Protective role of caffeic acid phenethyl ester on serum cholinesterase inhibition by acute exposure to diazinon in rats

Aim: To evaluate whether caffeic acid phenethyl ester (CAPE), a flavonoid-like natural compound plentifully found in beeswax, has a protective effect on diazinon-induced serum cholinesterase (ChE) inhibition in rats. Materials and methods: Animals were divided into 4 groups. The first animal group was not treated with any substance. The second animal group was orally given a 200 mg/kg body weight (bw) sublethal dose of diazinon. The third animal group was injected intraperitoneally with 2.84 mg (10 μmol)/kg bw of CAPE 1 day prior to administration of 200 mg/kg bw of diazinon orally. The fourth animal group was intraperitoneally injected with 2.84 mg (10 μmol)/kg bw of CAPE 30 min after 200 mg/kg bw of diazinon was orally administered. Results: Analysis of the animal blood samples obtained 48 h after diazinon administration revealed that diazinon decreased serum ChE activity by 75%, while CAPE administration 24 h prior to and 30 min following diazinon application improved serum ChE activity by 25%–32% as compared to levels with diazinon administration only. In silico studies suggest that CAPE prevents diazinon from binding to butyryl ChE due to a higher binding affinity than that of diazinon. Conclusion: Our laboratory findings suggest that CAPE plays a protective role against butyryl ChE inhibition by diazinon.