Protective Role of Salidroside against Aging in A Mouse Model Induced by D-galactose

Objective To investigate the protective effects of putative AGEs （advanced glycation endproducts） inhibitor salidroside against aging in an accelerated mouse aging model induced by D-galactose. Methods A group of 5-month-old C57BL/6J mice were treated daily with D-galactose, D-galactose combined with salidroside, salidroside alone, and control buffer for 8 weeks. At the end of the treatment, serum AGEs levels, neurological activities, expression of glial fibrillary acidic protein （GFAP） and neurotrophin-3 （NT-3） in the cerebral cortex, as well as lymphocyte proliferation and IL-2 production were determined. Results D-galactose induced mouse aging model was developed as described before. As expected, salidroside blocked D-galactose induced increase of serum AGEs levels. It also reversed D-galactose induced aging effects in neural and immune system, as evidenced by improving motor activity, increasing memory latency time, and enhancing lymphocyte mitogenesis and interleukin-2 （IL-2） production. Furthermore, elevated expression of GFAP and NT-3 in the aged model mice was also reduced upon salidroside treatment. Conclusion Salidroside inhibits AGEs formation in vivo, which at least partially contributes to its anti-aging effect in D-galactose induced aging model.

Inhibiting Effects of Achyranthes Bidentata Polysaccharide and Lycium Barbarum Polysaccharide on Nonenzyme Glycation in D-galactose Induced Mouse Aging Model

Objective To investigate the inhibiting effects and mechanism of achyranthes bidentata polysaccharide (ABP) and lycium barbarum polysaccharide (LBP) on nonenzyme glycation in D-galactose induced mouse aging model. Methods Serum AGE levels were determined by AGE-ELISA, MTT method was used to determine lymphocyte proliferation, IL-2 activity was determined by a bioassay method. Spontaneous motor activity was used to detect mouse's neuromuscular movement, latency of step-through method was used to examine learning and memory abilities of mouse, colormetric assay was used to determine hydroxyproline concentration in mouse skin, pyrogallol autoxidation method was used to determine superoxide dismutase (SOD) activity of erythrocytes. Results Decreased levels of serum AGE, hydroxyproline concentration in mouse skin and spontaneous motor activity in D-galactose mouse aging model were detected after treated with ABP or LBP, while lymphocyte proliferation and IL-2 activity, learning and memory abilities, SOD activity of erythrocytes, were enhanced. Conclusions ABP and LBP could inhibit nonenzyme glycation in D-galactose induced mouse aging model in vivo and ABP has a better inhibiting effect than LBP.

Antioxidant effect of Lactobacillus fermentum HFY02-fermented soy milk on D-galactose-induced aging mouse model

This study aimed to investigate the antioxidant effect of soybean milk fermented by a new type of Lactobacillus fermentum(LF-HFY02)by using D-galactose induced aging mice model.Firstly,the optimal fermentation conditions was screened out by detecting the effects of different fermentation temperature and time on the active components and antioxidant activity of soybean milk in viro.And then unfermented soybean milk and the soybean milk fermented by different Lactobacillus was given by gavage to D-galactose-induced aging mouse.The activities of GSH,GSH-Px,SOD,CAT and T-AOC in serum,brain and liver of soybean milk fermented by LF-HFY02 were significantly increased,while the content of MDA and the level of AGEs in hippocampal were significantly decreased compared with D-galactose induced group.Further more,the mRNA expression of GSH and SOD in mouse liver were obviously up-regulated by soybean milk fermented by LF-HFY02.The skin tissue structure of mice in the LF-HFY02 fermented soybean milk group was more complete,the collagen fibers were increased and arranged orderly and liver inflammation has improved compared with the model group.And Western blot analysis showed that LF-HFY02 effectively upregulated EGFR,SOD and GSH protein expression in mouse liver.These findings suggest that LF-HFY02 can effectively prevent D-galactose-induced oxidation and aging in mice,and the effect was even better than that of the Lactobacillus delbruechii subsp.bulgaricus and vitamin C.Thus,LF-HFY02 may be potentially employed as a probiotic strain.In conclusion,soybean milk fermented by LF-HFY02 can increase the content of antioxidant factors and the activity of antioxidant enzymes by regulating gene and protein expression,and finally inhibit the process of tissue cell peroxidation,and improve the oxidative damage of mouse skin and liver.The results could provide a basis for the research and development and industrial production of probiotic-related fermented soybean milk products.

Moderate exercise prevents neurodegeneration in D-galactose-induced aging mice

D-galactose has been widely used in aging research because of its efficacy in inducing senescence and accelerating aging in animal models. The present study investigated the benefits of exercise for preventing neurodegeneration, such as synaptic plasticity, spatial learning and memory abilities, in mouse models of aging. D-galactose-induced aging mice were administered daily subcutaneous injections of D-galactose at the base of the neck for 10 consecutive weeks. Then, the mice were subjected to exercise training by running on a treadmill for 6 days a week. Shortened escape latency in a Morris water maze test indicated that exercise improved learning and memory in aging mice. The ameliorative changes were likely induced by an upregulation of Bcl-2 and brain-derived neurotrophic factor, the repression of apoptosis factors such as Fas and Bax, and an increase in the activity of glucose transporters-1 and 4. The data suggest moderate exercise may retard or inhibit neurodegeneration in D-galactose-induced aging mice.

Effect of Schisandra chinensis polysaccharide on intracerebral acetylcholinesterase and monoamine neurotransmitters in a D-galactose-induced aging brain mouse model

BACKGROUND： The most prominent characteristic of brain aging is decreased learning and memory ability. The functions of learning and memory are closely related to intracerebral acetylcholinesterase （ACHE） and monoamine neurotransmitter activity. Previous studies have shown that Schisandra chinensis polysaccharide has an anti-aging effect. OBJECTIVE： To explore the effects of Schisandra chinensis polysaccharide on AChE activity and monoamine neurotransmitter content, as well as learning and memory ability in a D-galactose-induced aging mouse brain model compared with the positive control drug Kangnaoling. DESIGN, TIME AND SETTING： Completely randomized, controlled experiment based on neurobiochemistry was performed at the Pharmacological Laboratory, Henan University of Traditional Chinese Medicine from September to December 2003. MATERIALS： Schisandra chinensis was purchased from Henan Provincial Medicinal Company. Schisandra chinensis polysaccharide was obtained by water extraction and alcohol precipitation. Kangnaoling pellets were provided by Liaoning Tianlong Pharmaceutical （batch No. 20030804; state drug permit No. H21023095）. A total of 50 six-week-old Kunming mice were randomly divided into five groups： blank control, model, Kangnaoling, high and low dosage Schisandra chinensis polysaccharide groups, with 10 mice per group. METHODS： Mice in the blank control group were subcutaneously injected with 0.5 mL/20 g normal saline into the nape of the neck each day, while the remaining mice were subcutaneously injected with 5% D-galactose saline solution （0.5 mL/20 g） in the nape for 40 days to induce a brain aging model. On day 11, mice in the high and low dosage Schisandra chinensis polysaccharide groups were intragastrically infused with 20 mg/mL and 10 mg/mL Schisandra chinensis polysaccharide solution （0.2 mL/10 g）, respectively. Mice from the Kangnaoling group were intragastrically infused with 35 mg/mL Kangnaoling suspension （0.2 mL/10 g）, and the mice in the model group were intragastrically infused with the same volume of normal saline （0.2 mL/10 g） once per day for 30 consecutive days. MAIN OUTCOME MEASURES： Two hours after the final administration, pathohistological changes in the cerebral cortex and hippocampus were observed using hematoxylin ＆ eosin staining. AChE activity was detected using chromatometry. Monoamine neurotransmitter content was measured using fluorimetry. Learning and memory was measured using the step down test and darkness avoidance test. RESULTS： Both Schisandra chinensis polysaccharide and Kangnaoling improved pathological injury to the cerebral cortex and hippocampus in a mouse model of brain aging. Compared with the blank control group, AChE activity and content of norepinephrine （NA）, dopamine （DA）, and 5-hydroxytryptamine （5-HT） were significantly decreased in the model group （P 〈 0.01 ）. In contrast, AChE activity and NA, DA, and 5-HT levels significantly increased in the Kangnaoling and high dosage Schisandra chinensis polysaccharide groups （P 〈 0.01）, while NA levels significantly increased in the low dosage Schisandra chinensis polysaccharide group （P 〈 0.01）. Drug treatment improved learning and memory abilities （P 〈 0.01 or P 〈 0.05）. CONCLUSION： Schisandra chinensis polysaccharide significantly increased levels of central neurotransmitters and improved learning and memory in a mouse model of brain aging. The effects of Schisandra chinensis polysaccharide were equal to that of Kangnaoling pellets.

Protective effects of (-)-epigallocatechin-3-gallate on D-galactose-induced neuronal apoptosis in mice

BACKGROUND： The neuroprotective effects of （-）-epigallocatechin-3-gallate （EGCG）, the main polyphenolic constituent of green tea, have been widely reported. However, the action mechanisms, in particular in D-galactose-induced aging mice, remain poorly understood. OBJECTIVE： The present study investigated the protective effects of EGCG on D-galactose-induced hippocampus neuronal apoptosis in aging mice, as well as the relationship with expression of p751CD, JNK2, and p53 proteins. DESIGN, TIME AND SETTING： A randomized, controlled, molecular biological, animal experiment was performed at the Laboratory of Pharmacology, Pharmaceutical College of China Medical University, China, from September 2006 to July 2008. MATERIALS： D-galactose and EGCG （Sigma, USA）, as well as terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling （TUNEL） In Situ Cell Apoptosis Detection Kit （Promega, USA）, were used in this study. METHODS： A total of 64 mice were equally and randomly divided into D-galactose model, low-dose EGCG, high-dose EGCG, and control groups. Mice in the D-galactose model, low-dose EGCG, and high-dose EGCG groups were subcutaneously injected with 3% D-galactose （150 mg/kg）, daily for 6 weeks, to establish a mouse model of aging. Mice in the control group were treated with saline （5 mL/kg）. At 3 weeks following injection, mice in the low-dose EGCG and high-dose EGCG groups were orally administered EGCG at a dose of 2 mg/kg and 6 mg/kg, respectively, once a day, for 4 consecutive days. Mice in the control and D-galactose model groups received distilled water （5 mL/kg）. MAIN OUTCOME MEASURES： Memory function was evaluated using a step-through passive avoidance test. Neuronal apoptosis in the mouse hippocampus was detected using TUNEL staining. Expression levels of the intracellular domain of the p75 neurotrophin receptor （p75NTR）-p751CD, JNK2, and p53 proteins in the hippocampus were determined using Western blot analysis. RESULTS： The aging mouse model was induced by subcutaneous injection of D-galactose, which resulted in obvious memory impairment, increased apoptotic index, and increased protein expression levels of p751CD, JNK2, and p53 in the hippocampus, compared with control mice （P 〈 0.01）. Oral EGCG administration （2 or 6 mg/kg） for 4 weeks significantly improved levels of memory deficit in the aging mice and reduced apoptotic indices and protein expression levels of p751CD, JNK2, and p53 in the mouse hippocampus （P 〈 0.01）. CONCLUSION： Results from this study demonstrated increased protein expression levels of p751CD, JNK2, and p53, as well as increased hippocampal neuronal apoptosis in a D-galactose-induced mouse model of aging. EGCG provided protective effects against D-galactose-induced neuronal apoptosis in the hippocampus by reducing protein expression levels of p751CD, JNK2, and p53 proteins in the hippocampus of aging mice.

Dietary restriction to accompany the aging process in mice Can it be neuroprotective?

BACKGROUND： Prophylactic dietary restriction （DR）, whether lifelong or started in adulthood,retards the aging process and attenuates cognitive decline in rodents. However, whether the anti-aging and neuroprotective efficacy of DR initiate late in life or accompany the aging process remains unclear.OBJECTIVE： The present study sought to： （1） determine if DR could protect against behavioral decline in mice when implemented during the aging process induced by D-galactose and （2） examine neuronal apoptosis in these aged brains and whether DR could block apoptosis.DESIGN, TIME AND SETTING： The randomized controlled animal study. The experiment was performed at the Experimental Animal Center of Capital Medical University and the Laboratory Center of School of Public Health of Captial Medical University of China from April 2006 to October 2007.MATERIALS： D-galactose （D-gal） was purchased from Beijing Chemical-Regent Company （Beijing, China）. Terminal transferase dUTP nick end labeling （TUNEL） detection kit was obtained from Roche, Germany. Assay kits for antioxidant enzyme activities and malondialdehyde contents were purchased from Jiancheng Institute of Biotechnology （Nanjing, China）. Morris water maze （Friends Honesty Life Sciences Co. Ltd., Hong Kong, China） and Flow Cytometry （Coulter, USA） were used in this study.METHODS： A total of 40 male Institute of Cancer Research （lCR） mice, 3 months old, were equally and randomly divided into D-gal treatment, DR treatment, D-gal ＋ DR treatment and normal control groups, and were then randomly assigned to one of two feeding regimens： ad libitum access to food or DR which received a 70% amount of daily food intake as that by ad libitum fed mice. There were two replicates per feeding regimen and mice were fed for 10 weeks,with or without a daily subcutaneous injection of D-gal at 100 mg/kg.MAIN OUTCOME MEASURES： Animals＇ spatial learning and memory performance were tested in the Morris water maze. Neuronal apoptosis rates were evaluated by Annexin V/flow cytometry assay and TUNEL assay. Lipid peroxidation levels and antioxidant defense capacity of the brain were measured using testing kits.RESULTS： DR markedly reduced the prolonged escape latency of D-gal mice in the water maze test （P〈0.01）. Annexin V and TUNEL assays showed that the D-gal mice had a significant higher percentage of neuronal apoptosis compared with normal control mice （P〈0.05）, and that DR treatment markedly decreased this apoptotic cell death （P〈0.05）. DR also reversed the decline of total superoxide dismutase and glutathione peroxidase activities and the increase of malondialdehyde levels in the brain of D-gal mice （P〈0.05, respectively）.CONCLUSION： DR reduces the impact of D-gal-induced brain aging in mice and can reverse performance decline and neurobiochemical impairments. These results demonstrate that implementation of DR in conditions of chronic oxidative stress can be neuroprotective, and that senium DR can be beneficial for healthy aging.

Study on Learning and Memory Ability of Mice Induced by Different Doses of D-galactose

Aim:To explore the influence of different doses of D-galactose on learning memory capacity in mice.Methods:The 2-month-old KM mice were randomly divided into D-galactose-treated groups (75,100,150,300 mg·kg^-1) and normal control group,with 12 mice in each group.The corresponding dose of D-galactose was administered subcutaneously to the back of the neck,and normal control group was injected subcutaneously with saline for 8 weeks.Learning memory capacity of mice was detected through Morris water maze,step-down passive avoidance test and new object recognition test.Meanwhile,the enzymatic indicators in the brain were determined to detect the damage degree in mice with different doses of D-galactose.Results:Compared with the normal control group,the spatial and non-spatial cognitive functions and brain enzyme levels of D-galactose in each dose group was damaged to varying degrees,especially the dose of 100 mg·kg-1 group.In the water maze experiment,D-galactose groups significantly prolonged the time of crossing the platform for the first time and decreased the number of crossing platforms,especially at the dose of 100 mg·kg-1 (P < 0.05);in the new object recognition experiment,discrimination index was significantly decreased in each D-galactose group (P < 0.01),and the dose of 100 mg·kg-1 was most obvious;in addition,D-galactose could significantly increase the level of acetylcholinesterase (AChE)(P < 0.01),decrease the levels of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px),and total antioxidant capacity (T-AOC)(P < 0.05 or P < 0.01) in the mice brain.Conclusion:Subcutaneous injection of low-medium-high dose of D-galactose for 8 weeks in the back of the neck can cause changes in brain parameters in mice,but the effects of different doses of D-galactose on some indicators are significantly different.D-galactose model is effective and stable at the dose of 100 mg·kg-1.

Effect of Cistanche Desertica Polysaccharides on Learning and Memory Functions and Ultrastructure of Cerebral Neurons in Experimental Aging Mice

To observe the effects of Cistanche desertica polysaccharides (CDP) on the learning and memory functions and cerebral ultrastructure in experimental aging mice. Methods: CDP was administrated intragastrically 50 or 100 mg/kg per day for 64 successive days to experimental aging model mice induced by D-galactose, then the learning and memory functions of mice were estimated by step-down test and Y-maze test; organelles of brain tissue and cerebral ultrastructure were observed by transmission electron microscope and physical strength was determined by swimming test. Results: CDP could obviously enhance the learning and memory functions (P＜0.01) and prolong the swimming time (P＜0.05), decrease the number of lipofuscin and slow down the degeneration of mitochondria in neurons(P＜0.05), and improve the degeneration of cerebral ultra-structure in aging mice. Conclusion: CDP could improve the impaired physiological function and alleviate cerebral morphological change in experimental aging mice.

Transplanted bone marrow stromal cells improve cognitive dysfunction due to aging hypoperfusion in rats

Background Aging is an important risk factor for vascular dementia, and D-galactose （D-gal） injection can simulate the pathology of aging. Two-vessel occlusion of common carotid arteries （2VO） is the most popular model for vascular dementia. This study was aimed to investigate the possibility of D-gal injection plus 2VO simulating cognitive impairment of aging vascular dementia; and whether transplanted bone marrow stromal cells （BMSCs） can improve the cognitive function induced by D-gal injection plus 2VO.Methods Totally 30 male Sprague-Dawley rats were divided into 5 groups equivalently： control group, D-gal group,D-gal＋2VO group, D-gal＋2VO＋saline water group, and D-gal＋2VO＋BMSCs group. Aging hypoperfusion rats were created by subcutaneous injection of D-gal and occlusion of two common carotid arteries. BMSCs or saline water was stereotactically transplanted into the subventricular zone as treatment vehicles at 24 hours post operation. Two-way repeat analysis of variance （ANOVA） was used for significance analysis of 5 groups at 6 weeks post transplantation;moreover, Tamhane＇s test （equal variance not assumed） and least significant difference （LSD） test （equal variance assumed） were used for pairwise comparison in Morris water maze （MWM）.Results Transplanted BMSCs distributed around the lateral ventricles and acquired the phenotypes of neurons and astrocytes. In terms of swimming path distance and escape latency in MWM, D-gal＋2VO＋BMSC group showed significant improvement than the D-gal＋2VO group but was still obviously worse than the control group （both P ＜0.05）.There was no significant difference in swimming speed for all 5 groups.Conclusions D-gal plus 2VO induces cognitive dysfunction. The engrafted BMSCs exhibit the beneficial effect on cognitive function via promotion interactively with host brain.

Establishment of oxygen glucose deprivation reperfusion model of senescent SH-SY5Y cells

Obejective:To explore the establishment of an oxygen glucose deprivation/reperfusion model of senescent SH-SY5Y cells.Methods:SH-SY5Y cells were randomly divided into control(D-galactose 0 mmol/L group),D-galactose(25 mmol/L,50 mmol/L,100 mmol/L,200 mmol/L,400 mmol/L)groups,and treated with corresponding concentrations of D-galactose for 48 h.The changes of cell morphology,β-galactosidase,the cell morphology,β-galactosidase activity by microscopic observation,cell proliferation rate by EdU kit and cell survival rate by CCK-8 assay were used to determine the decaying concentration of D-galactose and to establish the senescence model.The senescent SH-SY5Y cells were randomly divided into control group(oxygen glucose deprivation without treatment group),oxygen glucose deprivation treatment(0.5 h,1 h,1.5 h,2 h)group,followed by re-glucose reoxygenation for 24 h,and CCK-8 assay for the survival rate of senescent SH-SY5Y cells.Results:There were no significant changes in cell morphology and β-gal activity in the 25 mmol/L and 50 mmol/L groups compared with the control group(P>0.05),cytosolic hypertrophy was seen in the cells of the 100 mmol/L group,chromatin fixation in the cells of the 200 mmol/L group,and massive vacuolization in the cells of the 400 mmol/L group;the positive rate ofβ-galactosidase staining in the cells of the(100-400 mmol/L)group was significantly higher compared with the control group(P<0.05),with little difference between the 100 mmol/L and 200 mmol/L groups(P>0.05);the cell proliferation ability of the(100-400 mmol/L)group was significantly decreased in a concentration-dependent manner(P<0.05);the cell survival rate was decreased in a concentration-dependent manner(P<0.05),with IC_(50) between 100 mmol/L and 200 mmol/L.The survival of senescent SH-SY5Y cells showed a time-dependent decrease in oxygen-glucose deprivation(P<0.05),with an IC_(50) close to 1 h.Conclusion:D-gal concentration of 100 mmoL/L and 48 h of cell action could establish a survival rate of about 50%of senescent SH-SY5Y cells,and oxygen glucose deprivation of senescent SH-SY5Y cells for 1 h and reperfusion for 24 h could establish an oxygen glucose deprivation/reperfusion model of senescent SH-SY5Y cells with a survival rate close to 50%.