example 1 below demonstrates the prior art and details the neuroprotective properties of cbd in two different models . it is demonstrated that the cbd enables repair of brain tissue after an hi injury . example 2 demonstrates the synergistic neuroprotective effect of cbd with therapeutic hypothermia . a piglet model of hi was used as described in ( alvarez et al . 2008 ). briefly , an hi insult is induced in anesthetized 1 - 3 day - old piglets by occluding both carotid arteries and decreasing inspired oxygen from 21 to 10 % for 30 min . thirty minutes after the recovery of hi the test compound was administered via the i . v . route . the test compounds were : cbd ( 1 mg / kg ) plus am630 which is a cb2 antagonist ( 1 mg / kg ); cbd ( 1 mg / kg ) plus way100635 which is a 5ht1a antagonist ( 0 . 1 mg / kg ); or cbd ( 1 mg / kg ) plus caffeine which is a non - specific adenosine receptor antagonist ( 10 mg / kg ). hemodynamic parameters ( cardiac output , blood pressure , heart rate and extravascular lung water content ), temperature , respiratory parameters ( lung compliance , airway resistance , oxygenation index ) were recorded for 6 hours from the end of hi . blood samples were obtained hourly and urine was collected . brain activity was recorded by amplitude - integrated eeg . at the end of the experiment , piglets are euthanized and the brain removed ; one hemisphere was immediately frozen and stored at − 80 ° c . whereas the other one was preserved in 4 % paraformaldehide . a sample of frozen brain was obtained to perform a proton magnetic resonance spectroscopy ( h +- mrs ). similarly managed piglets but without hi served as controls . blood samples from cbd - treated piglets were used to determine serum cbd concentration . a rat model of hi was used as described by ( fernandez - lopez et al ., 2007 ). briefly , an hi insult is induced in 7 - 10 day - old wistar rats by electro - coagulating the left carotid artery under anaesthesia following by the exposure to 10 % oxygen for 120 min . after the end of hi , pups were treated with 0 . 1 ml s . c . of vehicle or cbd ( 1 mg / kg ) in a single dose . sham operated pups without hypoxia served as controls , and were treated with vehicle or cbd as indicated . the pups were then returned to their dams . at day 35 rats underwent neurobehavioral tests : rotarod ( to test coordination ), cylinder ( to test unilateral deficits ) and novel object preference ( to test memory impairments ). rats were then euthanized and the brain removed and stored in 4 % paraforlmadehide . magnetic resonance imaging was performed on the brains to evaluate the damaged area . in some rats , mri was performed 7 days after hi . fig1 a ) and b ) shows the brain tissue obtained 6 h after the end of hypoxia - ischemia ( hi ). fig1 a ) compares nissl staining of brain slices from sham piglets to those exposed to hi and treated with vehicle or cbd 1 mg / kg i . v ., alone or with the cb2 antagonist am630 ( am ), the 5ht1a antagonist way100630 ( way ) or the adenosine antagonist caffeine ( caf ). as can be seen cbd reduces the percentage of necrotic tissue in both the cortex and the hippocampus . the cbd - induced reduction of neuronal death is blunted by either am or way , but not by caffeine . fig1 b ) shows the concentration of interleukin 1 in brain tissue determined by microarrays . again cbd reduces the production of il - 1 , which is blunted by am but not by way or caffeine . fig2 demonstrate the magnetic resonance imaging ( mri ) of the rat brains , these revealed that the volume of lesion was similar in hi + veh and hi + cbd 7 days after hi , suggesting that the severity of brain damage was similarly strong in both groups . one month later ( p37 ), the brain volume remained similar in hi + veh but was significantly reduced by cbd . fig3 demonstrates the protective effect of cbd included not only the volume of lesion but also the neurobehavioral performance of the rat . cbd administration led to the normalization of motor ( cylinder rear test ), coordination ( rotarod ) and memory ( novel object recognition ) tests , whereas the untreated rats performed poorly in the neurobehavioral tests . the piglet model showed that the cbd was able to reduce the amount of necrotic areas in the brain caused by hi . the rat model showed that cbd is neuroprotective and in addition to this effect a reduction of brain damage was observed after a month . the cannabinoid cbd is stimulating neuro - repair . synergistic administration of cannabidiol ( cbd ) with therapeutic hypothermia following hypdxic - ischemica ( hi ) sedated and ventilated piglets ( 1 - 2 day - old ) underwent hi brain damage ( hypoxia - fio2 10 %+ bilateral carotid artery compression for 30 min ). normothermic ( nt ) piglets were maintained at 37 - 38 ° c . using a warmed air blanket . hypothermic ( ht ) piglets were cooled by a cool water mattress to 33 - 34 ° c . thirty min after hi piglets received via the i . v . route either vehicle ( veh ) or cbd ( 1 mg / kg ). hi brains were obtained for histological studies quantifying the number of neurons ( nissl ), astrocytes ( gfap ) and microglial cells ( mgc ) ( iba - 1 ) in parietal cortex 6 hours after hi injury . by dividing the area percentage of gfap - or iba - 1 - immunoreactive processes and cell bodies ( imagej ) by the number of cells , a mean size of astrocytes or mgc was obtained . similarly studied animals without hi insult served as controls ( sham , shm ). neuronal protection was found to be best in the cbd plus hypothermia treated animals , ( p & lt ; 0 . 05 ). cbd prevented the hi - induced reduction in the number of astrocytes , particularly in the hypothermia treated animals . cbd also enhanced astrocyte activity ( increased processes equals an increased mean size ), particularly in cbd plus hypothermia . hypothermic treatment reduced the number of microglial cells , with no differences between the vehicle treated animals and those treated with cbd . table 2 . 1 demonstrates the mean size of the microglial cells after hi injury table 2 . 1 size of microglial cells after hi injury as can be seen from the table above the microglial cells were activated after hi , increasing their size , this is demonstrated in the normothermic plus vehicle treated animals where the size of pixels increased from 102 to 134 pixels a rise of 32 pixels . treatment with cbd and hypothermia produced the smallest increase 164 to 176 pixels a rise of just 12 pixels , compared to cbd alone ( 102 to 127 pixels , a rise of 25 pixels ) and hypothermia alone ( 164 to 219 pixels , a rise of 55 pixels ) table 2 . 2 below details the percentage of necrotic neurons found in the cortex of the test animals . as can be seen treatment with a combination of hypothermia and cbd produced the lowest percentage of necrotic neurons ( 4 . 5 %) compared to hypothermia alone ( 13 . 2 %) and treatment with cbd alone ( 8 . 4 %). cbd administration after hi protects neurons and astrocytes and modulates microglial activation . moreover cbd is slightly more effective than hypothermia , but when both therapies are used in combination statistically significant neuroprotective effects occur . this synergy provides a useful treatment option in newborns suffering from nhie . in addition such treatments could be used effectively in the treatment of other human patients suffering from hypoxic ischemic events or diseases such as stroke or cardiac arrest . cilio and ferriero , synergistic neuroprotective therapies with hypothermia , semin fetal neonatal med . october 2010 ; 15 ( 5 ): 293 - 298 .
the present invention relates to the combination of the phytocannabinoid cannabidiol with therapeutic hypothermia for use in the treatment of neuroprotection or astroprotection .