Astragalus membranaceus Bunge is widely used in Traditional Chinese Medicine to treat various cancers. Astragaloside‑IV (AS‑IV) is one of the major compounds isolated from A. membranaceus Bunge and has been demonstrated to have antitumor effects by inhibiting cell proliferation, invasion and metastasis in various cancer types. Numerous studies have used in vitro cell culture and in vivo animal models of cancer to explore the antitumor activities of AS‑IV. In the present study, the antitumor effects and mechanisms of AS‑IV reported in studies recorded in the PubMed database were reviewed. First, the antitumor effects of AS‑IV on proliferation, cell cycle, apoptosis, autophagy, invasion, migration, metastasis and epithelial‑mesenchymal transition processes in cancer cells and the tumor microenvironment, including angiogenesis, tumor immunity and macrophage‑related immune responses to cancer cells, were comprehensively discussed. Subsequently, the molecular mechanisms and related signaling pathways associated with antitumor effects of AS‑IV as indicated by in vitro and in vivo studies were summarized, including the Wnt/AKT/GSK-3β (glycogen synthase kinase‑3β)/β‑catenin, TGF‑β/PI3K/AKT/mTOR, PI3K/MAPK/mTOR, PI3K/AKT/NF‑κB, Rac family small GTPase 1/RAS/MAPK/ERK, TNF‑α/protein kinase C/ERK1/2‑NF‑κB and Tregs (T‑regulatory cells)/IL‑11/STAT3 signaling pathways. Of note, several novel mechanisms of Toll‑like receptor 4 (TLR4)/NF‑κB/STAT3, pSmad3C/3L, nuclear factor erythroid 2‑related factor (NrF2)/heme oxygenase 1, circDLST/microRNA‑489‑3p/eukaryotic translation initiation factor 4A1 and macrophage‑related high‑mobility group box 1‑TLR4 signaling pathways associated with the anticancer activity of AS‑IV were also included. Finally, the limitations of current studies that must be addressed in future studies were pointed out to facilitate the establishment of AS‑IV as a potent therapeutic drug in cancer treatment.
Keywords: antitumor; apoptosis; astragaloside‑IV; metastasis; migration; proliferation; signaling pathway; tumor microenvironment.