Inhibition of Acetylcholinesterase Activity and Fe ²⁺ -Induced Lipid Peroxidation in Rat Brain In Vitro by Some Citrus Fruit Juices

This study sought to characterize the effects of some citrus fruit juices (shaddock [Citrus maxima], grapefruit [Citrus paradisii], lemon [Citrus limoni], orange [Citrus sinensis], and tangerine [Citrus reticulata]) on acetylcholinesterase activity in vitro. The total phenolic content, radical scavenging abilities, and inhibition of Fe(2+)-induced malondialdehyde (MDA) production in rats brain homogenate in vitro were also assessed. Orange had significantly (P<.05) higher phenolic content than the other juices. The juices scavenged 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals in a dose-dependent manner with orange having the highest scavenging ability. Furthermore, the juices inhibited Fe(2+)-induced MDA production in rat brain homogenate in a dose-dependent manner with shaddock having the highest inhibitory ability. Acetylcholinesterase activity was also inhibited in vitro by the juices in a dose-dependent manner. The inhibition of acetylcholinesterase activity and antioxidant properties of the citrus juices could make them a good dietary means for the management of Alzheimer's disease.