Evidence for the involvement of opioid and cannabinoid systems in the peripheral antinociception mediated by resveratrol.

Despite all the development of modern medicine, around 100 compounds derived from natural products were undergoing clinical trials only at the end of 2013. Among these natural substances in clinical trials, we found the resveratrol (RES), a pharmacological multi-target drug. RES analgesic properties have been demonstrated, although the bases of these mechanisms have not been fully elucidated. The aim of this study was to evaluate the involvement of opioid and cannabinoid systems in RES-induced peripheral antinociception. Paw withdrawal method was used and hyperalgesia was induced by carrageenan (200 µg/paw). All drugs were given by intraplantar injection in male Swiss mice (n = 5). RES (100 µg/paw) administered in the right hind paw induced local antinociception that was antagonized by naloxone, non-selective opioid receptor antagonist, and clocinnamox, µOR selective antagonist. Naltrindole and nor-binaltorfimine, selective antagonists for δOR and kOR, respectively, did not reverse RES-induced peripheral antinociception. CB1R antagonist AM251, but not CB2R antagonist AM630, antagonized RES-induced peripheral antinociception. Peripheral antinociception of RES intermediate-dose (50 µg/paw) was increased by: (i) bestatin, inhibitor of endogenous opioid degradation involved-enzymes; (ii) MAFP, inhibitor of anandamide amidase; (iii) JZL184, inhibitor of 2-arachidonoylglycerol degradation involved-enzyme; (iv) VDM11, endocannabinoid reuptake inhibitor. Acute and peripheral administration of RES failed to affect the amount of µOR, CB1R and CB2R. Experimental data suggest that RES induces peripheral antinociception through µOR and CB1R activation by endogenous opioid and endocannabinoid releasing.

Serca2a and Na(+)/Ca(2+) exchanger are involved in left ventricular function following cardiac remodelling of female rats treated with anabolic androgenic steroid.

UNLABELLED: Anabolic-androgenic steroids are misused, including by women, but little is known about the cardiovascular effects of these drugs on women. AIM: To evaluated the effects of nandrolone decanoate (ND) and resistive physical exercise on cardiac contractility in young female rats. MAIN METHODS: Female Wistar rats were separated into 4 groups: C (untrained animals); E (animals were submitted to resistance exercise by jumping in water 5 times per week); ND (animals were treated with ND, 20mg/kg/week for 4weeks); and NDE (trained and treated). The haemodynamic parameters (+dP/dtmax, -dP/dtmin and Tau) were assessed in the left ventricle. The heart was collected for histological analyses and collagen deposition. The gastrocnemius muscle was weighed, and hypertrophy was assessed by the ratio of their weights to gastrocnemius/tibia length. The expression of calcium handling proteins was measured by western blot analysis. RESULTS: ND treatment and physical exercise increased cardiac contractility and relaxation. In addition, ND promoted increases in phospholamban phosphorylated (p-PLB) and isoforms of sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2a) expression, while resistance exercise increased the phosphorylation of PLB and expression of Na(+)/Ca(2+) exchangers (NCX). Cardiac hypertrophy and collagen deposition were observed after ND treatment. CONCLUSION: Regulatory components of cytosolic calcium, such as SERCA2a and p-PLB, play important roles in modulating the contractility and relaxation effects of ND in females.