Modulatory effect of some selected phenolic acids on enzyme activities of purinergic signaling

Abstract

This research assessed the antioxidant activities and effects of some selected phenolic acids (ferulic, Caffeic, p-coumaric and chlorogenic acid) on enzymes of the purinergic signalling in isolated rat brain which include ATPdase, ecto- 51nucleotidase, phosphodiesterase and Na+/ K+ ATPase. Standard stock solutions (13mM) of the selected phenolics (Caffeic acid, ferulic acid, chlorogenic acid, p-coumaric acid) were prepared and several dilutions (0.05mM-10mM) were subsequently prepared; the ability of the phenolic acids to inhibit Fe2+ induced malondialdehyde (MDA) production in rat’s brain homogenates were assessed. Furthermore, the antioxidant activities of the phenolic acids as typified by the radicals (DPPH* and ABTS*) scavenging abilities were investigated. The results revealed that ferulic acid had the highest Na+/K+ -ATPase (IC50 =3.48 /ml) stimulatory activityas well as the highest ecto-5'-nucleotidase (IC50 =6.222 μg/ml) inhibitory activity while chlorogenic acid had the highest phosphodiesterase-51 (IC50 =21.03μg/ml) inhibitory activity and P-coumaric acid had the highest inhibition of ATPDase (IC50 =17.56 μg/ml) activity. Also, chlorogenic acid had the highest ABTS* and DPPH* scavenging abilities and also the strongest inhibition of Fe2+ induced MDA production in rat brain. However, this study revealed that the phenolic acids altered critical enzymes of the purinergic signaling and therefore suggests their possible neuromodulatory effect.