Hairy roots as a potential source for the production of rosmarinic acid from genus Salvia

The Salvia genus, a member of the Lamiaceae family, exhibits a rich array of secondary metabolites, including di- and triterpenoids, phenols, polyphenols, and essential oil compounds. These constituents contribute to valuable pharmacological activities such as antibacterial, antiviral, anti-inflammatory, and antioxidant properties. Among these metabolites, rosmarinic acid stands out as a particularly promising compound, deriving from the precursors phenylalanine and tyrosine. It belongs to the phenolic compound class and acts as an ester of caffeic acid, showcasing diverse therapeutic potentials like antifungal, antibacterial, antiviral, antioxidant, anticancer, anti-ageing, anti-inflammatory, and anti-diabetic effects. To facilitate the production of such secondary metabolites, plant tissue culture techniques have played a pivotal role, with hairy root cultures being one of the preferred methods. This review provides an extensive examination of the biosynthetic pathway of rosmarinic acid and its successful generation using hairy root cultures. Additionally, the review highlights the utilization of genetic modification tools and various biotic and abiotic elicitors, including yeast extract, methyl jasmonate, and silver ion (Ag+), in hairy root cultures of diverse Salvia species to enhance the production of rosmarinic acid.