Anxiolytic Effect of Essential Oils and Their Constituents: A Review

Abstract

Essential oils are usually used in aromatherapy to alleviate anxiety symptoms. Compared to traditional drugs, essential oils have fewer side effects and more diversified application ways including inhalation. This review provides a comprehensive overview of studies on anxiolytic effects of essential oils in preclinical and clinical trials. Most of the essential oils that used in clinical researches had been proved to be anxiolytic in animal models. Inhalation and oral administration were two common methods for essential oil administration in preclinical and clinical trials. Massage was only used in the clinical trials while intraperitoneal injection was only used in the preclinical trails. In addition to essential oils that are commonly used in aromatherapy, essential oils from many folk medicinal plants have also been reported to be anxiolytic. More than 20 compounds derived from essential oils have shown anxiolytic effect in rodents, while two-thirds of them are alcohols and terpenes. Monoamine neurotransmitters, amino acid neurotransmitters and hypothalamic-pituitary-adrenal axis are thought to play important roles in the anxiolytic effects of essential oils.