AKR1B1 and metabolic disease: Regarding metabolic diseases, pheophytin a and pheophorbide a isolated from Laminaria japonica inhibited the formation of AGE (advanced glycation end-products) (half maximal inhibitory concentration (IC50) 228.71 μM and 49.43 μM, respectively) and of aldose reductase activity (IC50 >100 μM and 12.31 μM, respectively) [38].