The hallucinogenic herb Salvia divinorum and its active ingredient salvinorin A reduce inflammation-induced hypermotility in mice

Cannabidiol versus placebo as adjunctive treatment in early psychosis: study protocol for randomized controlled trial

BACKGROUND

Psychotic disorders are a leading cause of disability in young adults. Antipsychotics have been the primary intervention for psychosis for over 60 years, and yet, we have made little progress in treating negative symptoms, neurocognition, and functional disability. There is growing evidence that cannabidiol (CBD) is effective in treating positive psychotic symptoms, possibly also negative and neurocognitive symptoms, and moreover is well tolerated compared to other psychotropic medications. Anecdotally, patients participating in the Cognitive Assessment and Risk Evaluation (CARE) Early Psychosis Treatment Program at the University of California, San Diego, are self-administering CBD and report subjective improvement in stress, anxiety, and ability to cope with symptoms. The overarching aim of the trial is to explore the effectiveness of CBD augmentation on symptoms and neurocognition in early psychosis while also exploring the mechanism of action of CBD and predictors of response to treatment. The mechanism by which cannabidiol has a therapeutic effect on psychosis is poorly understood. Recent evidence has suggested that CBD may reduce stress and pro-inflammatory biomarker levels. Endocannabinoids also have powerful roles in eating behavior, reward, and mood, indicating these neurotransmitters may play a role in reducing hyperphagia and metabolic abnormalities that are present early in the course of psychotic illness and exacerbated by antipsychotic medication. The neurophysiological effects of CBD have been studied in animal models of psychosis that show improvements in information processing in response to CBD, but there are no studies in individuals with early psychosis.

METHOD

A total of 120 individuals in the early stages of psychosis will be randomized to 1000 mg of CBD versus placebo as an adjunct to existing treatment in a 8-week, double-blind superiority randomized control trial. The primary outcome measures are symptoms and neurocognition.

DISCUSSION

We hypothesized that CBD will improve symptoms and neurocognition as well as secondary outcome measures of neurohormones, inflammation, eating behaviors, and information processing. Importantly, predictors, moderators, and mediators of the CBD effects will be examined. A better understanding of which individuals are likely to respond to CBD can inform treatment planning and personalize treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04411225. Registered on June 2, 2020.

Pharmacokinetics and Pharmacodynamics of Salvinorin A and Salvia divinorum: Clinical and Forensic Aspects

Salvia divinorum Epling and Játiva is a perennial mint from the Lamiaceae family, endemic to Mexico, predominantly from the state of Oaxaca. Due to its psychoactive properties, S. divinorum had been used for centuries by Mazatecans for divinatory, religious, and medicinal purposes. In recent years, its use for recreational purposes, especially among adolescents and young adults, has progressively increased. The main bioactive compound underlying the hallucinogenic effects, salvinorin A, is a non-nitrogenous diterpenoid with high affinity and selectivity for the κ-opioid receptor. The aim of this work is to comprehensively review and discuss the toxicokinetics and toxicodynamics of S. divinorum and salvinorin A, highlighting their psychological, physiological, and toxic effects. Potential therapeutic applications and forensic aspects are also covered in this review. The leaves of S. divinorum can be chewed, drunk as an infusion, smoked, or vaporised. Absorption of salvinorin A occurs through the oral mucosa or the respiratory tract, being rapidly broken down in the gastrointestinal system to its major inactive metabolite, salvinorin B, when swallowed. Salvinorin A is rapidly distributed, with accumulation in the brain, and quickly eliminated. Its pharmacokinetic parameters parallel well with the short-lived psychoactive and physiological effects. No reports on toxicity or serious adverse outcomes were found. A variety of therapeutic applications have been proposed for S. divinorum which includes the treatment of chronic pain, gastrointestinal and mood disorders, neurological diseases, and treatment of drug dependence. Notwithstanding, there is still limited knowledge regarding the pharmacology and toxicology features of S. divinorum and salvinorin A, and this is needed due to its widespread use. Additionally, the clinical acceptance of salvinorin A has been hampered, especially due to the psychotropic side effects and misuse, turning the scientific community to the development of analogues with better pharmacological profiles.

DARK Classics in Chemical Neuroscience: Salvinorin A

Salvinorin A is the main bioactive compound in Salvia divinorum, an endemic plant with ancestral use by the inhabitants of the Mazateca mountain range (Sierra Mazateca) in Oaxaca, México. The main use of la pastora, as locally known, is in spiritual rites due to its extraordinary hallucinogenic effects. Being the first known nonalkaloidal opioid-mediated psychotropic molecule, salvinorin A set new research areas in neuroscience. The absence of a protonated amine group, common to all previously known opioids, results in a fast metabolism with the concomitant fast elimination and swift loss of activity. The worldwide spread and psychotropic effects of salvinorin A account for its misuse and classification as a drug of abuse. Consequently, salvinorin A and Salvia divinorum are now banned in many countries. Several synthetic efforts have been focused on the improvement of physicochemical and biological properties of salvinorin A: from total synthesis to hundreds of analogues. In this Review, we discuss the impact of salvinorin A in chemistry and neuroscience covering the historical relevance, isolation from natural sources, synthetic efforts, and pharmacological and safety profiles. Altogether, the chemistry behind and the taboo that encloses salvinorin A makes it one of the most exquisite naturally occurring drugs.

Salvia divinorum: from recreational hallucinogenic use to analgesic and anti-inflammatory action

Salvia divinorum is a herbal plant native to the southwest region of Mexico. Traditional preparations of this plant have been used in illness treatments that converge with inflammatory conditions and pain. Currently, S. divinorum extracts have become popular in several countries as a recreational drug due to its hallucinogenic effects. Its main active component is a diterpene named salvinorin A (SA), a potent naturally occurring hallucinogen with a great affinity to the κ opioid receptors and with allosteric modulation of cannabinoid type 1 receptors. Recent biochemical research has revealed the mechanism of action of the anti-inflammatory and analgesic effect of SA at the cellular and molecular level. Nevertheless, because of their short-lasting and hallucinogenic effect, the research has focused on discovering a new analogue of SA that is able to induce analgesia and reduce inflammation with a long-lasting effect but without the hallucinatory component. In this review, we explore the role of S. divinorum, SA and its analogues. We focus mainly on their analgesic and anti-inflammatory roles but also mention their psychoactive properties.

The Role of κ Opioid Receptor in Brain Ischemia

OBJECTIVES

Our previous studies indicated that highly selective κ opioid receptor agonists could protect the brain, indicating an important role of κ opioid receptor agonist in brain ischemia. In this study, we investigated the role and related mechanisms of κ opioid receptor agonists in brain ischemia in a middle cerebral artery occlusion mouse model.

DESIGN

Animal model.

SETTING

Laboratory.

SUBJECTS

The middle cerebral artery occlusion model was established by 120 minutes of ischemia followed by 24-hour reperfusion in male adult mice.

INTERVENTIONS

Various doses of salvinorin A, a highly selective and potent κ opioid receptor agonist, were administered intranasally 10 minutes after initiation of reperfusion. Norbinaltorphimine (2.5 mg/kg, IP) as a κ opioid receptor antagonist was administered in one group before administration of salvinorin A (50μg/kg) to investigate the specific role of κ opioid receptor.

MEASUREMENTS AND MAIN RESULTS

Infarct volume, κ opioid receptor expression, and Evans blue extravasation in the brain, and neurobehavioral outcome were determined. Immunohistochemistry and western blot were performed to detect the activated caspase-3, interleukin-10, and tumor necrosis factor-α levels to investigate the role of apoptosis and inflammation. κ opioid receptor expression was elevated significantly in the ischemic penumbral area compared with that in the nonischemic area. Salvinorin A reduced infarct volume and improved neurologic deficits dose-dependently. Salvinorin A at the dose of 50 μg/kg reduced Evans blue extravasation, suggesting reduced impairment of the blood-brain barrier and decreased the expression of cleaved caspase-3, interleukin-10, and tumor necrosis factor-α in the penumbral areas. All these changes were blocked or alleviated by norbinaltorphimine.

CONCLUSIONS

κ opioid receptors were up-regulated and played a critical role in brain ischemia and reperfusion. κ opioid receptor activation could potentially protect the brain and improve neurologic outcome via blood-brain barrier protection, apoptosis reduction, and inflammation inhibition.

Pathophysiology of functional heartburn based on Rome III criteria in Japanese patients

AIM: To investigate the pathophysiology of functional heartburn (FH) in Japanese patients.

METHODS: A total of 111 patients with proton pump inhibitor (PPI)-refractory non-erosive gastroesophageal reflux disease underwent intraesophageal pressure testing and 24-h multichannel intraluminal impedance-pH (24MII-pH) testing. The patients also completed several questionnaires while they were receiving the PPI treatment, including the questionnaire for the diagnosis of reflux disease (QUEST), the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), the gastrointestinal symptoms rating scale (GSRS), SF-36, and the Cornell Medical Index (CMI). The subjects were classified into FH and endoscopy-negative reflux disease (ENRD) groups based on the Rome III criteria.

RESULTS: Thirty-three patients with esophageal motility disorder were excluded from this study, while 22 patients with abnormal esophageal acid exposure time (pH-POS) and 34 with hypersensitive esophagus (HE) were included in the ENRD group. The FH group included 22 patients with no reflux involvement. Sex, age, and body mass index did not differ significantly between the groups. The mean SF-36 values were < 50 (normal) for all scales in these groups, with no significant differences. The GSRS scores in these groups were not different and showed overlap with other gastrointestinal symptoms. The QUEST and the FSSG scores did not differ significantly between the groups. Neuroticism was diagnosed using the CMI questionnaire in 17 of the 78 included subjects within the pH-POS (n = 4), HE (n = 8), and FH (n = 5) groups, with no significant differences.

CONCLUSION: Clinical characteristics of the FH and PPI-refractory ENRD groups were similar. Therefore, esophageal function should be examined via manometry and 24MII-pH testing to differentiate between them.

Anti-Inflammatory and Antihyperalgesic Activities of Ethanolic Extract and Fruticulin A from Salvia lachnostachys Leaves in Mice

The anti-inflammatory and analgesic effects of the ethanolic extract (SLEE) and fruticulin A from the leaves of Salvia lachnostachys were evaluated in mice, using experimental models of inflammation (paw oedema and pleurisy induced by carrageenan injection) and hyperalgesia (electronic Von Frey). Oral administration of SLEE (30, 100, and 300 mg/kg) and fruticulin A (0.3 and 3.0 mg/kg) decreased the total leucocytes number in pleural lavage, protein extravasation, and paw oedema. SLEE (100 mg/kg) and fruticulin A (3 mg/kg) also exhibited antihyperalgesic activity in carrageenan induced mechanical hyperalgesia. In addition, fruticulin A (3 mg/kg) prevented mechanical hyperalgesia, inhibiting TNF but not L-DOPA-induced mechanical hyperalgesia. In conclusion, SLEE and fruticulin A display anti-inflammatory and analgesic properties. Therefore, fruticulin A is at least partially responsible for the activity observed in the ethanolic extract of Salvia lachnostachys.

Salvinorin A reduces mechanical allodynia and spinal neuronal hyperexcitability induced by peripheral formalin injection

Background

Salvinorin A (SA), the main active component of Salvia Divinorum, is a non-nitrogenous kappa opioid receptor (KOR) agonist. It has been shown to reduce acute pain and to exert potent antinflammatory effects. This study assesses the effects and the mode of action of SA on formalin-induced persistent pain in mice. Specifically, the SA effects on long-term behavioural dysfuctions and changes in neuronal activity occurring at spinal level, after single peripheral formalin injection, have been investigated. Moreover, the involvement of microglial and glial cells in formalin-induced chronic pain condition and in SA-mediated effects has been evaluated.

Results

Formalin induced a significant decrease of mechanical withdrawal threshold at the injected and contralateral paw as well as an increase in the duration and frequency, and a rapid decrease in the onset of evoked activity of the nociceptive neurons 7 days after formalin injection. SA daily treatment significantly reduced mechanical allodynia in KOR and cannabinoid receptor 1 (CB1R) sensitive manner. SA treatment also normalized the spinal evoked activity. SA significantly reduced the formalin-mediated microglia and astrocytes activation and modulated pro and anti-inflammatory mediators in the spinal cord.

Conclusion

SA is effective in reducing formalin-induced mechanical allodynia and spinal neuronal hyperactivity. Our findings suggest that SA reduces glial activation and contributes in the establishment of dysfunctions associated with chronic pain with mechanisms involving KOR and CB1R. SA may provide a new lead compound for developing anti-allodynic agents via KOR and CB1R activation.

Inhibitory effect of salvinorin A, from Salvia divinorum, on ileitis-induced hypermotility: cross-talk between kappa-opioid and cannabinoid CB(1) receptors

BACKGROUND AND PURPOSE

Salvinorin A, the active component of the hallucinogenic herb Salvia divinorum, inhibits intestinal motility through activation of kappa-opioid receptors (KORs). However, this compound may have target(s) other than the KORs in the inflamed gut. Because intestinal inflammation upregulates cannabinoid receptors and endogenous cannabinoids, in the present study we investigated the possible involvement of the endogenous cannabinoid system in salvinorin A-induced delay in motility in the inflamed gut.

EXPERIMENTAL APPROACH

Motility in vivo was measured by evaluating the distribution of a fluorescent marker along the small intestine; intestinal inflammation was induced by the irritant croton oil; direct or indirect activity at cannabinoid receptors was evaluated by means of binding, enzymic and cellular uptake assays.

KEY RESULTS

Salvinorin A as well as the KOR agonist U-50488 reduced motility in croton oil treated mice. The inhibitory effect of both salvinorin A and U-50488 was counteracted by the KOR antagonist nor-binaltorphimine and by the cannabinoid CB(1) receptor antagonist rimonabant. Rimonabant, however, did not counteract the inhibitory effect of salvinorin A on motility in control mice. Binding experiments showed very weak affinity of salvinorin A for cannabinoid CB(1) and CB(2) and no inhibitory effect on 2-arachidonoylglycerol and anandamide hydrolysis and cellular uptake.

CONCLUSIONS AND IMPLICATIONS

The inhibitory effect of salvinorin A on motility reveals a functional interaction between cannabinoid CB(1) receptors and KORs in the inflamed--but not in the normal--gut in vivo.

Cannabidiol, extracted from Cannabis sativa, selectively inhibits inflammatory hypermotility in mice

BACKGROUND AND PURPOSE

Cannabidiol is a Cannabis-derived non-psychotropic compound that exerts a plethora of pharmacological actions, including anti-inflammatory, neuroprotective and antitumour effects, with potential therapeutic interest. However, the actions of cannabidiol in the digestive tract are largely unexplored. In the present study, we investigated the effect of cannabidiol on intestinal motility in normal (control) mice and in mice with intestinal inflammation.

EXPERIMENTAL APPROACH

Motility in vivo was measured by evaluating the distribution of an orally administered fluorescent marker along the small intestine; intestinal inflammation was induced by the irritant croton oil; contractility in vitro was evaluated by stimulating the isolated ileum, in an organ bath, with ACh.

KEY RESULTS

In vivo, cannabidiol did not affect motility in control mice, but normalized croton oil-induced hypermotility. The inhibitory effect of cannabidiol was counteracted by the cannabinoid CB1 receptor antagonist rimonabant, but not by the cannabinoid CB2 receptor antagonist SR144528 (N-[-1S-endo-1,3,3-trimethyl bicyclo [2.2.1] heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide), by the opioid receptor antagonist naloxone or by the alpha2-adrenergic antagonist yohimbine. Cannabidiol did not reduce motility in animals treated with the fatty acid amide hydrolase (FAAH) inhibitor N-arachidonoyl-5-hydroxytryptamine, whereas loperamide was still effective. In vitro, cannabidiol inhibited ACh-induced contractions in the isolated ileum from both control and croton oil-treated mice.

CONCLUSIONS AND IMPLICATIONS

Cannabidiol selectively reduces croton oil-induced hypermotility in mice in vivo and this effect involves cannabinoid CB1 receptors and FAAH. In view of its low toxicity in humans, cannabidiol may represent a good candidate to normalize motility in patients with inflammatory bowel disease.