Effects of Policosanol ( Sugar Cane Wax Alcohols ) and D - 003 ( Sugarcane Wax Acids ) on Cyclooxygenase ( Cox ) Enzyme Activity In Vitro

Both policosanol and D-003 are mixtures of higher aliphatic alcohols and acids, respectively, purified from sugarcane wax, whose main components are octacosanol and octacosanoic acid (an active metabolite of octacosanol), respectively. Both substances share some, not all, pharmacological effects, like cholesterol-lowering, antiplatelet and antioxidant effects. The mechanisms whereby they exhibit cholesterol-lowering have been investigated, but those supporting their antiplatelet effects remain unknown. We hypothesized that these substances could inhibit cyclooxygenase (COX) activity. The aim of this study was to investigate whether policosanol and D-003 may inhibit COX-1 and COX-2 enzyme activities, effects assessed in cytosolic microsomes from rat platelets and seminal vesicles, respectively. Vehicle, Policosanol or D-003 suspensions (0.6 to 6000 g/mL) were added to tubes containing a mixture of reactions and absorbance changes at 480 nm were measured. Both policosanol and D-003 inhibited significantly (maximal inhibition  80%) and dose-dependently COX-1 enzyme activity (IC50 = 312.5 g/ml and 14.84 g/ml, respectively) by modifying both kinetic parameters, so that the inhibition was uncompetitive. D-003, not policosanol, also inhibited significantly and dosedependently, but moderately (maximal inhibition  54%), COX-2 activity. Concluding, policosanol and D-003 produce marked and comparable in vitro inhibitions of COX-1 activity in rat platelet microsomes, D-003 being the most potent. D-003, not policosanol, also inhibits moderately COX-2 activity in rat seminal vesicles.