Alkaloids in Withania somnifera (L.) Dunal Root Extract Contribute to Its Anti-Inflammatory Activity.

The anti-inflammatory properties of the medicinal plant Withania somnifera (L.) Dunal (WS) are generally related to withanolides; consistently, several strategies are under investigation to increase the concentration of these compounds in WS extracts. However, a potential toxicity of withanolides has been highlighted, thus questioning the safety of such preparations. At variance, the relative contribution of alkaloids is underrated, in spite of preliminary evidence underlining a possible pharmacological relevance. Starting from these considerations, the efficacy/safety profile of WS root extract (WSE) was compared with those of WS extracts which are enriched in alkaloids (WSA) and withanolides (WSW), respectively. MTT assay was used to evaluate cell viability. The anti-inflammatory activities of the different extracts were estimated throughout the assessment of the inhibition of lipopolysaccharide (LPS)-activated release of nitric oxide (NO) and the upregulation of iNOS and COX-2 protein in RAW 264.7 cells. Both WSA and WSW were able to reduce LPS-mediated effects in RAW 264.7 cells, suggesting that alkaloids and withanolides may contribute to the anti-inflammatory activity of WSE. A significant higher anti-inflammatory activity and a lower toxicity were observed when WSA was compared to WSW. The present results highlighted that the contribution of alkaloids to WS pharmacological effects should not be neglected. Particularly, these compounds may concur to reach a more advantageous efficacy/safety profile when WS is used for anti-inflammatory purposes.

Ethnomedicine and neuropsychopharmacology in Mesoamerica.

ETHNOPHARMACOLOGICAL RELEVANCE: The burden of disease caused by mental and neurological disorders is increasing globally, to a disproportionate degree in Latin America. In contrast to the many psychoactive plants with a use history in Mesoamerican cultures, the translation to the wider population of knowledge around numerous botanicals used contemporarily by indigenous Mesoamerican societies to treat psychological and neurological disorders did not receive the same attention. MATERIAL AND METHODS: We used the previously published Mesoamerican Medicinal Plant Database to extract species and associated botanical drugs used as treatments for illnesses associated with the nervous system by Mesoamerican cultures in Belize, Guatemala, and Mexico. With the critical use of published pharmacological literature, the cross-culturally most salient genera are systematically reviewed. RESULTS: From 2188 plant taxa contained in the database 1324 are used as treatments for illnesses associated with the nervous system. The ethnomedical data was critically confronted with the available biomedical literature for the 58 cross-culturally most salient genera. For a considerable proportion of the frequently used taxa, preclinical data are available, mostly validating ethnomedicinal uses. CONCLUSION: This quantitative approach facilitates the prioritization of taxa for future pre-clinical, clinical and treatment outcome studies and gives patients, practitioners, and legislators a fundamental framework of evidence, on which to base decisions regarding phytomedicines.

Lights and shadows of schizophrenia therapy research: Lessons from oral risperidone and olanzapine.

BACKGROUND: Recently, patents of several atypical antipsychotics have reached their expiration date. AIMS: The purpose of the study was to highlight whether modifications of economic/scientific factors may be associated with possible changes in ongoing clinical research on antipsychotic drugs. METHODS: A large systematic analysis was used to depict the time-dependent distribution of published research articles addressing the clinical properties of oral risperidone and olanzapine conventional tablets, two largely prescribed atypical antipsychotics for which the patents have already expired in most of the countries. RESULTS: The systematic analysis indicated that the time-dependent distribution of the selected research articles followed a wave-shape pattern. A dramatic decline of primary and secondary analyses investigating the clinical effects of oral risperidone and olanzapine has occurred in the last decade, complemented by an expected strong reduction in the numbers of industrial-supported clinical studies and a smaller, but significant, decline in the amount of independent research articles. CONCLUSIONS: To date, greater involvement of independent research seems to be the only realistic chance to properly continue the investigation on the clinical properties of oral risperidone and olanzapine conventional tablets, as well as those of other off-patent antipsychotic drugs. However, the limits and potentialities of independent research in accomplishing such a demanding and enduring scientific effort should be addressed.

Phenotypic Evaluation of a Novel Nucleotide Substitution (HBD: c.442T>C) on the δ-Globin Gene.

HBD: c.442T>C is a new mutation at the stop codon (TGA>CGA) of the δ-globin gene, which produces a new codon for arginine. This substitution causes a 51 nucleotides longer open reading frame determining the synthesis of a potential larger δ subunit, which is a probable target of mechanisms for the degradation of aberrant proteins as well as the defective synthesized mRNA molecules, and may also be rapidly degraded by a variety of RNA surveillance pathways. We identified this molecular defect in four patients: three women with a reduced HbA2 level and a 37-year-old male showing the typical phenotype of an α-thalassemia (α-thal) carrier with reduced values of red cell indices and normal HbA2 level (2.5%). The mutation on the δ-globin gene was found to have been coinherited with a ß-globin gene defect leading to a normalized HbA2 level. These data support the necessity of investigating these cases at a molecular level, particularly if the partner is also a ß-thalassemia (ß-thal) carrier. The present data emphasizes the importance of a careful evaluation of correlation between genotypes resulting from DNA analysis and phenotypes, especially in cases of atypical hematological parameters, in order to carry out an adequate diagnostic process finalized to appropriate genetic counseling.

Withania somnifera (L.) Dunal root extract alleviates formalin-induced nociception in mice: involvement of the opioidergic system.

Withania somnifera (L.) Dunal extracts (WSEs) may possess therapeutic perspectives in the treatment of inflammation and pain. We aimed to evaluate the antinociceptive property of a WSE in the formalin test and to investigate the involvement of several neurotransmitter systems in this effect. The time spent licking the formalin-injected paw was recorded in CD1 mice after pretreatment with increasing doses of WSE. Also, c-Fos spinal cord expression and the effects of different compounds were investigated under these experimental conditions. Finally, the efficacy of WSE was analyzed following an injection of glutamate. WSE reduced the antinociceptive response during the tonic but not the acute phase of the formalin test and decreased formalin-induced c-Fos expression in spinal neurons. These effects were antagonized by the opioid antagonist naltrexone, whereas GABA, cannabinoid, δ-opioid, and nitric oxide compounds were ineffective. The administration of WSE also reduced nociception and c-Fos expression induced by glutamate injection. These results showed that WSE is effective in assays of chemical-induced nociception, indicating that this plant has potential valuable properties for the treatment of specific painful conditions. The antinocicetive effects of WSE in the formalin test appeared to be specifically mediated by the opioidergic system, although the involvement of the glutamatergic system cannot be excluded.

On the use of the Positive and Negative Syndrome Scale in randomized clinical trials.

In the last 25 years, the Positive and Negative Syndrome Scale (PANSS) has been largely used to assess schizophrenia symptom intensity, but little information is available on how this scale was generally applied when evaluating the efficacy of schizophrenia therapies in randomized clinical trials. In the attempt to address this topic, a systematic PubMed Search was carried out using the keywords "PANSS" and "Randomized Clinical Trials". The analysis of retrieved articles highlighted that PANSS has constituted a suitable psychometric instrument to investigate the efficacy of pharmacological and non-pharmacological therapies. However, the information potentially provided by this scale was only partially reported in research articles, when characterizing the symptomatic features of patients at baseline. Furthermore, a consensus is needed to identify methodological strategies that may properly adapt PANSS-subscale structure with the symptomatic profiles of individuals enrolled in randomized controlled trials. The possibility that PANSS interview procedures and enrollment eligibility criteria may influence the symptomatic composition of patients involved in these studies is also discussed.

Prediction and prevention of the first psychotic episode: new directions and opportunities.

In the last few decades, substantial research has focused on the possibility of early detection and prevention of the first psychotic episode in young individuals at risk of developing this mental disturbance; however, unresolved clinical and ethical issues still call for further investigations. New perspectives and opportunities may come from the identification of selective psychopathological and instrumental markers linking the appearance of subtle psychotic symptoms with the clinical outcome of specific mental pathologies. Furthermore, empirically derived algorithms and risk staging models should facilitate the identification of targeted prevention therapies, possibly improving the efficacy of well-tolerated therapeutic approaches, such as psychological interventions and natural compound supplementations. To date, the collected evidence on the efficacy and tolerability of pharmacological prevention therapies raises more doubts than hopes. A very early detection of risk and appropriate symptomatic pattern classifications may provide a chance to better match prevention strategies with the development of psychosis.

Withania somnifera root extract prolongs analgesia and suppresses hyperalgesia in mice treated with morphine.

Previous studies demonstrated that Withania somnifera Dunal (WS), a safe medicinal plant, prevents the development of tolerance to the analgesic effect of morphine. In the present study, we investigated whether WS extract (WSE) (100 mg/kg, i.p.) may also modulate the analgesic effect induced by acute morphine administration (2.5, 5, 10 mg/kg, s.c.) in the tail-flick and in the hot plate tests, and if it may prevent the development of 2.5 mg/kg morphine-induced rebound hyperalgesia in the low intensity tail-flick test. Further, to characterize the receptor(s) involved in these effects, we studied, by receptor-binding assay, the affinity of WSE for opioid (µ, δ, k), cannabinoid (CB1, CB2), glutamatergic (NMDA), GABAergic (GABAA, GABAB), serotoninergic (5HT2A) and adrenergic (α2) receptors. The results demonstrated that (i) WSE alone failed to alter basal nociceptive threshold in both tests, (ii) WSE pre-treatment significantly protracted the antinociceptive effect induced by 5 and 10 mg/kg of morphine only in tail-flick test, (iii) WSE pre-treatment prevented morphine-induced hyperalgesia in the low intensity tail-flick test, and (iv) WSE exhibited a high affinity for the GABAA and moderate affinity for GABAB, NMDA and δ opioid receptors. WSE prolongs morphine-induced analgesia and suppresses the development of morphine-induced rebound hyperalgesia probably through involvement of GABAA, GABAB, NMDA and δ opioid receptors. This study suggests the therapeutic potential of WSE as a valuable adjuvant agent in opioid-sparing therapies.

Synthesis and biological evaluation of novel delta (δ) opioid receptor ligands with diazatricyclodecane skeletons.

Considering the interesting pharmacological profile of the delta (δ) selective opioid agonist compound SNC-80, conformationally constrained analogs containing two diazatricyclodecane ring systems in place of dimethylpiperazine core motif were synthesized. The compounds showed subnanomolar or low nanomolar δ opioid receptor binding affinity. Depending upon the substituents on the diazatricyclodecane ring, these compounds displayed varying selectivity for δ opioid receptor over µ and κ receptors. Amongst the novel compounds, 1Aa showed the more interesting biological profile, with higher δ affinity and selectivity compared to SNC-80. The δ receptor agonist profile and antinociceptive activity of 1Aa were confirmed using ex-vivo (isolated mouse vas deferens) and in vivo (tail flick) assays.

Effects of controlled-release formulations of atypical antipsychotics on functioning and quality of life of schizophrenic individuals.

INTRODUCTION: Controlled-release formulations of atypical antipsychotics have recently been introduced into clinical practice. Clinical studies have indicated that these new therapies induce meaningful improvements in the functioning and quality of life of schizophrenic individuals. AREAS COVERED: The present analysis makes an attempt to address the clinical relevance of these studies and their contribution to the understanding of the mechanisms of action of these new drugs. A Medline search was done using the keywords 'antipsychotic', 'plasma level', 'quality of life' and 'functioning'. EXPERT OPINION: After reviewing the literature, it seems that symptom control and side effects may play a role in modulating the functioning and quality of life of schizophrenic individuals treated with controlled-release formulations of atypical antipsychotics. The analysis also highlights that these new drugs may possess peculiarities and similarities in regulating patient functioning. However, the low number of clinical analyses that have focused on these aspects of antipsychotic therapy limits the interpretation of the results. Additional comparative clinical trials are needed to evaluate how the pharmacokinetic/pharmacodynamic properties of antipsychotic drugs may modulate the functioning and quality of life of schizophrenic individuals, as well as to establish whether new clinical benefits may come from the use of these drugs in schizophrenia therapy.

Evaluation of amphetamine-induced hyperlocomotion and catalepsy following long-acting risperidone administration in rats.

It has been proposed that long-acting risperidone could provide a constant antipsychotic efficacy associated with a reduced liability to induce extra-pyramidal symptoms. To ascertain this hypothesis, antagonism of amphetamine-induced hyperlocomotion and catalepsy were analyzed in rats for a period of 1-6 weeks following long-acting risperidone (20-60 mg/kg) injection. Long-acting risperidone reduced amphetamine-induced hyperlocomotion after 2-5 weeks from drug injection, without producing significant extra-pyramidal symptoms. Following the administration of long-acting risperidone a constant ability to antagonize amphetamine-induced hyperlocomotion was observed during the day, but not when the antipsychotic was chronically administered using a short-acting formulation. The pre-clinical results confirmed that long-acting risperidone may represent an advance in antipsychotic therapy.

Expected clinical benefits of paliperidone extended-release formulation when compared with risperidone immediate-release.

BACKGROUND: The development of paliperidone extended release (ER) may represent a new strategy to improve the pharmacological treatment of schizophrenia. The drug maintains the atypical antipsychotic profile of its parent compound risperidone, but it is associated with an innovative delivery system (OROS technology) that offers the possibility to obtain smooth drug plasma levels using an oral antipsychotic. Clinical trials confirmed that paliperidone ER is efficacious in the management of schizophrenia and well tolerated, however no direct clinical comparisons between paliperidone ER and immediate-release formulations of risperidone have been conducted to date. OBJECTIVE: The present study evaluates possible differences between paliperidone ER and immediate-release formulations of risperidone due to structural/molecular and delivery system diversities, providing an estimation of their significance in the context of clinical results. METHODS: A search of Medline and EMBASE was performed using the keywords 'Risperidone', 'Paliperidone' and 'OROS technology'. RESULTS/CONCLUSION: The analysis suggests that the chemical structure and pharmacokinetic profile of paliperidone ER might provide clinical benefits in terms of efficacy, tolerability and more consistent drug response among patients, when compared with the parent compound risperidone in its immediate release formulations. The relevance of these differences is discussed, taking into account several clinical aspects involved in the drug therapy of schizophrenia.

Delta-9-tetrahydrocannabinol differently affects striatal c-Fos expression following haloperidol or clozapine administration.

It was previously shown that haloperidol, but not clozapine, induced intense rat catalepsy when co-administered with delta-9-tetrahydrocannabinol. The present study investigated whether similar alterations could be observed on striatal c-Fos immunoreactivity after administration of the same drug combinations. Western Blot and immunocytochemistry stereological analyses indicated that delta-9-tetrahydrocannabinol (0.5 mg/kg) increased striatal c-Fos immunoreactivity induced by haloperidol (0.1 mg/kg). Conversely, no significant alterations of striatal c-Fos immunoreactivity were observed after injections of clozapine (10 mg/kg)+vehicle, clozapine+delta-9-tetrahydrocannabinol or vehicle+delta-9-tetrahydrocannabinol. The present results indicate that the behavioral effects induced by delta-9-tetrahydrocannabinol in haloperidol- and clozapine-treated rats are associated with different striatal c-Fos expressions.

Antipsychotic efficacy: relationship to optimal D2-receptor occupancy.

Clinically important differences exist between antipsychotic agents and formulations in terms of safety and tolerability. Features of the biochemical interaction between the antipsychotic and the D2-receptor may underlie these differences. This article reviews current information on the relationship between antipsychotic receptor occupancy and clinical response. A literature search was performed using the keywords 'antipsychotic or neuroleptic', 'receptor' and 'occupancy' and 'dopamine' and 'D2' supplemented by the authors' knowledge of the literature. Imaging and clinical data have generally supported the hypotheses that optimal D2-receptor occupancy in the striatum lies in a 'therapeutic window' between approximately 65 and approximately 80%, however, pharmacokinetic and pharmacodynamic properties of a drug should also be taken into account to fully evaluate its therapeutic effects. Additional research, perhaps in preclinical models, is needed to establish D2-receptor occupancy in various regions of the brain and the optimal duration of D2-receptor blockade in order to maximise efficacy and tolerability profiles of atypical antipsychotics and thereby improve treatment outcomes for patients with schizophrenia.

Imbalance towards inhibition as a substrate of aging-associated cognitive impairment.

The number of synapses in the cerebral cortex decreases with aging. However, how this structural change translates into the cognitive impairment observed in aged animals remains unknown. Aged animals are not a homogenous group with respect to their cognitive performances; but instead, they can be separated into aged cognitively unimpaired ("normal") and aged cognitively impaired groups using a spatial memory task such as the Morris water maze. These two aged groups provide an unprecedented opportunity to isolate synaptic properties that relate to cognitive impairment from unrelated factors associated with normal aging. Using such classification, we conducted whole-cell patch-clamp recordings to measure basal spontaneous miniature excitatory (mEPSCs) and inhibitory synaptic currents (mIPSCs) bombarding layer V pyramidal neurons in the parietal cortex. We found that the frequencies of both mEPSC and mIPSC were lower in aged normal rats when compared with young rats. In contrast, aged cognitively impaired rats displayed a reduction in mEPSC frequency only. This results in an imbalance towards inhibition that may be an important substrate of the cognitive impairment in aged animals. We also found that pyramidal neurons in both aged normal and aged cognitively impaired rats exhibit similar structural attritions. Thus, cognitive impairment may be more related to an altered balance between different neurotransmitter systems than a mere reduction in synaptic structures.

Evaluation of tamsulosin and alfuzosin activity in the rat vas deferens: relevance to ejaculation delays.

The effect of two alpha-adrenergic receptor antagonists widely employed in the therapy of benign prostatic hyperplasia, tamsulosin [(-)-(R)-5-[2-[[2-(0-ethoxyphenoxy) ethyl]amino]propyl]-2-methoxybenzenesulfonamide] and alfuzosin [(+/-)-N-[3-[(4-amino-6,7-dimethoxy-2-quinazolinyl) methylamino]propyl] tetrahydro-2-furancarboxamide], was investigated in the rat vas deferens. Because several clinical studies have shown that tamsulosin causes ejaculatory disorders, this study also evaluated the possible mechanisms implicated in these disorders by comparing the effect of tamsulosin with that of alfuzosin. Tamsulosin competitively antagonized the contractions induced by noradrenaline in vitro in the epididymal portion of the vas deferens with a potency pA(2) value of 9.2 +/- 0.8. In the prostatic portion, tamsulosin increased the amplitude of intermittent spikes induced by exogenous noradrenaline (100-1000 microM). In both portions of the vas deferens, alfuzosin behaved as an alpha-adrenergic antagonist blocking the contractions induced by exogenous noradrenaline without altering spikes. The administration of tamsulosin (3 microg/kg i.v.) significantly reduced the contractions evoked by electrical pulses in the epididymal portion, whereas it increased those produced in the prostatic portion. Intravenous tamsulosin antagonized the contraction produced by exogenous noradrenaline, whereas alfuzosin administration (10 microg/kg i.v.) did not change the electrically induced contractions in both portions of the rat vas deferens and did not antagonize the contractions produced by exogenous noradrenaline. The fact that tamsulosin unusually enhances noradrenaline-induced intermittent spike contractions and nerve stimulation-induced twitches in the prostatic portions might be linked to its greater propensity to cause sexual dysfunctions.

Blockade of neurotensin receptors affects differently hypo-locomotion and catalepsy induced by haloperidol in mice.

Antipsychotic drug treatment increases neurotensin (NT) neurotransmission, and the exogenous administration of NT produces antipsychotic-like effects in rodents. In order to investigate whether "endogenous" NT may act as a natural occurring antipsychotic or may mediate antipsychotic drug activity, the effects of the selective NT receptor antagonists SR 48692 and SR 142948A were analyzed in different behavioural tests of locomotor activity using vehicle, amphetamine, or haloperidol in mice. SR 48692 (0.1-1 mg/kg, i.p.) and SR 142948A (0.03-0.1 mg/kg, i.p.) failed to affect mouse spontaneous locomotor activity and amphetamine-induced (2.5 mg/kg, i.p.) hyper-locomotion. However, SR 48692 (0.1 and 0.3 mg/kg, i.p.) and SR 142948A (0.03 and 0.05 mg/kg, i.p.) significantly alleviated the reduction of locomotor activity elicited by haloperidol (0.01 and 0.04 mg/kg, s.c.) in vehicle- or amphetamine-treated mice. Finally, SR 48692 (0.3 mg/kg, i.p.) and SR 142948A (0.05 and 0.1 mg/kg, i.p.) increased mouse catalepsy produced by haloperidol (0.3 mg/kg, s.c.). The present results indicate that while endogenous NT is not involved in the modulation of either mouse spontaneous locomotor activity or amphetamine-induced hyper-locomotion, it might act by enhancing the therapeutic effects of haloperidol and by attenuating the extrapyramidal side effects elicited by this antipsychotic.

Ritanserin counteracts both rat vacuous chewing movements and nigro-striatal tyrosine hydroxylase-immunostaining alterations induced by haloperidol.

The effect of subchronic co-administration of ritanserin (1.5 mg/kg, i.p., twice a day) and haloperidol (1 mg/kg, i.p., twice a day) on rat vacuous chewing movements and on tyrosine hydroxylase-immunostaining was investigated. Ritanserin significantly reduced rat vacuous chewing movements observed following 2, 3 and 4 weeks of haloperidol administration and after 5 days of haloperidol withdrawal. Furthermore, ritanserin prevented the reduction of striatal tyrosine hydroxylase-immunostaining and the shrinkage of nigral dopaminergic cell bodies induced by haloperidol. The present results indicate that ritanserin may possess protective properties on both dopaminergic nigro-striatal neuron alterations and vacuous chewing movements induced by haloperidol, and provide further evidence indicating a possible association between these two haloperidol-induced effects.

Haloperidol versus risperidone on rat "early onset" vacuous chewing.

Similarly to acute rat catalepsy, "early onset" vacuous chewing movements (VCMs) induced by subchronic treatment with antipsychotic have recently been proposed as a model of human extrapyramidal symptoms. In the present study, the propensities of haloperidol and risperidone in inducing rat "early onset" VCMs were compared using doses of the two antipsychotics that acutely induce similar catalepsy. Comparable rat catalepsy states were observed when the effects produced by 0.1, 0.5, and 1mg/kg of haloperidol were compared with those induced by 1, 4, and 10mg/kg of risperidone, respectively. These doses of the two antipsychotics were then administered twice a day for 4 weeks and VCMs scored after 12h, 5 days, or 3 weeks of drug withdrawal. Among the haloperidol-treated groups, only those rats injected with 0.5 and 1mg/kg showed high levels of VCMs after 12h and 5 days of drug withdrawal when compared to vehicle-treated rats, while basal levels of VCMs were reached after 3 weeks from the last injection. High VCMs levels were observed in risperidone-treated rats only at the dose of 10mg/kg and after 12h of drug withdrawal, but not after 5 days or 3 weeks. The present results indicated that haloperidol possessed a much higher propensity to induce rat "early onset" VCMs than risperidone.

The cerebellar GABAA alpha6 subunit is differentially modulated by chronic ethanol exposure in normal (R100R) and mutated (Q100Q) sNP rats.

Sardinian alcohol non-preferring (sNP) rats carry a point mutation (R100Q) in the cerebellar expressed GABAA receptor alpha6 subunit gene, leading to a higher sensitivity to ethanol and diazepam. The role of the alpha6 subunit gene cluster in the ethanol non-preferring phenotype was here investigated by measuring the levels of alpha1, alpha6 and gamma2 peptide in the cerebellum of normal (RR) and mutated (QQ) sNP rats after 2 weeks of chronic ethanol administration. Western blot analysis revealed that the alpha6 subunit is increased in RR sNP rats after chronic ethanol exposure (25.44%+/-8.69 versus control), while it remained unchanged in mutated QQ sNP rats. Interestingly, chronic ethanol administration decreased alpha1 peptide levels in the cerebellum of both rat lines to a similar extent (30.99%+/-6.74 and 27.12%+/-9.83 in RR and QQ rats, respectively), while gamma2 peptide levels remained unchanged. To further correlate the genetic and biochemical difference of the normal and mutated sNP rats with their aversive phenotype, we exposed sNP rats to a protocol of acquisition and maintenance of ethanol drinking. QQ sNP rats drank less ethanol than RR rats during the acquisition phase, but such difference was lost during the maintenance phase. These data may contribute to elucidating the mechanisms of alcohol avoidance in rat lines selected for this behavior when exposed to ethanol solution.