A review of the chemical composition and biological activity of Leonotis nepetifolia (Linn.) R. Br. (lion's ear)

Resumen

Introduction: For centuries, medicinal plants have been used to treat a variety of diseases. Leonotis nepetifolia (Linn.) R. Br. is a species native to tropical regions of Africa and southern India which is widely used for medicinal purposes.
Objective: Review the main publications about L. nepetifolia with a chemical and pharmacological approach, and describe the most relevant papers found in the databases.
Methods: Specialized databases were reviewed (LiLacs, PubMed, SciELO, ScienceDirect and Scopus) using the search terms Leonotis nepetifolia, phytochemistry, biological activity and Lamiaceae. Papers were selected whose titles and abstracts were related to the phytochemical characteristics and biological activity of the species, and their full text was analyzed.
Results: Several studies have been conducted of the species L. nepetifolia, verifying its potential use for the treatment of various diseases. In the review, 32 papers were selected which evaluated the biological activity of extracts from the species, and 11 which dealt with the isolation of compounds produced by the secondary metabolism of the plant, showing the anti-inflammatory and antioxidant activity of some of them. Antibacterial, antiviral, antifungal, anticonvulsant, anxiolytic, anticarcinogenic, analgesic, antidiarrheal, antidiabetic, antiplasmodial and anthelmintic activities were the most carefully evaluated, whereas the diterpenes labdane and bis-spirolabdane, flavonoids, fatty acids and esters, iridoids, and phenylethanoid glycosides and coumarins were the most common chemical compounds.
Conclusions: The presence of certain chemical substances accounts for the various potential biological applications of the extracts and compounds isolated from L. nepetifolia for the production of new drugs and phytomedicines.

Key words: Leonotis nepetifolia, medicinal plant, phytochemical, biological activity.