Astragalus membranaceus: A Review of its Protection Against Inflammation and Gastrointestinal Cancers

Astragalus membranaceus is a major medicinal herb commonly used in many herbal formulations in the practice of traditional Chinese medicine (TCM) to treat a wide variety of diseases and body disorders. Among its diversified clinical applications, the potential use of this herb and its chemical constituents in treatments of inflammatory diseases and cancers has been actively investigated in recent years. Astragalus-based treatments have demonstrated significant amelioration of the toxicity induced by other concurrently administered orthodox drugs (e.g., immunosuppressants and cancer chemotherapeutics). The major components of Astragalus membranaceus are polysaccharides, flavonoids, and saponins. Contemporary use of Astragalus membranaceus mainly focuses on its immunomodulating, anti-oxidant, and anti-inflammatory, as well as anticancer effects. In this paper, we summarize the properties of Astragalus membranaceus and its major constituents in the biological system based on experimental and clinical studies. The antitumorigenic mechanisms of a novel Astragalus saponins extract called AST in treating various gastrointestinal cancers are highlighted. We discuss in detail how the Astragalus herb and AST influence the immune system, modulate various cancer signaling pathways, and interact with specific transcription molecules during protection against gastrointestinal inflammation and cancers. This information could help clinicians and scientists develop novel target-specific and effective therapeutic agents that are deprived of major systemic side effects, so as to establish a better treatment regimen in the battle against inflammatory diseases and cancers of the gut.