Carnosine Exerts Neuroprotective Effect Against 6-Hydroxydopamine Toxicity in Hemiparkinsonian Rat

Parkinson�s disease (PD) is the second most common disorder of the central nervous system due to the degeneration of mesencephalic dopaminergic neurons. Current treatments for PD have a symptomatic relief strategy with no prevention of disease progression. Due to the neuroprotective and antiapoptotic potential of the natural dipeptide carnosine, this study was conducted to assess its beneficial effect in 6-hydroxydopamine (6-OHDA)-induced model of PD in rat. Unilateral intrastriatal 6-OHDA-lesioned rats received i.p. carnosine at a dose of 250 mg/kg twice at an interval of 24 h, which started presurgery. Apomorphine caused contralateral rotations, a significant reduction in the number of Nissl-stained neurons on the left side of the substantia nigra, and increased apoptosis was observed with enhanced oxidative stress burden in 6-OHDA-lesioned rats. Carnosine pretreatment significantly reduced rotations, attenuated apoptosis, and restored malondialdehyde and nitrite content and catalase activity with no significant effect on reduced glutathione (GSH). These results indicate that prelesion administration of carnosine could exert neuroprotection against 6-OHDA toxicity, and this may be of benefit in patients with early PD. © 2014, Springer Science+Business Media New York

Anti-aging Klotho Protects SH-SY5Y Cells Against Amyloid β1�42 Neurotoxicity: Involvement of Wnt1/pCREB/Nrf2/HO-1 Signaling

Alzheimer�s disease (AD) is considered a prevalent neurological disorder with a neurodegenerative nature in elderly people. Oxidative stress and neuroinflammation due to amyloid β (Aβ) peptides are strongly involved in AD pathogenesis. Klotho is an anti-aging protein with multiple protective effects that its deficiency is involved in development of age-related disorders. In this study, we investigated the beneficial effect of Klotho pretreatment at different concentrations of 0.5, 1, and 2 nM against Aβ1�42 toxicity at a concentration of 20 μM in human SH-SY5Y neuroblastoma cells. Our findings showed that Klotho could significantly and partially restore cell viability and decrease reactive oxygen species (known as ROS) and improve superoxide dismutase activity (SOD) in addition to reduction of caspase 3 activity and DNA fragmentation following Aβ1�42 challenge. In addition, exogenous Klotho also reduced inflammatory biomarkers consisting of nuclear factor-kB (NF-kB), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in Aβ-exposed cells. Besides, Klotho caused downregulation of Wnt1 level, upregulation of phosphorylated cyclic AMP response element binding (pCREB), and mRNA levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) with no significant alteration of epsilon isoform of protein kinase C (PKCε) after Aβ toxicity. In summary, Klotho could alleviate apoptosis, oxidative stress, and inflammation in human neuroblastoma cells after Aβ challenge and its beneficial effect is partially exerted through appropriate modulation of Wnt1/pCREB/Nrf2/HO-1 signaling. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

Berberine ameliorates lipopolysaccharide-induced learning and memory deficit in the rat: insights into underlying molecular mechanisms

Systemic lipopolysaccharide (LPS) triggers neuroinflammation with consequent development of behavioral and cognitive deficits. Neuroinflammation plays a crucial role in the pathogenesis of neurodegenerative disorders including Alzheimer�s disease (AD). Berberine is an isoquinoline alkaloid in Berberis genus with antioxidant and anti-inflammatory property and protective effects in neurodegenerative disorders. In this research, beneficial effect of this alkaloid against LPS-induced cognitive decline was assessed in the adult male rats. LPS was intraperitoneally administered at a dose of 1 mg/kg to induce neuroinflammation and berberine was given via gavage at doses of 10 or 50 mg/kg, one h after LPS, for 7 days. Treatment of LPS group with berberine at a dose of 50 mg/kg (but not at a dose of 10 mg/kg) improved spatial recognition memory in Y maze, performance in novel object recognition task (NORT), and prevented learning and memory dysfunction in passive avoidance tasks. Furthermore, berberine lowered hippocampal activity of acetylcholinesterase (AChE), malondialdehyde (MDA), protein carbonyl, activity of caspase 3, and DNA fragmentation and improved antioxidant capacity through enhancing glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase, and glutathione (GSH). Besides, berberine attenuated inflammation-related indices, as was evident by lower levels of nuclear factor-kappa B (NF-κB), toll-like receptor 4 (TLR4), tumor necrosis factor α (TNFα), and interleukin 6 (IL-6). Berberine also appropriately restored hippocampal 3-nitrotyrosine (3-NT), cyclooxygenase 2 (Cox 2), glial fibrillary acidic protein (GFAP), sirtuin 1, and mitogen-activated protein kinase (p38 MAPK) with no significant alteration of brain-derived neurotrophic factor (BDNF). In summary, berberine could partially ameliorate LPS-induced cognitive deficits via partial suppression of apoptotic cascade, neuroinflammation, oxido-nitrosative stress, AChE, MAPK, and restoration of sirtuin 1. © 2018, Springer Science+Business Media, LLC, part of Springer Nature

Naringenin ameliorates learning and memory impairment following systemic lipopolysaccharide challenge in the rat

Systemic inflammation following infection is usually associated with long-term complications including cognitive deficit and dementia. Neuroinflammation and cognitive decline are also main hallmarks of several neurological conditions. Naringenin is a citrus flavanone with anti-inflammatory, neuroprotective, and antioxidant potential. In this study, the protective effect of naringenin against lipopolysaccharide (LPS)-induced cognitive decline was evaluated in the rat. LPS was daily injected at a dose of 167 μg/kg for 1 week and naringenin was administered p.o. at doses of 25, 50, or 100 mg/kg/day. Treatment of LPS-injected rats with naringenin dose-dependently improved spatial recognition memory in Y maze, discrimination ratio in novel object discrimination task, and retention and recall capability in passive avoidance test. Furthermore, naringenin lowered hippocampal malondialdehyde (MDA) as an index of lipid peroxidation and improved antioxidant defensive system comprising superoxide dismutase (SOD), catalase, and glutathione (GSH) in addition to decreasing acetylcholinesterase (AChE) activity. Additionally, naringenin was able to lower hippocampal nuclear factor-kappaB (NF-κB), toll-like receptor 4 (TLR4), tumor necrosis factor α (TNFα), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), glial fibrillary acidic protein (GFAP) level and its immunoreactivity, and to elevate nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Taken together, naringenin could alleviate LPS-induced cognitive deficits and neuroinflammation, as was evident from attenuation of oxidative stress and AChE and modulation of Nrf2/NF-κB/TNFα/COX2/iNOS/TLR4/GFAP. © 2018 Elsevier B.V

Naringenin ameliorates learning and memory impairment following systemic lipopolysaccharide challenge in the rat

Systemic inflammation following infection is usually associated with long-term complications including cognitive deficit and dementia. Neuroinflammation and cognitive decline are also main hallmarks of several neurological conditions. Naringenin is a citrus flavanone with anti-inflammatory, neuroprotective, and antioxidant potential. In this study, the protective effect of naringenin against lipopolysaccharide (LPS)-induced cognitive decline was evaluated in the rat. LPS was daily injected at a dose of 167 μg/kg for 1 week and naringenin was administered p.o. at doses of 25, 50, or 100 mg/kg/day. Treatment of LPS-injected rats with naringenin dose-dependently improved spatial recognition memory in Y maze, discrimination ratio in novel object discrimination task, and retention and recall capability in passive avoidance test. Furthermore, naringenin lowered hippocampal malondialdehyde (MDA) as an index of lipid peroxidation and improved antioxidant defensive system comprising superoxide dismutase (SOD), catalase, and glutathione (GSH) in addition to decreasing acetylcholinesterase (AChE) activity. Additionally, naringenin was able to lower hippocampal nuclear factor-kappaB (NF-κB), toll-like receptor 4 (TLR4), tumor necrosis factor α (TNFα), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), glial fibrillary acidic protein (GFAP) level and its immunoreactivity, and to elevate nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Taken together, naringenin could alleviate LPS-induced cognitive deficits and neuroinflammation, as was evident from attenuation of oxidative stress and AChE and modulation of Nrf2/NF-κB/TNFα/COX2/iNOS/TLR4/GFAP. © 2018 Elsevier B.V

Diosgenin Attenuates Cognitive Impairment in Streptozotocin-Induced Diabetic Rats: Underlying Mechanisms

Objective: Prolonged diabetes mellitus causes impairments of cognition and attentional dysfunctions. Diosgenin belongs to a group of steroidal saponins with reported anti-diabetic and numerous protective properties. This research aimed to assess the effect of diosgenin on beneficially ameliorating learning and memory decline in a rat model of type 1 diabetes caused by streptozotocin (STZ) and to explore its modes of action including involvement in oxidative stress and inflammation.Methods:Rats were assigned to one of four experimental groups, comprising control, control under treatment with diosgenin, diabetic, and diabetic under treatment with diosgenin. Diosgenin was given daily p.o. (40 mg/kg) for 5 weeks. Results: The administration of diosgenin to the diabetic group reduced the deficits of functional performance in behavioral tests, consisting of Y-maze, passive avoidance, radial arm maze, and novel object discrimination tasks (recognitive). Furthermore, diosgenin treatment attenuated hippocampal acetylcholinesterase activity and malon-dialdehyde, along with improvement of antioxidants such as superoxide dismutase and glutathione. Meanwhile, the hippocampal levels of inflammatory indicators, namely interleukin 6, nuclear factor-κB, toll-like receptor 4, tumor necrosis factor α, and astrocyte-specific biomarker glial fibrillary acidic protein, were lower and, on the other hand, tissue levels of nuclear factor (erythroid-derived 2)-related factor 2 were elevated upon diosgenin administration. Besides, the mushroom-like spines of the pyramidal neurons of the hippocampal CA1 area decreased in the diabetic group, and this was alleviated following diosgenin medication. Conclusions: Taken together, diosgenin is capable of ameliorating cognitive deficits in STZ-diabetic animals, partly due to its amelioration of oxidative stress, inflammation, astrogliosis, and possibly improvement of cholinergic function in addition to its neuroprotective potential. © 2020 S. Karger AG, Basel. Copyright: All rights reserved

Sinomenine Alleviates Murine Experimental Autoimmune Encephalomyelitis Model of Multiple Sclerosis through Inhibiting NLRP3 Inflammasome

Multiple sclerosis (MS) is known as a chronic neuroinflammatory disorder typified by an immune-mediated demyelination process with ensuing axonal damage and loss. Sinomenine is a natural alkaloid with different therapeutic benefits, including anti-inflammatory and immunosuppressive activities. In this study, possible beneficial effects of sinomenine in an MOG-induced model of MS were determined. Sinomenine was given to MOG35�55-immunized C57BL/6 mice at doses of 25 or 100 mg/kg/day after onset of MS clinical signs till day 30 post-immunization. Analyzed data showed that sinomenine reduces severity of the clinical signs and to some extent decreases tissue level of pro-inflammatory cytokines IL-1β, IL-6, IL-18, TNFα, IL-17A, and increases level of anti-inflammatory IL-10. In addition, sinomenine successfully attenuated tissue levels of inflammasome NLRP3, ASC, and caspase 1 besides its reduction of intensity of neuroinflammation, demyelination, and axonal damage and loss in lumbar spinal cord specimens. Furthermore, immunoreactivity for MBP decreased and increased for GFAP and Iba1 after MOG-immunization, which was in part reversed upon sinomenine administration. Overall, sinomenine decreases EAE severity, which is attributed to its alleviation of microglial and astrocytic mobilization, demyelination, and axonal damage along with its suppression of neuroinflammation, and its beneficial effect is also associated with its inhibitory effects on inflammasome and pyroptotic pathways; this may be of potential benefit for the primary progressive phenotype of MS. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

Outcomes of two different polytetrafluoroethylene graft sizes in patients undergoing maintenance hemodialysis

Arteriovenous access creation is mandatory for maintenance hemodialysis. If native fistula placement was not possible or failed, a prosthetic conduit would be the best substitute. The purpose of this prospective study was to compare outcomes of two different sizes of polytetrafluoroethylene (PTFE) grafts, in hemodialysis patients, at the Mustafa Khomeini Hospital in Iran. The study population consisted of 586 end-stage renal disease referrals for vascular access construction (January 2003 to January 2007) of which eventually 102 subjects were candidates for PTFE graft who were followed for one year. Data were collected by a questionnaire and analyzed using the SPSS, life table, Kaplan- Meier and Log-Rank tests. Out of 102 PTFE implantation candidates (mean value of age 51.7 ± 17.06 yrs), 56% were male and 44% female. PTFE grafts of 8 mm and 6 mm sizes were randomly placed in 57 and 45 subjects, with distribution of 83%, 12% and 5% in arm, forearm and thigh. The most underlying diseases were hypertension and diabetes. There was a significant difference in complication rates between patients with and without underlying diseases [42% vs. 10% (P = 0.03)]. One-year patency rates were 42.2% and 36.5% for 6 mm and 8 mm grafts and 28.2% vs. 52% in patients with and without underlying diseases respectively. Despite more complication frequency in 8 mm grafts, the patency and complication rates of two graft groups did not significantly differ. Hypertension and diabetes could have contributory roles in graft complication rate, which may be preventable. Non-tapered grafts of 6 mm and 8 mm sizes have not significant different outcomes. Further research is recommended with larger sample size and longer duration

Ellagic acid ameliorates neuroinflammation and demyelination in experimental autoimmune encephalomyelitis: Involvement of NLRP3 and pyroptosis

Multiple sclerosis (MS) is presented as the most common autoimmune and demyelinating neurological disorder with incapacitating complications and with no definite therapy. Most treatments for MS mainly focus on attenuation of its severity and recurrence. To model MS reliably to study pathogenesis and efficacy of possible chemicals, experimental autoimmune encephalomyelitis (EAE) condition is induced in rodents. Ellagic acid is a neuroprotective polyphenol that can protect against demyelination. This study was planned and conducted to assess its possible beneficial effect in MOG-induced EAE model of MS with emphasis on uncovering its modes of action. Ellagic acid was given p.o. (at doses of 10 or 50 mg/kg/day) after development of clinical signs of MS to C57BL/6 mice immunized with MOG35�55. Results showed that ellagic acid can ameliorate severity of the disease and partially restore tissue level of TNFα, IL-6, IL-17A and IL-10. Besides, ellagic acid lowered tissue levels of NLRP3 and caspase 1 in addition to its mitigation of neuroinflammation, demyelination and axonal damage in spinal cord specimens of EAE group. As well, ellagic acid treatment prevented reduction of MBP and decreased GFAP and Iba1 immunoreactivity. Taken together, ellagic acid can decrease severity of EAE via amelioration of astrogliosis, astrocyte activation, demyelination, neuroinflammation and axonal damage that is partly related to its effects on NLRP3 inflammasome and pyroptotic pathway. © 2020 Elsevier B.V