The effect of protocatechuic acid on neuropathic pain and possible mechanism

The goal of the research is to investigate the protocatechuic acid (PCA) potential action, a phenolic acid derivative, on pain induced by neuropathy and to determine its efficacy on activation of K_ATP type channels and A₁ receptors.

Neuropathic pain by cause of sciatic nerve damage was induced in Sprague-Dawley rats. Anti-allodynic and anti-hyperalgesic effects were evaluated with von Frey apparatus and Hargreave's plantar test apparatus, respectively. The effects of PCA at the doses of 75, 150 and 300 mg/kg, carbamazepine at the doses of 50 and 100 mg/kg, combination of low effective doses of PCA and carbamazepine were tested. Pretreatments 3 μg/kg DPCPX as adenosine A₁ receptor antagonist and 60.7 nmol glibenclamide as K_ATP channel blocker were applied for mechanistic studies.

PCA showed anti-allodynic and anti-hyperalgesic effects without impairing locomotor activity. In addition, the combination treatment was found to be more effective than the separate individual treatments of drugs. K_ATP channel activation related with A₁ receptor stimulation makes a significant contribution to the anti-allodynia and anti-hyperalgesia induced by PCA.

It can be said that PCA has similar effects with carbamazepine, which is used in clinical practice, and that PCA can take place as an adjuvant drug in neuropathic pain with the combination group. In addition, it is seen that the undesirable effects that drugs can cause alone can be avoided and a more effective treatment potential can be created with multiple mechanisms.