Natural products targeting STAT3 signaling pathways in cancer cells

Cancer is a leading cause of death worldwide. The roles and significance of Signal Transducer and Activator of Transcription 3 (STAT3) in human cancers have been extensively studied. STAT3 is a promising therapeutic target for cancer drug discovery. Herbal medicine-derived secondary metabolites efficiently impact all cancer hallmarks; therefore, natural products are a major source of new cancer drug development. Many natural products can inhibit STAT signaling pathways in cancer cells by targeting different pathways. In this review, we describe the structures of STAT3 inhibitors isolated from herbal medicines and discuss their targeting molecules and modes of action.