A Review of the Phytochemistry, Traditional Uses and Biological Activities of the Essential Oils of Genus Teucrium

Abstract

The genus Teucrium is a large and polymorphic genus of the Lamiaceae family distributed in mild climate zones, particularly in the Mediterranean basin and Central Asia. Studies of nonvolatile constituents of Teucrium species showed that they are a rich source of neo-clerodane diterpenoids, considered as chemotaxonomic markers of the genus. In addition to the nonvolatile metabolites, there has been a large interest in the essential oils of this genus. In this review, a complete survey of the chemical composition and biological properties of the essential oils isolated from Teucrium taxa is provided. In traditional medicine, since ancient times, species of this genus have been widely implemented for their biological properties, including antimicrobial, anti-inflammatory, antispasmodic, insecticidal, anti-malaria, etc. Therefore, a complete review of all of the traditional uses of Teucrium taxa are also reported.

Characterization of Essential Oils from Different Taxa Belonging to the Genus Teucrium in Sardinia Island, Italy

“…Many Teucrium species exhibited interesting biological properties such as antioxidant [31], anti-inflammatory [32,33], antitumor [32][33][34], and antimicrobial [5,31], justifying the widespread applications in the ethnomedicine of several countries. A comprehensive survey of traditional uses, chemical composition, and biological properties of the essential oils isolated from Teucrium taxa has been recently published [7]. In our study, all samples were collected during the full flowering period (June-July).…”

“…The aim of our study was to investigate the volatile fraction obtained from eight Sardinian Teucrium taxa ( Figure 1 ), to improve the knowledge on this genus. In fact, even though the Teucrium genus has been largely studied all over the world, especially for the chemical composition of the essential oils [ 7 ], to our knowledge, a comprehensive analysis focusing on Sardinian taxa has never been provided. Furthermore, a comparison between our results and literature data was performed.…”

“…It is represented by herbs or shrubs, with tubular or campanulate calyx, 2-lipped or actinomorphic, 5-toothed, the teeth equal or the upper larger; corolla with one 5-lobed lip; tube without a ring of hairs inside, often included in the calyx; and nutlets smooth or reticulate. Many taxa of the genus Teucrium have been used in traditional medicine as stimulants, tonics, and stomach-ache remedies, for their antioxidant, antifungal, antibacterial, antidiabetic, antiseptic, astringent, antispasmodic, anti-inflammatory, antianemic, and cicatrizant properties, and to treat skin diseases [ 3 , 4 , 5 , 6 , 7 ]. Phytochemical studies reported the presence of both volatile and non-volatile compounds.…”

“…Of the latter, several neo-clerodane diterpenoids were isolated and considered as chemotaxonomic markers of the genus [ 4 , 8 , 9 , 10 ], along with iridoids, sesquiterpenes, triterpenes, abietane diterpenes, flavonoids, and other classes of specialized metabolites [ 11 ]. Much scientific research has already been carried out on essential oils (EOs), since 99 Teucrium taxa have been investigated to date [ 7 ], highlighting the main volatile compounds, which are generally sesquiterpene hydrocarbons. The interest in studying this genus lies also in its documented in vitro and in vivo biological activities, such as antimicrobial, antioxidant, anti-inflammatory, anticancer, antinociceptive, and antifungal properties [ 4 , 7 , 12 , 13 ].…”

“…Much scientific research has already been carried out on essential oils (EOs), since 99 Teucrium taxa have been investigated to date [ 7 ], highlighting the main volatile compounds, which are generally sesquiterpene hydrocarbons. The interest in studying this genus lies also in its documented in vitro and in vivo biological activities, such as antimicrobial, antioxidant, anti-inflammatory, anticancer, antinociceptive, and antifungal properties [ 4 , 7 , 12 , 13 ]. Moreover, phytotoxic, insecticidal, and antileishmanial effects have also been reported for several species, especially for T. polium [ 14 , 15 , 16 ].…”