Steroidal Glycosides in Intact Plants and Plant Cell Culture

Steroidal glycosides are a group of triterpene compounds of the plant secondary metabolism. They possess a broad spectrum of biological activities (from immunomodulatory to anticarcinogenic) and are found in plants from at least 19 different families. Steroidal glycosides are the “champions” in terms of the length of time they have been studied in vitro: the first steroidal glycosides-producing plant cell cultures (Dioscorea deltoidea Wall.) were obtained over 50 years ago. The experience accumulated over this time has both theoretical and practical significance. The patterns and mechanisms of secondary metabolite formation in dedifferentiated proliferating cells in vitro typically differ from those in intact plants. Comparison of these biological systems is highly informative for studying the principles of regulation, organization and functioning of secondary metabolism. The practical significance of such research stems from the potential for biotechnological use of plant cell cultures as a source of biologically active substances (steroidal glycosides) for medicine, cosmetics and food industry. An acute shortage of medicinal plant materials, the development of such biotechnologies is highly promising. Interest for use of steroidal glycoside-producing plant cell cultures is currently growing significantly due to the discovery of new properties of these compounds, including hypoglycemic and hypocholesterolemic activity. This review discusses data on the structure and biosynthetic pathways of steroidal glycosides, their distribution in plants, and their biological activity. The focus is on information on the obtaining of steroidal glycoside-producing plant cell cultures, the patterns of formation of these compounds, and the mechanisms regulating their biosynthesis in dedifferentiated cells in vitro, as well as the potential for their biotechnological use.