Tricetin and Tricin: An Overview of the Chemistry, Sources, Contents, and Pharmacological Properties of these Flavones

In this overview, information on the chemistry, sources, contents, and pharmacological properties of two flavones, namely, tricetin (TCT) and tricin (TC), is updated. TCT occurs mainly in honey and pollen of plant species belonging to the genus Eucalyptus of the family Myrtaceae. TC is found in monocotyledon species of the family Poaceae, occurring mainly in cereal crops such as oats, barley, rice, wheat, and corn, and in bamboo species. The chemical structure of TCT contains two hydroxyl (OH) groups at C5 and C7 of ring A and three OH groups at C3’, C4’, and C5’ of ring B, with no methoxy (OCH3) groups. TC has two OH groups at C5 and C7 of ring A, two OCH3 groups at C3’ and C5’, and one OH group at C4’ of ring B, i.e., at both sides of the C4’ OH group. This renders greater bioavailability, higher metabolic stability, and better intestinal absorption to TC than TCT. In this overview, TCT and TC have eight and seven studies on anti-cancer properties, and 14 and 31 studies on other pharmacological properties, respectively. Both flavones are equally strong in terms of cytotoxicity towards cancer cells. With greater bioavailability, higher metabolic stability, and better intestinal absorption, the other pharmacological properties of TC are stronger than TCT, but not for anti-cancer properties.