5-Lipoxygenase inhibitor IC50 values

Seven Artocarpus flavonoids and morusin (3) were tested for their inhibitory actions on arachidonate-5-lipoxygenase purified from porcine leukocyte [84]. As shown in Fig. (13), the IC50 values varied depending on the structural modification of the compound. The compounds having three hydroxyl groups at positions 2, 4, and 5 on the B ring (compounds 7, 8, 52 and 55) were more potent inhibitors. Thus, the vicinal diol partial structure was important for 5-lipoxygenase inhibition. 

E-isolinaridial and E-isolinaridial methylketone are two neo-clerodane diterpenoids isolated from the aerial parts of Linaria saxatilis var. glutinosa (Schrophulariaceae). Benrezzouk et al. evaluated these compounds on multiple inflammation pathways and found that they were not COX-1/COX-2 inhibitors [139]. However, E-isolinaridial and E-isolinaridial methylketone were dual inhibitors against purified phospholipase A2 and 5-lipoxygenase. E-isolinaridial and E-isolinaridial methylketone showed potent inhibition of cell-free 5-LOX enzyme with IC50 values of 0.42 pM and 1.41 pM,... 

All eight natural prenyl-flavones evaluated by Reddy et al. showed potent inhibitory effects on 5-lipoxygenase with IC50 from 0.36 to 4.3 pM. Artonin E isolated from the bark of Artocarpus communis Forst. (Moraceae) was the most potent dual LOX and COX inhibitor with IC50 values of 0.36 pM and 2.5 pM, respectively. It also inhibited leukocyte and platelet 12-... 

Various flavonoids and related compounds have been tested as inhibitors for cyclooxygenase and lipoxygenase. Some are more effective as lipoxygenase inhibitors, and some more effective as cyclooxygenase inhibitors. Thus, 3, 4 -dihydroxy-flavone and 1,5-dihydroxy-naphthalene are potent inhibitors of 12-HETE formation in rat lung and spleen homogenates. IC50 values are 3.3 X 10 M and 2 X 10 M, respectively [394],... 

---