Aloysia citrodora Palau (Lemon verbena): A review of phytochemistry and pharmacology

Ethnopharmacological relevance: Aloysia citrodora Palau (Lippia citriodora Kunth), commonly known as lemon verbena is a medicinal plant native to South America, North Africa, and South of Europe which is used by native people for several indications such as diarrhea, flatulence, insomnia, and rheumatism. Aim of the review: Despite the wide biological activities of lemon verbena, there is no current review summarizing medicinal properties of the plant; thus, this paper aims to discuss current state of the art regarding the phytochemistry, pharmacology, and therapeutic applications of A. citrodora considering in vitro, in vivo, and clinical studies. Materials and methods: Electronic databases including PubMed, Scifinder, Cochrane library, Scopus, and Science direct were searched with the scientific name of the plant and its synonyms, as well as the common name. All studies on the ethnobotany, phytochemistry, pharmacology, and clinical application of the plant until October 2017 were included in this review. Results: Despite the few number of studies on the ethnopharmacology of the plant, A. citrodora is widely assessed regarding its phytochemistry and biological activities. Neral and geranial are the main ingredients of the essential oil; whereas verbascoside is the most significant component of the extract. Biological activities such as antioxidant, anxiolytic, neuroprotective, anticancer, anesthetic, antimicrobial, and sedative effects are proved in cell cultures, as well as animal studies. Conclusions: Several pharmacological activities have been reported for A. citrodora; however, the plant is not fully assessed regarding its safety and efficacy in human. Future well-designed human studies are essential to confirm the therapeutic benefits of this plant in clinical settings.