cannabidiol and Hypoxia-Ischemia--Brain

Therapeutic hypothermia is well established as a standard treatment for infants with hypoxic-ischemic (HI) encephalopathy but it is only partially effective. The potential for combination treatments to augment hypothermic neuroprotection has major relevance. Our aim was to assess the effects of treating newborn rats following HI injury with cannabidiol (CBD) at 0.1 or 1 mg/kg, i.p., in normothermic (37.5°C) and hypothermic (32.0°C) conditions, from 7 d of age (neonatal phase) to 37 d of age (juvenile phase). Placebo or CBD was administered at 0.5, 24, and 48 h after HI injury. Two sensorimotor (rotarod and cylinder rearing) and two cognitive (novel object recognition and T-maze) tests were conducted 30 d after HI. The extent of brain damage was determined by magnetic resonance imaging, histologic evaluation, magnetic resonance spectroscopy, amplitude-integrated electroencephalography, and Western blotting. At 37 d, the HI insult produced impairments in all neurobehavioral scores (cognitive and sensorimotor tests), brain activity (electroencephalography), neuropathological score (temporoparietal cortexes and CA1 layer of hippocampus), lesion volume, magnetic resonance biomarkers of brain injury (metabolic dysfunction, excitotoxicity, neural damage, and mitochondrial impairment), oxidative stress, and inflammation (TNFα). We observed that CBD or hypothermia (to a lesser extent than CBD) alone improved cognitive and motor functions, as well as brain activity. When used together, CBD and hypothermia ameliorated brain excitotoxicity, oxidative stress, and inflammation, reduced brain infarct volume, lessened the extent of histologic damage, and demonstrated additivity in some parameters. Thus, coadministration of CBD and hypothermia could complement each other in their specific mechanisms to provide neuroprotection.

Topics: Animals; Animals, Newborn; Brain Injuries; Cannabidiol; Hypothermia; Hypoxia-Ischemia, Brain; Inflammation; Neuroprotective Agents; Rats

Hypothermia, the gold standard after a hypoxic-ischemic insult, is not beneficial in all treated newborns. Cannabidiol is neuroprotective in animal models of newborn hypoxic-ischemic encephalopathy. This study compared the relative efficacies of cannabidiol and hypothermia in newborn hypoxic-ischemic piglets and assessed whether addition of cannabidiol augments hypothermic neuroprotection.. HI led to sustained depressed brain activity and increased microglial activation, which was significantly improved by cannabidiol alone or with hypothermia but not by hypothermia alone. Hypoxic-ischemic-induced increases in Lac/NAA, Glu/NAA, TNFα or apoptosis were not reversed by either hypothermia or cannabidiol alone, but combination of the therapies did. No treatment modified the effects of HI on oxidative stress or astroglial activation. Cannabidiol treatment was well tolerated.. cannabidiol administration after hypoxia-ischemia in piglets offers some neuroprotective effects but the combination of cannabidiol and hypothermia shows some additive effect leading to more complete neuroprotection than cannabidiol or hypothermia alone.

Topics: Animals; Animals, Newborn; Apoptosis; Asphyxia; Brain; Brain Injuries; Cannabidiol; Disease Models, Animal; Drug Therapy, Combination; Hemodynamics; Hypothermia; Hypothermia, Induced; Hypoxia-Ischemia, Brain; Inflammation; Microglia; Neuroprotection; Neuroprotective Agents; Respiratory Physiological Phenomena; Swine

BackgroundBrain hypoxic-ischemic (HI) damage induces distant inflammatory lung damage in newborn pigs. We aimed to investigate the effects of cannabidiol (CBD) on lung damage in this scenario.MethodsNewborn piglets received intravenous vehicle, CBD, or CBD+WAY100635 (5-HT

Topics: Animals; Animals, Newborn; Brain; Bronchoalveolar Lavage Fluid; Cannabidiol; Disease Models, Animal; Hemodynamics; Hypoxia; Hypoxia-Ischemia, Brain; Inflammation; Interleukin-1beta; Lung; Lung Injury; Male; Oxidative Stress; Oxygen; Swine

Cannabidiol (CBD) is considered a promising neuroprotectant after perinatal hypoxia-ischemia (HI). We have previously studied the effects of CBD 1 mg/kg in the early phase after global HI in piglets. In contrast to prior studies, we found no evidence of neuroprotection and hypothesized that higher doses might be required to demonstrate efficacy in this animal model.. To assess the safety and potential neuroprotective effects of high-dose CBD.. Anesthetized newborn piglets underwent global HI by ventilation with 8% O2 until the point of severe metabolic acidosis (base excess -20 mmol/L) and/or hypotension (mean arterial blood pressure ≤20 mm Hg). Piglets were randomized to intravenous treatment with vehicle (n = 9) or CBD (n = 13). The starting dose, CBD 50 mg/kg, was reduced if adverse effects occurred. The piglets were euthanized 9.5 h after HI and tissue was collected for analysis.. CBD 50 mg/kg (n = 4) induced significant hypotension in 2 out of 4 piglets, and 1 out of 4 piglets suffered a fatal cardiac arrest. CBD 25 mg/kg (n = 4) induced significant hypotension in 1 out of 4 piglets, while 10 mg/kg (n = 5) was well tolerated. A significant negative correlation between the plasma concentration of CBD and hypotension during drug infusion was observed (p < 0.005). Neuroprotective effects were evaluated in piglets that did not display significant hypotension (n = 9) and CBD did not alter the degree of neuronal damage as measured by a neuropathology score, levels of the astrocytic marker S100B in CSF, magnetic resonance spectroscopy markers (Lac/NAA and Glu/NAA ratios), or plasma troponin T.. High-dose CBD can induce severe hypotension and did not offer neuroprotection in the early phase after global HI in piglets.

Topics: Animals; Animals, Newborn; Arterial Pressure; Brain; Cannabidiol; Disease Models, Animal; Hypotension; Hypoxia-Ischemia, Brain; Infusions, Intravenous; Neuroprotective Agents; Risk Assessment; S100 Calcium Binding Protein beta Subunit; Sus scrofa; Time Factors; Troponin T

A relevant therapeutic time window (TTW) is an important criterion for considering the clinical relevance of a substance preventing newborn hypoxic-ischemic (HI) brain damage.. To test the TTW of the neuroprotective effects of cannabidol (CBD), a non-psychoactive cannabinoid in a model of newborn HI brain damage.. 9-10 day-old C57BL6 mice underwent a HI insult (10% oxygen for 90 min after left carotid artery electrocoagulation). Then, CBD 1 mg/kg or vehicle were administered s.c. 15 min, or 1, 3, 6, 12, 18 or 24 h after the end of the HI insult. Seven days later brain damage was assessed using T2W Magnetic Resonance Imaging scan (ipsilateral hemisphere volume loss, IVHL) and histological studies: Nissl staining (neuropathological score), TUNEL staining (apoptotic damage) and immunohistochemistry with glial fibrillary acidic protein (astrocyte viability) or ionized calcium binding adaptor molecule (microglial activation).. CBD administered up to 18 h after HI reduced IHVL and neuropathological score by 60%, TUNEL+ count by 90% and astrocyte damage by 50%. In addition, CBD blunted the HI-induced increase in microglial population. When CBD administration was delayed 24 h, however, the neuroprotective effect was lost in terms of IHVL, apoptosis or astrogliosis reduction.. CBD shows a TTW of 18 h when administered to HI newborn mice, which represents a broader TTW than reported for other neuroprotective treatments including hypothermia.

Topics: Animals; Animals, Newborn; Apoptosis; Astrocytes; Cannabidiol; Dose-Response Relationship, Drug; Gliosis; Hypoxia-Ischemia, Brain; Immunohistochemistry; In Situ Nick-End Labeling; Injections, Subcutaneous; Magnetic Resonance Imaging; Mice; Mice, Inbred C57BL; Microglia; Neuroprotective Agents

Cannabidiol (CBD), a nonpsychoactive cannabinoid, has shown neuroprotective actions after neonatal hypoxia-ischemia (HI) in animals. We wanted to further explore the effects of CBD, alone and in conjunction with hypothermia, in a piglet model of global HI.. HI induced global damage with significantly increased neuropathology score, S100B in cerebrospinal fluid, hippocampal proton magnetic resonance spectroscopy biomarkers, plasma troponin-T, and urinary neutrophil gelatinase-associated lipocalin. CBD alone did not have any significant effects on these parameters while CBD+H reduced urinary neutrophil gelatinase-associated lipocalin compared with VEH+H (P < 0.05). Both hypothermic groups had significantly lower glutamate/N-acetylaspartate ratios (P < 0.01) and plasma troponin-T (P<0.05) levels compared with normothermic groups.. In contrast to previous studies, we do not find significant protective effects of CBD after HI in piglets. Evaluation of CBD in higher doses might be warranted.

Topics: Animals; Animals, Newborn; Biomarkers; Blood Pressure; Body Weight; Cannabidiol; Disease Models, Animal; Hippocampus; Hypothermia, Induced; Hypoxia-Ischemia, Brain; Inflammation; Kidney; Magnetic Resonance Spectroscopy; Myocardium; Neuroprotective Agents; Oxidative Stress; Oxygen; Swine

The mechanisms underlying the neuroprotective effects of cannabidiol (CBD) were studied in vivo using a hypoxic-ischemic (HI) brain injury model in newborn pigs. One- to two-day-old piglets were exposed to HI for 30 min by interrupting carotid blood flow and reducing the fraction of inspired oxygen to 10%. Thirty minutes after HI, the piglets were treated with vehicle (HV) or 1 mg/kg CBD, alone (HC) or in combination with 1 mg/kg of a CB₂ receptor antagonist (AM630) or a serotonin 5HT(1A) receptor antagonist (WAY100635). HI decreased the number of viable neurons and affected the amplitude-integrated EEG background activity as well as different prognostic proton-magnetic-resonance-spectroscopy (H(±)-MRS)-detectable biomarkers (lactate/N-acetylaspartate and N-acetylaspartate/choline ratios). HI brain damage was also associated with increases in excitotoxicity (increased glutamate/N-acetylaspartate ratio), oxidative stress (decreased glutathione/creatine ratio and increased protein carbonylation) and inflammation (increased brain IL-1 levels). CBD administration after HI prevented all these alterations, although this CBD-mediated neuroprotection was reversed by co-administration of either WAY100635 or AM630, suggesting the involvement of CB₂ and 5HT(1A) receptors. The involvement of CB₂ receptors was not dependent on a CBD-mediated increase in endocannabinoids. Finally, bioluminescence resonance energy transfer studies indicated that CB₂ and 5HT(1A) receptors may form heteromers in living HEK-293T cells. In conclusion, our findings demonstrate that CBD exerts robust neuroprotective effects in vivo in HI piglets, modulating excitotoxicity, oxidative stress and inflammation, and that both CB₂ and 5HT(1A) receptors are implicated in these effects.

Topics: Animals; Animals, Newborn; Brain; Brain Injuries; Cannabidiol; Cannabinoid Receptor Antagonists; Cannabinoids; Disease Models, Animal; HEK293 Cells; Humans; Hypoxia-Ischemia, Brain; Male; Nerve Tissue Proteins; Neurons; Neuroprotective Agents; Protein Multimerization; Random Allocation; Receptor, Cannabinoid, CB2; Receptor, Serotonin, 5-HT1A; Recombinant Fusion Proteins; Reperfusion Injury; Serotonin 5-HT1 Receptor Antagonists; Sus scrofa

Cannabidiol (CBD) demonstrated short-term neuroprotective effects in the immature brain following hypoxia-ischemia (HI). We examined whether CBD neuroprotection is sustained over a prolonged period. Newborn Wistar rats underwent HI injury (10% oxygen for 120 min after left carotid artery electrocoagulation) and then received vehicle (HV, n = 22) or 1 mg/kg CBD (HC, n = 23). Sham animals were similarly treated (SV, n = 16 and SC, n = 16). The extent of brain damage was determined by magnetic resonance imaging, histological evaluation (neuropathological score, 0-5), magnetic resonance spectroscopy and Western blotting. Several neurobehavioral tests (RotaRod, cylinder rear test[CRT],and novel object recognition[NOR]) were carried out 30 days after HI (P37). CBD modulated brain excitotoxicity, oxidative stress and inflammation seven days after HI. We observed that HI led to long-lasting functional impairment, as observed in all neurobehavioral tests at P37, whereas the results of HC animals were similar to those of sham animals (all p < 0.05 vs. HV). CBD reduced brain infarct volume by 17% (p < 0.05) and lessened the extent of histological damage. No differences were observed between the SV and SC groups in any of the experiments. In conclusion, CBD administration after HI injury to newborn rats led to long-lasting neuroprotection, with the overall effect of promoting greater functional rather than histological recovery. These effects of CBD were not associated with any side effects. These results emphasize the interest in CBD as a neuroprotective agent for neonatal HI.

Topics: Animals; Animals, Newborn; Anti-Inflammatory Agents, Non-Steroidal; Behavior, Animal; Cannabidiol; Cerebral Cortex; Disease Models, Animal; Female; Hypoxia-Ischemia, Brain; Male; Motor Activity; Neurons; Neuroprotective Agents; Oxidative Stress; Psychomotor Disorders; Random Allocation; Rats; Rats, Wistar; Reperfusion Injury; Time Factors

Newborn piglets exposed to acute hypoxia-ischemia (HI) received i.v. cannabidiol (HI + CBD) or vehicle (HI + VEH). In HI + VEH, 72 h post-HI brain activity as assessed by amplitude-integrated EEG (aEEG) had only recovered to 42 ± 9% of baseline, near-infrared spectroscopy (NIRS) parameters remained lower than normal, and neurobehavioral performance was abnormal (27.8 ± 2.3 points, normal 36). In the brain, there were fewer normal and more pyknotic neurons, while astrocytes were less numerous and swollen. Cerebrospinal fluid concentration of neuronal-specific enolase (NSE) and S100β protein and brain tissue percentage of TNFα(+) cells were all higher. In contrast, in HI + CBD, aEEG had recovered to 86 ± 5%, NIRS parameters increased, and the neurobehavioral score normalized (34.3 ± 1.4 points). HI induced histological changes, and NSE and S100β concentration and TNFα(+) cell increases were suppressed by CBD. In conclusion, post-HI administration of CBD protects neurons and astrocytes, leading to histological, functional, biochemical, and neurobehavioral improvements.

Topics: Animals; Animals, Newborn; Behavior, Animal; Brain; Cannabidiol; Electroencephalography; Humans; Hypoxia-Ischemia, Brain; Neuroprotective Agents; Neuropsychological Tests; Sus scrofa

To investigate the mechanisms involved in cannabidiol (CBD)-induced neuroprotection in hypoxic-ischemic (HI) immature brain, forebrain slices from newborn mice underwent oxygen and glucose deprivation in the presence of vehicle, or CBD alone or with selective antagonists of cannabinoid CB(1) and CB(2), and adenosine A(1) and A(2) receptors. CBD reduced acute (LDH efflux to the incubation medium) and apoptotic (caspase-9 concentration in tissue) HI brain damage by reducing glutamate and IL-6 concentration, and TNFalpha, COX-2, and iNOS expression. CBD effects were reversed by the CB(2) antagonist AM630 and by the A(2A) antagonist SCH58261. The A(1A) antagonist DPCPX only counteracted the CBD reduction of glutamate release, while the CB(1) antagonist SR141716 did not modify any effect of CBD. In conclusion, CBD induces robust neuroprotection in immature brain, by acting on some of the major mechanisms underlying HI cell death; these effects are mediated by CB(2) and adenosine, mainly A(2A), receptors.

Topics: Adenosine A1 Receptor Agonists; Adenosine A1 Receptor Antagonists; Adenosine A2 Receptor Agonists; Adenosine A2 Receptor Antagonists; Aging; Animals; Animals, Newborn; Apoptosis; Brain; Cannabidiol; Caspase Inhibitors; Caspases; Cytoprotection; Disease Models, Animal; Down-Regulation; Glutamic Acid; Hypoxia-Ischemia, Brain; Inflammation Mediators; Interleukin-6; Mice; Mice, Inbred C57BL; Nerve Degeneration; Neuroprotective Agents; Organ Culture Techniques; Purinergic P1 Receptor Agonists; Purinergic P1 Receptor Antagonists; Receptor, Adenosine A1; Receptor, Adenosine A2A; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Receptors, Purinergic P1

To test the neuroprotective effects of the nonpsychoactive cannabinoid cannabidiol (CBD), piglets received i.v. CBD or vehicle after hypoxia-ischemia (HI: temporary occlusion of both carotid arteries plus hypoxia). Nonhypoxic-ischemic sham-operated piglets remained as controls. Brain damage was studied by near-infrared spectroscopy (NIRS) and amplitude-integrated electroencephalography (aEEG) and by histologic assessment (Nissl and FluoroJadeB staining). In HI+vehicle, HI led to severe cerebral hemodynamic and metabolic impairment, as reflected in NIRS by an increase in total Hb index (THI) and a decrease in the fractional tissue oxygenation extraction (FTOE); in HI+CBD the increase of THI was blunted and FTOE remained similar to SHAM. HI profoundly decreased EEG amplitude, which was not recovered in HI+vehicle, indicating cerebral hypofunction; seizures were observed in all HI+vehicle. In HI+CBD, however, EEG amplitude recovered to 46.4 7.8% baseline and seizures appeared only in 4/8 piglets (both p < 0.05). The number of viable neurons decreased and that of degenerating neurons increased in HI+vehicle; CBD reduced both effects by more than 50%. CBD administration was free from side effects; moreover, CBD administration was associated with cardiac, hemodynamic, and ventilatory beneficial effects. In conclusion, administration of CBD after HI reduced short-term brain damage and was associated with extracerebral benefits.

Topics: Animals; Animals, Newborn; Brain; Cannabidiol; Electroencephalography; Hemodynamics; Hypoxia-Ischemia, Brain; Neuroprotective Agents; Swine