A Review of the Main Biologically Active Compounds of the Genus Echium L., Naturally Distributed in Bulgaria, and...

Worldwide, the genus Echium L. (Boraginaceae) is represented by over 60 species of herbaceous plants and shrubs. The species are widely distributed all around the Mediterranean basin, Europe, and the Macaronesian Islands and are known for their analgesic, diuretic, antioxidant, antimicrobial, and antitumor properties. In traditional medicine, they are widely used as a wound-healing and anti-inflammatory agent, for respiratory problems and problems related to mental health, and for general abrasions and fissures of the hands. Four species are naturally distributed in Bulgaria-E. russicum J.F. Gmel., E. vulgare L., E. italicum L., E. plantagineum L., the first three being medicinal. The review aims to summarize the literature describing the content of biologically active substances and the therapeutic effects of Echium spp., with an emphasis on medicinal species distributed in Bulgaria. The content of biologically active substances was monitored, in particular, terpenes, phenolic compounds, flavonoids, naphthoquinones, omega-3 and omega-6 fatty acids, and pyrrolizidine alkaloids. The relationship between bioactive compounds, biological activities, and medicinal uses was researched. After the analysis made in the present review, it can be summarized: Despite extensive research, knowledge of their pharmacological potential is still incomplete. An attempt has therefore been made to outline directions for future research.