Metabolic side effects induced by olanzapine treatment are neutralized by CB1 receptor antagonist compounds co-administration in female rats

Changes in hypothalamic mu-opioid receptor expression following acute olanzapine treatment in female rats: Implications for feeding behavior

Advances have been made in recent years in using opioid receptor antagonists as an adjunct therapy to psychotropic medication to reduce debilitating weight gain and metabolic adverse effects associated with in particular second generation antipsychotics. However, it is unknown whether second generation antipsychotics produce a change in opioid receptor expression in the brain. The present study investigated early changes in opioid receptor expression in the female rat hypothalamus, a master controller of hunger and metabolic regulation, after acute treatment with olanzapine, a commonly used second generation antipsychotic. Using quantitative spatial in situ hybridization and receptor autoradiography, expression levels of the three opioid receptors; kappa, mu and delta, were determined at mRNA and protein level, respectively, in the five hypothalamic areas: paraventricular nucleus, arcuate nucleus, ventromedial nucleus, dorsomedial nucleus and lateral hypothalamus. After 48 h of olanzapine treatment at clinically relevant plasma concentration weight gain and food intake changes, and increased plasma glucose were observed in female rats. Olanzapine treatment also led to a significant increase in mu opioid receptor availability in the arcuate nucleus, which contains both satiety and hunger controlling neurons. No other areas showed any opioid receptor expressional changes with olanzapine treatment on neither at mRNA nor protein level. Technical difficulties made it impossible to analyze mRNA levels in the lateral hypothalamus and overall binding of delta opioid receptors. Thus, the present study provided insights in to how olanzapine at clinically relevant plasma levels already at an early stage modulated the opioid system in the hypothalamus.

The role of hypothalamic endoplasmic reticulum stress in schizophrenia and antipsychotic-induced weight gain: A narrative review

Schizophrenia (SCZ) is a serious mental illness that affects 1% of people worldwide. SCZ is associated with a higher risk of developing metabolic disorders such as obesity. Antipsychotics are the main treatment for SCZ, but their side effects include significant weight gain/obesity. Despite extensive research, the underlying mechanisms by which SCZ and antipsychotic treatment induce weight gain/obesity remain unclear. Hypothalamic endoplasmic reticulum (ER) stress is one of the most important pathways that modulates inflammation, neuronal function, and energy balance. This review aimed to investigate the role of hypothalamic ER stress in SCZ and antipsychotic-induced weight gain/obesity. Preliminary evidence indicates that SCZ is associated with reduced dopamine D2 receptor (DRD2) signaling, which significantly regulates the ER stress pathway, suggesting the importance of ER stress in SCZ and its related metabolic disorders. Antipsychotics such as olanzapine activate ER stress in hypothalamic neurons. These effects may induce decreased proopiomelanocortin (POMC) processing, increased neuropeptide Y (NPY) and agouti-related protein (AgRP) expression, autophagy, and leptin and insulin resistance, resulting in hyperphagia, decreased energy expenditure, and central inflammation, thereby causing weight gain. By activating ER stress, antipsychotics such as olanzapine activate hypothalamic astrocytes and Toll-like receptor 4 signaling, thereby causing inflammation and weight gain/obesity. Moreover, evidence suggests that antipsychotic-induced ER stress may be related to their antagonistic effects on neurotransmitter receptors such as DRD2 and the histamine H1 receptor. Taken together, ER stress inhibitors could be a potential effective intervention against SCZ and antipsychotic-induced weight gain and inflammation.

Gold nanoclusters eliminate obesity induced by antipsychotics

Obesity induced by antipsychotics have plagued more than 20 million people worldwide. However, no drug is available to eliminate the obesity induced by antipsychotics. Here we examined the effect and potential mechanisms of a gold nanoclusters (AuNCs) modified by N-isobutyryl-L-cysteine on the obesity induced by olanzapine, the most prescribed but obesogenic antipsychotics, in a rat model. Our results showed that AuNCs completely prevented and reversed the obesity induced by olanzapine and improved glucose metabolism profile in rats. Further mechanism investigations revealed that AuNCs exert its anti-obesity function through inhibition of olanzapine-induced dysfunction of histamine H1 receptor and proopiomelanocortin signaling therefore reducing hyperphagia, and reversing olanzapine-induced inhibition of uncoupling-protein-1 signaling which increases thermogenesis. Together with AuNCs' good biocompatibility, these findings not only provide AuNCs as a promising nanodrug candidate for treating obesity induced by antipsychotics, but also open an avenue for the potential application of AuNCs-based nanodrugs in treating general obesity.

Understanding the Effects of Antipsychotics on Appetite Control

Antipsychotic drugs (APDs) represent a cornerstone in the treatment of schizophrenia and other psychoses. The effectiveness of the first generation (typical) APDs are hampered by so-called extrapyramidal side effects, and they have gradually been replaced by second (atypical) and third-generation APDs, with less extrapyramidal side effects and, in some cases, improved efficacy. However, the use of many of the current APDs has been limited due to their propensity to stimulate appetite, weight gain, and increased risk for developing type 2 diabetes and cardiovascular disease in this patient group. The mechanisms behind the appetite-stimulating effects of the various APDs are not fully elucidated, partly because their diverse receptor binding profiles may affect different downstream pathways. It is critical to identify the molecular mechanisms underlying drug-induced hyperphagia, both because this may lead to the development of new APDs, with lower appetite-stimulating effects but also because such insight may provide new knowledge about appetite regulation in general. Hence, in this review, we discuss the receptor binding profile of various APDs in relation to the potential mechanisms by which they affect appetite.

Role of cannabinoids in various diseases: A review

BACKGROUND

The plant, Cannabis sativa is heavily explored and researched with many industrial and pharmaceutical applications. The medicinal and therapeutic role of cannabis Sativa has been summarized in the paper, citing its mechanism of action and influence on the human body. Diseases like metabolic disorders, infectious diseases, and psychological disorders pose negative and long-term drastic effects on the body like neurodegeneration and other chronic system failures. Several existing literature has proved its effectiveness against such diseases.

OBJECTIVES

This review aims to provide an overview of the role of cannabinoids in various diseases like metabolic disorders, infectious diseases, and psychological disorders.

METHOD

Various e-resources like Pubmed, Science Direct, and Google Scholar were thoroughly searched and read to form a well-informed and information-heavy manuscript. Here we tried to summaries the therapeutic aspect of Cannabis sativa and its bioactive compound cannabinoids in various diseases.

RESULT

This review highlights the various constituents which are present in Cannabis sativa, the Endocannabinoid system, and the role of cannabinoids in various diseases Conclusion: Recent research on Cannabis has suggested its role in neurodegenerative diseases, inflammation, sleep disorders, pediatric diseases, and their analgesic nature. Therefore, the authors majorly focus on the therapeutic aspect of Cannabis sativa in various diseases. The focus is also on the endocannabinoid system (ECS) and its role in fighting or preventing bacterial, parasitic, fungal, and viral infections.

Assessment of the Effects of Dietary Vitamin D Levels on Olanzapine-Induced Metabolic Side Effects: Focus on the Endocannabinoidome-Gut Microbiome Axis

Vitamin D deficiency is associated with poor mental health and dysmetabolism. Several metabolic abnormalities are associated with psychotic diseases, which can be compounded by atypical antipsychotics that induce weight gain and insulin resistance. These side-effects may be affected by vitamin D levels. The gut microbiota and endocannabinoidome (eCBome) are significant regulators of both metabolism and mental health, but their role in the development of atypical antipsychotic drug metabolic side-effects and their interaction with vitamin D status is unknown. We studied the effects of different combinations of vitamin D levels and atypical antipsychotic drug (olanzapine) exposure on whole-body metabolism and the eCBome-gut microbiota axis in female C57BL/6J mice under a high fat/high sucrose (HFHS) diet in an attempt to identify a link between the latter and the different metabolic outputs induced by the treatments. Olanzapine exerted a protective effect against diet-induced obesity and insulin resistance, largely independent of dietary vitamin D status. These changes were concomitant with olanzapine-mediated decreases in Trpv1 expression and increases in the levels of its agonists, including various N-acylethanolamines and 2-monoacylglycerols, which are consistent with the observed improvement in adiposity and metabolic status. Furthermore, while global gut bacteria community architecture was not altered by olanzapine, we identified changes in the relative abundances of various commensal bacterial families. Taken together, changes of eCBome and gut microbiota families under our experimental conditions might contribute to olanzapine and vitamin D-mediated inhibition of weight gain in mice on a HFHS diet.

Obesity as a Condition Determined by Food Addiction: Should Brain Endocannabinoid System Alterations Be the Cause and Its Modulation the Solution?

Obesity is a complex disorder, and the number of people affected is growing every day. In recent years, research has confirmed the hypothesis that food addiction is a determining factor in obesity. Food addiction is a behavioral disorder characterized by disruptions in the reward system in response to hedonic eating. The endocannabinoid system (ECS) plays an important role in the central and peripheral control of food intake and reward-related behaviors. Moreover, both obesity and food addiction have been linked to impairments in the ECS function in various brain regions integrating peripheral metabolic signals and modulating appetite. For these reasons, targeting the ECS could be a valid pharmacological therapy for these pathologies. However, targeting the cannabinoid receptors with inverse agonists failed when used in clinical contexts as a consequence of the induction of affective disorders. In this context, new classes of drugs acting either on CB1 and/or CB2 receptors or on synthetic and degradation enzymes of endogenous cannabinoids are being studied. However, further investigation is necessary to find safe and effective treatments that can exert anti-obesity effects, normalizing reward-related behaviors without causing important adverse mood effects.

Tricyclic Pyrazole-Based Compounds as Useful Scaffolds for Cannabinoid CB1/CB2 Receptor Interaction

Cannabinoids comprise different classes of compounds, which aroused interest in recent years because of their several pharmacological properties. Such properties include analgesic activity, bodyweight reduction, the antiemetic effect, the reduction of intraocular pressure and many others, which appear correlated to the affinity of cannabinoids towards CB₁ and/or CB₂ receptors. Within the search aiming to identify novel chemical scaffolds for cannabinoid receptor interaction, the CB₁ antagonist/inverse agonist pyrazole-based derivative rimonabant has been modified, giving rise to several tricyclic pyrazole-based compounds, most of which endowed of high affinity and selectivity for CB₁ or CB₂ receptors. The aim of this review is to present the synthesis and summarize the SAR study of such tricyclic pyrazole-based compounds, evidencing, for some derivatives, their potential in the treatment of neuropathic pain, obesity or in the management of glaucoma.

Critical Review on the Chemical Aspects of Cannabidiol (CBD) and Harmonization of Computational Bioactivity Data

Cannabidiol (CBD) is a non-psychotropic phytocannabinoid which represents one of the constituents of the "phytocomplex" of Cannabis sativa. This natural compound is attracting growing interest since when CBD-based remedies and commercial products were marketed. This review aims to exhaustively address the extractive and analytical approaches that have been developed for the isolation and quantification of CBD. Recent updates on cutting-edge technologies were critically examined in terms of yield, sensitivity, flexibility and performances in general, and are reviewed alongside original representative results. As an add-on to currently available contributions in the literature, the evolution of the novel, efficient synthetic approaches for the preparation of CBD, a procedure which is appealing for the pharmaceutical industry, is also discussed. Moreover, with the increasing interest on the therapeutic potential of CBD and the limited understanding of the undergoing biochemical pathways, the reader will be updated about recent in silico studies on the molecular interactions of CBD towards several different targets attempting to fill this gap. Computational data retrieved from the literature have been integrated with novel in silico experiments, critically discussed to provide a comprehensive and updated overview on the undebatable potential of CBD and its therapeutic profile.

Understanding the possible role of endocannabinoid system in obesity

BACKGROUND

Maintenance of weight is essential for sustenance, well-being and to endorse prolonged life. The prevalence of obesity is increasing at an alarming rate globally, due to modern lifestyle and dietary habits. Endocannabinoids are fatty acid derivatives and numerous studies are carried out which focuses and targets their relationship with obesity, via multiple signals which have been recently known for exerting crucial role in regulating energy balance.

PURPOSE

This article aims at examining the prospects of endocannabinoids in obesity via directing the role of ECs in stimulating hunger.

RESULT

In last few years, irregular stimulation of endocannabinoid system has been suggested as a chief element in the progression of obesity-associated metabolic complications. Certainly, this cascade system comprises of cannabinoid type1 and 2 receptors (CB1R and CB2R) along with their endogenous lipid ligands which are responsible for enhanced feeding behavior as well as lipid metabolism. Significantly, inhibiting CB1R activity might reduce metabolic abnormality linked with obesity.

CONCLUSION

Conclusion withdrawn on the basis of supporting scientific data and evidences report that the blockade of cannabinoids can serve as a therapeutic potential for treatment of obesity. Future prospective aims at assessing molecular pathways which contributes towards ECS, elicited weight control and to evaluate how these mechanisms are presently relocated into the production of novel cannabinoid drugs exhibiting enriched care.

The protein kinase D1-mediated inflammatory pathway is involved in olanzapine-induced impairment of skeletal muscle insulin signaling in rats

AIMS

Skeletal muscle insulin resistance (SMIR) contributes to the metabolic syndrome. Mounting evidence has demonstrated that the second generation antipsychotic olanzapine causes SMIR. The present study sought to investigate the molecular mechanisms underlying olanzapine-induced SMIR.

MAIN METHODS

Male rats were given olanzapine (5 mg/kg, by a gavage method) for consecutive eight weeks. Plasma glucose and insulin concentrations were determined enzymatically or by ELISA. Gene/protein expression was analyzed by Real-Time PCR, Western blot and/or immunohistochemistry.

KEY FINDINGS

Olanzapine increased fasting plasma insulin concentration, and decreased glucose clearance during insulin tolerance test in rats. In skeletal muscle, it decreased protein expression of membrane glucose transporter (GLUT) 4, the ratio of membrane to total GLUT4, and total insulin receptor substrate 1 (IRS1). However, it increased protein phosphorylation of Ser³⁰⁷ in IRS1, Y⁶⁰⁷ in phosphoinositide 3-kinase p85α and Ser³⁰⁷ in AKT. These results indicate olanzapine-induced impairment of skeletal muscle insulin signaling. Mechanistically, olanzapine upregulated mRNA expression of TNFα, IL6 and IL1β, and protein phosphorylation of both IκB kinase (IKK)α/β and nuclear factor (NF)κB p65. Furthermore, it increased protein phosphorylation of Ser^485/491 in AMPKα2, whereas it decreased AMPKα2 activity. More importantly, both Western blot and immunohistochemical analyses revealed that olanzapine increased protein phosphorylation of Ser^744/748 in protein kinase D1 (PKD1).

SIGNIFICANCE

The present results suggest that the PKD1-mediated inflammatory pathway is involved in olanzapine-induced impairment of skeletal muscle insulin signaling in rats. Our findings may go new insight into the mechanisms underlying olanzapine-induced SMIR.

Olanzapine-Induced Activation of Hypothalamic Astrocytes and Toll-Like Receptor-4 Signaling via Endoplasmic Reticulum Stress Were Related to Olanzapine-Induced Weight Gain

The antipsychotic drug olanzapine is associated with serious obesity side effects. Hypothalamic astrocytes and associated toll-like receptor-4 (TLR4) signaling play an essential role in obesity pathogenesis. This study investigated the effect of olanzapine on astrocytes and TLR4 signaling both in vitro and in the rat hypothalamus and their potential role in olanzapine-induced weight gain. We found that olanzapine treatment for 24 h dose-dependently increased cell viability, increased the protein expression of astrocyte markers including glial fibrillary acidic protein (GFAP) and S100 calcium binding protein B (S100B), and activated TLR4 signaling in vitro. In rats, 8- and 36-day olanzapine treatment caused weight gain accompanied by increased GFAP and S100B protein expression and activated TLR4 signaling in the hypothalamus. These effects still existed in pair-fed rats, suggesting that these effects were not secondary effects of olanzapine-induced hyperphagia. Moreover, treatment with an endoplasmic reticulum (ER) stress inhibitor, 4-phenylbutyrate, inhibited olanzapine-induced weight gain and ameliorated olanzapine-induced changes in hypothalamic GFAP, S100B, and TLR4 signaling. The expression of GFAP, S100B, and TLR4 correlated with food intake and weight gain. These findings suggested that olanzapine-induced increase in hypothalamic astrocytes and activation of TLR4 signaling were related to ER stress, and these effects may be related to olanzapine-induced obesity.

Effect on Body Weight and Adipose Tissue by Cariprazine: A Head-to-Head Comparison Study to Olanzapine and Aripiprazole in Rats

Cariprazine (Car) is a recently approved second generation antipsychotic (SGA) with unique pharmacodynamic profile, being a partial agonist at both dopamine D2/3 receptor subtypes, with almost 10 times greater affinity towards D3. SGAs are known to increase body weight, alter serum lipids, and stimulate adipogenesis but so far, limited information about the adverse effects is available with this drug. In order to study this new SGA with such a unique mechanism of action, we compared Car to substances that are considered references and are well characterized: olanzapine (Ola) and aripiprazole (Ari). We studied the effects on body weight and also assessed the adipogenesis in rats. The drugs were self-administered in two different doses to female, adult, Wistar rats for six weeks. Weekly body weight change, vacuole size of adipocytes, Sterol Regulatory Element Binding Protein-1 (SREBP-1) and Uncoupling Protein-1 (UCP-1) expression were measured from the visceral adipose tissue (AT). The adipocyte’s vacuole size, and UCP-1 expression were increased while body weight gain was diminished by Car. by increasing UCP-1 might stimulate the thermogenesis, that could potentially explain the weight gain lowering effect through enhanced lipolysis.

Targeting the Endocannabinoid CB1 Receptor to Treat Body Weight Disorders: A Preclinical and Clinical Review of the Therapeutic Potential of Past and Present CB1 Drugs

Obesity rates are increasing worldwide and there is a need for novel therapeutic treatment options. The endocannabinoid system has been linked to homeostatic processes, including metabolism, food intake, and the regulation of body weight. Rimonabant, an inverse agonist for the cannabinoid CB1 receptor, was effective at producing weight loss in obese subjects. However, due to adverse psychiatric side effects, rimonabant was removed from the market. More recently, we reported an inverse relationship between cannabis use and BMI, which has now been duplicated by several groups. As those results may appear contradictory, we review here preclinical and clinical studies that have studied the impact on body weight of various cannabinoid CB1 drugs. Notably, we will review the impact of CB1 inverse agonists, agonists, partial agonists, and neutral antagonists. Those findings clearly point out the cannabinoid CB1 as a potential effective target for the treatment of obesity. Recent preclinical studies suggest that ligands targeting the CB1 may retain the therapeutic potential of rimonabant without the negative side effect profile. Such approaches should be tested in clinical trials for validation.

Progress in Genetic Polymorphisms Related to Lipid Disturbances Induced by Atypical Antipsychotic Drugs

Metabolic side effects such as weight gain and disturbed lipid metabolism are often observed in the treatment of atypical antipsychotic drugs (AAPDs), which contribute to an excessive prevalence of metabolic syndrome among schizophrenic patients. Great individual differences are observed but the underlying mechanisms are still uncertain. Research on pharmacogenomics indicates that gene polymorphisms involved in the pathways controlling food intake and lipid metabolism may play a significant role. In this review, relevant genes (HTR2C, DRD2, LEP, NPY, MC4R, BDNF, MC4R, CNR1, INSIG2, ADRA2A) and genetic polymorphisms related to metabolic side effects of AAPDs especially dyslipidemia were summarized. Apart from clinical studies, in vitro and in vivo evidence is also analyzed to support related theories. The association of central and peripheral mechanisms is emphasized, enabling the possibility of using peripheral gene expression to predict the central status. Novel methodological development of pharmacogenomics is in urgent need, so as to provide references for individualized medication and further to shed some light on the mechanisms underlying AAPD-induced lipid disturbances.

Second-Generation Antipsychotics and Dysregulation of Glucose Metabolism: Beyond Weight Gain

Second-generation antipsychotics (SGAs) are the cornerstone of treatment for schizophrenia because of their high clinical efficacy. However, SGA treatment is associated with severe metabolic alterations and body weight gain, which can increase the risk of type 2 diabetes and cardiovascular disease, and greatly accelerate mortality. Several underlying mechanisms have been proposed for antipsychotic-induced weight gain (AIWG), but some studies suggest that metabolic changes in insulin-sensitive tissues can be triggered before the onset of AIWG. In this review, we give an outlook on current research about the metabolic disturbances provoked by SGAs, with a particular focus on whole-body glucose homeostasis disturbances induced independently of AIWG, lipid dysregulation or adipose tissue disturbances. Specifically, we discuss the mechanistic insights gleamed from cellular and preclinical animal studies that have reported on the impact of SGAs on insulin signaling, endogenous glucose production, glucose uptake and insulin secretion in the liver, skeletal muscle and the endocrine pancreas. Finally, we discuss some of the genetic and epigenetic changes that might explain the different susceptibilities of SGA-treated patients to the metabolic side-effects of antipsychotics.

Overcoming the Psychiatric Side Effects of the Cannabinoid CB1 Receptor Antagonists: Current Approaches for Therapeutics Development

The Cannabinoid CB1 Receptor (CB1R) is involved in a variety of physiological pathways and has long been considered a golden target for therapeutic manipulation. A large body of evidence in both animal and human studies suggests that CB1R antagonism is highly effective for the treatment of obesity, metabolic disorders and drug addiction. However, the first-in-class CB1R antagonist/inverse agonist, rimonabant, though demonstrating effectiveness for obesity treatment and smoking cessation, displays serious psychiatric side effects, including anxiety, depression and even suicidal ideation, resulting in its eventual withdrawal from the European market. Several strategies are currently being pursued to circumvent the mechanisms leading to these side effects by developing neutral antagonists, peripherally restricted ligands, and allosteric modulators. In this review, we describe the progress in the development of therapeutics targeting the CB1R in the last two decades.

Cannabinoid-deficient Benin republic hemp (Cannabis sativa L.) improves semen parameters by reducing prolactin and enhancing anti-oxidant status

BACKGROUND

Nigerian Cannabis sativa (hemp) causes male gonadotoxicity by inducing hyperprolactinemia, down-regulation of hypothalamic-pituitary-testicular axis, and oxidative stress. Benin republic hemp has been preferred by illicit users in Nigeria but its effect on male fertility is not understood. This study determined and compared the compositions of Benin republic hemp ethanol extract (BHE) and Nigerian hemp. The effects of BHE on semen parameters, reproductive hormones, and anti-oxidant status, and the possibility of bromocriptine (prolactin inhibitor) to abolish hemp-induced toxicities in rats were also investigated.

METHODS

Thirty-six male Wistar rats were blindly randomized into 6 oral treatment groups (n = 6 each). Groups I (control) and II received normal saline and bromocriptine (3 mg/kg) respectively. Groups III and IV received 2 mg/kg of BHE alone and in combination with bromocriptine respectively, while groups V and VI received 10 mg/kg BHE alone and in combination with bromocriptine respectively. Comparisons among the groups were done by one-way analysis of variance, followed by post-hoc Tukey multiple comparison test. Statistical significance was considered at p < 0.05.

RESULTS

The BHE has no cannabichromene and tetrahydrocannabinol but a very small quantity of cannabinol and higher quantity of fatty acids when compared to Nigerian hemp. Both doses of BHE increased sperm count, morphology and viability but not motility. Co-administration of BHE with bromocriptine lowered sperm count but increased sperm morphology and viability. Bromocriptine and/or BHE caused reduction in the plasma prolactin level, increase in the plasma superoxide dismutase activity, but no significant change in the plasma gonadotropin releasing hormone, follicle stimulating hormone (except for the increase in rats that received bromocriptine+ 10 mg/kg BHE), luteinizing hormone, estradiol, malondialdehyde and glutathione peroxidase. The 10 mg/kg BHE or bromocriptine+BHE (both doses) increased total anti-oxidant capacity and catalase.

CONCLUSIONS

The BHE improves semen parameters by reducing plasma prolactin and enhancing plasma anti-oxidant status. Its pro-fertility potential might be associated with its deficiency in the widely known gonadotoxic phytocannabinoids.

Cannabimimetic plants: are they new cannabinoidergic modulators?

Phytochemicals and secondary metabolites able to interact with the endocannabinoid system (Cannabimimetics) have been recently described in a broad range of plants and fruits. These findings can open new alternative avenues to explore for the development of novel therapeutic compounds. The cannabinoids regulate many physiological and pathological functions in both animals and plants. Cannabis sativa is the main plant that produces phytocannabinoids inside resins capable to defend the plant from the aggression of parasites and herbivores. Animals produce anandamide and 2-arachidonoyl glycerol, which thanks to binding with main receptors such as type-1 cannabinoid receptor (CB1R) and the type-2 cannabinoid receptor (CB2R) are involved in inflammation processes and several brain functions. Endogenous cannabinoids, enzymes for synthesis and degradation of cannabinoids, and CB1R and CB2R constitute the endocannabinoid system (ECS). Other plants can produce cannabinoid-like molecules such as perrottetinene extracted from Radula perrottetii, or anandamide and 2-arachidonoyl glycerol extracted from some bryophytes. Moreover, several other secondary metabolites can also interact with the ECS of animals and take the name of cannabimimetics. These phytoextracts not derived from Cannabis sativa can act as receptor agonists or antagonist, or enzyme inhibitors of ECS and can be involved in the inflammation, oxidative stress, cancer, and neuroprotection. Finally, given the evolutionary heterogeneity of the cannabimimetic plants, some authors speculated on the fascinating thesis of the evolutionary convergence between plants and animals regarding biological functions of ECS. The review aims to provide a critical and complete assessment of the botanical, chemical and therapeutic aspects of cannabimimetic plants to evaluate their spread in the world and medicinal potentiality.

Olanzapine-induced endoplasmic reticulum stress and inflammation in the hypothalamus were inhibited by an ER stress inhibitor 4-phenylbutyrate

Antipsychotics are the most important treatment for schizophrenia. However, antipsychotics, particularly olanzapine and clozapine, are associated with severe weight gain/obesity side-effects. Although numerous studies have been carried out to identify the exact mechanisms of antipsychotic-induced weight gain, it is still important to consider other pathways. Endoplasmic reticulum (ER) stress signaling and its associated inflammation pathway is one of the most important pathways involved in regulation of energy balance. In the present study, we examined the role of hypothalamic protein kinase R like endoplasmic reticulum kinase- eukaryotic initiation factor 2α (PERK-eIF2α) signaling and the inflammatory IkappaB kinase β- nuclear factor kappa B (IKKβ-NFκB) signaling pathway in olanzapine-induced weight gain in female rats. In this study, we found that olanzapine significantly activated PERK-eIF2α and IKKβ-NFκB signaling in SH-SY5Y cells in a dose-dependent manner. Olanzapine treatment for 8 days in rats was associated with activated PERK-eIF2α signaling and IKKβ-NFκB signaling in the hypothalamus, accompanied by increased food intake and weight gain. Co-treatment with an ER stress inhibitor, 4-phenylbutyrate (4-PBA), decreased olanzapine-induced food intake and weight gain in a dose- and time-dependent manner. Moreover, 4-PBA dose-dependently inhibited olanzapine-induced activated PERK-eIF2α and IKKβ-NFκB signaling in the hypothalamus. These results suggested that hypothalamic ER stress may play an important role in antipsychotic-induced weight gain.

Cannabis: From a Plant That Modulates Feeding Behaviors toward Developing Selective Inhibitors of the Peripheral Endocannabinoid System for the Treatment of Obesity and Metabolic Syndrome

In this review, we discuss the role of the endocannabinoid (eCB) system in regulating energy and metabolic homeostasis. Endocannabinoids, via activating the cannabinoid type-1 receptor (CB₁R), are commonly known as mediators of the thrifty phenotype hypothesis due to their activity in the central nervous system, which in turn regulates food intake and underlies the development of metabolic syndrome. Indeed, these findings led to the clinical testing of globally acting CB₁R blockers for obesity and various metabolic complications. However, their therapeutic potential was halted due to centrally mediated adverse effects. Recent observations that highlighted the key role of the peripheral eCB system in metabolic regulation led to the preclinical development of various novel compounds that block CB₁R only in peripheral organs with very limited brain penetration and without causing behavioral side effects. These unique molecules, which effectively ameliorate obesity, type II diabetes, fatty liver, insulin resistance, and chronic kidney disease in several animal models, are likely to be further developed in the clinic and may revive the therapeutic potential of blocking CB₁R once again.

Olanzapine Induced Dysmetabolic Changes Involving Tissue Chromium Mobilization in Female Rats

Atypical antipsychotics, such as olanzapine, are commonly prescribed to patients with schizophrenic symptoms and other psychiatric disorders. However, weight gain and metabolic disturbance cause adverse effects, impair patient compliance and limit clinical utility. Thus, a better understanding of treatment-acquired adverse effects and identification of targets for therapeutic intervention are believed to offer more clinical benefits for patients with schizophrenia. Beyond its nutritional effects, studies have indicated that supplementation of chromium brings about beneficial outcomes against numerous metabolic disorders. In this study, we investigated whether olanzapine-induced weight gain and metabolic disturbance involved chromium dynamic mobilization in a female Sprague-Dawley rat model, and whether a dietary supplement of chromium improved olanzapine-acquired adverse effects. Olanzapine medicated rats experienced weight gain and adiposity, as well as the development of hyperglycemia, hyperinsulinemia, insulin resistance, hyperlipidemia, and inflammation. The olanzapine-induced metabolic disturbance was accompanied by a decrease in hepatic Akt and AMP-activated Protein Kinase (AMPK) actions, as well as an increase in serum interleukin-6 (IL-6), along with tissue chromium depletion. A daily intake of chromium supplements increased tissue chromium levels and thermogenic uncoupling protein-1 (UCP-1) expression in white adipose tissues, as well as improved both post-olanzapine weight gain and metabolic disturbance. Our findings suggest that olanzapine medicated rats showed a disturbance of tissue chromium homeostasis by inducing tissue depletion and urinary excretion. This loss may be an alternative mechanism responsible for olanzapine-induced weight gain and metabolic disturbance.

Drug Bioavailability Enhancing Agents of Natural Origin (Bioenhancers) that Modulate Drug Membrane Permeation and Pre-Systemic Metabolism

Many new chemical entities are discovered with high therapeutic potential, however, many of these compounds exhibit unfavorable pharmacokinetic properties due to poor solubility and/or poor membrane permeation characteristics. The latter is mainly due to the lipid-like barrier imposed by epithelial mucosal layers, which have to be crossed by drug molecules in order to exert a therapeutic effect. Another barrier is the pre-systemic metabolic degradation of drug molecules, mainly by cytochrome P450 enzymes located in the intestinal enterocytes and liver hepatocytes. Although the nasal, buccal and pulmonary routes of administration avoid the first-pass effect, they are still dependent on absorption of drug molecules across the mucosal surfaces to achieve systemic drug delivery. Bioenhancers (drug absorption enhancers of natural origin) have been identified that can increase the quantity of unchanged drug that appears in the systemic blood circulation by means of modulating membrane permeation and/or pre-systemic metabolism. The aim of this paper is to provide an overview of natural bioenhancers and their main mechanisms of action for the nasal, buccal, pulmonary and oral routes of drug administration. Poorly bioavailable drugs such as large, hydrophilic therapeutics are often administered by injections. Bioenhancers may potentially be used to benefit patients by making systemic delivery of these poorly bioavailable drugs possible via alternative routes of administration (i.e., oral, nasal, buccal or pulmonary routes of administration) and may also reduce dosages of small molecular drugs and thereby reduce treatment costs.

Inhibition of RAGE Axis Signaling: A Pharmacological Challenge

The Receptor for Advanced Glycation End Products (RAGE) is an important cell surface receptor, which belongs to the IgG super family and is now considered as a pattern recognition receptor. Because of its relevance in many human clinical settings, it is now pursued as a very attractive therapeutic target. However, particular features of this receptor such as a wide repertoire of ligands with different binding domains, the existence of many RAGE variants as well as the presence of cytoplasmatic adaptors leading a diverse signaling, are important limitations in the search for successful pharmacological approaches to inhibit RAGE signaling. Therefore, the present review aimed to display the most promising approaches to inhibit RAGE signaling, and provide an up to date review of progress in this area.

A phenotypic Caenorhabditis elegans screen identifies a selective suppressor of antipsychotic-induced hyperphagia

Antipsychotic (AP) drugs are used to treat psychiatric disorders but are associated with significant weight gain and metabolic disease. Increased food intake (hyperphagia) appears to be a driving force by which APs induce weight gain but the mechanisms are poorly understood. Here we report that administration of APs to C. elegans induces hyperphagia by a mechanism that is genetically distinct from basal food intake. We exploit this finding to screen for adjuvant drugs that suppress AP-induced hyperphagia in C. elegans and mice. In mice AP-induced hyperphagia is associated with a unique hypothalamic gene expression signature that is abrogated by adjuvant drug treatment. Genetic analysis of this signature using C. elegans identifies two transcription factors, nhr-25/Nr5a2 and nfyb-1/NFYB to be required for AP-induced hyperphagia. Our study reveals that AP-induced hyperphagia can be selectively suppressed without affecting basal food intake allowing for novel drug discovery strategies to combat AP-induced metabolic side effects.

Cannabis sativa: A comprehensive ethnopharmacological review of a medicinal plant with a long history

ETHNOPHARMACOLOGICAL RELEVANCE

Cannabis sativa L. (C. sativa) is an annual dioecious plant, which shares its origins with the inception of the first agricultural human societies in Asia. Over the course of time different parts of the plant have been utilized for therapeutic and recreational purposes, for instance, extraction of healing oils from seed, or the use of inflorescences for their psychoactive effects. The key psychoactive constituent in C. sativa is called Δ-9-tetrahydrocannabinol (D9-THC). The endocannabinoid system seems to be phylogenetically ancient, as it was present in the most primitive vertebrates with a neuronal network. N-arachidonoylethanolamine (AEA) and 2-arachidonoyl glycerol (2-AG) are the main endocannabinoids ligands present in the animal kingdom, and the main endocannabinoid receptors are cannabinoid type-1 (CB1) receptor and cannabinoid type-2 (CB2) receptor.

AIM OF THE STUDY

The review aims to provide a critical and comprehensive evaluation, from the ancient times to our days, of the ethnological, botanical, chemical and pharmacological aspects of C. sativa, with a vision for promoting further pharmaceutical research to explore its complete potential as a therapeutic agent.

MATERIALS AND METHODS

This study was performed by reviewing in extensive details the studies on historical significance and ethnopharmacological applications of C. sativa by using international scientific databases, books, Master's and Ph.D. dissertations and government reports. In addition, we also try to gather relevant information from large regional as well as global unpublished resources. In addition, the plant taxonomy was validated using certified databases such as Medicinal Plant Names Services (MPNS) and The Plant List.

RESULTS AND CONCLUSIONS

A detailed comparative analysis of the available resources for C. sativa confirmed its origin and traditional spiritual, household and therapeutic uses and most importantly its popularity as a recreational drug. The result of several studies suggested a deeper involvement of phytocannabinoids (the key compounds in C. sativa) in several others central and peripheral pathophysiological mechanisms such as food intake, inflammation, pain, colitis, sleep disorders, neurological and psychiatric illness. However, despite their numerous medicinal benefits, they are still considered as a menace to the society and banned throughout the world, except for few countries. We believe that this review will help lay the foundation for promoting exhaustive pharmacological and pharmaceutical studies in order to better understand the clinical relevance and applications of non-psychoactive cannabinoids in the prevention and treatment of life-threatening diseases and help to improve the legal status of C. sativa.

Cannabinoids in health and disease: pharmacological potential in metabolic syndrome and neuroinflammation

The use of different natural and/or synthetic preparations of Cannabis sativa is associated with therapeutic strategies for many diseases. Indeed, thanks to the widespread diffusion of the cannabinoidergic system in the brain and in the peripheral districts, its stimulation, or inhibition, regulates many pathophysiological phenomena. In particular, central activation of the cannabinoidergic system modulates the limbic and mesolimbic response which leads to food craving. Moreover, cannabinoid agonists are able to reduce inflammatory response. In this review a brief history of cannabinoids and the protagonists of the endocannabinoidergic system, i.e. synthesis and degradation enzymes and main receptors, will be described. Furthermore, the pharmacological effects of cannabinoids will be outlined. An overview of the involvement of the endocannabinoidergic system in neuroinflammatory and metabolic pathologies will be made. Finally, particular attention will also be given to the new pharmacological entities acting on the two main receptors, cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 2 (CB2), with particular focus on the neuroinflammatory and metabolic mechanisms involved.

Antipsychotic Drugs: From Receptor-binding Profiles to Metabolic Side Effects

BACKGROUND

Antipsychotic-induced metabolic side effects are major concerns in psychopharmacology and clinical psychiatry. Their pathogenetic mechanisms are still not elucidated.

METHODS

Herein, we review the impact of neurotransmitters on metabolic regulation, providing insights into antipsychotic-induced metabolic side effects.

RESULTS

Antipsychotic drugs seem to interfere with feeding behaviors and energy balance, processes that control metabolic regulation. Reward and energy balance centers in central nervous system constitute the central level of metabolic regulation. The peripheral level consists of skeletal muscles, the liver, the pancreas, the adipose tissue and neuroendocrine connections. Neurotransmitter receptors have crucial roles in metabolic regulation and they are also targets of antipsychotic drugs. Interaction of antipsychotics with neurotransmitters could have both protective and harmful effects on metabolism.

CONCLUSION

Emerging evidence suggests that antipsychotics have different liabilities to induce obesity, diabetes and dyslipidemia. However this diversity cannot be explained merely by drugs'pharmacodynamic profiles, highlighting the need for further research.

Oral haloperidol or olanzapine intake produces distinct and region-specific increase in cannabinoid receptor levels that is prevented by high fat diet

Clinical studies show higher levels of cannabinoid CB1 receptors (CB1R) in the brain of schizophrenic patients while preclinical studies report a significant functional interaction between dopamine D2 receptors and CB1Rs as well as an upregulation of CB1Rs after antipsychotic treatment. These findings prompted us to study the effects of chronic oral intake of a first and a second generation antipsychotic, haloperidol and olanzapine, on the levels and distribution of CB1Rs in the rat brain. Rats consumed either regular chow or high-fat food and drank water, haloperidol drinking solution (1.5mg/kg), or olanzapine drinking solution (10mg/kg) for four weeks. Motor and cognitive functions were tested at the end of treatment week 3 and upon drug discontinuation. Two days after drug discontinuation, rats were euthanized and brains were processed for in vitro receptor autoradiography. In chow-fed animals, haloperidol and olanzapine increased CB1R levels in the basal ganglia and the hippocampus, in a similar, but not identical pattern. In addition, olanzapine had unique effects in CB1R upregulation in higher order cognitive areas, in the secondary somatosensory cortex, in the visual and auditory cortices and the geniculate nuclei, as well as in the hypothalamus. High fat food consumption prevented antipsychotic-induced increase in CB1R levels in all regions examined, with one exception, the globus pallidus, in which they were higher in haloperidol-treated rats. The results point towards the hypothesis that increased CB1R levels could be a confounding effect of antipsychotic medication in schizophrenia that is circumveneted by high fat feeding.

Re-visiting the Endocannabinoid System and Its Therapeutic Potential in Obesity and Associated Diseases

PURPOSE OF REVIEW

The purpose of the review was to revisit the possibility of the endocannabinoid system being a therapeutic target for the treatment of obesity by focusing on the peripheral roles in regulating appetite and energy metabolism.

RECENT FINDINGS

Previous studies with the global cannabinoid receptor blocker rimonabant, which has both central and peripheral properties, showed that this drug has beneficial effects on cardiometabolic function but severe adverse psychiatric side effects. Consequently, focus has shifted to peripherally restricted cannabinoid 1 (CB1) receptor blockers as possible therapeutic agents that mitigate or eliminate the untoward effects in the central nervous system. Targeting the endocannabinoid system using novel peripheral CB1 receptor blockers with negligible penetrance across the blood-brain barrier may prove to be effective therapy for obesity and its co-morbidities. Perhaps the future of blockers targeting CB1 receptors will be tissue-specific neutral antagonists (e.g., skeletal muscle specific to treat peripheral insulin resistance, adipocyte-specific to treat fat excess, liver-specific to treat fatty liver and hepatic insulin resistance).