lavender extract inhibited lymphocyte proliferation in Hodgkin’s lymphoma cell lines via apoptosis ⁽⁴⁷⁾. In addition, lavender extracts and essential oil exhibited cytotoxicity in malignant cells, upregulated Bax expression, and induced PARP cleavage in HeLa cells, and caused a sub-G1 peak in treated cells compared with controls ⁽⁴⁸⁾. Perillyl alcohol (POH), derived from botanicals including lavender, may affect transforming growth factor-beta and/or Ras signaling pathways ⁽⁵⁹⁾ and Na/K-ATPase inhibition ⁽⁶⁰⁾.

Lavender oil has weak estrogenic and antiandrogenic activities that could alter estrogen and androgen signaling pathways ⁽¹⁴⁾.