Hesperidin, a citrus bioflavonoid, decreases the oxidative stress produced by carbon tetrachloride in rat liver and kidney

BACKGROUND: CCl(4 )is a well-established hepatotoxin inducing liver injury by producing free radicals. Exposure to CCl(4 )also induces acute and chronic renal injuries. The present study was designed to establish the protective effect of hesperidin (HDN), a citrus bioflavonoid, on CCl(4)-induced oxidative stress and resultant dysfunction of rat liver and kidney. METHODS: Animals were pretreated with HDN (100 and 200 mg/kg orally) for one week and then challenged with CCl(4 )(2 ml/kg/s.c.) in olive oil. Rats were sacrificed by carotid bleeding under ether anesthesia. Liver enzymes, urea and creatinine were estimated in serum. Oxidative stress in liver and kidney tissue was estimated using Thiobarbituric acid reactive substances (TBARS), glutathione (GSH) content, superoxide dismutase(SOD), and Catalase (CAT) RESULTS: CCl(4 )caused a marked rise in serum levels of ALT and AST (P < 0.05). TBARS levels were significantly increased whereas GSH, SOD and CAT levels decreased in the liver and kidney homogenates of CCl(4 )treated rats. HDN (200 mg/kg) successfully attenuated these effects of CCl(4) CONCLUSION: In conclusion, our study demonstrated a protective effect of HDN in CCl(4 )induced oxidative stress in rat liver and kidney. This protective effect of HDN can be correlated to its direct antioxidant effect

Role of 5-HT in Cerebral Edema after Traumatic Brain Injury

The pathogenesis of edema after traumatic brain injury is complex including the destruction of micro-vessels and alterations in microcirculation around the primary injury and leakage of plasma constituents into the tissue, due to permeability changes of the vessel walls. Many functional molecules like histamine, serotonin, arachidonic acid, prostaglandins and thromboxane have been shown to induce blood–brain barrier (BBB) disruption or cell swelling. It is believed that released 5-HT binds to 5-HT2 receptors stimulating cAMP and prostaglandins in vessels that cause more vesicular transport in endothelial cells leading to serum component’s extravasation. The additional amount of serotonin into the tissue due to injury maintains the state of increased vascular permeability that ultimately causes edema. Serotonin is clearly involved in early cytotoxic edema after TBI. Reduction of serotonin in the nervous tissue reduces swelling and the milder cell changes in the brain or spinal cord of traumatized rats. Inhibition of serotonin synthesis before closed head injury (CHI) in rat models or administration of serotonin antiserum after injury attenuates BBB disruption and brain edema volume swelling, and brain pathology. Maintaining low serotonin levels immediately after injury may show neuroprotection and combat various secondary outcomes that occur after traumatic brain injury

Quinolinic Acid and Nuclear Factor Erythroid 2-Related Factor 2 in Depression: Role in Neuroprogression

Depression is an incapacitating neuropsychiatric disorder. The serotonergic system in the brain plays an important role in the pathophysiology of depression. However, due to delayed and/or poor performance of selective serotonin reuptake inhibitors in treating depressive symptoms, the role of the serotonergic system in depression has been recently questioned further. Evidence from recent studies suggests that increased inflammation and oxidative stress may play significant roles in the pathophysiology of depression. The consequences of these factors can lead to the neuroprogression of depression, involving neurodegeneration, astrocytic apoptosis, reduced neurogenesis, reduced plasticity (neuronal and synaptic), and enhanced immunoreactivity. Specifically, increased proinflammatory cytokine levels have been shown to activate the kynurenine pathway, which causes increased production of quinolinic acid (QA, an N-Methyl-D-aspartate agonist) and decreases the synthesis of serotonin. QA exerts many deleterious effects on the brain via mechanisms including N-methyl-D-aspartate excitotoxicity, increased oxidative stress, astrocyte degeneration, and neuronal apoptosis. QA may also act directly as a pro-oxidant. Additionally, the nuclear translocation of antioxidant defense factors, such as nuclear factor (erythroid-derived 2)-like 2 (Nrf2), is downregulated in depression. Hence, in the present review, we discuss the role of QA in increasing oxidative stress in depression by modulating the nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 and thus affecting the synthesis of antioxidant enzymes

Lycopene ameliorates thermal hyperalgesia and cold allodynia in STZ-induced diabetic rat

108-111Peripheral neuropathy is one of the common complications of diabetes mellitus. It is frequently associated with debilitating pain. The present study was designed to investigate effect of Lycopene, a carotenoid found in tomatoes, on hyperalgesia and cold allodynia in streptozotocin (STZ) induced diabetic rats. After 4-weeks of STZ injection, diabetic mice exhibited a significant thermal hyperalgesia cold allodynia, hyperglycemia and loss of body weights as compared with control rats. Chronic treatment of lycopene for 4 weeks significantly attenuated the cold allodynia and thermal hyperalgesia. The results emphasize the role of antioxidant such as lycopene as an adjuvant therapy in the treatment of diabetic neuropathy

Development of a new, sensitive, and robust analytical and bio-analytical RP-HPLC method for in-vitro and in-vivo quantification of naringenin in polymeric nanocarriers

Abstract Background Naringenin is a flavanone having strong antioxidant potential. It is an anti-hyperlipidemic, anti-depressant, anti-cancer, and neuroprotective agent. However, its major limitation is its low oral bioavailability. Objective In order to overcome this limitation and to explore its antioxidant potential in autism spectrum disorders, we developed brain targeting PLGA nanocarriers of naringenin. Current study involves development of a sensitive and robust RP-HPLC method for detection and quantification (in vitro and in vivo) of naringenin in nanoparticles. Methods An isocratic RP-HPLC method was developed using C18 reversed-phase column (250 × 4.6 mm internal diameter and 5 μm particle size). Flow rate of mobile phase was 1 ml/min and temperature of column was 30 °C. Methanol and 0.5% ortho-phosphoric acid in MilliQ water (pH 2) (70:30) was used as mobile phase. The ultraviolet detection wavelength for quantification was at 289 nm. Results Calibration curve showed linearity within the concentration range from 0.5 to 40 μg/ml (R 2 = 1) for the analytical method and for plasma (6.3–200 ng/ml (R 2 = 0.9975)) and brain tissue samples (31.25–12,500 ng/ml (R 2 = 1)). Limit of detection (LOD) and limit of quantification (LOQ) were 0.15 μg/ml and 0.44 μg/ml for the analytical method. For bio-analytical method, LOD and LOQ were 9.71 ng/ml and 29.44 ng/ml for plasma and 9.06 ng/ml and 27.44 ng/ml for brain sample. Both the method was precise, accurate, and robust. Bio-analytical method showed good recovery from plasma and brain samples (> 95%). Conclusion This analytical and bio-analytical method was applied to detect entrapment efficiency, in-vitro release, and pharmacokinetic parameters of naringenin nanoparticles

Neurobiological effect of 7-nitroindazole, a neuronal nitric oxide synthase inhibitor, in experimental paradigm of Alzheimer’s disease

1086-1093Nitric oxide plays a role in a series of neurobiological functions, underlying behaviour and memory. The functional role of nNOS derived nitric oxide in cognitive functions is elusive. The present study was designed to investigate the effect of specific neuronal nitric oxide synthase inhibitor, 7-nitroindazole, against intracerebroventricular streptozotocin-induced cognitive impairment in rats. Learning and memory behaviour was assessed using Morris water maze and elevated plus maze. 7-nitroindazole (25 mg/kg, ip) was administered as prophylactically (30 min before intracerebroventricular streptozotocin injection on day 1) and therapeutically (30 min before the assessment of memory by Morris water maze on day 15). Intracerebroventricular streptozotocin produced significant cognitive deficits coupled with alterations in biochemical indices.These behavioural and biochemical changes were significantly prevented by prophylactic treatment of 7-nitroindazole. However, therapeutic intervention of 7-nitroindazole did not show any significant reversal. The results suggests that 7-nitroindazole can be effective in the protection of dementiainduced by intracerebroventricular streptozotocin only when given prophylactically but not therapeutically

Anti-nociceptive effect of duloxetine in mouse model of diabetic neuropathic pain

193-197The involvement of adenosinergic pathway in the anti-nociceptive effect of duloxetine, a balanced 5-HT/NE reuptake inhibitor, was evaluated in streptozotocin induced diabetic male albino mice of Laca strain. After four weeks of single injection of streptozotocin (200 mg/kg, ip), mice were tested in the tail immersion and hot-plate assays. Cerebral adenosine levels were measured by high-performance liquid chromatography (HPLC/PDA detector). Diabetic mice exhibited significant hyperalgesia along with increased plasma glucose, decreased body weights and reduced cerebral adenosine levels. Administration of duloxetine (5, 10 and 20 mg/kg, ip) to diabetic mice produced dose-dependent anti-nociceptive effect in both tail-immersion and hot-plate assays. Adenosine levels were also significantly and dose-dependently increased by different doses of duloxetine. The results demonstrated the involvement of adenosinergic pathway in duloxetine mediated anti-hyperalgesia in diabetic neuropathic pain

Taurine as a potential therapeutic agent interacting with multiple signaling pathways implicated in autism spectrum disorder (ASD): An in-silico analysis

Autism spectrum disorders (ASD) are a complex sequelae of neurodevelopmental disorders which manifest in the form of communication and social deficits. Currently, only two agents, namely risperidone and aripiprazole have been approved for the treatment of ASD, and there is a dearth of more drugs for the disorder. The exact pathophysiology of autism is not understood clearly, but research has implicated multiple pathways at different points in the neuronal circuitry, suggesting their role in ASD. Among these, the role played by neuroinflammatory cascades like the NF-KB and Nrf2 pathways, and the excitotoxic glutamatergic system, are said to have a bearing on the development of ASD. Similarly, the GPR40 receptor, present in both the gut and the blood brain barrier, has also been said to be involved in the disorder. Consequently, molecules which can act by interacting with one or multiple of these targets might have a potential in the therapy of the disorder, and for this reason, this study was designed to assess the binding affinity of taurine, a naturally-occurring amino acid, with these target molecules. The same was scored against these targets using in-silico docking studies, with Risperidone and Aripiprazole being used as standard comparators. Encouraging docking scores were obtained for taurine across all the selected targets, indicating promising target interaction. But the affinity for targets actually varied in the order NRF-KEAP > NF-κB > NMDA > Calcium channel > GPR 40. Given the potential implication of these targets in the pathogenesis of ASD, the drug might show promising results in the therapy of the disorder if subjected to further evaluations