Post-treatment with maropitant reduces oxidative stress, endoplasmic reticulum stress and neuroinflammation on peripheral nerve injury in rats

Objective To determine the effective dose and therapeutic potential of maropitant using through expression of mediators of oxidative stress, inflammatory and of the unfolded protein response (UPR) (bio) markers on spinal cord using a model of neuropathic pain induced through chronic constriction injury (CCI) in rats.Study design Randomized, blinded, prospective experimental study.Animals 98 male Wistar rats.Methods Rats were anesthetized with sevoflurane and after CCI, they were randomly assigned to the following groups that received: vehicle, 3, 6, 15, 30 e 50 mg/kg/24q of maropitant. The effect on inflammatory mediators (IL10, TNF alpha), oxidative stress (GPx, CAT, SOD), microglial (IBA-1) and neuronal (NeuN, TACR1) markers was evaluated though immunohistochemistry and expression levels of markers of hypoxia (HIF1 alpha, Nrf2), antioxidant enzymes (Catalse, Sod1 and GPx1), and endoplasmic reticulum stress mediators (GRP78, CHOP and PERK) through qRT-PCR.Results Intraperitoneal injection (IP) of maropitant inhibited nociception with ID50 values of 4,1 mg/kg (5,85-19,36) in a neuropathic pain model through CCI. A dose of 30 mg/kg/24q was significantly effective in reducing mechanical allodynia 1 to 4h after treatment with nociception inhibition (145,83%). A reduction in the expression of hypoxia factors (HIF1 alpha, Nrf2) was observed, along with an increase in antioxidant activity (CAT, SOD and GPX). Additionally, there was a reduction in inflammatory markes (IL10, TNF alpha), microglial (IBA-1), and neuronal markers (NeuN, TACR1).Conclusion and clinical relevance These findings demonstrate that the determined dose, administered daily for seven days, had an antinociceptive effect, as well as anti-inflammatory and antioxidant activity.