OPEN Foundation

Day: 12 July 2017

Neuropathic and inflammatory antinociceptive effects and electrocortical changes produced by Salvia divinorum in rats

July 12, 2017 / Medicine, Neuroscience, Other subjects, Papers, Salvia / Salvinorin A / By / , , , , , ,

Abstract

Ethnopharmacological relevance

Salvia divinorum is a medicinal plant traditionally used in hallucinogenic ethnopharmacological practices and for its analgesic and antinflammatory properties. Its active compounds include diterpenes known as salvinorins which act as potent κ opioid receptor agonists.

Aim of the study

Given its effects in acute animal models of pain, as well as its antinflammatory attributes, we decided to investigate the analgesic effects of an SD extract in neuropathic (sciatic loose nerve ligature) and inflammatory (intra plantar carrageenan) pain models in rats. We also determined in this study the electrocorticographic changes to correlate similar hallucinogenic state and behavior as those produced in humans.

Material and methods

Mechanical and thermonociceptive responses, plantar test and von Frey assay, respectively, were measured in adult Wistar rats 30 min, 3 h and 24 h after the intraperitoneal administration of saline or an hydroponic SD extract. We also evaluated carbamazepine and celecoxib, as gold reference drugs, to compare its antinociceptive effects.

Results

Our results showed that administration of SD extract induced antialgesic effects in both neuropathic and inflammatory pain models. All those effects were blocked by nor-binaltorphimine (a Kappa opioid receptor antagonist). Moreover, it was observed an increase of the anterior power spectral density and a decrease in the posterior region as electrocorticographic changes.

Conclusion

The present investigation give evidence that SD is capable to reduce algesic response associated to neuropathic and inflammatory nociception. This study support therapeutic alternatives for a disabling health problem due to the long term pain with high impact on population and personal and social implications.

Simón-Arceo, K., González-Trujano, M. E., Coffeen, U., Fernández-Mas, R., Mercado, F., Almanza, A., … & Pellicer, F. (2017). Neuropathic and inflammatory antinociceptive effects and electrocortical changes produced by Salvia divinorum in rats. Journal of Ethnopharmacology, 206, 115-124. 10.1016/j.jep.2017.05.016
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Two dose investigation of the 5-HT-agonist psilocybin on relative and global cerebral blood flow

July 12, 2017 / Mushrooms / Psilocybin, Neuroscience, Other subjects, Papers, Psychopharmacology / By / , , , , ,

Abstract

Psilocybin, the active compound in psychedelic mushrooms, is an agonist of various serotonin receptors. Seminal psilocybin positron emission tomography (PET) research suggested regional increases in glucose metabolism in frontal cortex (hyperfrontality). However, a recent arterial spin labeling (ASL) study suggests psilocybin may lead to hypo-perfusion in various brain regions. In this placebo-controlled, double-blind study we used pseudo-continuous ASL (pCASL) to measure perfusion changes, with and without adjustment for global brain perfusion, after two doses of oral psilocybin (low dose: 0.160 mg/kg; high dose: 0.215 mg/kg) in two groups of healthy controls (n = 29 in both groups, total N = 58) during rest. We controlled for sex and age and used family-wise error corrected p values in all neuroimaging analyses. Both dose groups reported profound subjective drug effects as measured by the Altered States of Consciousness Rating Scale (5D-ASC) with the high dose inducing significantly larger effects in four out of the 11 scales. After adjusting for global brain perfusion, psilocybin increased relative perfusion in distinct right hemispheric frontal and temporal regions and bilaterally in the anterior insula and decreased perfusion in left hemispheric parietal and temporal cortices and left subcortical regions. Whereas, psilocybin significantly reduced absolute perfusion in frontal, temporal, parietal, and occipital lobes, and bilateral amygdalae, anterior cingulate, insula, striatal regions, and hippocampi. Our analyses demonstrate consistency with both the hyperfrontal hypothesis of psilocybin and the more recent study demonstrating decreased perfusion, depending on analysis method. Importantly, our data illustrate that relative changes in perfusion should be understood and interpreted in relation to absolute signal variations.
Lewis, C. R., Preller, K. H., Kraehenmann, R., Michels, L., Stämpfli, P., & Vollenweider, F. X. (2017). Two dose investigation of the 5-HT-agonist psilocybin on relative and global cerebral blood flow. NeuroImage. 10.1016/j.neuroimage.2017.07.020
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30 April - Q&A with Rick Strassman

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