Candesartan protects against d-galactose induced - Neurotoxicity and memory deficit via modulation of autophagy and oxidative stress.

PURPOSE: d-galactose induces neuroinflammation and memory deficit via oxidative stress. Candesartan is an angiotensin II-receptor blocker and has proved neuroprotective properties. This study aimed to investigate the neuroprotective effect of candesartan against d-galactose induced neuroinflammation and memory deficit via autophagy. METHODS: Twenty-eight male Wistar rats aged 3 months were divided into four equal groups: control (vehicle), d-gal (100 mg/kg d-galactose), cand (1 mg/kg candesartan), and cand+d-gal (100 mg/kg d-galactose & 1 mg/kg candesartan). All treatments were given orally and daily for 4 weeks. Assessment of memory was done using Morris water maze (MWM) test. Brain tissue was assessed for malondialdehyde (MDA), total thiol, catalase activity, glial fibrillary acidic protein (GFAP) and gene expression of TNF-α, GDNF-1 as well as autophagy genes (Beclin 1 and ATG 5). RESULTS: Prophylactic treatment of candesartan in d-galactose-treated rats significantly (p < 0.001) reduced oxidative stress via reduction of MDA as well as elevation of catalase activity and total thiol levels. Additionally, candesartan prophylactic treatment significantly increased gene expression of GDNF-1 and decreased gene expression of TNF-α. Furthermore, candesartan significantly increased the expression of autophagy related gene (Beclin 1 and ATG 5) in cand+d-gal treated rats. These results were supported by the histopathological findings which showed that candesartan prevented the neuronal injury in the cerebral cortex and hippocampus and decreased GFAP positive cells of the d-galactose-treated rats. Moreover, MWM test showed that candesartan significantly improved memory deficit in cand+d-gal treated rats. CONCLUSION: Candesartan prevents d-galactose-induced neurotoxicity and memory deficit via activating autophagy and decreasing oxidative stress. Therefore, candesartan was a good candidate for age-related neurodegenerative disorders and memory deficit.

Protective Effects of Silymarin Against D-Gal/LPS-Induced Organ Damage and Inflammation in Mice.

AIM: Silymarin contains various flavonoids and exhibits antioxidative, anti-inflammatory, and anticancer effects, in addition to other pharmacological properties. This study explored the alleviating effect of silymarin on multiple-organ damage induced by D-galactose/lipopolysaccharide in Kunming mice. METHODS: Kunming mice were injected intraperitoneally with D-galactose (30 mg/kg·BW)/LPS (3 µg/kg·BW) and then treated using silymarin with different doses (75 mg/kg·bw and 150 mg/kg·bw) via intragastric administration. Changes in organ indexes, pathological changes, liver-function index, biochemical indexes, molecular biological indexes, and genes related to the oxidation and inflammation of main organs were evaluated. RESULTS: After the mice were treated with silymarin, their body weight showed no significant change, and the liver, kidney, and lung indexes of the treated mice were higher than those of the model group; meanwhile, the corresponding histopathological formation was reduced. Compared with the model group, the silymarin-treated group showed reductions in ALT, AST, and liver function indexes in the mouse serum. Silymarin treatment also increased the SOD, CAT, GSH, GSH-Px, T-AOC, IL-10, and IL-12 levels, as well as reduced the MDA, NO, IL-6, IL-1ß, TNF-α, IFN-γ levels in the mouse serum and liver tissues. In addition, quantitative polymerase chain reaction analysis indicated that the mRNA expression levels of SOD1, SOD2, CAT, GSH-Px, IL-10, Nrf2, HO-1, NQO1, Trx, and IκB-α were higher in the liver tissue of the silymarin-treated mice than in those of the model group; meanwhile, the mRNA expression levels of IL-6, IL-1ß, TNF-α, IFN-γ, NF-κB, NLRP3, COX2, and p38 were lower than those in the model group. CONCLUSION: Silymarin, which exhibits antioxidative and anti-inflammatory effects, can alleviate the liver, lung, and kidney damage induced by D-galactose/lipopolysaccharide. High-dose (150 mg/kg·bw) silymarin can more effectively inhibit organ damage, compared with low-dose silymarin (75 mg/kg·bw) in Kunming mice.

Gensenoside Rg1 protects against lipopolysaccharide- and d-galactose-induced acute liver failure via suppressing HMGB1-mediated TLR4-NF-κB pathway.

AIM: Acute liver failure (ALF) is a life-threatening acute liver injury (ALI) with high mortality. Gensenoside Rg1 (G-Rg1) effects on Lipopolysaccharide- (LPS-) and d-galactose-(D-gal-) induced ALI, but its effects on ALF remained unclear. This paper aimed to validate its possible efficacy on ALF prevention. METHODS: For in vivo studies, histological examination was performed using hematoxylin-eosin (H&E) staining, and alanine aminotransferase (ALT), aspartate aminotransminase (AST), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) contents were measured. Levels of inflammatory cytokines tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) were quantified via enzyme-linked immunosorbent assay (ELISA). Human bronchial epithelial cell line BEAS-2B was used for ALF model in vitro and its viability was measured by MTT assay. Expressions of high mobility group box 1 (HMGB1) and toll-like receptor 4-Nuclear Factor-κB (TLR4-NF-κB) pathway-related proteins were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot as needed. RESULTS: G-Rg1 relieved LPS- and D-gal-induced hepatic injury, and reduced ALT, AST and MDA levels but upregulated SOD and GSH levels, with downregulation on TNF-α and IL-6 levels. Expressions of HMGB1, TLR4 and NF-κB pathway-related proteins were also down-regulated after G-Rg1 treatment both in vivo and in vitro, while BEAS-2B cell viability was increased. However, overexpressed HMGB1 reversed the effects of G-Rg1 treatment in vitro. CONCLUSION: G-Rg1 had a protective effect against LPS- and D-gal-induced ALF both in vitro and in vivo, which might be related to inhibited HMGB1-mediated TLR4-NF-κB Pathway. These discoveries suggested that G-Rg1 could be a potential agent for prevention against ALF.

Melatonin alleviates d-galactose-decreased hyaluronic acid production in synovial membrane cells via Sirt1 signalling.

Hyaluronic acid (HA) exerts a critical role in the lubricating and buffering properties of synovial fluid in joints. The production of HA is regulated by growth factors, hormones, inflammatory cytokines and mechanical load. The reduction of HA contributes to the progression of osteoarthritis. Herein, we found that d-galactose (d-gal) induced the senescence of rabbit synovial membrane cells, accompanied by decreased HA production. The mRNA level of HA synthase 2 (HAS2) was downregulated by d-gal, as analysed by real-time polymerase chain reaction. Melatonin, an endocrine hormone, can regulate the homeostasis of bone and cartilage. We found that melatonin treatment attenuated d-gal-induced cell senescence and decreased the expression of p21, p16 and pp65 proteins. Melatonin could reverse HA production and maintain HAS2 expression. Furthermore, we revealed that Sirt1 signalling was required for melatonin effects. Sirt1 inhibitor could counteract melatonin-mediated HA production and HAS2 expression. Additionally, Sirt1 overexpression directly antagonized d-gal-induced cell aging and HA downregulation. Taken together, our results suggest that melatonin-Sirt1 signal has a protective effect on synovial membrane cells, enhancing HA synthesis and interrupting cell senescence.

Rescue from galactose-induced death of Leigh Syndrome patient cells by pyruvate and NAD.

Cell models of mitochondrial complex I (CI) deficiency display activation of glycolysis to compensate for the loss in mitochondrial ATP production. This adaptation can mask other relevant deficiency-induced aberrations in cell physiology. Here we investigated the viability, mitochondrial morphofunction, ROS levels and ATP homeostasis of primary skin fibroblasts from Leigh Syndrome (LS) patients with isolated CI deficiency. These cell lines harbored mutations in nuclear DNA (nDNA)-encoded CI genes (NDUFS7, NDUFS8, NDUFV1) and, to prevent glycolysis upregulation, were cultured in a pyruvate-free medium in which glucose was replaced by galactose. Following optimization of the cell culture protocol, LS fibroblasts died in the galactose medium, whereas control cells did not. LS cell death was dose-dependently inhibited by pyruvate, malate, oxaloacetate, α-ketoglutarate, aspartate, and exogenous NAD+ (eNAD), but not by lactate, succinate, α-ketobutyrate, and uridine. Pyruvate and eNAD increased the cellular NAD+ content in galactose-treated LS cells to a different extent and co-incubation studies revealed that pyruvate-induced rescue was not primarily mediated by NAD+. Functionally, in LS cells glucose-by-galactose replacement increased mitochondrial fragmentation and mass, depolarized the mitochondrial membrane potential (Δψ), increased H2DCFDA-oxidizing ROS levels, increased mitochondrial ATP generation, and reduced the total cellular ATP content. These aberrations were differentially rescued by pyruvate and eNAD, supporting the conclusion that these compounds rescue galactose-induced LS cell death via different mechanisms. These findings establish a cell-based strategy for intervention testing and enhance our understanding of CI deficiency pathophysiology.

In Vitro and In Vivo Antioxidant Activities of the Flowers and Leaves from Paeonia rockii and Identification of Their Antioxidant Constituents by UHPLC-ESI-HRMSn via Pre-Column DPPH Reaction.

The genus Paeonia, also known as the "King of Flowers" in China, is an important source of traditional Chinese medicine (TCM). Plants of this genus have been used to treat a range of cardiovascular and gynecological diseases. However, the potential pharmacological activity of one particular species, Paeonia rockii, has not been fully investigated. In the first part of the present study, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS), reducing power assays, and metal ion chelating assays were used to investigate the in vitro antioxidant activities of Paeonia rockii. In the second portion of the study, a mouse model of d-galactose-induced aging was used to validate the antioxidant effects of the flowers from Paeonia rockii in vivo. Lastly, potential antioxidant constituents were screened and identified by ultra-high pressure liquid chromatography and electrospray ionization coupled with high-resolution mass spectrometry (UHPLC-ESI-HRMSn) combined with the DPPH assay. Results indicated that the flowers and leaves exhibited stronger antioxidant activity than ascorbic acid in vitro. The therapeutic effect of Paeoniarockii was determined in relation to the levels of biochemical indicators, such as 8-iso-prostaglandin F2α (8-iso PGF2α) in the serum, superoxide dismutase (SOD), protein carbonyl, malondialdehyde (MDA), and glutathione (GSH) in the liver and brain, after daily intra-gastric administration of different concentrations of extracts (100, 200 and 400 mg/kg) for three weeks. The levels of 8-iso PGF2α (p < 0.01) and protein carbonyl groups (p < 0.01) were significantly reduced, whereas those of SOD (p < 0.05) had significantly increased, indicating that components of the flowers of Paeonia rockii had favorable antioxidant activities in vivo. Furthermore, UHPLC-ESI-HRMSn, combined with pre-column DPPH reaction, detected 25 potential antioxidant compounds. Of these, 18 compounds were tentatively identified, including 11 flavonoids, four phenolic acids, two tannins, and one monoterpene glycoside. This study concluded that the leaves and flowers from Paeonia rockii possess excellent antioxidant properties, highlighting their candidacy as "new" antioxidants, which can be utilized therapeutically to protect the body from diseases caused by oxidative stress.

Blueberry treatment decreased D-galactose-induced oxidative stress and brain damage in rats.

D-galactose (GAL) causes aging-related changes and oxidative stress in the organism. We investigated the effect of whole fresh blueberry (BB) (Vaccinium corymbosum L.) treatment on oxidative stress in age-related brain damage model. Rats received GAL (300 mg/kg; s.c.; 5 days per week) alone or together with 5 % (BB1) and 10 % (BB2) BB containing chow for two months. Malondialdehyde (MDA),protein carbonyl (PC) and glutathione (GSH) levels, and Cu Zn-superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione transferase (GST) activities as well as acetylcholinesterase (AChE) activities were determined. Expressions of B cell lymphoma-2 (Bcl-2), Bax and caspase-3 were also evaluated in the brain by immunohistochemistry. MDA and PC levels and AChE activity increased, but GSH levels, SOD and GSH-Px activities decreased together with histopathological structural damage in the brain of GAL-treated rats. BB treatments, especially BB2 reduced MDA and PC levels and AChE activity and elevated GSH levels and GSH-Px activity. BB1 and BB2 treatments diminished apoptosis and ameliorated histopathological findings in the brain of GAL-treated rats. These results indicate that BB partially prevented the shift towards an imbalanced prooxidative status and apoptosis together with histopathological amelioration by acting as an antioxidant (radical scavenger) itself in GAL-treated rats.

Curcumin and hesperidin improve cognition by suppressing mitochondrial dysfunction and apoptosis induced by D-galactose in rat brain.

D-galactose, a reducing sugar, induces oxidative stress resulting in alteration in mitochondrial dynamics and apoptosis of neurons. Curcumin and hesperidin are antioxidants possessing multimodal functions; hence, their contribution in minimizing D-galactose induced ageing was assessed in the present study. A week prior to D-galactose treatment (150 mg/kg; s.c. for 56 days), animals were treated with curcumin alone, hesperidin alone and a combination of curcumin (50 and 100 mg/kg; orally) with hesperidin (10 and 25 mg/kg; orally) for 63 days. A naïve control was also maintained. Behavioural studies, tricarboxylic acid cycle enzymes, mitochondrial complexes, protein and lipid oxidation and glutathione levels were assessed in the brain mitochondrial fraction. Western blot analysis of caspase-3, cleaved caspase-3 and histological assessment of the CA1 region of the hippocampus were carried out. D-galactose induced significant cognitive deficits, biochemical changes and histological alterations. Individually, curcumin was more effective than hesperidin in reducing the levels of oxidized lipids, proteins, cleaved caspase-3 expression and mitochondrial enzymes. The combination reduced the expression of cleaved caspase-3, malondialdehyde, improved mitochondrial enzymes and glutathione levels. In combination, curcumin and hesperidin protect the morphological facets and improve biochemical functions of neurons thereby improving cognition.

Comparison of behavioral and biochemical deficits in rats with hereditary defined or D-galactose-induced accelerated senescence: evaluating the protective effects of diosgenin.

One of the important factors in aging is oxidative stress and aging-related disturbances are believed be ameliorated by antioxidants. Diosgenin is a bio-active ingredient of dioscorea that is widely used in Chinese medicine, shows anti-oxidant activity and improves some aging-related deficits in senescent and menopausal animals. We compared alterations in behavior, biochemical parameters (plasma levels of the uric acid, creatinine, calcium, phosphate, total cholesterol, low-density lipoprotein cholesterol and triglycerides, and the plasma activity of aminotransferases AST and ALT), and sperm motility in two models of accelerated senescence (d-galactose-induced (150 mg/kg/day, i.p., 57 days) aging in Wistar rats vs. genetically defined in OXYS rats) and examined the protective effects of diosgenin (10 or 50mg/kg/day, p.o., 57 days). Both models had augmented levels of ALT activity indicating hepatopathology. Compared to d-galactose-treated animals, OXYS rats demonstrated profound biochemical alterations (hypocalcemia, hypophosphatemia, and hypocholesterolemia) and behavioral deficits (impaired object recognition, decreased sexual motivation and locomotor activity, retarded learning) that confirmed the difference in the mechanisms of accelerated senescence in these models. We first showed diminished sperm motility in males of both models of accelerated senescence studied. Chronic diosgenin treatment failed to improve biochemical and behavioral disturbances and had some undesirable side effects on body weight and working memory in OXYS rats. However, diosgenin restored moderately decreased sperm motility in d-galactose-treated Wistar males and might be recommended for treatment of mild age-related reproductive dysfunctions.

Curcumin and piperine abrogate lipid and protein oxidation induced by D-galactose in rat brain.

Cerebellar atrophy during ageing can produce neurobehavioural changes characterized by cognitive and motor impairment. Chronic exposure to D-galactose, a reducing sugar can accelerate ageing by producing an unprecedented rise in oxidative load. This can enhance neuronal damage by promoting the oxidation of protein and lipids. We perceived that the simultaneous administration of piperine and curcumin, two powerful antioxidants can exert neuroprotective effect by inhibiting damage caused by the chronic exposure to D-galactose. Young Wistar rats treated with D-galactose (150 mg/kg, s.c.) were simultaneously treated with piperine alone, curcumin separately; and in combination for a period of 56 days by the oral route. A vehicle control, D-galactose alone and naturally aged control were also evaluated. Cognitive changes, motor impairment, protein carbonyls, protein thiols, advanced oxidation protein products, 4 hydroxynonenol and nitric oxide levels were determined in the brain homogenate. In order to ascertain the impact of cerebellum on motor performance, histopathological changes in the cerebellum were also established. Results obtained from our studies reflect a marked improvement in memory, sensorimotor performance, reduced oxidative and nitrosative burden on simultaneous treatment with piperine and curcumin. Furthermore, alterations produced in the Purkinje cells were minimized on treatment with the combination. Our studies demonstrated the influence of protein and lipid oxidation products on behavioural changes in D-galactose induced ageing model. Incorporation of these antioxidants might reduce the risk of developing neurodegenerative disorders, an important counterpart of advancing age.

Phycocyanin may suppress D-galactose-induced human lens epithelial cell apoptosis through mitochondrial and unfolded protein response pathways.

Apoptosis of lens epithelial cell (LEC) plays an important role in cataract formation, and its prevention may be one of the therapeutic strategies in treating cataract. This study used human lens epithelial cell (hLEC) line SRA01/04 to investigate the protective effect and mechanism of phycocyanin on glactose-induced apoptosis in hLEC. hLECs were cultured in D/F(12)-10% FBS medium containing 125mM d-galactose with or without phycocyanin. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay. Cell apoptosis was elevated with Wright-Giemsa staining, AO/EB double staining, and DNA fragmentation assay. Mitochondrial apoptosis-associated molecules and unfolded protein response-associated molecules from cultured SRA01/04 cells were quantified using protein blot analysis. The results demonstrated that phycocyanin suppressed SRA01/04 cells' morphologic changes and apoptosis induced by d-galactose, inhibited the expression and activation of caspase 3, alternated the Bax/Bcl-2 ratio, and down-regulated the level of p53, GRP78, and CHOP in d-galactose-treated SRA01/04 cells. These results suggest that phycocyanin might suppress d-galactose-induced hLEC apoptosis through two pathways: mitochondrial pathway, involving p53 and Bcl-2 family protein expression, and unfolded protein response pathway, involving GRP78 and CHOP expression.

Purification and characterization of a novel anti-proliferative lectin from Morus alba L. leaves.

A novel anti-proliferative lectin was purified from Morus alba L. (Mulberry) leaves by a two step chromatographic procedure namely, immobilized metal ion affinity chromatography (IMAC) and convective interaction media (CIM) based anion exchange chromatography. The purified mulberry leaf lectin (MLL) was specific to galactose, galactosamine and N-acetyl galactosamine (GalNAc). MLL was homogenous with a molecular weight of ~56kDa in silver stained SDS-PAGE. The lectin showed RBC agglutination activity up to 40°C and was independent of pH above pH 6. Haemagglutination activity of purified MLL was not dependent on any metal ions. However, with high concentration of trivalent metal ions, Fe3+ and Al3+ and the divalent metal ion Fe2+, a three fold increase in agglutination activity was observed. The purified MLL showed an anti-proliferative activity towards human breast cancer cells (MCF-7) and colon cancer cells (HCT-15) with a higher potency towards MCF-7 cells. This is the first report on the anti-proliferative activity of a GalNAc specific lectin from M. alba.

Purple sweet potato color protects mouse liver against d-galactose-induced apoptosis via inhibiting caspase-3 activation and enhancing PI3K/Akt pathway.

Purple sweet potato color (PSPC) has been shown to possess hepatoprotective effects in our previous study. To clarify the detailed mechanism of hepatoprotective effects of PSPC, we investigated the potential protective effect of PSPC against caspase-3 activation induced by d-gal, as well as its influence on Bcl-2 levels and PI3K/Akt cell survival pathway. The results of TUNEL assay showed that PSPC effectively suppressed the d-gal-induced hepatocytes apoptosis, suggesting that anti-apoptosis mechanism was involved in PSPC-mediated protection against d-gal-induced liver injury in mouse. PSPC significantly increased GSH levels and promoted a marked increase in the activities of GSH related enzymes including GR, GST in d-gal-treated mice. The activation and activity of caspase-3 were markedly inhibited by the treatment of PSPC in the livers of d-gal-treated mice. Furthermore, the level of Bcl-2 was significantly raised, and the levels of PI3K p110 and phosphorylated Akt were also largely enhanced by the treatment of PSPC in the livers of d-gal-treated mice. In conclusion, these results suggested that PSPC could protect mouse liver against d-gal-induced hepatocyte apoptosis via attenuating oxidative stress, inhibiting the activation of caspase-3 and enhancing cell survival signaling (enhancing the level of anti-apoptotic protein Bcl-2 and the activation of PI3K/Akt pathway).

Chronic administration of troxerutin protects mouse kidney against D-galactose-induced oxidative DNA damage.

Troxerutin, a natural bioflavonoid, has been reported to have many benefits and medicinal properties. In this study, we evaluated the protective effect of troxerutin against D-gal-induced oxidative DNA damage in mouse kidney, and explored the potential mechanism of its action. Our data showed that troxerutin significantly decreased levels of urea, uric acid and creatinine in serum and the renal histological injury in D-gal-treated mice. Troxerutin markedly restored Cu/Zn-SOD, CAT and GPx activities in the kidney of D-gal-treated mouse. Furthermore, the increase of 8-hydroxydeoxyguanosine (a marker of oxidative DNA damage) induced by d-gal was effectively suppressed by troxerutin. Internucleosomal DNA ladder fragmentation and the number of terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end-labeling (TUNEL)-positive cells in D-gal-treated mice were inhibited by troxerutin, which might be attributed to its antioxidant property by decreasing activities of nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) and levels of reactive oxygen species (ROS). In conclusion, these results suggested that troxerutin could protect the mouse kidney against D-gal-induced injury by improving renal function, attenuating histopathologic changes, reducing ROS production, renewing the activities of antioxidant enzymes and decreasing DNA oxidative damage. This study provided novel insights into the protective mechanisms of troxerutin in D-gal-induced kidney injury.

Icariin isolated from Epimedium brevicornum Maxim attenuates learning and memory deficits induced by d-galactose in rats.

The effects of icariin (ICA), a major constituent of flavonoids from the Chinese medical herb Epimedium brevicornum Maxim, on spatial memory performances and expressions of hippocampus brain-derived neurotrophic factor (BDNF) and tyrosine kinase TrkB (tropomyosin receptor kinase B) were investigated in d-galactose (d-gal)-treated rats. Subcutaneous injection of d-gal (500mg/kg/d) for four months caused memory loss as detected by the Morris water maze, morphologic abnormalities of neurons in hippocampus region and the reduced expression of BDNF and TrkB were observed. ICA (60mg/kg/d) given orally 1h after subcutaneous injection of d-gal daily for 4months markedly attenuated d-gal-induced rats behavioral dysfunction and neurodegeneration, as evidenced by shortened escape latency and searching distance and rescued morphologic abnormalities, and also elevated the mRNA levels and the protein expressions of BDNF and TrkB in hippocampus, as evidenced by quantitative real-time RT-PCR and Western blotting analysis. But ICA had no significant influence on normal rats which were not injected d-gal. These results clearly demonstrated that d-gal produced learning and memory deficits after chronic administration, and ICA can protect neuron from d-gal insults and improve the memory loss.

Purple sweet potato color alleviates D-galactose-induced brain aging in old mice by promoting survival of neurons via PI3K pathway and inhibiting cytochrome C-mediated apoptosis.

Purple sweet potato color (PSPC), a class of naturally occurring anthocyanins, protects brain function against oxidative stress induced by D-galactose (D-gal) (Sigma-Aldrich, St. Louis, MO, USA). Our data showed that PSPC enhanced open-field activity, decreased step-through latency, and improved spatial learning and memory ability in D-gal-treated old mice by decreasing advanced glycation end-products' (AGEs) formation and the AGE receptor (RAGE) expression, and by elevating Cu,Zn-superoxide dismutase (Cu,Zn-SOD) (Sigma-Aldrich) and catalase (CAT) expression and activity. Cleavage of caspase-3 and increased terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end-labeling (TUNEL)-positive cells in D-gal-treated old mice were inhibited by PSPC, which might be attributed to its antioxidant property. PSPC also suppressed the activation of c-Jun NH(2)-terminal kinase (JNK) and the release of cytochrome c from mitochondria that counteracted the onset of neuronal apoptosis in D-gal-treated old mice. Furthermore, it was demonstrated that phosphoinositide 3-kinase (PI3K) activation was required for PSPC to promote the neuronal survival accompanied with phosphorylation and activation of Akt and p44/42 mitogen-activated protein kinase (MAPK) by using PI3K inhibitor LY294002 (Cell Signaling Technology, Inc., Beverly, MA, USA), implicating a neuronal survival mechanism. The present results suggest that neuronal survival promoted by PSPC may be a potentially effective method to enhance resistance of neurons to age-related disease.

[Inhibition effect of epalrestat on rat lens osmotic expansion].

Epalrestat is the unique aldose reductase inhibitor on the market, which was mainly used for the diabetic neuropathy. Lenses osmotic expansion could be induced by galactose to mimic the pathological process of diabetic cataract in vitro. In present study, we mainly investigated whether epalrestat possesses inhibitory effect on the lens osmotic expansion. The results indicated that epalrestat could not only markedly inhibit rat lens osmotic expansion in vitro, but also significantly reduced the high expression of the osmotic expansion-related genes such as AR and AQP1 in mRNA and protein levels. The findings may provide an important reference to epalrestat in the clinical application for the treatment of diabetic cataract.

Troxerutin protects the mouse kidney from d-galactose-caused injury through anti-inflammation and anti-oxidation.

This study was carried out to investigate the protective effect of troxerutin against D-galactose (D-gal)-induced renal injury in mice. Hematoxylin and eosin (H&E) stained sections of kidneys revealed D-gal could cause renal injury and troxerutin could significantly attenuate the injury. We further investigated the mechanisms involved in the protective effects of troxerutin on mouse kidney. The following antioxidant defense enzymes were measured: cytosolic Cu/Zn superoxide dismutase (SOD-1), catalase (CAT) and glutathione peroxidase (GPx). The content of the lipid peroxidation product malondialdehyde (MDA) was also analyzed. In D-gal-treated mice, antioxidant enzymes activities were significantly decreased and the level of MDA was significantly higher than those in the vehicle controls. Our results indicated that the protective effect of troxerutin against D-gal induced renal injury might be caused, at least in part, by increasing the activity of antioxidant enzymes with a reduction in lipid peroxidation product. Furthermore, we also examined the inflammatory signal mediators of nuclear factor-kappaB (NF-kappaB), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and prostanoid receptor subtype EP2 by Western blot. After treatment with D-gal, the NF-kappaB p65, iNOS, COX-2 and EP2 were markedly upregulated. Upon co-treatment with the troxerutin, however, the expressions of the NF-kappaB p65, iNOS, COX-2 and EP2 markedly reduced, compared to D-gal treatment alone. These results indicated that troxerutin has significantly inhibitory effects on the NF-kappaB-mediated inflammatory response. These findings suggest troxerutin could attenuate renal injury induced by D-gal probably through its antioxidant and anti-inflammation properties.