Chemopreventive potential of quinones: Molecular targets and therapeutic potential.

Chemoprevention refers to the use of natural or synthetic substances to prevent, delay, or reverse the development of cancer. It has become an essential part of current cancer management strategies, particularly as the global cancer burden continues to rise. With growing interest in natural alternatives, plant-based compounds have gained significant attention. According to the World Health Organization (WHO), nearly 80% of the world's population relies on traditional medicine, mainly using plant-derived materials for healthcare. Medicinal herbs have long served as a rich source of therapeutic agents, and recent advances in natural product research have led to the discovery of new compounds with chemopreventive potential. Among these, quinones are naturally occurring compounds found in plants, fungi, and bacteria that have shown notable promise. This group, which includes polyquinones, naphthoquinones, and anthraquinones, exhibits a wide range of biological activities such as antioxidant, anti-inflammatory, and immunomodulatory effects. Quinones are particularly recognized for their anticancer potential through mechanisms like the induction of apoptosis, inhibition of cancer cell proliferation, and modulation of key cancer-related signaling pathways. Additionally, quinones are being evaluated as adjuncts to conventional cancer therapies. Their ability to enhance the effectiveness of chemotherapy and radiotherapy, while reducing toxicity and drug resistance, underscores their therapeutic value. This review highlights the molecular mechanisms and chemopreventive capabilities of quinones. Given their broad biological activity, natural origin, and relative safety, quinones hold promise as effective agents for integration into existing cancer prevention and treatment strategies, contributing to a more holistic and potentially improved approach to cancer care.