Saponins from the genus Astragalus: Chemical diversity, biological activities, pharmacological effects, and therapeutic potential

Abstract

Saponins derived from various Astragalus species have been recognized for many years as biologically active compounds and are associated with a variety of biological and pharmaceutical activities. Among these, cycloartane- and oleanane-type saponins have been reported to exert immunomodulatory, anti-inflammatory, antioxidant, and cytoprotective effects. Preclinical studies demonstrate that these compounds modulate key cell-signaling pathways and exhibit significant antiproliferative activity in vitro and in vivo, inhibiting cancer cell growth and tumor progression. Beyond oncology, Astragalus saponins have shown protective effects in experimental models of inflammatory disorders, hepatic and metabolic dysfunction, cardiovascular disease, and neurodegenerative conditions, suggesting broad pharmacological relevance. Despite the growing body of literature, current evidence remains fragmented and predominantly focused on a limited number of compounds, highlighting the need for a comprehensive synthesis of available data. This narrative review aims to provide an integrated overview of the chemical diversity of Astragalus saponins, critically summarize their reported biological and pharmacological activities, and identify current limitations and research priorities. Despite progress, several barriers to clinical translation remain. These include a lack of published comparative and clinical data, as most available studies have focused primarily on astragaloside IV. Additionally, there is limited pharmacokinetic and bioavailability data, no detailed human studies, and no long-term safety data. Based on these identified gaps, future studies should focus on the following areas: extracting high-quality saponins using a standardized extraction procedure; conducting comprehensive evaluations of other saponins; optimizing saponin delivery formats; and conducting well-designed clinical trials to assess the safety and efficacy of Astragalus saponins in therapeutic applications.

Keywords: Triterpenoid saponins, Cycloartane-type triterpenes, Immunomodulation, Inflammation mediators, Signal transduction