Effects of chlorogenic acid on adenine nucleotides hydrolyzing enzyme activities and expression in platelets of rats experimentally demyelinated with ethidium bromide

The effects of chlorogenic acid (one of the major phenolic acid found in human diets) were investigated on the adenine nucleotides hydrolyzing enzymes; ecto-nucleotide pyrophosphatase/phophodiesterase (E-NPP), ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), E-5′- nucleotidase and ecto-adenosine deaminase (E-ADA) activities and expression in platelets of rats experimentally demyelinated with ethidium bromide. Rats were divided into four groups of eight animals each. Group I rats were control rats; injected with saline (CT), group II rats were injected with saline and treated with chlorogenic acid (AC), group III rats were injected with 0.1% ethidium bromide (EB) and group IV rats were injected with 0.1% EB and treated with chlorogenic acid (EB + AC). The activities of the enzymes were analyzed using colorimetric methods, and the gene expression of NTPDase 1, 2 and 3 were analyzed using the polymerase chain reaction (PCR). The results revealed that there was a significant (P < 0.01) reduction in E-NPP activity in EB group (1.63 ± 0.10 nmol p-nitrophenol released/min/mg protein) when compared to CT group (2.33 ± 0.14 nmol p-nitrophenol released/min/mg protein). However, treatment with chlorogenic acid significantly (P < 0.05) increased E-NPP activity in EB group. Furthermore, no significant (P > 0.05) change was observed in the E-NPP activity of EB + AC group (2.19 ± 0.08 nmol p-nitrophenol released/min/mg protein) when compared to CT group (2.33 ± 0.14 nmol p-nitrophenol released/min/mg protein). In addition, there was a significant (P < 0.05) increase in AMP hydrolysis in EB rat group when compared to CT group. No significant (P > 0.05) difference was observed in AMP hydrolysis between AC, AC + EB and CT groups. Conversely, there were no significant (P > 0.05) differences in ATP and ADP hydrolyses between all the groups (AC, EB, AC + EB and CT groups). Likewise, there were no significant (P > 0.05) changes in E-ADA activity and percentage platelet aggregation among all groups studied. Similarly, no significant (P > 0.05) change was observed in the expression of E-NTPDase 1, 2 and 3 in all the groups tested. Our study revealed that chlorogenic acid may modulate the hydrolysis of adenine nucleotides in platelets of rats demyelinated and treated with chlorogenic acid via alteration of E-NPP and ecto-5′-nucleotidase activities.