Quercetin: A Comprehensive Review

Quercetin is a plant pigment found in many fruits, vegetables, beverages, and other parts of plants, such as leaves, flowers, bark, stems, and roots. The rich sources of quercetin are the dock, watercress, sweet potato, onion, grapes, berries, cherries, and broccoli. Quercetin exhibits various pharmacological activities, such as anticancer, antiviral, anti-inflammatory, and antioxidant. Several studies have reported quercetin as a potential anticancer compound. This review article provides information on the role of quercetin in many types of cancer, such as breast cancer, colon cancer, liver cancer, lung cancer, prostate cancer, bladder cancer, gastric cancer, bone cancer, blood cancer, brain cancer, cervical cancer, head and neck cancer, skin cancer, eye cancer, thyroid cancer, ovarian cancer, kidney cancer, and mesothelioma cancer. The present review emphasizes the anticancer activity of quercetin via different mechanisms, such as induced apoptosis, inhibition of tumor progression, cancer cell cycle arrest via different pathways, decreased proliferation, modification of the tumor microenvironment, etc.