Stationary, Agitated, and Bioreactor Cultures of Verbena officinalis L. (Common Vervain): A Potential Rich Source of Bioactive Phenolic Compounds for Pharmacy, Health Food Industry, and Cosmetology

Verbena officinalis L. is a medicinal plant widespread in the wild throughout almost of all continents. The medicinal raw material obtained from this species is the herb. Its main constituents include iridoids (e.g., verbenalin, hastatoside), different groups of polyphenols (e.g., phenylpropanoid glycosides, simple phenolic acids and depsides, and flavonoids), triterpenoids (e.g., ursolic acid), phytosterols, essential oil, and bioelements. This species has an important position both in traditional European and North American medicine as well as in Traditional Chinese Medicine (TCM). In 2008, Verbenae herba was introduced into official European medicine. In the United States, this species has long been known and used in official allopathic and homeopathic medicine. The vervain herb also appears in the Chinese Pharmacopoeia (2005). This article presents basic information on the morphology, ecology, and distribution of natural habitats of this species worldwide and reviews the main groups of its chemical components occurring in the herb and possible therapeutic uses of this raw material. The important position of this species in cosmetology was also underlined. In addition, biotechnological studies maintained by our research teams on the biosynthetic potential of cells cultured in vitro were presented. These studies aimed to optimize conditions for in vitro cultures in order to facilitate the accumulation of bioactive phenolic compounds. The optimization was performed by testing a wide range of plant growth regulators, light conditions (white fluorescent light, darkness, monochromatic LED lights), and culture types differing in the degree of organogenesis, that is, undifferentiated callus cultures and microshoot cultures (stationary, agitated, and bioreactor cultures). The results of the biotechnological studies have indicated that the biosynthetic potential of cells in in vitro cultures is specifically oriented toward the production of phenylpropanoid glycosides: verbascoside and isoverbascoside. The maximum contents of these compounds reaching ca. 9 g% of verbascoside (stirred tank bioreactor cultures) and ca. 0.6 g% of isoverbascoside (agitated cultures) obtained in undifferentiated cultures are interesting from practical perspective. On the other hand, microshoot cultures of this species produce essential oil at quantities comparable to its contents in the soil-grown plants (ca. 8 g/kg DW in a Plantform bioreactor) but differing in chemical composition, which is also the result offering the potential for application.