Chronic administration of troxerutin protects mouse brain against d-galactose-induced impairment of cholinergic system

Lonicera japonica polysaccharides alleviate D-galactose-induced oxidative stress and restore gut microbiota in ICR mice

Lonicera japonica polysaccharides (LJPs) exhibit anti-aging effect in nematodes. Here, we further studied the function of LJPs on aging-related disorders in D-galactose (D-gal)-induced ICR mice. Four groups of mice including the control group, the D-gal-treated group, the intervening groups with low and high dose of LJPs (50 and 100 mg/kg/day) were raised for 8 weeks. The results showed that intragastric administration with LJPs improved the organ indexes of D-gal-treated mice. Moreover, LJPs improved the activity of superoxide dismutase (SOD), catalase (CAT) as well as glutathione peroxidase (GSH-Px) and decreasing the malondialdehyde (MDA) level in serum, liver and brain. Meanwhile, LJPs restored the content of acetylcholinesterase (AChE) in the brain. Further, LJPs reversed the liver tissue damages in aging mice. Mechanistically, LJPs alleviate oxidative stress at least partially through regulating Nrf2 signaling. Additionally, LJPs restored the gut microbiota composition of D-gal-treated mice by adjusting the Firmicutes/Bacteroidetes ratio at the phylum level and upregulating the relative abundances of Lactobacillaceae and Bifidobacteriacesa. Notably, the KEGG pathways involved in hazardous substances degradation and flavone and flavonol biosynthesis were significantly enhanced by LJPs treatment. Overall, our study uncovers the role of LJPs in modulating oxidative stress and gut microbiota in the D-gal-induced aging mice.

In vivo antioxidant activity of Cinnamomum cassia leaf residues and their effect on gut microbiota of d-galactose-induced aging model mice

BACKGROUND

To thoroughly explore the values of Cinnamomum cassia leaf residues (CcLR), their antioxidant activity in vivo and the relationship with gut microbiota were investigated using d-galactose-induced aging mice.

RESULTS

Results showed that CcLR extract treatment exerted antioxidant activity by increasing the levels of superoxide dismutase (P < 0.01) and glutathione peroxidase (P < 0.05), as well as inhibiting the formation of malondialdehyde (P < 0.01). Meanwhile, the inflammatory response was also alleviated as the ratio of pro-inflammatory tumor necrosis factor-α (P < 0.01) and interleukin-1β (P < 0.01))/anti-inflammatory cytokines (interleukin-10; P < 0.05) in serum was decreased and the contents of inflammatory markers (induced nitrogen monoxide synthase and nitric oxide) in brain and liver tissues (P < 0.01) were reduced. Moreover, through inhibiting acetylcholinesterase activity and improving choline acetyltransferase activity, the cholinergic system in aging mice recovered to levels comparable to the normal control group. In addition, 16S rRNA sequencing results demonstrated that CcLR extract promoted the growth of beneficial bacteria. In particular, Spearman correlation analysis revealed that the abundance of Colidextribacter was negatively correlated with serum superoxide dismutase (P < 0.05, R = -0.943), and Helicobacter displayed a positive correlation with the content of brain nitric oxide (P < 0.05, R = 0.899), suggesting that regulating gut microbiota might be one of the mechanisms for reducing oxidative stress, thus postponing the aging process.

CONCLUSION

It is suggested that CcLR extract could be used as a novel antioxidant and anti-aging resource in the pharmaceutical and food industries. © 2022 Society of Chemical Industry.

Phytochemicals: A potential next generation agent for radioprotection

BACKGROUND

Radiation hazards are accountable for extensive damage in the biological system and acts as a public health burden. Owing to the rapid increasing in radiation technology, both Ionizing radiation (IR) from natural and man made source poses detrimental outcome to public health. IR releases free radicals which induces oxidative stress and deleterious biological damage by modulating radiation induced signalling intermediates. The efficacy of existing therapeutic approach and treatment strategy are limited owing to their toxicity and associated side effects. Indian system of traditional medicine is enriched with prospective phytochemicals with potential radioprotection ability.

PURPOSE

The present review elucidated and summarized the potential role of plant derived novel chemical compound with prospective radioprotective potential.

METHOD

So far as the traditional system of Indian medicine is concerned, plant kingdom is enriched with potential bioactive molecules with diverse pharmacological activities. We reviewed several compounds mostly secondary metabolites from plant origin using various search engines.

RESULTS

Both compounds from land plants and marine source exhibited antioxidant antiinflammatory, free radical scavenging ability. These compounds have tremendous potential in fine-tuning of several signalling intermediates, which are actively participated in the progression and development of a pathological condition associated with radiation stress.

CONCLUSION

Development and explore of an operational radioprotective agent from originated from plant source that can be used as a novel molecular tool to eliminate the widespread damage caused by space exploration, ionizing radiation, nuclear war and radiotherapy has been significantly appreciated. Through extensive literature search we highlighted several compounds from both land plant and marine origin can be implemented for a better therapeutic potential against radiation induced injury. Furthermore, extensive clinical trials must be carried out in near future for better therapeutic modality and clinical efficacy.

p-Coumaric acid protects against D-galactose induced neurotoxicity by attenuating neuroinflammation and apoptosis in mice brain

D-galactose (D-gal) induced senescence in rodents is a widely used model for assessment of molecules affecting brain ageing. Chronic administration of D-gal causes neuroinflammation leading to cognitive deficit and memory impairment which represent Alzheimer's dementia. In present study, we investigated the neuroprotective effects of the natural phenol, p-Coumaric acid (PCA) and its underlying mechanism in the chronic D-gal treated mice. Subcutaneous administration of D-gal (150 mg/kg) to Swiss albino mice for 42 consecutive days resulted in cognitive impairment as observed in Morris water maize (MWM) and Y maze test, which was ameliorated by concurrent treatment with PCA (80 mg/kg, and 100 mg/kg, p.o.). Importantly, PCA treatment attenuated the D-gal induced oxidative stress and significantly inhibited acetylcholinesterase (AChE) activity in mice brain. Furthermore, PCA treatment significantly lowered levels of inflammatory marker nuclear factor kappa B (NFκB) and reduced levels of proapoptotic enzyme caspase3. We also observed that PCA treatment exhibited β-secretase enzyme (BACE1) inhibitory effect. However, our results revealed that PCA treatment failed to decrease the level of advanced glycation end products both in vitro and in vivo. Taken together, current study demonstrated the significant neuroprotective effect of PCA against D-gal induced oxidative stress, neuroinflammation, cognitive impairment and apoptosis.

Dihydromyricetin Improves Cognitive Impairments in d-Galactose-Induced Aging Mice through Regulating Oxidative Stress and Inhibition of Acetylcholinesterase

SCOPE

Alzheimer's disease (AD) is a neurodegenerative disease with phenomena of cognitive impairments. Oxidative stress and cholinergic system dysfunction are two widely studied pathogenesis of AD. Dihydromyricetin (DMY) is a natural dihydroflavonol with many bioactivities. In this study, it is aimed to investigate the effects of DMY on cognitive impairment in d-galactose (d-gal) induced aging mice.

METHODS AND RESULTS

Mice are intraperitoneally injected with d-gal for 16 weeks, and DMY is supplemented in drinking water. The results show that DMY significantly improves d-gal-induced cognitive impairments in novel object recognition and Y-maze studies. H&E and TUNEL staining show that DMY could improve histopathological changes and cell apoptosis in mice brain. DMY effectively induces the activities of catalase, superoxide dismutase and glutathione peroxidase, and reduces malondialdehyde level in mice brain and liver. Furthermore, DMY reduces cholinergic injury by inhibiting the activity of Acetylcholinesterase (AChE) in mice brain. In vitro studies show that DMY is a non-competitive inhibitor of AChE with IC50 value of 161.2 µg mL^-1 .

CONCLUSION

DMY alleviates the cognitive impairments in d-gal-induced aging mice partly through regulating oxidative stress and inhibition of acetylcholinesterase.

DL0410 Alleviates Memory Impairment in D-Galactose-Induced Aging Rats by Suppressing Neuroinflammation via the TLR4/MyD88/NF-κB Pathway

Oxidative stress and neuroinflammation have been demonstrated to be linked with Alzheimer's disease (AD). In this study, we examined the protective effects of DL0410 in aging rats and explored the underlying mechanism against oxidative damage and neuroinflammation, which was then validated in LPS-stimulated BV2 microglia. We firstly investigated the improvement effects of DL0410 on learning and memory abilities and explored the potential mechanisms in D-gal-induced aging rats. An 8-week treatment with DL0410 significantly improved the learning and cognitive function of D-gal-stimulated Alzheimer's-like rats in the Morris water maze test, step-down test, and novel object recognition test, and the therapeutic effect of DL0410 at 10 mg/kg was even better than that of donepezil. What is more, the results showed that DL0410 alleviated neuron injury, increased the number of synapses, and improved the level of postsynaptic density protein 95 (PSD95) in the hippocampus and cortex. Next, we examined the protective effects of DL0410 against oxidative damage and neuroinflammation. Our observations indicated that DL0410 reduced the production of harmful oxidation products and promoted the antioxidative system, decreased the levels of proinflammatory cytokines, including tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and interleukin 6 (IL-6), and increased anti-inflammatory cytokines IL-10. Moreover, DL0410 inhibited the activation of astrocytes and microglia and suppressed the activation of the TLR4/MyD88/NF-κB signaling pathway. The anti-inflammation effect of DL0410 was further confirmed in LPS-stimulated BV2 cells, and the results showed that DL0410 reduced the level of inflammatory factors and inhibited the activation of the TLR4/MyD88/TRAF6/NF-κB signaling pathway in BV2 microglia. Molecular docking results indicated that DL0410 occupied the LPS recognition site in the TLR4/MD2 complex. Furthermore, the enhanced expression of claudin-1, claudin-5, occludin, CX43, and ZO-1 indicated that DL0410 protected the blood-brain barrier (BBB) integrity. Together, these results suggest that DL0410 exerts neuroprotective effects against hippocampus and cortex injury induced by D-galactose, and the possible mechanisms include antioxidative stress, antineuroinflammation, improving synaptic plasticity, and maintaining BBB integrity, which is mediated by the TLR4/MyD88/NF-κB signaling pathway inhibition. We suggest that DL0410 is a promising candidate for AD treatment.

Natural products attenuate PI3K/Akt/mTOR signaling pathway: A promising strategy in regulating neurodegeneration

BACKGROUND

As common, progressive, and chronic causes of disability and death, neurodegenerative diseases (NDDs) significantly threaten human health, while no effective treatment is available. Given the engagement of multiple dysregulated pathways in neurodegeneration, there is an imperative need to target the axis and provide effective/multi-target agents to tackle neurodegeneration. Recent studies have revealed the role of phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) in some diseases and natural products with therapeutic potentials.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating various neuronal disorders via the PI3K/Akt/mTOR signaling pathway.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was done based on the PubMed, Scopus, Web of Science, and Cochrane electronic databases. Two independent investigators followed the PRISMA guidelines and included papers on PI3K/Akt/mTOR and interconnected pathways/mediators targeted by phytochemicals in NDDs.

RESULTS

Natural products are multi-target agents with diverse pharmacological and biological activities and rich sources for discovering and developing novel therapeutic agents. Accordingly, recent studies have shown increasing phytochemicals in combating Alzheimer's disease, aging, Parkinson's disease, brain/spinal cord damages, depression, and other neuronal-associated dysfunctions. Amongst the emerging targets in neurodegeneration, PI3K/Akt/mTOR is of great importance. Therefore, attenuation of these mediators would be a great step towards neuroprotection in such NDDs.

CONCLUSION

The application of plant-derived secondary metabolites in managing and/or treating various neuronal disorders through the PI3K/Akt/mTOR signaling pathway is a promising strategy towards neuroprotection.

p-Coumaric acid mitigates lipopolysaccharide induced brain damage via alleviating oxidative stress, inflammation and apoptosis

Objectives

Systemic administration of lipopolysaccharide induces neuroinflammation leading to cognitive deficit and memory impairment. Herein, we investigated the effects of p-Coumaric acid (PCA) in LPS induced neuroinflammation in mice. PCA is reported to possess free radicle scavenging and neuroprotective action.

Methods

Mice received treatment with PCA (80 mg/kg, and 100 mg/kg, p.o.) for 28 days. LPS (0.25 mg/kg) was administered intraperitoneally from Day 15 to 21, to all groups. Memory impairment and cognitive deficit were assessed by MWM and Y maze test, followed by estimation of ROS, TNF-α, IL-6, caspase-3 and c-Jun in the brain homogenate by ELISA. Histopathological changes were investigated using Nissl and H&E staining.

Key findings

PCA attenuated increased oxidative stress, significantly increasing SOD, GSH levels and decreasing MDA level and AChE activity in mice brain, lowered the levels of TNF-α and IL-6 indicating protection against neuroinflammatory reaction. PCA also suppressed neuronal apoptosis, as indicated by decreased levels of caspase-3 and c-Jun. Further, histopathological findings revealed that PCA attenuated neuronal loss and pathological abnormalities in the hippocampus.

Conclusions

Our findings give compulsive evidence suggesting a protective effect of PCA in neuroinflammation, cognitive impairment and neuronal apoptosis induced by LPS, through its antioxidant, AChE inhibitory, anti-inflammatory and antiapoptotic activity determined by behavioural, biochemical and histopathological measures.

Application of carbohydrates in approved small molecule drugs: A review

Carbohydrates are an important energy source and play numerous key roles in all living organisms. Carbohydrates chemistry involved in diagnosis and treatment of diseases has been attracting increasing attention. Carbohydrates could be one of the major focuses of new drug discovery. Currently, however, carbohydrate-containing drugs account for only a small percentage of all drugs in clinical use, which does not match the important roles of carbohydrates in the organism. In other words, carbohydrates are a relatively untapped source of new drugs and therefore may offer exciting novel therapeutic opportunities. Here, we presented an overview of the application of carbohydrates in approved small molecule drugs and emphasized and evaluated the roles of carbohydrates in those drugs. The potential development direction of carbohydrate-containing drugs was presented after summarizing the advantages and challenges of carbohydrates in the development of new drugs.

Role of natural plant products against Alzheimer's disease

Alzheimer's disease (AD) is one of the major neurodegenerative disorder. Deposition of amyloid fibrils and tau protein are associated with various pathological symptoms. Currently limited medication is available for AD treatment. Most of the drugs are basically cholinesterase inhibitors and associated with various side effects. Natural plant products have shown potential as a therapeutic agent for the treatment of AD symptoms. Variety of secondary metabolites like flavonoids, tannins, terpenoids, alkaloids and phenols are used to reduce the progression of the disease. Plant products have less or no side effect and are easily available. The present review gives a detailed account of the potential of natural plant products against the AD symptoms.

Hyperbaric oxygen therapy restores cognitive function and hippocampal pathologies in both aging and aging-obese rats

The population of obese-elderly has increased prominently around the world. Both aging and obesity are major factors of neurodegeneration. The present study hypothesizes that HBOT attenuates metabolic disturbance, cognitive decline, hippocampal pathologies in aging and aging-obese model. Sixty Wistar rats were separated into 2 groups to receive normal-diet (ND) or high-fat diet (HFD) for 22 weeks. At week 13, ND rats were divided into two subgroups to receive vehicle (0.9 % NSS, s.c) or d-gal (150 mg/kg/d, s.c) for total 10 weeks. HFD rats were injected only d-gal (150 mg/kg/d, s.c; HFDD) for total 10 weeks. At week 20, rats in each subgroup were given sham-treatment (1ATA, 80 L/min, 80 min/day), or HBOT (2ATA, pure O₂, 250 L/min, 80 min/day) for 14 days. Novel object location test, metabolic parameters, and hippocampal pathologies were determined after HBOT. d-gal induced insulin resistance, increased oxidative stress, autophagy impairment, microglial hyperactivation, apoptosis, synaptic dysplasticity which resulted in cognitive impairment. d-gal-treated HFD-fed rats had the highest levels of oxidative stress, apoptosis, dendritic spine loss. HBOT attenuated insulin resistance, cognitive impairment, hippocampal aging and pathologies in both models. These findings suggest that HBOT restored insulin sensitivity, hippocampal functions, cognition in aging and aging-obese models.

Features of T-cell subset composition in a D-galactose-induced senescence mouse model

Long-term administration of D-galactose induces oxidative stress and accelerates normal age-related changes. Hence, the D-galactose-treated rodent model has been widely used for aging research. In this study, we examined the immunological characteristics, especially CD4⁺ T-cell subset composition, of D-galactose-induced aging model mice to evaluate the model’s utility in immunosenescence studies. The spleens of aging model mice subjected to repeated subcutaneous injections of D-galactose exhibited significant increases in T cells with the memory phenotype (CD62L^low CD44^high) and individual T-cell subsets (Th1, Th2, Th17 and T_reg). Furthermore, cells with the phenotype of T follicular helper (Tfh) cells were spontaneously increased. The features of T-cell subset composition in D-galactose-treated mice were in close agreement with those observed in normal aged mice and appeared to mimic the currently known normal aging processes associated with T-cell homeostasis. Our results suggest that D-galactose-induced aging models would be useful for immunosenescence studies focusing on T-cell homeostasis and give valuable insight into age-related immune system dysregulation.

The Protective Roles and Molecular Mechanisms of Troxerutin (Vitamin P4) for the Treatment of Chronic Diseases: A Mechanistic Review

Troxerutin (TRX), a semi-synthetic bioflavonoid derived from rutin, has been reported to exert several pharmacological effects including antioxidant, anti-inflammatory, antihyperlipidemic, and nephroprotective. However, the related molecular details and its mechanisms remain poorly understood. In the present review, we presented evidences from the diversity in vitro and in vivo studies on the therapeutic potential of TRX against neurodegenerative, diabetes, cancer and cardiovascular diseases with the purpose to find molecular pathways related to the treatment efficacy. TRX has a beneficial role in many diseases through multiple mechanisms including, increasing antioxidant enzymes and reducing oxidative damage, decreasing in proapoptotic proteins (APAF-1, BAX, caspases-9 and-3) and increasing the antiapoptotic BCL-2, increasing the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and downregulating the nuclear factor κB (NFκ). TRX also reduces acetylcholinesterase activity and upregulates phosphoinositide 3- kinase/Akt signaling pathway in Alzheimer's disease models. Natural products such as TRX may develop numerous and intracellular pathways at several steps in the treatment of many diseases. Molecular mechanisms of action are revealing novel, possible combinational beneficial approaches to treat multiple pathological conditions.

Effect of troxerutin on oxidative stress and expression of genes regulating mitochondrial biogenesis in doxorubicin-induced myocardial injury in rats

Because of limitation of doxorubicin (DOX) clinical application in chemotherapy due to its cardiotoxicity, finding new strategies to reduce DOX challenge and improve patients' outcomes is crucial. Due to positive cardiovascular impacts of troxerutin (TXR), here we have investigated the effect of TXR on DOX-induced cardiotoxicity by evaluating the myocardial oxidative stress and expression of genes regulating mitochondrial biogenesis. Male Wistar rats (250-300 g) were randomly allocated into four groups: control, TXR, DOX, and TXR + DOX. Troxerutin (150 mg/kg) was orally administrated once a day through a gavage tube for 4 weeks before DOX challenge. The TXR-treated and time-matched control rats received intraperitoneal injection of DOX (20 mg/kg). Three days after DOX challenge, the left ventricular samples were obtained to determine the expression of genes regulating mitochondrial biogenesis via real-time PCR. Myocardial creatine kinase (CK-mB), oxidative stress markers, and mitochondrial function (generation of reactive oxygen species or ROS and ATP levels) were also evaluated using commercial kits and spectrophotometric and fluorometric methods. DOX administration significantly increased the levels of CK-mB, malondialdehyde (MDA), and mitochondrial ROS levels, while reduced the cellular ATP production and expression levels of SIRT-1, PGC-1α, and NRF-2 as well as superoxide dismutase, glutathione peroxidase, and catalase activity in comparison to control group (P < 0.05 to P < 0.01). Pretreatment of DOX-received rats with TXR significantly upregulated the expression of all biogenesis genes and antioxidant enzymes with non-significant effect on catalase activity, and significantly reduced CK-mB and MDA levels toward control values (P < 0.05 to P < 0.01). Mitochondrial ROS and ATP levels were also restored significantly by pretreatment with TXR (P < 0.05). The data suggested that preconditioning of rats with TXR had protective effect on DOX-induced cardiotoxicity through inducing antioxidative properties and restoring the mitochondrial function and the expression profiles of myocardial SIRT-1/PGC-1α/NRF-2 network.

Troxerutin downregulates C/EBP-β gene expression via modulating the IFNγ-ERK1/2 signaling pathway to ameliorate rotenone-induced retinal neurodegeneration

Troxerutin, a natural flavonoid guards against oxidative stress and apoptosis with a high capability of passing through the blood-brain barrier. Our aim was to investigate the role of troxerutin in experimentally induced retinal neurodegeneration by modulating the interferon-gamma (IFNγ)-extracellular signal-regulated kinases 1/2 (ERK1/2)-CCAAT enhancer-binding protein β (C/EBP-β) signaling pathway. Three groups of rats (10 each group) were included. Group I (control group), group II (rotenone treated group): the rats were injected subcutaneously with a single rotenone dosage of 3 mg/kg repeated every 48 hours for 60 days to trigger retinal neurodegeneration. Group III (troxerutin-treated group): rats received troxerutin (150 mg/kg/day) by oral gavage 1 hour before rotenone administration. A real-time polymerase chain reaction technique was applied to measure messenger RNA (mRNA) levels of retinal C/EBP-β. Enzyme-linked immunosorbent assay technique was utilized to assay tumor necrosis factor-α (TNF-α), IFNγ, and ERK1/2 levels. Finally, reactive oxygen species (ROS), as well as carbonylated protein (CP) levels, were assessed spectrophotometrically. Improved retinal neurodegeneration by downregulation of C/EBP-β mRNA gene expression, also caused a significant reduction of TNF-α, IFNγ, ERK1/2 as well as ROS and CP levels compared with the diseased group. These findings could hold promise for the usage of troxerutin as a protective agent against rotenone-induced retinal neurodegeneration.

The effect of troxerutin on anxiety- and depressive-like behaviours in the offspring of high-fat diet fed dams

This study aimed at investigating the metabolic and behavioural effects of troxerutin treatment in the offspring of high fat diet (HFD) fed dams. Female Wistar rats (n = 40) received normal diet (ND) or HFD for 8 weeks prior to breeding. After mating, pregnant animals were assigned to four subgroups: ND, ND + Tro (troxerutin 150 mg/kg/day), HFD, and HFD + Tro. On the 21st day, male offspring were weaned and fed ND until 12 weeks old. Behavioural tests were performed on postnatal day (PND) 80 and 90. Compared to the controls, the HFD offspring showed more anxiety- and depressive-like behaviours, higher blood glucose, cholesterol, and cortisol levels. On the other hand, chronic troxerutin administration during gestation restored metabolic and behavioural changes to normal. In summary, troxerutin improved anxiety- and depressive-like behaviours, as well as metabolic status in the offspring of the HFD fed dams. More studies are needed to determine the underlying mechanisms.

Troxerutin affects the male fertility in prepubertal type 1 diabetic male rats

OBJECTIVES

Diabetes can gradually cause damage to the function and structure of male gonads. This survey was conducted to investigate the effect of troxerutin on hormonal changes, serum oxidative stress indices, and testicular function and structure in prepubertal diabetic rats.

MATERIALS AND METHODS

Fifty prepubertal (6 weeks old) male Wistar rats were divided into five groups including Control, Troxerutin, Diabetic, Diabetic+Troxerutin, and Diabetic+Insulin. Type I diabetes was induced by 55 mg/kg of streptozotocin intraperitoneally. The groups were treated with 150 mg/kg/day troxerutin via oral gavage or 4-6 IU/day insulin via subcutaneous injection for 4 consecutive weeks. Blood sugar (BS) and serum levels of insulin, FSH, LH, testosterone, glutathione peroxidase (GPX), superoxide dismutase (SOD), malondialdehyde (MDA), and total antioxidant capacity (TAC) were analyzed. Testis and epididymis were removed for histopathologic study and analysis of sperm parameters.

RESULTS

Troxerutin significantly reduced the BS in the diabetic group similar to insulin but could not affect insulin, FSH, or LH significantly. Troxerutin caused a significant increase in testosterone and GPX but had no significant effect on serum MDA, TAC, and SOD levels. In addition, troxerutin had a better effect than insulin on diabetes-induced testicular structural damage. Sperm analysis results also revealed that troxerutin and insulin could improve sperm number, motility, and viability in diabetic rats.

CONCLUSION

According to these results, it can be derived that administration of troxerutin is a suitable protective strategy for side effects of diabetes in testis of prepubertal diabetic male rats.

Ascorbic Acid Mitigates D-galactose-Induced Brain Aging by Increasing Hippocampal Neurogenesis and Improving Memory Function

Ascorbic acid is essential for normal brain development and homeostasis. However, the effect of ascorbic acid on adult brain aging has not been determined. Long-term treatment with high levels of D-galactose (D-gal) induces brain aging by accumulated oxidative stress. In the present study, mice were subcutaneously administered with D-gal (150 mg/kg/day) for 10 weeks; from the seventh week, ascorbic acid (150 mg/kg/day) was orally co-administered for four weeks. Although D-gal administration alone reduced hippocampal neurogenesis and cognitive functions, co-treatment of ascorbic acid with D-gal effectively prevented D-gal-induced reduced hippocampal neurogenesis through improved cellular proliferation, neuronal differentiation, and neuronal maturation. Long-term D-gal treatment also reduced expression levels of synaptic plasticity-related markers, i.e., synaptophysin and phosphorylated Ca²⁺/calmodulin-dependent protein kinase II, while ascorbic acid prevented the reduction in the hippocampus. Furthermore, ascorbic acid ameliorated D-gal-induced downregulation of superoxide dismutase 1 and 2, sirtuin1, caveolin-1, and brain-derived neurotrophic factor and upregulation of interleukin 1 beta and tumor necrosis factor alpha in the hippocampus. Ascorbic acid-mediated hippocampal restoration from D-gal-induced impairment was associated with an enhanced hippocampus-dependent memory function. Therefore, ascorbic acid ameliorates D-gal-induced impairments through anti-oxidative and anti-inflammatory effects, and it could be an effective dietary supplement against adult brain aging.

Troxerutin Protects Kidney Tissue against BDE-47-Induced Inflammatory Damage through CXCR4-TXNIP/NLRP3 Signaling

2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47) induces oxidative stress in kidney cells, but the underlying mechanism remains poorly understood. Troxerutin, a natural flavonoid, has potential antioxidant and anti-inflammatory efficacy. In this study, we assessed the effect of troxerutin on kidney damage caused by BDE-47 and investigated the underlying mechanism. The results showed troxerutin reduced reactive oxygen species (ROS) level and urine albumin-to-creatinine ratio (ACR), decreased the activities of inflammatory factors including cyclooxygenase-2 (COX-2), induced nitric oxide synthase (iNOS) and nuclear factor kappa B (NF-κB) in the kidney tissues of BDE-47-treated mice. Furthermore, troxerutin significantly weakened the expression of kidney NLRP3 inflammasome containing NLRP3, ASC, and caspase-1, contributing to the decline of IL-1β. Additionally, troxerutin inhibited the increased protein level of stromal-derived factor-1(SDF-1), C-X-C chemokine ligand 12 receptor 4 (CXCR4), and thioredoxin interaction protein (TXNIP) caused by BDE-47. Specifically, the immunoprecipitation assay indicated that there was a direct interaction between CXCR4 and TXNIP. CXCR4 siRNA and TXNIP siRNA also decreased the inflammatory damage, which was similar to the action of troxerutin. Our data demonstrated that troxerutin regulated the inflammatory lesions via CXCR4-TXNIP/NLRP3 inflammasome in the kidney of mice induced by BDE-47.

Anti-arrhythmogenic and anti-inflammatory effects of troxerutin in ischemia/reperfusion injury of diabetic myocardium

INTRODUCTION

Medicinal plants are increasingly used in the treatment of cardiovascular diseases due to their multifaceted properties. This study was designed to investigate anti-arrhythmic and anti-inflammatory potentials of the natural bioflavonoid, troxerutin (TXR) in myocardial ischemia/reperfusion (I/R) injury in diabetic rats.

METHODS

Male Wistar rats were randomly divided into 4 groups (control, control + TXR [150 mg/kg, daily], diabetic, and diabetic + TXR). Type-1 diabetes was induced by an intraperitoneal injection of streptozotocin (50 mg/kg) and lasted for 10 weeks. After mounting on the Langendorff apparatus, isolated hearts in all groups received a normal Krebs-Henseleit solution for 20 min of stabilization period, followed by 30 min of regional ischemia through ligation of the left anterior descending coronary artery, and 60 min of full reperfusion. During the experiment, the electrocardiograms were recorded and the arrhythmias [number, duration and incidence of premature ventricular complexes (PVC), ventricular tachycardia (VT), ventricular fibrillation (VF), and arrhythmia score] during I/R phases were assessed based on the Lambeth Convention. Ischemic left ventricular samples were used to determine the activities of lactate dehydrogenase (LDH), interleukin-1beta (IL-1β), and tumor necrosis factor (TNF-α).

RESULTS

The arrhythmias induced by I/R were not significantly changed in diabetic group as compared to the control group. However, pretreatment with TXR significantly reduced the number of PVC and duration and incidence of VF in ischemic phase in comparison to the untreated animals (P < 0.05). In addition, the duration, and incidence of most arrhythmias during reperfusion phase were significantly declined by TXR administration in both control and diabetic groups (P < 0.05). Pretreatment of rats with TXR significantly reduced myocardial inflammatory cytokines TNF-α and IL-1β levels after I/R insult in diabetic as well as control hearts (P < 0.05).

CONCLUSION

Preconditioning with TXR could provide cardioprotection by anti-arrhythmic and anti-inflammatory effects against I/R injury in rat hearts. This effect of TXR can introduce this material as a protective agent in cardiovascular diseases.

Transcriptomic analysis of gene expression in mice treated with troxerutin

Troxerutin, a semi-synthetic derivative of the natural bioflavanoid rutin, has been reported to possess many beneficial effects in human bodies, such as vasoprotection, immune support, anti-inflammation and anti-aging. However, the effects of troxerutin on genome-wide transcription in blood cells are still unknown. In order to find out effects of troxerutin on gene transcription, a high-throughput RNA sequencing was employed to analysis differential gene expression in blood cells consisting of leucocytes, erythrocytes and platelets isolated from the mice received subcutaneous injection of troxerutin. Transcriptome analysis demonstrated that the expression of only fifteen genes was significantly changed by the treatment with troxerutin, among which 5 genes were up-regulated and 10 genes were down-regulated. Bioinformatic analysis of the fifteen differentially expressed genes was made by utilizing the Gene Ontology (GO), and the differential expression induced by troxerutin was further evaluated by real-time quantitative PCR (Q-PCR).

Role of D-galactose-induced brain aging and its potential used for therapeutic interventions

Aging is a phenomenon that all living organisms inevitably face. Every year, 9.9million people, globally, suffer from dementia, an indicator of the aging brain. Brain aging is significantly associated with mitochondrial dysfunction. This is characterized by a decrease in the activity of respiratory chain enzymes and ATP production, and increased free radical generation, mitochondrial deoxyribonucleic acid (DNA) mutations, and impaired mitochondrial structures. To get a better understanding of aging and to prevent its effects on many organs, chronic systemic administration of D-galactose was used to artificially create brain senescence in animal models and established to be beneficial for studies of anti-aging therapeutic interventions. Several studies have shown that D-galactose-induced brain aging which does so not only by causing mitochondrial dysfunction, but also by increasing oxidative stress, inflammation, and apoptosis, as well as lowering brain-derived neurotrophic factors. All of these defects finally lead to cognitive decline. Various therapeutic approaches which act on mitochondria and cognition were evaluated to assess their effectiveness in the battle to reverse brain aging. The aim of this article is to comprehensively summarize and discuss the underlying mechanisms involved in D-galactose-induced brain aging, particularly as regards alterations in brain mitochondria and cognitive function. In addition, the aim is to summarize the different therapeutic approaches which have been utilized to address D-galactose-induced brain aging.

Troxerutin Reduces Kidney Damage against BDE-47-Induced Apoptosis via Inhibiting NOX2 Activity and Increasing Nrf2 Activity

2,2,4,4-Tetrabromodiphenyl ether (BDE-47), one of the persistent organic pollutants, seriously influences the quality of life; however, its pathological mechanism remains unclear. Troxerutin is a flavonoid with pharmacological activity of antioxidation and anti-inflammation. In the present study, we investigated troxerutin against BDE-47-induced kidney cell apoptosis and explored the underlying mechanism. The results show that troxerutin reduced renal cell apoptosis and urinary protein secretion in BDE-47-treated mice. Western blot analysis shows that troxerutin supplement enhanced the ratio of Bcl-2/Bax; inhibited the release of cytochrome c from mitochondria, the activation of procaspase-9 and procaspase-3, and the cleavage of PARP; and reduced FAS, FASL, and caspase-8 levels induced by BDE-47. In addition, troxerutin decreased the production of reactive oxygen species (ROS) and increased the activities of antioxidative enzymes. Furthermore, troxerutin blunted Nrf2 ubiquitylation, enhanced the activity of Nrf2, decreased the activity of NOX2, and ameliorated kidney oxidant status of BDE-47-treated mice. Together, these results confirm that troxerutin could alleviate the cytotoxicity of BDE-47 through antioxidation and antiapoptosis, which suggests that its protective mechanism is involved in the inhibition of apoptosis via suppressing NOX2 activity and increasing Nrf2 signaling pathway.

In vitro antiglycating effect and in vivo neuroprotective activity of Trigonelline in d-galactose induced cognitive impairment

BACKGROUND

Alzheimer's disease (AD) is characterized by amyloid beta (Aβ) plaques, neurofibrillary tangles (NFTs) and cognitive impairment. Literature cites the role of advanced glycation end products (AGEs) in AD due to increased cytotoxicity via oxidative stress. d-galactose (d-gal) induced amnesia stimulates Aβ overproduction via increased oxidative stress and AGEs. Trigonelline (TRG), a naturally occurring alkaloid has been reported to have neuroprotective and antidiabetic properties.

METHODS

Present study assessed the protective effect of TRG against in vitro AGEs formation. Since chronic administration of d-gal increases AGEs, we subsequently investigated the neuroprotective role of TRG (50 and 100 mg/kg as per body weight) against d-gal induced amnesia. Mice were subcutaneously (sc) injected with d-gal (150 mg/kg) for 6 weeks. Behavioral assessments in Morris water maze (MWM) and Y-maze were performed, followed by biochemical estimations to deduce the probable mechanism of action.

RESULTS

In vitro experiments demonstrated that TRG stalled early and late AGEs formation. Chronic d-gal administration significantly impaired cognitive performance in MWM and Y maze, caused marked oxidative damage, elevated the AGEs levels and significantly increased the acetylcholinesterase levels as compared to sham group. TRG (50 and 100 mg/kg) treatment significantly ameliorated cognitive performance, reversed the oxidative damage, decreased AGE levels and caused significant decline in acetylcholine esterase levels as compared to d-gal group.

CONCLUSION

Present study highlights the neuroprotective role of TRG against d-gal induced amnesia due to the antioxidant, antiglycative and anticholinesterase properties.

Troxerutin protects hippocampal neurons against amyloid beta-induced oxidative stress and apoptosis

Alzheimer's disease (AD) is an age-related neurodegenerative disease linked with increased production and/or deposition of amyloid-beta (Aβ) in the brain. The aim of the present study was to investigate the possible neuroprotective effect of troxerutin on an animal model of Alzheimer's disease. Alzheimer model was induced by a single dose intracerebroventricular (ICV) injection of Aβ 1-42 (5 nmol/5 µl). Thereafter, troxerutin (300 mg/kg) was gavaged for 14 days. The hippocampal malondialdehyde (MDA) levels and enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and acetylcholinesterase (AChE) were measured using enzyme-linked immunosorbent assay (ELISA) method. In addition, the number of apoptotic cells in the dentate gyrus (DG) was assessed by TUNEL kit. The results showed that ICV microinjection of Aβ 1-42 increased MDA levels, reduced SOD and GPx, and increased AChE activities in the hippocampus. Chronic administration of troxerutin significantly attenuated MDA levels and AChE activity and increased SOD and GPx activities in the hippocampus. Moreover, the number of apoptotic cells was decreased by troxerutin treatment. Taken together, our study demonstrated that troxerutin could increase the resistance of hippocampal neurons against apoptosis, at least in part, by diminishing the activity of AChE and oxidative stress. Therefore, troxerutin may have beneficial effects in the management of Alzheimer's disease.

Enhanced neuroprotection of anthocyanin-loaded PEG-gold nanoparticles against Aβ1-42-induced neuroinflammation and neurodegeneration via the NF-KB /JNK/GSK3β signaling pathway

Amyloid-beta (Aβ_1-42) plaques and neurofibrillary tangles (NFTs) are the main hallmarks considered to be associated with neuroinflammation in Alzheimer's disease (AD). Recently, nanoparticle-based targeted drug delivery approaches have been found to be a useful tool in the neurotherapeutics field. Therefore, we examined and compared the neuroprotective effect of anthocyanins alone and anthocyanin-loaded poly (ethylene glycol)-gold nanoparticles (PEG-AuNPs) in Aβ_1-42-injected mouse and in vitro models of AD. We determined that anthocyanins alone or conjugated with PEG-AuNPs (AnPEG-AuNPs) reduced Aβ_1-42-induced neuroinflammatory and neuroapoptotic markers via inhibiting the p-JNK/NF-κB/p-GSK3β pathway in both in vivo and in vitro AD models. However, anthocyanins loaded with PEG-AuNPs were more effective compared to anthocyanins alone. Taken together, these results demonstrate that PEG-coated gold anthocyanins nanoparticles could be a new therapeutic agent in the field of nanomedicine to prevent neurodegenerative diseases such as AD.

Modulation of hippocampal gene expression of microRNA-146a/microRNA-155-nuclear factor-kappa B inflammatory signaling by troxerutin in healthy and diabetic rats

Objectives:

Inflammation plays a critical role in the progression of diabetic complications such as neurological disorders. Previous reports have indicated the memory-improving effect of troxerutin, in rat hippocampus, but the underlying mechanisms are unclear. Hence, we have investigated the effect of troxerutin pretreatment on gene expressions of inflammation-related microRNAs (miRs), miR-146a and miR-155, and nuclear factor-kappa B (NF-κB) signaling pathway in the hippocampus of healthy and diabetic rats.

Materials and Methods:

Wistar rats were randomly divided into four groups (control, control + troxerutin, diabetic, and diabetic + troxerutin). Diabetes was induced by a single i.p. injection of streptozotocin (50 mg/kg). Troxerutin (150 mg/kg) was orally administered in animals for 1 month. After 10 weeks of diabetes, animals were anesthetized and decapitated for the isolation of hippocampus. The expression of miR-146a and miR-155 and the messenger RNA (mRNA) expressions of NF-κB, interleukin-1 receptor-associated kinase-1 (IRAK-1), and tumor necrosis factor receptor-associated factor-6 (TRAF-6) were analyzed by real-time polymerase chain reaction.

Results:

Diabetes significantly increased hippocampal mRNA levels of NF-κB, IRAK-1, and TRAF-6 compared with nondiabetic rats (P < 0.05); however, pretreatment with troxerutin decreased them in both diabetic and nondiabetic animals, independent of its glycemic effect (P < 0.05). The expression levels of miR-146a and miR-155 were decreased in diabetic group as compared to the control (P < 0.01).

Conclusion:

These findings showed that troxerutin could inhibit the inflammatory NF-κB pathway in the hippocampus of diabetic rats, which may be due to the negative feedback loop regulated by miR-146a.

The oral administration of D-galactose induces abnormalities within the mitochondrial respiratory chain in the brain of rats

D-Galactose (D-gal) chronic administration via intraperitoneal and subcutaneous routes has been used as a model of aging and Alzheimer disease in rodents. Intraperitoneal and subcutaneous administration of D-gal causes memory impairments, a reduction in the neurogenesis of adult mice, an increase in the levels of the amyloid precursor protein and oxidative damage; However, the effects of oral D-gal remain unclear. The aim of this study was to evaluate whether the oral administration of D-gal induces abnormalities within the mitochondrial respiratory chain of rats. Male Wistar rats (4 months old) received D-gal (100 mg/kg v.o.), during the 1st, 2nd, 4th, 6th or 8th weeks by oral gavage. The activity of the mitochondrial respiratory chain complexes was measured in the 1st, 2nd, 4th, 6th and 8th weeks after the administration of D-gal. The activity of the respiratory chain complex I was found to have increased in the prefrontal cortex and hippocampus in the 1st, 6th and 8th weeks, while the activity of the respiratory chain complex II increased in the 1st, 2nd, 4th, 6th and 8th weeks within the hippocampus and in the 2nd, 4th, 6th and 8th weeks within the prefrontal cortex. The activity of complex II-III increased within the prefrontal cortex and hippocampus in each week of oral D-gal treatment. The activity of complex IV increased within the prefrontal cortex and hippocampus in the 1st, 2nd, 6th and 8th weeks of treatment. After 4 weeks of treatment the activity increased only in hippocampus. In conclusion, the present study showed that the oral administration of D-gal increased the activity of the mitochondrial respiratory chain complexes I, II, II-III and IV in the prefrontal cortex and hippocampus. Furthermore, the administration of D-gal via the oral route seems to cause the alterations in the mitochondrial respiratory complexes observed in brain neurodegeneration.

Prunella vulgaris L., an Edible and Medicinal Plant, Attenuates Scopolamine-Induced Memory Impairment in Rats

Prunella vulgaris L. is as a major plant in the Chinese traditional functional beverage Guangdong herbal tea for the treatment of fevers, diarrhea, and sore mouth. In this study, ethyl acetate parts of aqueous extracts from P. vulgaris L. (EtOAc-APV) were found to demonstrate potent acetylcholinesterase (AChE) inhibition in vitro. Therefore, this study was designed to further investigate the effects of EtOAc-APV on scopolamine (SCOP)-induced aging rats. Male Wistar rats were randomly divided into four groups (n = 12) and given orally by gavage EtOAc-APV (100 mg/kg) for 3 weeks. SCOP (1 mg/kg, ip) was administered to rats 30 min before starting behavioral tests consecutively for 3 days. EtOAc-APV could attenuate SCOP-induced brain senescence in rats by improving behavioral performance and decreasing brain cell damage, which was associated with a notable reduction in AChE activity and MDA level, as well as an increase in SOD and GPx activities. Additionally, EtOAc-APV administration could reduce the expression of NF-κB and GFAP, which showed an anti-neuroinflammatory effect on the SCOP-treated rat. Overall, the current study highlights P. vulgaris L. as an antidementia dietary supplement.

Intranasal Cerebrolysin Attenuates Learning and Memory Impairments in D-galactose-Induced Senescence in Mice

Neurotrophic factors are currently being considered as pro-cognitive therapeutic approaches for management of cognitive deficits. This study aims to evaluate the effects of intranasal (i.n.) or intraperitoneal (i.p.) administration of Cerebrolysin (CBL) (as a mixture of neurotrophic factors) on the d-galactose-induced oxidative stress, apoptosis and memory as well as learning impairment in mice. For this purpose, CBL (1, 2.5, 5 ml/kg/i.p.) or (1 ml/kg/i.n.), were administrated daily in d-galactose-received (100 mg/kg/subcutaneous (s.c.)) mice model of aging for eight weeks. Spatial and recognition memories were assessed by the Morris water maze and novel object recognition tasks. Brain and blood of animals were analysed for oxidative stress biomarkers including malondialdehyde, total antioxidant capacity, glutathione peroxidase and superoxide dismutase. Apoptosis rate in the hippocampus was evaluated by TUNEL staining of brain tissue. 5 ml/kg/i.p. dose of CBL increased the locomotor activity but, 1 ml/kg/i.p. dose didn't show detectable behavioural or molecular effects on aged mice. Treatment with 2.5 ml/kg/i.p. and 1 ml/kg/i.n. doses attenuated d-galactose-impaired spatial and recognition memories. Results showed an obvious increase in the antioxidant biomarkers and decrease in the malondialdehyde levels both in the blood and brain of aged mice in 2.5 ml/kg/i.p. dose, and only in the brain in 1 ml/kg/i.n. dose of CBL. Anti-apoptotic effects also were seen in the same dose/rout of CBL administration in aged animals. This study proves the usefulness of i.n. CBL administration as a non-invasive and efficient method of drug delivery to the brain to improve aging-induced oxidative stress, apoptosis and learning as well as memory impairment.

Ferulic acid ameliorates memory impairment in d-galactose-induced aging mouse model

Ferulic acid (FA) acts as a powerful antioxidant against various age-related diseases. To investigate the effect and underlying mechanism of FA against d-galactose(d-gal)-induced memory deficit, mice were injected with d-gal to induce memory impairment and simultaneously treated with FA and donepezil. The behavioral results revealed that chronic FA treatment reversed d-gal-induced memory impairment. Further, FA treatment inhibited d-gal-induced AChE activity and oxidative stress via increase of superoxide dismutase activity and reduced glutathione content, as well as decrease of malondialdehyde and nitric oxide levels. We also observed that FA significantly inhibits inflammation in the brain through reduction of NF-κB and IL-1β by enzyme-linked immunosorbent assay. Additionally, FA treatment significantly reduces the caspase-3 level in the hippocampus of d-gal-treated mice. Hematoxylin and eosin and Nissl staining showed that FA prevents neurodegeneration induced by d-gal. These findings showed that FA inhibits d-gal-induced AChE activity, oxidative stress, neuroinflammation and neurodegeneration, and consequently ameliorates memory impairment.

Cerebralcare Granule(®), a Chinese Herb Compound Preparation, Attenuates D-Galactose Induced Memory Impairment in Mice

Cerebralcare granule(®) (CG) is a preparation of Traditional Chinese Medicine that widely used in China. It was approved by the China State Food and Drug Administration for treatment of headache and dizziness associated with cerebrovascular diseases. In the present study, we aimed to investigate whether CG had protective effect against D-galactose (gal)-induced memory impairment and to explore the mechanism of its action. D-gal was administered (100 mg/kg, subcutaneously) once daily for 8 weeks to induced memory deficit and neurotoxicity in the brain of aging mouse and CG (7.5, 15, and 30 g/kg) were simultaneously administered orally. The present study demonstrates that CG can alleviate aging in the mouse brain induced by D-gal through improving behavioral performance and reducing brain cell damage in the hippocampus. CG prevents aging mainly via suppression of oxidative stress response, such as decreasing NO and MDA levels, renewing activities of SOD, CAT, and GPx, as well as decreasing AChE activity in the brain of D-gal-treated mice. In addition, CG prevents aging through inhibiting NF-κB-mediated inflammatory response and caspase-3-medicated neurodegeneration in the brain of D-gal treated mice. Taken together, these data clearly demonstrates that subcutaneous injection of D-gal produced memory deficit, meanwhile CG can protect neuron from D-gal insults and improve memory ability.

Oral administration of d-galactose induces cognitive impairments and oxidative damage in rats

d-Galactose (d-gal) is a reducing sugar that can be used to mimic the characteristics of aging in rodents; however, the effects of d-gal administration by oral route are not clear. Therefore, the aim of this study was to elucidate if the oral administration of d-gal induces cognitive impairments, neuronal loss, and oxidative damage, mimicking an animal model of aging. Male adult Wistar rats (4 months old) received d-gal (100mg/kg) via the oral route for a period of 1, 2, 4, 6 or 8 weeks. The results showed cognitive impairments in the open-field test in the 4th and 6th weeks after d-gal administration, as well as an impairment in spatial memory in the radial maze test after the 6th week of d-gal administration. The results indicated increase of levels of thiobarbituric acid reactive species-TBARS-and carbonyl group content in the prefrontal cortex from the 4th week, and in all weeks of d-gal administration, respectively. An increase in the levels of TBARS and carbonyl group content was observed in the hippocampus over the entire period of d-gal treatment. In the 8th week of d-gal administration, we also observed reductions in synaptophysin and TAU protein levels in the prefrontal cortex. Thus, d-gal given by oral route caused cognitive impairments which were accompanied by oxidative damage. Therefore, these results indicate that orally administered d-gal can induce the behavioral and neurochemical alterations that are observed in the natural aging process. However, oral d-gal effect in rats deserve further studies to be better described.

A high-fat diet increases oxidative renal injury and protein glycation in D-galactose-induced aging rats and its prevention by Korea red ginseng

Declining renal function is commonly observed with age. Obesity induced by a high-fat diet (HFD) may reduce renal function. Korean red ginseng (KRG) has been reported to ameliorate oxidative tissue injury and have an anti-aging effect. This study was designed to investigate whether HFD would accelerate the D-galactose-induced aging process in the rat kidney and to examine the preventive effect of KRG on HFD and D-galactose-induced aging-related renal injury. When rats with D-galactose-induced aging were fed an HFD for 9 wk, enhanced oxidative DNA damage, renal cell apoptosis, protein glycation, and extracellular high mobility group box 1 protein (HMGB1), a signal of tissue damage, were observed in renal glomerular cells and tubular epithelial cells. However, treatment of rats with HFD- plus D-galactose-induced aging with KRG restored all of these renal changes. Our data suggested that a long-term HFD may enhance D-galactose-induced oxidative renal injury in rats and that this age-related renal injury could be suppressed by KRG through the repression of oxidative injury.

Attenuation of cyclophosphamide-induced pulmonary toxicity in Swiss albino mice by naphthalimide-based organoselenium compound 2-(5-selenocyanatopentyl)-benzo[de]isoquinoline 1,3-dione

CONTEXT

The widely used antineoplastic drug cyclophosphamide causes pulmonary toxicity by inducing oxidative stress. Selenium, a dietary micronutrient, has been found to protect various organs from oxidative injuries.

OBJECTIVE

This study was designed to investigate the protective efficacy of an organoselenium compound 2-(5-selenocyanato-pentyl)-benzo[de]isoquinoline 1,3-dione against cyclophosphamide-induced pulmonary toxicity in Swiss albino mice.

MATERIALS AND METHODS

Cyclophosphamide (25 mg/kg b.w.) was administered intraperitoneally for 10 d and the organoselenium compound (3 mg/kg b.w.) was given by oral gavage in concomitant and pretreatment schedules. Various biochemical parameters related to oxidative stress and antioxidant enzymes along with histology of lungs were evaluated to assess the effect of the test compound.

RESULTS

The oral LD50 of the test compound was more than 1000 mg/kg b.w. in Swiss albino mice. The test compound substantially ameliorated cyclophosphamide-induced pulmonary injury by reducing the levels of reactive oxygen species, reactive nitrogen species, and lipid peroxidation, respectively, by 14.88, 18.54, and 21.10% in concomitant treatment schedule and by 23.89, 35.73, and 30.76% in the pretreatment schedule as well as by restoring the level of reduced glutathione and activities of glutathione-S-transferase, superoxide dismutase, catalase, and glutathione peroxidase, respectively, by 36.88, 42.43, 38.0, 35.0, and 34.06% in the concomitant treatment schedule and by 66.02, 59.29, 57.23, 71.59, and 57.22% in the pretreatment schedule. The test compound also attenuated cyclophosphamide-induced histological alterations of lung tissue.

DISCUSSION AND CONCLUSION

The test compound emerged as an efficient antioxidant protecting lungs tissue from cyclophosphamide-induced injury.

Beneficial effect of troxerutin on diabetes-induced vascular damages in rat aorta: histopathological alterations and antioxidation mechanism

BACKGROUND

Diabetes is associated with micro- and macro-vascular complications affecting several organs. Oxidative stress plays a crucial role in the etiology of vascular disease in diabetes.

OBJECTIVES

The present study aimed to investigate the beneficial effect of troxerutin on diabetes-induced histopathological damages in rat aorta with focusing on its antioxidative actions.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into four groups (n = 8/each): control, control plus troxerutin, diabetic and diabetic plus troxerutin. Diabetes was induced in rats by a single intraperitoneal injection of streptozotocin (50 mg/kg) and lasted for 10 weeks. Troxerutin was administered orally in concentration of 150 mg/kg/daily for one month before killing rats. At the end of treatment period, thoracic aorta was isolated and divided into two parts; one part was immersed in 10% formalin for histopathological evaluations and the other was frozen by liquid nitrogen for assessment of malondialdehyde (MDA, the main product of lipid peroxidation), activity of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX).

RESULTS

Lipid deposition in tunica intimae and media, thickening and structural deformity of vascular tissues as well as the level of plasma glucose and aortic tissue levels of lipid peroxidation were significantly increased in diabetic rats compared to control ones (P < 0.05). Troxerutin significantly reduced the severity of all vascular histopathological damages in treated versus untreated diabetic rats. In addition, treatment of diabetic rats with troxerutin significantly decreased the levels of MDA (5.1 ± 0.3 vs. 9.3 ± 1.2 nmol/mL) (P < 0.01) and increased the activity of antioxidant enzyme GPX compared to untreated-diabetic groups.

CONCLUSIONS

Troxerutin may reduce the vascular complications and tissue injuries induced by chronic diabetes in rat aorta through increasing the activity of tissue antioxidant system and reducing the level of lipid peroxidation.

Sensitization of cisplatin therapy by a naphthalimide based organoselenium compound through modulation of antioxidant enzymes and p53 mediated apoptosis

The widely used anti-cancer drug cisplatin imparts various toxic manifestations in the host, with nephrotoxicity being the most severe one. The trace element selenium shows antioxidant activity in both human and animals. The present study was designed to assess the chemoprotecting and chemoenhancing efficacy of a naphthalimide based organoselenium compound 2-(5-selenocyanato-pentyl)-benzo[de]isoquinoline 1,3-dione during cisplatin chemotherapy in mice bearing Ehrlich ascites carcinoma cells. Cisplatin (5 mg/kg b.w.) was administered intraperitoneally and the organoselenium compound (3 mg/kg b.w.) was given by oral gavage in concomitant and pretreatment schedule. The effects of the test compound was evaluated by assaying biochemical, hematological, histological, genotoxicity parameters and by investigating induction of apoptosis in tumor cells, and calculating tumor growth response in the host. The organoselenium compound significantly prevented cisplatin induced generation of reactive oxygen species (ROS), reactive nitrogen species, and onset of lipid peroxidation in the kidney tissue of the experimental mice. In addition, the test compound was also substantially restored cisplatin induced depleted activities of the renal antioxidant enzymes and reduced glutathione level; prevented the serum blood urea nitrogen level, creatinine level, chromosomal aberration, DNA damage, histological alterations of kidney, and normalized the hematological profile of the tumor bearing mice. Furthermore, the organoselenium compound alone or during combination therapy induced apoptosis in tumor cells through mitochondria mediated and DNA damage mediated pathway and ultimately increased the life span of the tumor bearing host. Hence, the results showed that the test compound not only reduced the toxicity of cisplatin but also enhanced its anti-tumor efficacy.

Physical exercise ameliorates the reduction of neural stem cell, cell proliferation and neuroblast differentiation in senescent mice induced by D-galactose

Background

Aging negatively affects adult hippocampal neurogenesis, and exercise attenuates the age-related reduction in adult hippocampal neurogenesis. In the present study, we used senescent mice induced by D-galactose to examine neural stem cells, cell proliferation, and neuronal differentiation with or without exercise treatment. D-galactose (100 mg/kg) was injected to six-week-old C57BL/6 J mice for 6 weeks to induce the senescent model. During these periods, the animals were placed on a treadmill and acclimated to exercise for 1 week. Then treadmill running was conducted for 1 h/day for 5 consecutive days at 10-12 m/min for 5 weeks.

Results

Body weight and food intake did not change significantly after D-galactose administration with/without treadmill exercise, although body weight and food intake was highest after treadmill exercise in adult animals and lowest after treadmill exercise in D-galactose-induced senescent model animals. D-galactose treatment significantly decreased the number of nestin (a neural stem cell marker), Ki67 (a cell proliferation marker), and doublecortin (DCX, a differentiating neuroblast marker) positive cells compared to those in the control group. In contrast, treadmill exercise significantly increased Ki67- and DCX-positive cell numbers in both the vehicle- and D-galactose treated groups. In addition, phosphorylated cAMP-response element binding protein (pCREB) and brain derived neurotrophic factor (BDNF) was significantly decreased in the D-galactose treated group, whereas exercise increased their expression in the subgranular zone of the dentate gyrus in both the vehicle- and D-galactose-treated groups.

Conclusion

These results suggest that treadmill exercise attenuates the D-galactose-induced reduction in neural stem cells, cell proliferation, and neuronal differentiation by enhancing the expression of pCREB and BDNF in the dentate gyrus of the hippocampus.

Electronic supplementary material

The online version of this article (doi:10.1186/s12868-014-0116-4) contains supplementary material, which is available to authorized users.

Differential contribution of key metabolic substrates and cellular oxygen in HIF signalling

Changes in availability and utilisation of O2 and metabolic substrates are common in ischemia and cancer. We examined effects of substrate deprivation on HIF signalling in PC12 cells exposed to different atmospheric O2. Upon 2-4h moderate hypoxia, HIF-α protein levels were dictated by the availability of glutamine and glucose, essential for deep cell deoxygenation and glycolytic ATP flux. Nuclear accumulation of HIF-1α dramatically decreased upon inhibition of glutaminolysis or glutamine deprivation. Elevation of HIF-2α levels was transcription-independent and associated with the activation of Akt and Erk1/2. Upon 2h anoxia, HIF-2α levels strongly correlated with cellular ATP, produced exclusively via glycolysis. Without glucose, HIF signalling was suppressed, giving way to other regulators of cell adaptation to energy crisis, e.g. AMPK. Consequently, viability of cells deprived of O2 and glucose decreased upon inhibition of AMPK with dorsomorphin. The capacity of cells to accumulate HIF-2α decreased after 24h glucose deprivation. This effect, associated with increased AMPKα phosphorylation, was sensitive to dorsomorphin. In chronically hypoxic cells, glutamine played no major role in HIF-2α accumulation, which became mainly glucose-dependent. Overall, the availability of O2 and metabolic substrates intricately regulates HIF signalling by affecting cell oxygenation, ATP levels and pathways involved in production of HIF-α.