Biotin, coenzyme Q10, and their combination ameliorate aluminium chloride-induced Alzheimer's disease via attenuating neuroinflammation and improving brain insulin signaling.

Insulin is important for brain function and neuronal survival. Insulin signaling is initiated by the phosphorylation of insulin receptor substrate-1 (IRS-1) at tyrosine (pTyr) residue. However, IRS-1 is inhibited by phosphorylation at serine (pSer). In Alzheimer's disease (AD), oxidative stress and accumulation of amyloid beta (Aß) induce neuroinflammation, which augments pSer-IRS-1 and reduces pTyr-IRS-1 disturbing insulin signaling pathway. Coenzyme Q10 (CoQ10) and biotin possess antioxidant and anti-inflammatory properties, and, in this study, their impact on insulin signaling is investigated in an aluminium chloride (AlCl3 ) model of AD. AD was induced by oral administration of AlCl3 (75 mg/kg) for 60 days. Biotin (2 mg/kg), CoQ10 (10 mg/kg), and their combination were supplemented concomitantly with AlCl3 for 60 days. Memory test and histological examination were performed. Brain levels of lipid peroxides, antioxidants (reduced glutathione and superoxide dismutase), inflammatory markers (tumor necrosis factor-α, interleukin-6 [IL-6], IL-1, and nuclear factor κB), and phosphorylated Akt (survival kinase) as well as protein levels of Aß, IRS-1 (pTyr and pSer), and caspase-3 (apoptotic marker) were determined. AlCl3 resulted in impaired memory, significant increase in Aß, lipid peroxides, inflammatory markers, caspase-3, and pSer-IRS-1, with significant reduction of the antioxidants, pTyr-IRS-1, and p-Akt reflecting Aß-induced inflammation and defective insulin signaling. Histological examination revealed focal aggregations of inflammatory cells and neuronal degeneration. The biochemical deviations and histological changes were attenuated by the concomitant treatment with biotin and, to greater extent, with CoQ10 and the combination. In conclusion, biotin and CoQ10 could protect against AD via attenuating inflammatory response and enhancing insulin signaling.

Analysis of the molecular and behavioral effects of acute social isolation on rats.

The mechanism underlying depression, anxiety, and stress-related psychiatric disorders is far from understood. The utilization of animal models of anxiety and stress can improve our knowledge of the pathology of these disorders as well as aiding in the identification of pharmacological therapeutic targets. The involvement of inflammation in the pathology of stress-related disorders is widely acknowledged. This study was therefore undertaken to assess depressive and anxiety-like behavior as well as neuroinflammation in acute-isolated rats. The study design comprised two main groups:1) rats in acute isolation (one rat per cage) and 2) standard housing (two rats per cage). Within ten days of acute isolation, we carried behavioral tests including Sucrose Neophobia (SNP), Sucrose Preference Test (SPT), Open field (OPF), and a Forced swim test (FST). In a separate set of experiments, we examined the molecular changes after five days of isolations, we examined the mRNA expression of Toll-like receptors (TLRs) and inflammatory markers in the hippocampal brain region. We found that acute social isolation did not have profound functional effects and the behavioral analysis revealed similarities between the isolated and standard housed rats. However, the molecular studies showed a significant increase in TLRs. An increase in Interleukin 6 (IL-6) and Tumor necrosis factor-alpha (TNF-alpha) was observed in the hippocampus of isolated rats but not the control rats. The results suggest that acute environmental isolation does not significantly affect depressive and anxiety-like behavior but does contribute to upregulations in neuroinflammatory responses. This indicates the initiation of neuronal insults following exposure to short-term isolation.

Assessing the role of toll-like receptor in isolated, standard and enriched housing conditions.

Depression is a common psychiatric disorder that has been poorly understood. Consequently, current antidepressant agents have clinical limitations. Until today, most have exhibited the slow onset of therapeutic action and, more importantly, their effect on remission has been minimal. Thus, the need to find new forms of therapeutic intervention is urgent. The inflammation hypothesis of depression is widely acknowledged and is one that theories the relationship between the function of the immune system and its contribution to the neurobiology of depression. In this research, we utilized an environmental isolation (EI) approach as a valid animal model of depression, employing biochemical, molecular, and behavioral studies. The aim was to investigate the anti-inflammatory effect of etanercept, a tumor necrosis factor-α inhibitor on a toll-like receptor 7 (TLR 7) signaling pathway in a depressive rat model, and compare these actions to fluoxetine, a standard antidepressant agent. The behavioral analysis indicates that depression-related symptoms are reduced after acute administration of fluoxetine and, to a lesser extent, etanercept, and are prevented by enriched environment (EE) housing conditions. Experimental studies were conducted by evaluating immobility time in the force swim test and pleasant feeling in the sucrose preference test. The mRNA expression of the TLR 7 pathway in the hippocampus showed that TLR 7, MYD88, and TRAF6 were elevated in isolated rats compared to the standard group, and that acute treatment with an antidepressant and anti-inflammatory drugs reversed these effects. This research indicates that stressful events have an impact on behavioral well-being, TLR7 gene expression, and the TLR7 pathway. We also found that peripheral administration of etanercept reduces depressive-like behaviour in isolated rats: this could be due to the indirect modulation of the TLR7 pathway and other TLRs in the brain. Furthermore, fluoxetine treatment reversed depressive-like behaviour and molecularly modulated the expression of TLR7, suggesting that fluoxetine exerts antidepressant effects partially by modulating the TLR7 signaling pathway.

Protective Effects of Silymarin, Alone or in Combination with Chlorogenic Acid and/or Melatonin, Against Carbon Tetrachloride-induced Hepatotoxicity.

OBJECTIVE: The aim of this study was to evaluate the hepatoprotective effects of silymarin (SIL), alone and combined with chlorogenic acid (CA) and/or melatonin (ME), using a rat model of carbon tetrachloride (CCl4)-induced injury. MATERIALS AND METHODS: Hepatotoxicity was induced by a single dose of CCl4 (1 ml/kg, IP). One day after, rats were received SIL (200 mg/kg) alone or in combination with CA (60 mg/kg) and/or ME (20 mg/kg) for 21 days. RESULTS: SIL significantly decreased serum alanine aminotransferase, inflammatory cytokines, and vascular endothelial growth factor levels. Histological alterations, fibrogenesis, oxidative DNA damage, inflammatory mediators, and caspase-3 activity were significantly attenuated in SIL treated CCl4-intoxicated rats. On the other hand, cytochrome P450 2E1 activity showed a significant decrease in the liver of CCl4-intoxicated rats, an effect that was reversed following treatment with SIL. All beneficial effects of SIL were markedly potentiated when combined with CA and/or ME. CONCLUSIONS: These data indicate that SIL, alone and combined with CA and/or ME, protected the liver against CCl4-induced hepatotoxicity via attenuating inflammation, oxidative DNA damage, apoptosis, and fibrotic changes. The significantly intensified hepatoprotective effects of SIL when combined with both CA and ME suggest a possible synergism. These synergistic effects need to be further confirmed using detailed studies. SUMMARY: Silymarin, chlorogenic acid and melatonin possess in vivo hepatoprotective activitySilymarin, chlorogenic acid and melatonin attenuate fibrogenesis, oxidative DNA damage, inflammation and apoptosisChlorogenic acid and melatonin enhance the hepatoprotective effect of silymarin. Abbreviations used: SIL: silymarin, CA: chlorogenic acid, ME: melatonin, CCl4: carbon tetrachloride, CYP2E1, cytochrome P450 2E1, ALT: alanine aminotransferase, IL-6: interleukin 6, IFN-γ: interferon gamma, VEGF: vascular endothelial growth factor, TNF-α: tumor necrosis factor alpha, CRP: C-reactive protein, 8-OxodG: 8-Oxo-2'-deoxyguanosine, TGF-B1: transforming growth factor beta 1, HSCs: hepatic stellate cells.

New mechanism in the modulation of carbon tetrachloride hepatotoxicity in rats using different natural antioxidants.

Transforming growth factor-ß (TGF-ß1) enhances the expression of apoptosis induced by certain cytokines and oncogenes. Activation of small mother against decapentaplegic (Smads) by TGF-ß results in fibrotic, apoptotic processes. PI-3/AKT focal adhesion kinase-phosphatidylinositol3-kinase (AKT), the mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription-3 (STAT3) pathways are influence in COX-2 and VEGF-stimulating pathways. NF-E2-related factor-2 (Nrf2) is an essential transcription factor that regulates an array of detoxifying and antioxidant defense genes expression in the liver. The objective of this study is to examine whether silymarin alone or in combination with vitamin E and/or curcumin plays a modulatory role against MAPK, STAT3, AKT, Smad-2 and TGF-ß protein expressions that produced apoptotic damage in rat's liver by the administration of carbon tetrachloride (CCl4). The results of the present work revealed that CCl4-induced an elevation of serum alanine aminotransferase (ALT) with concomitant increase in MAPK, STAT3, AKT, Smad-2 and TGF-ß hepatic protein expression, administration of silymarin alone down regulates these expressions. Treatment with vitamin E and/or curcumin along with silymarin produced best results in this concern. On the other hand, Nrf2 protein expression was down regulated by CCl4 whereas concurrent treatment with vitamin E and/or curcumin along with silymarin increased this expression. It was concluded that CCl4-induced protein expression of apoptotic and fibenorgenic factors. Whereas administration of silymarin alone or in combination with vitamin E and/or curcumin plays a modulatory role against the previous aforementioned apoptotic factors expressions. The use of vitamin E and/or curcumin potentiates the anti-apoptotic action of silymarin. So this combination can be used as hepatoprotective agent against other hepatotoxic substances.

Neuroprotective effect of carnosine and cyclosporine-A against inflammation, apoptosis, and oxidative brain damage after closed head injury in immature rats.

CONTEXT: Traumatic brain injury in the pediatric population can have a great economic and emotional impact on both the child's family and society. OBJECTIVE: The present study aimed to compare the effects of carnosine (CAR) and/or cyclosporine A (CyA) on oxidative brain damage after closed head injury (CHI) in immature rats. MATERIALS AND METHODS: Thirty-day-old rat pups were divided into five groups: non-traumatic control group, trauma group underwent CHI, trauma group injected with CAR (200 mg/kg, i.p.) following CHI for 7 d, trauma group injected with CyA (20 mg/kg, i.p.) given 15 min and 24 h after CHI, and trauma group treated with CAR and CyA. At the end of the treatment, rats were sacrificed; blood and brains were collected for assessing different biochemical parameters. RESULTS: Trauma significantly increased brain level of malondialdehyde, nitric oxide, glucose, calcium, inflammatory mediators. Brain DNA damage was confirmed by comet assay and the significant increase in brain caspase-3 activity. Moreover, the serum level of Fas ligand in traumatized animals was significantly elevated. Concomitant decrease in brain-reduced glutathione (GSH) and calcium-adenosine triphosphatase activity was observed in the traumatized-untreated group. Treatment of traumatized animals with CAR and/or CyA ameliorated all the biochemical changes induced by CHI with marked protective effect in the combination group. DISCUSSION AND CONCLUSION: CAR and CyA exerted a synergistic neuroprotective effect against CHI through blocking the induction of lipid peroxidation, reducing inflammatory, and oxidative stress biomarkers, preserving brain GSH content, and reducing the alterations in brain apoptotic biomarkers in traumatized animals.

Down-Regulation of NFkB, Bax,TGF-β, Smad-2mRNA expression in the Livers of Carbon Tetrachloride Treated Rats using Different Natural Antioxidants

The objective of this study is to examine whether silymarin alone or in combination with chlorogenic acid and/ or melatonin plays a modulatory role against apoptotic damage in rats liver induced by of CCl4. The present work revealed that CCl4 induced elevation of in Bax, Smad, TGF-β and NFkBhepatic mRNA expression, administration of silymarin alone down regulates these expressions. Treatment with chlorogenic acid and/ or melatonin along with silymarin produced best results in this concern. Bcl-2 expression was down regulated by CCl4 whereas concurrent treatment of chlorogenic acid and/ or melatonin along with silymarin increased this expression. On conclusion, the use of chlorogenic acid and/ or melatonin potentiates the anti-apoptotic action of silymarin.