Selective Modulator of Cannabinoid Receptor Type 2 Reduces Memory Impairment and Infarct Size During Cerebral Hypoperfusion and Vascular Dementia.

Vascular dementia is the highly devastating neurodegenerative disorder after Alzheimer's disease (AD) and mainly found in aged people but the effectual therapeutic target is still not there. Chronic cerebral hypoperfusion (CCH) has been broadly found in vascular dementia (VaD) patients. CCH is thought to link with neurodegenerative disorders and their subsequent cognitive deteriorate on. This study has been framed to examine the role of a selective agonist of cannabinoid receptor type 2(CB2); 1-phenylisatin in CCH induced VaD. Permanent bilateral common carotid arteries ligation or two vessels occlusion (2VO) technique was used to induce CCH in rats. 2VO animals have shown significant impairment in learning-memory (Morris water maze) and in executive functioning (Attentional set-shifting test). These animals have shown a considerable reduction in brain oxidative stress (thiobarbituric reactive acid substance-TBARS; glutathione-GSH; catalase-CAT and superoxide dismutase-SOD), mitochondrial dysfunction (complexes I, II, IV) with a significant enhancement in cholinergic activity- AChE and brain infarct size2,3,5-triphenylterazolium chloride staining (TTC staining). Animals treated with 2VO have also demonstrated a considerable augmentation in brain edema (water content). Oral administration of 1-phenylisatin has significantly recuperated 2VO induced impairment in learning-memory, an increase in TBARS, GSH, CAT, SOD, mitochondrial activity with a significant reduction in AChE activity and brain damage. Administration of 1- phenylisatin has also reported recovering brain edema in these animals. These results indicate that 2VO induced CCH in rats, which was attenuated with the treatment of 1-phenylisatin. Hence, it may be suggested that modulation of cannabinoid receptor may provide benefits in CCH as cognitive impairment and VaD. Therefore, selective agonists of CB2 receptors may be a potential research target for the alleviation of VaD.