Comparative Antioxidant and Anti-cholinesterase Properties of Catechin, Caffeine and Theobromine

Abstract

Catechin, caffeine and theobromine are three bioactive compounds that are present in plant foods and are major constituent of tea, coffee and cocoa drinks respectively. Although not structurally related, catechin, caffeine and theobromine have been reported to elicit psychostimulatory properties.   In this study, we investigated the antioxidant properties of the compounds through their radicals [1,1 diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonate (ABTS), nitric oxide (NO), and hydroxyl (OH)] scavenging abilities, ferric reducing potentials and Fe2+ chelating abilities. The effect of the compounds on different prooxidants (FeSO4, cisplatin and sodium nitroprusside) induced lipid peroxidation in rat brain homogenates was assessed. Also, the effects of the compounds on some cholinergic [acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)] enzymes in rats brain homogenates were assessed in vitro. The stock concentration of catechin, caffeine and theobromine were prepared and their inhibition of these enzymes were assessed (in vitro) in brain homogenate. The results revealed that caffeine, catechin and theobromine had antioxidant properties and exhibited inhibitory effects on activities of AChE and BChE. Catechin had the best antioxidant property while theobromine produced the highest enzyme inhibition effect. These findings may provide new insight into the effects of these bioactive compounds as obtained in many foods especially with respect to their antioxidant and neuroprotective effects.