Lemon Verbena (Aloysia citrodora) and Muscle soreness: evidence and sources

Ethnopharmacological relevance Aloysia citrodora Paláu (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.

Background Exhaustive exercise causes muscle damage accompanied by oxidative stress and inflammation leading to muscle fatigue and muscle soreness. Lemon verbena leaves, commonly used as tea and refreshing beverage, demonstrated antioxidant and anti-inflammatory properties. The aim of this study was to investigate the effects of a proprietary lemon verbena extract (Recoverben®) on muscle strength and recovery after exhaustive exercise in comparison to a placebo product. Methods The study was performed as a randomized, placebo-controlled, double-blind study with parallel design. Forty-four healthy males and females, which were 22-50 years old and active in sports, were randomized to 400 mg lemon verbena extract once daily or placebo. The 15 days intervention was divided into 10 days supplementation prior to the exhaustive exercise day (intensive jump-protocol), one day during the test and four days after. Muscle strength (MVC), muscle damage (CK), oxidative stress (GPx), inflammation (IL6) and volunteer-reported muscle soreness intensity were assessed pre and post exercise. Results Participants in the lemon verbena group benefited from less muscle damage as well as faster and full recovery. Compared to placebo, lemon verbena extract receiving participants had significantly less exercise-related loss of muscle strength ( p = 0.0311) over all timepoints, improved glutathione peroxidase activity by trend ( p = 0.0681) and less movement induced pain ( p = 0.0788) by trend. Creatine kinase and IL-6 didn't show significant discrimmination between groups. Conclusion Lemon verbena extract (Recoverben®) has been shown to be a safe and well-tolerated natural sports ingredient, by reducing muscle damage after exhaustive exercise. Trial registration The trial was registered in the clinical trials registry (clinical trial.gov NCT02923102). Registered 28 September 2016.