Hidden in Plants—A Review of the Anticancer Potential of the Solanaceae Family in In Vitro and In Vivo Studies

SIMPLE SUMMARY: The Solanaceae family is one of the most important arable and economic families in the world. In addition, it includes a wide range of valuable active secondary metabolites of species with biological and medical properties. This literature review focuses on the assessment of the anticancer properties of the extracts and pure compounds, and the synergistic effects with chemotherapeutic agents and nanoparticles from various species of the Solanaceae family, as well as their potential molecular mechanisms of action in in vitro and in vivo studies in various types of tumours. ABSTRACT: Many of the anticancer agents that are currently in use demonstrate severe side effects and encounter increasing resistance from the target cancer cells. Thus, despite significant advances in cancer therapy in recent decades, there is still a need to discover and develop new, alternative anticancer agents. The plant kingdom contains a range of phytochemicals that play important roles in the prevention and treatment of many diseases. The Solanaceae family is widely used in the treatment of various diseases, including cancer, due to its bioactive ingredient content. The purpose of this literature review is to highlight the antitumour activity of Solanaceae extracts—single isolated compounds and nanoparticles with extracts—and their synergistic effect with chemotherapeutic agents in various in vitro and in vivo cancer models. In addition, the biological properties of many plants of the Solanaceae family have not yet been investigated, which represents a challenge and an opportunity for future anticancer therapy.