Potential of Dietary Agent Daidzein in Cancer Prevention and Treatment: Opportunities and Challenges

Background: Daidzein, a secondary metabolite primarily obtained from soybean (Glycine max L.) and other legumes, has significant nutritional and pharmacological value. Chemically, daidzein is an isoflavone and plays a crucial role in the therapeutic amelioration of numerous disorders, including allergies, inflammation, diabetes, cardiovascular, and neurodegenerative diseases. Emerging preclinical evidence suggests potential antineoplastic activity of daidzein against various cancers. This current work aims to perform a critical evaluation of daidzein's potential as an anticancer molecule with an in-depth understanding of its mechanisms of action. Methods: The data for this review were obtained from various sources, including PubMed, Scopus, and Web of Science. Results: Daidzein, as a pure phytochemical or in combination with other phytochemicals and anticancer drugs, has been reported to induce apoptotic and autophagic cell death, impeding cell growth, viability, proliferation, and angiogenesis, and arresting cell division at various phases in vitro. Various daidzein formulations also exhibited similar anticancer effects by immunomodulation and genetic alteration in the cancer cells. In vivo anticancer studies of daidzein also suggest modulation of several hallmark pathways, such as inhibition of nuclear factor-κB, Janus kinase/signal transducer and activator of transcription, and rat sarcoma virus/rapidly accelerated fibrosarcoma. Conclusions: Irrespective of numerous promising preclinical studies, the absence of clinical studies provides a major challenge to establishing daidzein's safety and efficacy in human cancers. Therefore, further advancements in clinical research of daidzein are vital for manifesting as an antineoplastic drug.