Renato Malcher-Lopes

Dr. Renato Malcher-Lopes

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Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 June 2006 in Journal of Neuroscience
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Journal Article
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RMRenato Malcher-Lopes
Renato Malcher-Lopes
SDShi Di
Shi Di
VMVictor S. Marcheselli
Victor S. Marcheselli
FWFeng-Ju Weng
Feng-Ju Weng
CSChristopher T. Stuart
Christopher T. Stuart
JTJeffrey G. Tasker
Jeffrey G. Tasker
The hypothalamic paraventricular nucleus (PVN) integrates preautonomic and neuroendocrine control of energy homeostasis, fluid balance, and the stress response. We recently demonstrated that glucocorticoids act via a membrane receptor to rapidly cause endocannabinoid-mediated suppression of synaptic excitation in PVN neurosecretory neurons. Leptin, a major signal of nutritional state, suppresses CB1 cannabinoid receptor-dependent hyperphagia (increased appetite) in fasting animals by reducing hypothalamic levels of endocannabinoids. Here we show that glucocorticoids stimulate endocannabinoid biosynthesis and release via a Gαs–cAMP–protein kinase A-dependent mechanism and that leptin blocks glucocorticoid-induced endocannabinoid biosynthesis and suppression of excitation in the PVN via a phosphodiesterase-3B-mediated reduction in intracellular cAMP levels. We demonstrate this rapid hormonal interaction in both PVN magnocellular and parvocellular neurosecretory cells. Leptin blockade of the glucocorticoid-induced, endocannabinoid-mediated suppression of excitation was absent in leptin receptor-deficient obese Zucker rats. Our findings reveal a novel hormonal crosstalk that rapidly modulates synaptic excitation via endocannabinoid release in the hypothalamus and that provides a nutritional state-sensitive mechanism to integrate the neuroendocrine regulation of energy homeostasis, fluid balance, and the stress response.

31 October 2019 in Frontiers in Neurology
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PFPaulo Fleury-Teixeira
Paulo Fleury-Teixeira
FCFabio Viegas Caixeta
Fabio Viegas Caixeta
LSLeandro Cruz Ramires da Silva
Leandro Cruz Ramires da Silva
JBJoaquim Pereira Brasil-Neto
Joaquim Pereira Brasil-Neto
RMRenato Malcher-Lopes
Renato Malcher-Lopes
Autism Spectrum Disorders comprise conditions that may affect cognitive development, motor skills, social interaction, communication, and behavior. This set of functional deficits often results in lack of independence for the diagnosed individuals, and severe distress for patients, families, and caregivers. There is a mounting body of evidence indicating the effectiveness of pure cannabidiol (CBD) and CBD-enriched Cannabis sativa extract (CE) for the treatment of autistic symptoms in refractory epilepsy patients. There is also increasing data support for the hypothesis that non-epileptic autism shares underlying etiological mechanisms with epilepsy. Here we report an observational study with a cohort of 18 autistic patients undergoing treatment with compassionate use of standardized CBD-enriched CE (with a CBD to THC ratio of 75/1). Among the 15 patients who adhered to the treatment (10 non-epileptic and five epileptic) only one patient showed lack of improvement in autistic symptoms. Due to adverse effects, three patients discontinued CE use before 1 month. After 6–9 months of treatment, most patients, including epileptic and non-epileptic, showed some level of improvement in more than one of the eight symptom categories evaluated: Attention Deficit/Hyperactivity Disorder; Behavioral Disorders; Motor Deficits; Autonomy Deficits; Communication and Social Interaction Deficits; Cognitive Deficits; Sleep Disorders and Seizures, with very infrequent and mild adverse effects. The strongest improvements were reported for Seizures, Attention Deficit/Hyperactivity Disorder, Sleep Disorders, and Communication and Social Interaction Deficits. This was especially true for the 10 non-epileptic patients, nine of which presented improvement equal to or above 30% in at least one of the eight categories, six presented improvement of 30% or more in at least two categories and four presented improvement equal to or above 30% in at least four symptom categories. Ten out of the 15 patients were using other medicines, and nine of these were able to keep the improvements even after reducing or withdrawing other medications. The results reported here are very promising and indicate that CBD-enriched CE may ameliorate multiple ASD symptoms even in non-epileptic patients, with substantial increase in life quality for both ASD patients and caretakers.

1 April 2008 in European Journal of Pharmacology
Verified
Journal Article
Closed access
RMRenato Malcher-Lopes
Renato Malcher-Lopes
AFAlier Franco
Alier Franco
JTJeffrey G. Tasker
Jeffrey G. Tasker

21 August 2023 in Frontiers in Psychiatry
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Journal Article
Open access
PMPatrícia Soares Silva Montagner
Patrícia Soares Silva Montagner
WMWesley Medeiros
Wesley Medeiros
LSLeandro Cruz Ramires da Silva
Leandro Cruz Ramires da Silva
CBClarissa Nogueira Borges
Clarissa Nogueira Borges
JBJoaquim Brasil-Neto
Joaquim Brasil-Neto
RMRenato Malcher-Lopes
Renato Malcher-Lopes
Autism Spectrum Disorders (ASD) may significantly impact the well-being of patients and their families. The therapeutic use of cannabis for ASD has gained interest due to its promising results and low side effects, but a consensus on treatment guidelines is lacking. In this study, we conducted a retrospective analysis of 20 patients with autistic symptoms who were treated with full-spectrum cannabis extracts (FCEs) in a response-based, individually-tailored dosage regimen. The daily dosage and relative proportions of cannabidiol (CBD) and tetrahydrocannabinol (THC) were adjusted based on treatment results following periodic clinical evaluation. Most patients (80%) were treated for a minimum of 6 months. We have used a novel, detailed online patient- or caregiver-reported outcome survey that inquired about core and comorbid symptoms, and quality of life. We also reviewed patients’ clinical files, and no individual condition within the autistic spectrum was excluded. This real-life approach enabled us to gain a clearer appraisal of the ample scope of benefits that FCEs can provide for ASD patients and their families. Eighteen patients started with a CBD-rich FCE titrating protocol, and in three of them, the CBD-rich (CBD-dominant) FCE was gradually complemented with low doses of a THC-rich (THC-dominant) FCE based on observed effects. Two other patients have used throughout treatment a blend of two FCEs, one CBD-rich and the other THC-rich. The outcomes were mainly positive for most symptoms, and only one patient from each of the two above-mentioned situations displayed important side effects one who has used only CBD-rich FCE throughout the treatment, and another who has used a blend of CBD-Rich and THC-rich FCEs. Therefore, after FCE treatment, 18 out of 20 patients showed improvement in most core and comorbid symptoms of autism, and in quality of life for patients and their families. For them, side effects were mild and infrequent. Additionally, we show, for the first time, that allotriophagy (Pica) can be treated by FCEs. Other medications were reduced or completely discontinued in most cases. Based on our findings, we propose guidelines for individually tailored dosage regimens that may be adapted to locally available qualified FCEs and guide further clinical trials.

27 May 2024 in Pharmaceuticals
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JMJeanne Alves de Souza Mazza
Jeanne Alves de Souza Mazza
LFLisiane Seguti Ferreira
Lisiane Seguti Ferreira
AMAlice de Faria Martins-Vieira
Alice de Faria Martins-Vieira
DBDoris Day Lopes Beserra
Doris Day Lopes Beserra
VRVictor Alves Rodrigues
Victor Alves Rodrigues
FCFabio Viegas Caixeta
Fabio Viegas Caixeta
Autism Spectrum Disorder (ASD) encompasses a wide range of neurodevelopmental conditions characterized by deficits in social interaction, communication and behavior. Current pharmacological options are limited and feature significant side effects. In this study, we conducted a retrospective, observational, and cross-sectional cohort study to evaluate the effects of Cannabidiol (CBD)-dominant, full-spectrum cannabis extract, containing Tetrahydrocannabinol (THC) in a ratio of 33:1 (CBD:THC), on non-syndromic children and adolescents (5–18 years old) with moderate to severe ASD. Thirty volunteers were recruited, underwent neuropsychological evaluations and were treated with individualized doses of CBD-dominant extract. Clinical assessments were conducted by the designated clinician. Additionally, parents or caregivers were independently interviewed to assess perceived treatment effects. We found significant improvements in various symptomatic and non-symptomatic aspects of ASD, with minimal untoward effects, as reported by both clinical assessments and parental perceptions. The observed improvements included increased communicative skills, attention, learning, eye contact, diminished aggression and irritability, and an overall increase in both the patient’s and family’s quality of life. Despite its limitations, our findings suggest that treatment with full-spectrum CBD-dominant extract may be a safe and effective option for core and comorbid symptoms of ASD, and it may also increase overall quality of life for individuals with ASD and their families.

8 April 2024 in International Journal of Mental Health and Addiction
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Journal Article
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AGAndrea Donatti Gallassi
Andrea Donatti Gallassi
AOAndré Wagner Carvalho de Oliveira
André Wagner Carvalho de Oliveira
LRLarissa Alencar Rodrigues
Larissa Alencar Rodrigues
Eduardo Yoshio NakanoEduardo Yoshio Nakano
Eduardo Yoshio Nakano
PRPedro A. S. Ruas
Pedro A. S. Ruas
RMRenato Malcher-Lopes
Renato Malcher-Lopes
Cannabidiol (CBD) has been studied for substance use disorders treatment due to its anxiolytic effects, for sleep, appetite, reduction of craving, and maintenance of abstinence. The study aims to assess CBD’s feasibility, safety/tolerability, and preliminary efficacy compared to pharmacological treatment as usual for reducing crack use in people with crack use disorder (CUD) and investigate other parameters: adverse events, physical health symptoms, and craving. A double-blind, randomized clinical trial (RCT) with two treatment arms (CBD and control group) was conducted. Ninety participants were randomized and 73 were allocated: 37 control group and 36 CBD group for a 10-week treatment, comparing CBD (600 mg) with three drugs (fluoxetine, valproic acid, and clonazepam). The per-protocol analysis of participants who did not deviate from the study protocol compared the control and CBD treatment groups. Thirty-four completed at least half of the study and 25 finished. Participants attended weekly meetings for the study procedures (e.g., to receive the medication and provide urine for toxicological tests). Inter-group differences were performed with the Mann–Whitney test, the Wilcoxon test for differences intra-group, and Pearson’s Chi-square test or Fisher’s exact test to compare inter-group demographic data. The significance level was 5%. A “veracity index” (VI) was created as counterevidence (questionnaire data vs. the toxicological test result). Medications were considered safe/tolerable. The CBD group presented significantly fewer adverse events compared to the control group [e.g., dizziness (p = 0.001), memory impairment (p = 0.043)], which performed better in the reduction of clinical and psychiatric complaints (p = 0.008). In the intra-group analyses, the CBD group performed better in more parameters than the control group [e.g., reducing crack use (p = 0.016; T0 to T1)]. Data questionnaires were reliable regarding the use/non-use of crack (VI = 0.787). CBD is a safe/tolerable product. The CBD group manifested fewer adverse events than the control group, which had better clinical and psychiatric complaints results. There are some advantages for the CBD group in the intra-group analysis. Drug use self-report methodologies can be reliable. Trial registration details: This study is registered with Universal Trial Number (UTN) code: U1111-1234-0806. Available at https://ensaiosclinicos.gov.br/rg/RBR-4stgs8 (Effect of cannabidiol in the treatment of crack dependents)