Flavonoid glycosides from Japanese Camellia oil cakes and their inhibitory activity against advanced glycation end-products formation

Phytochemical investigation of the oil cakes of Camellia japonica L. seeds resulted in the isolation and structural elucidation of thirteen flavonoid glycosides (1-13), including four novel compounds (6, 1012). Chemical profiling of the oil cake extract was characterized by HPLC-PDA analysis. The extract and isolated compounds 1-12 exhibited potent inhibitory activities against advanced glycation end products (AGES) formation between D-ribose and bovine serum albumin (BSA). The major compound 7 exhibited the most potent inhibitory activity among the isolated compounds. The extract and 7 also inhibited AGEs formation between human serum albumin (HSA) and three intermediates: glycolaldehyde (GA), methyl glyoxal (MGO), and glyoxal (GO). Moreover, extract and compound 7 decreased the GA-HSA enhanced expression of macrophage inflammatory protein-1 beta (MIP-1 beta) mRNA in differentiated U937 cells. The extract and its flavonoid glycoside constituents from the oil cakes of C. japonica seeds possessed potential usability as health materials against AGE-associated chronic diseases. (C) 2017 Elsevier Ltd. All rights reserved.