A study conducted in 2016 on the effects of cannabidiol (CBD) on behavior impairment of mice with bilateral common carotide artery occlusion (BCCAO) resulted in interesting findings related to the potential benefits of this major non-psychotropic phytocannabinoid. The purpose of the research was to evaluate mice overall functional recovery after BCCAO induced cerebral ischemia in the course of several days. So far no one never explored the action of CBD in the neuronal reorganization after a brain damage induced by the ischemic injury. This kind of issue can usually result after a stroke or cardiac arrest and patients suffering from brain ischemia can usually suffer from cognitive impairment, depression and anxiety. [1] There is still lack of a specific therapy to recover after transient ischemic attack and current methods using neuroprotective agents are usually linked too much on specific neuronal targets. Moreover in all the research on the action of these medicaments, the functional improvements were evaluated only on short-term treatment.
CBD was first highlighted in 2008 as capable of reducing neuronal damage both in vitro and in vivo hypoxia-ischemia models, improving the survival rate and the mice movements coordination. [1]
The experiments on mice subjected to surgery causing transient cerebral ischemia through BCCAO were conducted on 2- to 3-month-old male C57BL/6 mice, weighing 25-30 g. Randomly some mice were assigned to receive an intraperitoneal injection of 10 mg/kg of 1% CBD diluted in saline solution and the others were injected only with the vehicle as control. The CBD injections were performed half an hour before the BCCAO surgery and 3, 24 and 48 hours after the surgery. Behavioural tests were performed after 7 days from the surgery and lasted over 21 days. The tests included the evaluation of motor activity through the Open Field Test (OFT), investigating the anxious-like behavior through the Elevated Zero Maze (EZM) and the spatial recognition through the Y-Maze test. To measure the spatial
memory performance the Object Location Test (OLT) was performed and finally the Forced Swim Test (FST) was
conducted to assess mice behavioral despair.
Afterwards, the mice brain was subjected to immunohistochemistry and neurochemistry assays in order to evaluate if CBD is able to stimulate the expression of hippocampal neurochemical biomarkers associated to plastic changes promoting functional recovery. Within such plasticity markers there are doublecortin (DCX), microtubule- associated protein 2 (MAP-2), and brain-derived neurotrophic factor (BDNF). It was found that BCCAO mice treated with CBD exhibited increased DCX neurons, MAP-2 and BDNF protein levels, indicating that short-term pretreatment of CBD may prevent hippocampal neuronal loss, improve neurogenesis and brain plasticity while decreasing
neuroinflammation. [1] The collected data on the recovery of BCCAO mice after brain-ischemia suggest that short-term
CBD treatment can have a promising therapeutic function against long-term issues related to transient ischemic attacks.
References:
[1] Mori, Marco Aurélio; Meyer, Erika; Soares, Ligia Mendes; Milani, Humberto; Guimarães, Francisco Silveira; deOliveira, Rúbia Maria Weffort (2016). Cannabidiol reduces neuroinflammation and promotes neuroplasticity and
functional recovery after brain ischemia. Progress in Neuro-Psychopharmacology and Biological Psychiatry, (),
S0278584616302524–.doi:10.
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