Neuroprotective Effect of New Nanochelating-Based Nano Complex, ALZc3, Against Aß (1-42)-Induced Toxicity in Rat: a Comparison with Memantine.

PURPOSE: The current drugs for Alzheimer's disease (AD) are only used to slow or delay the progression of the pathology. So using a novel technology is a necessity to synthesize more effective medications to control this most common cause of dementia. In this study, using nanochelating technology, ALZc3 was synthesized and its therapeutic effects were evaluated in comparison with memantine on a well-known rat model of AD, which is based on Amyloid-ßeta (Aß) injection into the brain. MATERIALS AND METHODS: Aß (1-42) was injected bilaterally into the CA1 area of the hippocampus of male rats and then animals were treated daily by oral administration of Alz-C3, memantine or their vehicles. Activities of antioxidant enzymes catalase and superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA) levels, as well as Bax/Bcl-2 ratio, caspase-3 activation, and TNF-α expression were evaluated 7 days after Aß injection. Finally, learning and memory of the rats were assessed by Morris water maze test. RESULTS: ALZc3 and memantine improved memory impairment and antioxidant activity and reduced TNF-α expression, caspase-3 activity and Bax/Bcl-2 ratio in the rat's hippocampus. The results showed a superiority of ALZC3 compared to memantine in reducing caspase-3, increasing CAT activity in Aß (1-42)-injected groups and improving apoptosis factor in healthy mice. CONCLUSION: These results indicated that ALZc3 could significantly prevent the memory impairment and Aß (1-42) toxicity. Thus, ALZc3 could be a promising novel anti-AD agent.

Digitoflavone provokes mitochondrial biogenesis in PC12 cells: A protective approach to oxidative stress.

CONTEXT: Reactive oxygen species (ROS) are known to be one of the main causes of neurodegenerative disorders, and flavonoids play characteristic roles in a variety of biological activities, and specially are known to be antioxidant reagents. OBJECTIVE: In this study, we investigated neuroprotective effects of digitoflavone to suppress H2O2 -induced cell death in neuron-like PC12 cells. MATERIAL AND METHODS: PC12 cells were pre-treated with digitoflavone for 2 h and then cells were exposed to H2O2 for 18 h. The cells' viability was evaluated by MTT assay. Rhodamine 123 staining was used for the determination of mitochondrial membrane potential (ΔΨm). The intracellular ROS aggregation was determined by using 2',7'-dichlorofluorescein diacetate. Also, the level of mitochondrial biogenesis factors was measured by western blot. The antioxidant capacity of digitoflavone was also determined by measuring reduced glutathione (GSH) level and catalase (CAT) activity quantification. RESULTS: Digitoflavone significantly elevated cells' viability at concentrations of 10 and 20 µM. Also, digitoflavone attenuated intracellular level of ROS, and stabilized ΔΨm. Moreover, digitoflavone increased phosphorylation of AMP-activated protein kinase (AMPK) and, consequently, elevated mitochondrial biogenesis factors which were reduced after H2O2 exposure. We emphasized on the protective effect of digitoflavone through increasing mitochondrial biogenesis by specifically inhibiting AMPK. Antioxidant ability of digitoflavone was indicated by the elevation of GSH level and CAT activity. CONCLUSION: As a result, digitoflavone stabilize ΔΨm, enhanced cell viability through inducing mitochondrial biogenesis pathway, and increased antioxidant capacity of the cells which lead to better combating the oxidative stress.

Homology modeling, docking, molecular dynamics simulation, and structural analyses of coxsakievirus B3 2A protease: an enzyme involved in the pathogenesis of inflammatory myocarditis.

2A protease of the pathogenic coxsackievirus B3 is key to the pathogenesis of inflammatory myocarditis and, therefore, an attractive drug target. However lack of a crystal structure impedes design of inhibitors. Here we predict 3D structure of CVB3 2A(pro) based on sequence comparison and homology modeling with human rhinovirus 2A(pro). The two enzymes are remarkably similar in their core regions. However they have different conformations at the N-terminal. A large number of N-terminal hydrophobic residues reduce the thermal stability of CVB3 2A(pro), as we confirmed by fluorescence, western blot and turbidity measurement. Molecular dynamic simulation revealed that elevated temperature induces protein motion that results in frequent movement of the N-terminal coil. This may therefore induce successive active site changes and thus play an important role in destabilization of CVB3 2A(pro) structure.

Agmatine prevents LPS-induced spatial memory impairment and hippocampal apoptosis.

Neuroinflammation is associated with a number of neurodegenerative diseases. It is known that lipopolysaccharide (LPS) treatment induces neuroinflammation and memory deterioration. Agmatine, the metabolite of arginine by arginine decarboxylase, is suggested to be a neuroprotective agent. The aim of this study was to explore if agmatine can prevent LPS-induced spatial memory impairment and hippocampal apoptosis. Adult male Wistar rats (200-250 g) were trained in water maze for 4 days (3 days in hidden platform and the last day in visible platform task). Saline, LPS (250 microg/kg/ip) or (and) agmatine (5 or 10 mg/kg) were administered 4h before every training session. LPS treatment impaired water maze place learning while agmatine co-administration prevented it. Also western blot studies revealed that LPS induces hippocampal caspase-3 activation while agmatine treatment prevented it.

Targeting enteroviral 2A protease by a 16-mer synthetic peptide: inhibition of 2Apro-induced apoptosis in a stable Tet-on HeLa cell line.

Enteroviridae such as coxsackievirus are important infectious agents causing viral heart diseases. Viral protease 2A (2Apro) initiates the virus life cycle, and is an excellent target for developing antiviral drugs. Here, to evaluate the validity of the 2Apro as a proper therapeutic target, and based on the existing information and molecular dynamics, a 16-mer peptide was designed to specifically target the active site of protease 2Apro in order to block the activity of CVB3 2Apro. We showed that the peptide could compete with endogenous substrate in a concentration-dependent manner. Further, we established a HeLa cell line that expressed 2Apro. Expression of 2Apro resulted in significant morphological alteration and eventual cell death. Western blot and viability assay showed that the 16-mer peptide (200 microg/ml) could significantly block 2Apro activity and its cytotoxic effect. Future modification of the 16-mer peptide can improve its affinity for 2Apro and therefore develop effective antiviral drug.