Trends in prescription and cost of Sativex, a cannabinoid-based medicine, in treating patients with multiple sclerosis in England.

Aim: Cannabis-based medication has recently been made available in the NHS for reducing pain and spasticity in patients with multiple sclerosis (MS). The currently available preparation of Sativex (nabiximols) contains a combination of botanical cannabis extracts with cannabidiol (CBD) and tetrahydrocannabinol (THC) with almost equal amounts in addition to minor cannabinoids and terpenoids and is delivered via an oro-mucosal spray. The present study aims to examine the use and trends in prescribing cannabinoid-based Sativex to control pain in patients diagnosed with MS. Methods: Primary care prescribing data for cannabinoid-based Sativex (2013-2022) from the Prescription Cost Analysis were extracted and analysed. Linear regression analyses were performed to examine prescription trends and prescription costs (average change per year). Results: There was a general increasing trend in the number of prescriptions each year, from 4.42 items dispensed per 100,000 people in 2013 to 5.15 in 2022. Overall, prescription items for cannabinoid-based Sativex increased by 0.34% per year (95% CI:-3.98, 4.67, p = 0.860) on average between 2013 and 2022. On average, a 2.43% (95% CI: -5.78, 0.92, p = 0.133) increase per year was observed for the costs of cannabinoid-based Sativex from 2013 to 2022. Conclusion: The results suggested that cannabinoid-based Sativex should be considered an option due to its effectiveness, acceptable tolerance, and safety profile in the prescribing of Sativex.

Investigation of the cytotoxicity induced by cannabinoids on human ovarian carcinoma cells.

Cannabinoids have been shown to induce anti-tumor activity in a variety of carcinoma cells such as breast, prostate, and brain. The aim of the present study is to investigate the anti-tumor activity of cannabinoids, CBD (cannbidiol), and CBG (cannabigerol) in ovarian carcinoma cells sensitive and resistant to chemotherapeutic drugs. Sensitive A2780 cells and resistant A2780/CP70 carcinoma cells and non-carcinoma cells were exposed to varying concentrations of CBD, CBG, carboplatin or CB1 and CB2 receptor antagonists, AM251 and AM630, respectively, alone or in combination, at different exposure times and cytotoxicity was measured by MTT assay. The mechanism of action of CBD and CB in inducing cytotoxicity was investigated involving a variety of apoptotic and cell cycle assays. Treatment with CBD and CBG selectively, dose and time dependently reduced cell viability and induced apoptosis. The effect of CBD was stronger than CBG in all cell lines tested. Both CBD and CBG induced stronger cytotoxicity than afforded by carboplatin in resistant cells. The cytotoxicity induced by CBD was not CB1 or CB2 receptor dependent in both carcinoma cells, however, CBG-induced cytotoxicity may involve CB1 receptor activity in cisplatin-resistant carcinoma cells. A synergistic effect was observed when cannabinoids at sublethal doses were combined with carboplatin in both carcinoma cells. The apoptotic event may involve loss of mitochondrial membrane potential, Annexin V, caspase 3/7, ROS activities, and cell cycle arrest. Further studies are required to investigate whether these results are translatable in the clinic. Combination therapies with conventional cancer treatments using cannabinoids are suggested.

Could cannabinoids provide a new hope for ovarian cancer patients?

It is known that gynecological cancers remain a worldwide problem and as shown by the statistics, there is a need for new gynecological cancer treatments. Cannabinoids, the pharmacologically active compounds of the Cannabis sativa plant, have been used for many centuries by individuals as a symptomatic treatment to alleviate pain, nausea, vomiting, and to help stimulate appetite. Research has revealed that cannabinoids also exert anti-cancer activity such as anti-proliferative and pro-apoptotic effects through a variety of mechanisms. There is significant value in the development of these compounds as anti-cancer therapies in clinical practice as they do not produce the typical toxic side effects that exist with conventional therapies and recent clinical trials have shown their great tolerability by patients at high doses. Cannabinoids can induce psychoactive effects that could limit their progression. Therefore, non-psychoactive cannabinoids are attracting pharmacological interest due to their inability to produce psychological effects. Recent studies have focussed on non-psychoactive cannabinoids in ovarian cancer and have revealed promising pre-clinical results that indicate that these compounds may have potential benefits in the treatment of these cancers. However, there are still unanswered questions and research gaps that need to be addressed. This review summarizes the current understanding of this topic and identifies the current gaps in knowledge that provide a useful direction for future work.

The impact of COVID-19 on electronic repeat dispensing (eRD) in general practice.

BACKGROUND: Electronic repeat dispensing (eRD) has been part of the community pharmacy contact since 2005 and a requirement in the General Medical Services contract since 2019. NHS England highlights benefits of eRD as increased efficiency in general practice of 2.7 million hours annually if 80% of all repeat prescriptions are issued as eRD. Despite clear benefits to patients, community pharmacies and general practices, the uptake of eRD remains low and variable across general practices in West Yorkshire, UK. OBJECTIVES: To investigate the impact of COVID-19 on eRD in general practice and understand the key enablers to its uptake. METHODS: A 19-item questionnaire was developed and piloted during cognitive interviews. A cross-sectional survey was conducted via emails to general practices in West Yorkshire, UK, between July 2020 and November 2020. RESULTS: Sixty-seven complete responses were received (23 pharmacists, 21 practice managers, 11 general practitioners, seven pharmacy technicians, four advanced practitioners, one prescription clerk). 59% of respondents were aware of eRD uptake in their surgery (mean value 4.56% ± 0.229%). Higher uptake of eRD was demonstrated where the general practice integrated eRD into routine workflows during the repeat prescription reauthorisation process (P < 0.001) and where an eRD service lead is nominated (P = 0.04). CONCLUSION: Utilising eRD in the respective practices should be considered due to potential efficiency gains and the increase in average eRD utilisation observed in the study participating general practices was from 7.2% average uptake in March 2020 to 10.4% November 2020, as the response to COVID-19. The stated benefits of eRD by NHS England of 2.7 million hours per annum predates the roll out of electronic transmission of prescriptions suggesting further research is needed to quantify the efficiency gains in present NHS general practice environments.

COVID-19 and diabetes in 2020: a systematic review.

Attempts were made to review the literature on diabetic patients who experience complications when they contract COVID-19, and to determine whether ethnicity and other risk factors play an important role in the development of symptoms and their severity, as well as responding to medications. A literature search was performed using five keywords, namely COVID-19, diabetes, ethnicity, medications, and risk factors between January 2019 and December 2020 using electronic databases such as PubMed, Science Direct, Google Scholar, Springer Link, and Scopus. Forty studies were included. The review indicated that diabetes was a significant risk factor for poorer outcomes and increased mortality associated with COVID-19. There were several risk factors for diabetic patients that increased their likelihood of poorer outcomes associated with COVID-19. These included black and Asian ethnicity, male sex with high BMI. In conclusion, patients with diabetes of black or Asian origin with high BMI, male sex, and older age had an increased risk of poorer outcomes associated with COVID-19. This highlights the importance of considering the history of the patient in prioritising care and treatment.

Investigation of the cytotoxicity induced by didocosahexaenoin, an omega 3 derivative, in human prostate carcinoma cell lines.

The aim of the present study was to investigate the cytotoxicity induced by an omega-3 derivative, didocosahexaenoin (Dido) on human prostate carcinoma cells and to compare the cytotoxicity to that of docosahexaenoic acid (DHA). Different carcinoma- and non-carcinoma cells were exposed to various concentrations of omega-3 compounds at varying exposure times and the cytotoxicity was measured by MTT assay. The mechanism of Dido-induced apoptosis was investigated in prostate carcinoma cells. Dido induced stronger cytotoxicity than DHA in human prostate carcinoma cells in a dose- and time-dependent manner. Dido was also more selective and potent in inducing cytotoxicity in prostate carcinoma cells than other carcinoma cell lines tested. Pre-treatment with Dido increased the level of reactive oxygen species (ROS) in prostate carcinoma cells. Pre-treatment with various antioxidants reduced the cytotoxicity induced by Dido. Pre-treatment with Dido ≥30 â€‹µM also induced apoptosis which was suggested to involve an externalisation of phosphatidyl serine, a significant increase in the mitochondrial membrane potential (p â€‹< â€‹0.01) and the level of activated caspase 3/7 (p â€‹< â€‹0.05) in prostate carcinoma cells. This study is the first to show that Dido induced cytotoxicity with high selectivity and higher potency than DHA in human prostate carcinoma cells. The mechanism of action is likely to involve an increase in the level of ROS, loss in the mitochondrial membrane potential as well as externalisation of phosphatidyl serine and increase in the caspase 3/7 activity. Dido may have potential to be used for the adjuvant therapy or combination therapy with conventional chemotherapeutic drugs.

Ovarian cancer and KiSS-1 gene expression: A consideration of the use of Kisspeptin plus Kisspeptin aptamers in diagnostics and therapy.

Gynaecological cancers continue to present a significant health burden upon the health of the global female population. This deficit is most prominent with ovarian cancer which possesses the lowest survival rate compared to all other cancers occurring within this anatomical region, with an annual UK-mortality of 7,300. The poor tolerability and selectively of the treatment options that are currently available is likely to have contributed to this high mortality rate thus, demonstrating the need for the development of enhanced therapeutic approaches. Aptamer technology would involve the engineering of specifically sequenced oligonucleotide chains, which bind to macromolecular targets with a high degree of affinity and selectively. Recent in-vitro studies conducted upon the clinical utility of this technique have supported its superiority in targeting individual therapeutic drug targets compared to various other targeting moieties currently within therapeutic use such as, monoclonal antibodies. For this reason, the employment of this technique is likely to be favourable in reducing the incidence of non-specific, chemotherapy-associated adverse effects. Kisspeptin is a naturally expressed polypeptide with an established role in the development of the reproductive system and other proposed roles in influencing the ability of ovarian cancer growths to exhibit the metastasis hallmark. This distinctive feature would indicate the potential for the manipulation of this pathway through the application of aptamer structures in developing a novel prophylactic strategy and improve the long-term outcome for ovarian cancer patients.

Establishing and Evaluating a Study Questionnaire on Knowledge and Attitudes of Healthcare Professionals Towards Recreational and Medical Cannabis Across Europe.

BACKGROUND AND OBJECTIVE: The present survey was a preliminary to a European research project on the attitude and knowledge of healthcare professionals towards the use of medical cannabis. The objective was to evaluate the readability, understandability, and relevance of a first version of the study questionnaire before preparing the finalized questionnaire, which will be subsequently proposed to European healthcare professionals on a large scale. METHODS: A cross-sectional study was conducted between December 2019 and May 2020. We established an electronic evaluation questionnaire relating to the study questionnaire. This evaluation questionnaire was proposed to multidisciplinary experts from all over Europe. Feedback from the evaluation questionnaire was considered for improving and finalizing the study questionnaire. RESULTS: 66 evaluation questionnaires were collected from nine European countries (Cyprus, France, Germany, Italy, Lithuania, Portugal, Spain, Sweden, United Kingdom), which corresponded to a participation rate of 41.5%. Most participants were women (65.2%, n = 43). The mean age was 39.5 years ± 11.6. Each participant could specify several occupations. There were 25 pharmacologists, 24 physicians, ten pharmacists, four university teachers, three epidemiologists or public health experts, one nurse, one biotechnologist, one microbiologist, and one police researcher. Overall, 84.8% of participants were interested in the topic of the survey on the knowledge and attitudes of healthcare professionals towards recreational and medical cannabis across Europe. Participants were satisfied with all but six of the proposed questions. In addition, two additional questions were subject for comments despite a high level of satisfaction. Consequently, the concerned questions (n = 8) were modified. CONCLUSION: This evaluation survey was a necessary step to improve the quality of the future research project. The positive feedback encourages the authors to proceed with the project on a European scale, scheduled for 2021.

Frequency of beta S globin gene haplotypes among sickle cell patients in Nigeria.

OBJECTIVE: To determine the frequency of beta s globin gene haplotypes in Nigerian patients with sickle cell disease (SCD) and to measure their correlation with clinical and haematological characteristics. METHODS: This study enrolled patients with SCD and collected their peripheral blood for restriction fragment length polymorphism analysis in order to identify five polymorphic sites in the ß-globin gene cluster. RESULTS: A total of 245 homozygous SCD patients (490 alleles) were included in the study. Among the analysed alleles, 426 (86.9%) had the Benin (BEN) haplotype; 19 (3.9%) had the Senegal (SEN) haplotype; 31 (6.3%) had the Cameroon haplotype; five (1.0%) had the Bantu/Central African Republic haplotype; and nine 9 (1.8%) had atypical haplotypes. No significant association was observed between the haplotypes and haematological events, although patients with the BEN/SEN haplotype showed improved red blood cell counts, haemoglobin levels and red blood cell width index. No significant association was observed between the haplotypes and the three clinical manifestations, although patients with the BEN/SEN haplotype showed a four-fold lower frequency of painful episodes. CONCLUSION: These findings suggest that the SEN haplotype combined with the BEN haplotype might contribute toward a better haematological profile and milder clinical severity in SCD.

Fluoxetine selectively induces p53-independent apoptosis in human colorectal cancer cells.

Fluoxetine has been shown to induce anti-tumour activity. The aim of this study was to determine the effect of fluoxetine on HCT116+/+ and p53 gene-depleted HCT116-/- human colorectal cancer cells and the mechanisms, including potential p53-dependence, of its action. Fluoxetine-induced apoptosis was investigated by mitochondrial membrane potential assay, Annexin V assay, two-step cell cycle analysis using NC-3000™ system and pharmacological inhibition assays. Fluoxetine induced very selectively concentration-dependent apoptosis in human colorectal cancer cells by altering mitochondrial membrane potential and inducing translocation of phosphatidylserine to the outer membrane layer. Further evidence of the preponderance of apoptosis in fluoxetine-induced cell death is provided by the finding that the cell death was not blocked by inhibitors of parthanatos, a form of cell death that results from overactivation of the enzyme poly (ADP-ribose) polymerase (PARP) but is different from apoptosis. Data obtained indicate fluoxetine caused cell cycle event at Sub-G1 and G0/G1 phases in both cell lines. In terms of apoptosis, there is no significant difference between the responses of the two cell lines to fluoxetine. In conclusion, fluoxetine's cytotoxicity induces mainly apoptosis and causes DNA fragmentation in human colorectal cancer cells, which seemed to be independent of the p53 protein, as no significant difference in death profiles in response to fluoxetine treatment was observed in both the p53-intact and the p53-deleted cell lines. Fluoxetine, therefore, has potential for being repurposed as a drug for the treatment of colon cancer and thus deserves further investigations in this context.

Selective in vitro anti-cancer activity of non-alkylating minor groove binders.

Traditional cytotoxic agents which act through a DNA-alkylating mechanism are relatively non-specific, resulting in a small therapeutic window and thus limiting their effectiveness. In this study, we evaluate a panel of 24 non-alkylating Strathclyde Minor Groove Binders (S-MGBs), including 14 novel compounds, for in vitro anti-cancer activity against a human colon carcinoma cell line, a cisplatin-sensitive ovarian cancer cell line and a cisplatin-resistant ovarian cancer cell line. A human non-cancerous retinal epithelial cell line was used to measure selectivity of any response. We have identified several S-MGBs with activities comparable to cis-platin and carboplatin, but with better in vitro selectivity indices, particularly S-MGB-4, S-MGB-74 and S-MGB-317. Moreover, a comparison of the cis-platin resistant and cis-platin sensitive ovarian cancer cell lines reveals that our S-MGBs do not show cross resistance with cisplatin or carboplatin and that they likely have a different mechanism of action. Finally, we present an initial investigation into the mechanism of action of one compound from this class, S-MGB-4, demonstrating that neither DNA double strand breaks nor the DNA damage stress sensor protein p53 are induced. This indicates that our S-MGBs are unlikely to act through an alkylating or DNA damage response mechanism.

Further investigation of the effects of 5-hydroxytryptamine, 8-OH-DPAT and DOI to mediate contraction and relaxation responses in the intestine and emesis in Suncus murinus.

5-HT receptors are implicated in many gastrointestinal disorders. However, the precise role of 5-HT in mediating GI responses in Suncus murnius is still unclear. Therefore in this study, the effects of 5-HT and its agonists were investigated in Suncus. The involvement of 5-HT2C receptors in mediating emesis was also investigated. The ability of 5-HT and its agonists/antagonists at 5-HT1A and 5-HT2 to modify GI motility was investigated in vitro and in vivo. WAY100635 (a 5-HT1A antagonist) inhibited the contraction response to 5-HT in the proximal segments without affecting the maximum response; whilst enhancing the contraction to 5-HT (>30.0nM) in the distal intestine. The selective 5-HT2A and 5-HT2B receptor antagonists MDL-100907 and RS-127445 attenuated 5-HT-induced contractions (<10.0µM) in the distal segments. RS-127445 also attenuated 5-HT-induced contractions in the central segments. The selective 5-HT2C receptor antagonist SB-242084, attenuated the responses to 5-HT (> 3.0nM) in the proximal and central but not the distal regions. 8-OH-DPAT-induced relaxation was resistant to the antagonism by 5-HT1A/7 antagonists. DOI in the presence of 5-HT1A/2A/2B/2C antagonists induced greater contraction responses (>1.0µM) in most tissues, whilst RS-127445, or SB-242084, reduced the responses to DOI (< 1.0µM) in some tissues. SB-242084 also suppressed emesis-induced by motion and intragastric CuSO4. In conclusion, within different regions of intestine, 5-HT2 receptors are differently involved in contraction and emetic responses and that 8-OH-DPAT induces relaxation via non-5-HT1A/7 receptors. Suncus could provide a model to investigate these diverse actions of 5-HT.

Cannabinoid pharmacology in cancer research: A new hope for cancer patients?

Cannabinoids have been used for many centuries to ease pain and in the past decade, the endocannabinoid system has been implicated in a number of pathophysiological conditions, such as mood and anxiety disorders, movement disorders such as Parkinson's and Huntington's disease, neuropathic pain, multiple sclerosis, spinal cord injury, atherosclerosis, myocardial infarction, stroke, hypertension, glaucoma, obesity, and osteoporosis. Several studies have demonstrated that cannabinoids also have anti-cancer activity and as cannabinoids are usually well tolerated and do not produce the typical toxic effects of conventional chemotherapies, there is considerable merit in the development of cannabinoids as potential anticancer therapies. Whilst the presence of psychoactive effects of cannabinoids could prevent any progress in this field, recent studies have shown the value of the non-psychoactive components of cannabinoids in activating apoptotic pathways, inducing anti-proliferative and anti-angiogenic effects. The aforementioned effects are suggested to be through pathways such as ERK, Akt, mitogen-activated protein kinase (MAPK) pathways, phosphoinositide 3-kinase (PI3K) pathways and hypoxia inducible factor 1 (HIF1), all of which are important contributors to the hallmarks of cancer. Many important questions still remain unanswered or are poorly addressed thus necessitating further research at basic pre-clinical and clinical levels. In this review, we address these issues with a view to identifying the key challenges that future research needs to address.

The effect of 5-HT and electrical field stimulation on the contractility of the whole isolated urinary bladder of Suncus murinus.

The present study used the whole isolated urinary bladder of Suncus murinus, to investigate the effect of exogenously added serotonin (5-HT) and electrical field stimulation (EFS) in the absence and presence of methysergide, a 5-HT1/2/7 receptor antagonist or the selective 5-HT7 receptor antagonist, SB269970. Further experiments investigated the involvement of potassium channel, cholinergic and purinergic systems in mediating the contractile response to EFS. Pre-treatment with methysergide reduced and increased the contractile responses to 5-HT and EFS, respectively. Pre-treatment with SB269970 increased the responses to 5-HT without modifying the EFS-induced contractions. EFS-induced contractions were not modified by pre-treatment with atropine (10µM), α-ß-methylene ATP or glibenclamide. EFS-induced contractions were attenuated by cromakalim (10µM) or atropine (0.1 µM). In conclusion, the 5-HT2 receptors are likely to play a role in mediating the contractile response to 5-HT in detrusor muscle. Furthermore, EFS-induced contractions are mediated through cholinergic and an unknown neurotransmitter which is modulated by K(ATP) channels in the detrusor muscle of Suncus murinus.

Anti-emetic and emetic effects of erythromycin in Suncus murinus: role of vagal nerve activation, gastric motility stimulation and motilin receptors.

Paradoxically, erythromycin is associated with nausea when used as an antibiotic but at lower doses erythromycin activates motilin receptors and is used to treat delayed gastric emptying and nausea. The aim of this study was to characterise pro- and anti-emetic activity of erythromycin and investigate mechanisms of action. Japanese House musk shrews (Suncus murinus) were used. Erythromycin was administered alone or prior to induction of emesis with abnormal motion or subcutaneous nicotine (10mg/kg). The effects of erythromycin and motilin on vagal nerve activity and on cholinergically mediated contractions of the stomach (evoked by electrical field stimulation) were studied in vitro. The results showed that erythromycin (1 and 5mg/kg) reduced vomiting caused by abnormal motion (e.g., from 10.3 ± 1.8 to 4.0 ± 1.1 emetic episodes at 5mg/kg) or by nicotine (from 9.5 ± 2.0 to 3.1 ± 2.0 at 5mg/kg), increasing latency of onset to emesis; lower or higher doses had no effects. When administered alone, erythromycin 100mg/kg induced vomiting in two of four animals, whereas lower doses did not. In vitro, motilin (1, 100 nM) increased gastric vagal afferent activity without affecting jejunal afferent mesenteric nerve activity. Cholinergically mediated contractions of the stomach (prevented by tetrodotoxin 1 µM or atropine 1 µM, facilitated by l-NAME 300 µM) were facilitated by motilin (1-100 nM) and erythromycin (10-30 µM). In conclusion, low doses of erythromycin have anti-emetic activity. Potential mechanisms of action include increased gastric motility (overcoming gastric stasis) and/ or modulation of vagal nerve pathways involved in emesis, demonstrated by first-time direct recording of vagal activation by motilin.

The effects of cannabidiolic acid and cannabidiol on contractility of the gastrointestinal tract of Suncus murinus.

Cannabidiol (CBD) has been shown to inhibit gastrointestinal (GI) transit in pathophysiologic in vivo models, while having no effect in physiologic controls. The actions of the precursor of CBD, cannabidiolic acid (CBDA), have not been investigated in the GI tract. The actions of these phytocannabinoids on the contractility of the GI tract of Suncus murinus were investigated in the current study. The effects of CBDA and CBD in resting state and pre-contracted isolated intestinal segments, and on the contractile effects of carbachol and electrical field stimulation (EFS) on the intestines of S. murinus were examined. CBDA and CBD induced a reduction in resting tissue tension of isolated intestinal segments which was not blocked by the cannabinoid CB1 receptor antagonist, AM251, the CB(2) receptor antagonist AM630, or tetrodotoxin. CBDA and CBD reduced the magnitude of contractions induced by carbachol and the tension of intestinal segments that were pre-contracted with potassium chloride. In tissues stimulated by EFS, CBDA inhibited contractions induced by lower frequencies (0.1-4.0 Hz) of EFS, while CBD inhibited contractions induced by higher frequencies (4.0-20.0 Hz) of EFS. The data suggest that CBDA and CBD have inhibitory actions on the intestines of S. murinus that are not neuronallymediated or mediated via CB(1) or CB(2) receptors.

The effects of cannabidiol and tetrahydrocannabinol on motion-induced emesis in Suncus murinus.

The effect of cannabinoids on motion-induced emesis is unknown. The present study investigated the action of phytocannabinoids against motion-induced emesis in Suncus murinus. Suncus murinus were injected intraperitoneally with either cannabidiol (CBD) (0.5, 1, 2, 5, 10, 20 and 40 mg/kg), Delta(9)-tetrahydrocannabinol (Delta(9)-THC; 0.5, 3, 5 and 10 mg/kg) or vehicle 45 min. before exposure to a 10-min. horizontal motion stimulus (amplitude 40 mm, frequency 1 Hz). In further investigations, the CB(1) receptor antagonist, N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM 251; 5 mg/kg), was injected 15 min. prior to an injection of Delta(9)-THC (3 mg/kg). The motion stimulus was applied 45 min. later. The number of emetic episodes and latency of onset to the first emetic episode were recorded. Pre-treatment with the above doses of CBD did not modify the emetic response to the motion stimulus as compared to the vehicle-treated controls. Application of the higher doses of Delta(9)-THC induced emesis in its own right, which was inhibited by AM 251. Furthermore, pre-treatment with Delta(9)-THC dose-dependently attenuated motion-induced emesis, an effect that was inhibited by AM 251. AM 251 neither induced an emetic response nor modified motion-induced emesis. The present study indicates that Delta(9)-THC, acting via the CB(1) receptors, is anti-emetic to motion, and that CBD has no effect on motion-induced emesis in Suncus murinus.

The effect of the 5-HT1A receptor agonist, 8-OH-DPAT, on motion-induced emesis in Suncus murinus.

In the present study we evaluated the role of 5-HT(1A) receptors in mediating the inhibitory action of 8-OH-DPAT, a 5-HT(1A) receptor agonist, in motion sickness in Suncus murinus. 8-OH-DPAT (0.1 mg/kg, i. p) attenuated motion-induced emesis which was associated with an increase in the latency of the onset to the first emetic episode. Pre-treatment with methysergide (a 5-HT(1/2/7) receptor antagonist, 1.0 mg/kg, i. p.), WAY-100635 (a 5-HT(1A) receptor antagonist, 1.0 mg/kg, i. p.), SB269970A (a 5-HT(7) receptor antagonist, 1.0 and 5.0 mg/kg, i. p.), ondansetron (a 5-HT(3) receptor antagonist, 1.0 mg/kg, i. p) or GR13808 (a 5-HT(4) receptor antagonist, 0.5 mg/kg, i. p) failed to modify the inhibitory action of 8-OH-DPAT on motion sickness. Furthermore, the application of either methysergide, WAY-100635, SB269970A, ondansetron or GR13808 alone had no effect on motion sickness in its own right. These data indicate that neither 5-HT(1A) nor any 5-HT(2) receptor subtypes, 5-HT(3), 5-HT(4) and 5-HT(7) receptors are likely to be involved in the inhibition of motion-induced emesis mediated by 8-OH-DPAT.

The effect of serotonin and serotonin receptor antagonists on motion sickness in Suncus murinus.

In the present study, we investigated the effect of 5-hydroxytryptamine (5-HT) and 5-HT receptor agonists and antagonists on motion sickness in Suncus murinus, and the possibility that the emetic stimulus of 5-HT can alter the sensitivity of the animals to the different emetic stimulus of motion sickness. 5-HT (1.0, 2.0, 4.0 and 8.0 mg/kg ip) induced emesis and that was antagonised by methysergide (1.0 mg/kg ip), the 5-HT(4) receptor antagonist sulphamate[1-[2-[(methylsulphonyl)amino]ethyl]-4-piperidinyl]methyl-5-fluoro-2-methoxy-1H-indole-3-carboxylate (GR125487D; 1.0 mg/kg ip) and granisetron (0.5 mg/kg ip). Pretreatment with 5-HT caused a dose-related attenuation of the emetic response induced by a subsequent motion stimulus, which was not significantly modified by methysergide, granisetron or GR125487D pretreatment. (+)-1-(2,5-Dimethoxy-4-iodophenyl)-2-amino-propane (DOI; 0.5 and 1.0 mg/kg ip), 8-hydroxy-2(di-n-propylamino)tetralin (8-OH-DPAT; 0.1 mg/kg ip) but not methysergide, GR125487D or granisetron, attenuated motion-induced emesis, and that was not affected by pretreatment with ketanserin (2.0 mg/kg, ip) or N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohexanecarboxamide trihydrocholoride (WAY-100635; 1.0 mg/kg ip), respectively. Indeed, ketanserin alone (0.1, 0.3, 1.0 and 2.0 mg/kg ip) attenuated motion sickness. These data indicate that 5-HT(1/2), 5-HT(3) and 5-HT(4) receptors are involved in the induction of 5-HT-induced emesis. However, agonist action at the 5-HT(1A/7) and 5-HT(2) receptors, and antagonist action at the 5-HT(2A) receptors can attenuate motion sickness in S. murinus.