Flavonoids: biological activities, nutritional and immunological aspects, therapeutic potential, food applications, and human health benefits—A comprehensive review - Mohamed T. El-Saadony; Ahmed M. Saad; Mohamed A. Fahmy; Dina Mostafa Mohammed; Dina Khodeer; Esmael M. Alyami; Samar Sami Alkafaas; Mthokozisi Dladla; Soumya Ghosh; Mohammad A. A. Al-Najjar; Synan F. AbuQamar; Khaled A. El-Tarabily (Frontiers in Nutrition, 2026)