Possibilities of using secondary plant metabolites as antitumor agents

The review summarized the literature data of recent years on the antitumor effect of secondary plant metabolites, as well as their immunotropic and anti-inflammatory effects as components of the antitumor response. The biological basis for the action of secondary plant metabolites was characterized in the form of influence on potential targets: transcription factors, signaling pathways and receptors responsible for proliferation and apoptosis. The ways of increasing the bioavailability of secondary plant metabolites to enhance the effectiveness and possibility of their medicinal use were considered, the effects of berberine, curcumin and their derivatives were described. The search for scientific publications was conducted in foreign (PubMed) and domestic (eLibrary) electronic libraries. It was found that the multiplicity of molecular targets of secondary plant metabolites and the pleiotropy of their effects suggest the possibility of their use for the regulation of various processes in tumor and normal cells. There was a connection between the antitumor effect of secondary plant metabolites and their anti-inflammatory and immunomodulatory action. However, a significant limitation of their use was the fact that most studies were conducted on cell cultures, which was insufficient to judge the antitumor effect. Clinical trials were few and their results were contradictory. In addition, a certain contradiction has been noted between the idea of a more effective action when using a pure substance or a complex composition of various plant components. An important problem was the low bioavailability of most secondary plant metabolites, for which various methods have been proposed. Despite the long history of phytotherapy in oncology, the development of new derivatives of secondary plant metabolites with high water solubility remains relevant, including modified molecules of known secondary plant metabolites and the search for new ones with unexplored biological activity. Modern methods of chemical synthesis and delivery systems of derivatives of secondary plant metabolites, as well as the study of their effects in model experiments, seem to be promising scientific directions for the creation of new drugs with antitumor activity.