Clopidogrel combats neuroinflammation and enhances learning behavior and memory in a rat model of Alzheimer's disease.

BACKGROUND AND AIM: Alzheimer's disease (AD) is a progressive neurodegenerative disease. Multiple molecular mechanisms have been employed in its pathogenesis such as Amyloid ß (Aß) formation, tau protein hyperphosphorylation, reduced acetylcholine (ACh) level, and neuroinflammation. This study aimed to assess the possible neuroprotective effect of clopidogrel in AD model induced by aluminum chloride (AlCl3) in rats. METHODS: Sixty adult male Sprague-Dawley rats were divided into four different groups: Control, AlCl3, AlCl3 + donepezil, and AlCl3 + Clopidogrel. AlCl3 and the drugs were given orally once/day for 42 days. The spatial learning and memory and recognition memory were evaluated using Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests, respectively. After euthanasia, hippocampal acetylcholinesterase (AChE) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1ß (IL-1ß) levels were biochemically assessed. Moreover, amyloid precursor protein (APP) mRNA gene expression was analyzed in the hippocampi of all rats. Histopathology for amyloid plaques was done. RESULTS: Clopidogrel co-treatment significantly ameliorated the cognitive deficits induced by AlCl3 in rats. Besides, clopidogrel significantly reduced AChE activity, TNF-α and IL-1ß concentrations, and APP mRNA gene expression in the hippocampi of rats compared to AlCl3 rats. The decrease of hippocampal TNF-α and IL-1ß concentrations by clopidogrel was significant compared to donepezil co-treated rats. Clopidogrel co-treatment lessened amyloid plaque deposition in the hippocampal tissues of rats compared to AlCl3 rats. CONCLUSION: These findings demonstrate that clopidogrel could alleviate learning and memory deficit induced by AlCl3 in rats and significantly reduced AChE activity. The neuroprotective outcome of clopidogrel might be assigned to its anti-inflammatory effect.

In vivo studies of the effect of PPQ-6, a quinoline-based agent against Schistosoma mansoni in mice.

Schistosomiasis is still a public health problem. Praziquantel is the only drug available for treatment of all forms of human schistosomiasis. Although praziquantel is an effective drug against all species of human schistosomes, concerns about resistance have been raised, especially in endemic areas. A hybrid compound containing several pharmacophore within a single molecule is a promising strategy. Here, we described the anti-schistosomal effect of 4-(2-Chloroquinolin-3-yl)-2-oxo-6-(p-tolyl)-1,2-dihydropyridine-3-carbonitrile (PPQ-6), a hybrid drug based on quinoline and pyridine. PPQ-6 was given as two regimens (20 or 40 mg/kg). In both regimens, PPQ-6 significantly reduced liver and spleen indices, nitric oxide production, tissue egg load, hepatic granuloma size and count, immature eggs and total worm burden especially females. Our findings suggested that PPQ-6 is a promising anti-schistosomal agent; however more research is needed to elucidate its mechanism of action and report its activity on juvenile schistosomes and other species of human schistosomes.

Biological evaluation of newly synthesized quinoline-based compound PPQ-8 in acute and chronic toxoplasmosis: An experimental study.

Toxoplasma gondii is a widely distributed protozoan parasite, which affects worm-blooded animals including human. The commonest chemotherapeutics used for treatment of symptomatic toxoplasmosis have numerous adverse effects. Thus there is an eminent need to develop new therapeutic agents. Here we described the therapeutic efficacy of 4-(2-chloroquinolin-3-yl)-6-(2,5-dimethoxyphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile (PPQ-8); a quinoline-related compound in a mouse model of acute and chronic toxoplasmosis. In acute infection, PPQ-8 decreased the parasite load in liver and spleen with amelioration of the hepatic and splenic pathology. In addition, recovered tachyzoites showed distorted shapes, reduced sizes, irregularities, surface protrusions, erosions and peeling besides apical region distortion when seen by scanning electron microscopy. In chronic toxoplasmosis, PPQ-8 produced degeneration and reduction of the brain cysts without stimulating a damaging inflammatory response within the brain. In both models acute and chronic, PPQ-8 prolonged the survival time of mice. These findings hold promise for the development of a novel anti-toxoplasmosis drug using PPQ-8, but further in vivo studies should be carried out to elucidate PPQ-8 mechanism of action and to report its efficacy in combination with other anti-toxoplasmosis agents.