Calcium Dobesilate Reverses Cognitive Deficits and Anxiety-Like Behaviors in the D-Galactose-Induced Aging Mouse Model through Modulation of Oxidative Stress

Mitigation of oxidative stress-induced aging by extracellular polysaccharides from Lactiplantibacillus plantarum R6-1 from Sayram ketteki

Oxidative stress within the body is associated with aging, playing a crucial role in its progression. Polysaccharides from lactic acid bacteria are well recognized for their antioxidant effects, potentially improving the aging process. This study investigated the characterization and antioxidant activities of extracellular polysaccharides (EPS-1: 59,978 Da, 40.9 % mannose, 4.5 % ribose, 5.8 % glucuronic acid, 44.1 % glucose, 2.9 % galactose; EPS-2: 25,686 Da, 22.9 % mannose, 5.4 % ribose, 5.5 % glucuronic acid, 59.6 % glucose, 5.4 % galactose) produced by Lactiplantibacillus plantarum R6-1. The results showed that EPS could increase the survival rates of Caco-2 cells exposed to hydrogen peroxide and mitigate the D-galactose (D-Gal)-induced oxidative stress in mice. Administration of EPS activated the hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in mice. Subsequently, this pathway activated various oxidation-related enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. Meanwhile, EPS regulated mouse intestinal microbiota by increasing the relative abundance of beneficial bacteria secreting anti-inflammatory factors, such as Norank_f_Muribaculaceae and Dubosiella, and restoring the imbalance of Firmicutes to Bacteroidetes caused by oxidative stress. This study shows that L. plantarum R6-1's EPS exhibited the ability to concurrently influence both the liver and intestinal microbiota of mice, thereby achieving an anti-oxidative effect through their interconnected interactions.

Association of α-Klotho with anti-aging effects of Ganoderma lucidum in animal models

ETHNOPHARMACOLOGICAL RELEVANCE

Aging is a complex, universal process characterized by structural and functional decline across multiple organs. Ganoderma lucidum (G. lucidum), a renowned traditional Chinese medicinal fungus, has long been recognized for its anti-aging properties. However, the underlying mechanisms remain incompletely understood.

AIM OF THE STUDY

This study aimed to investigate the anti-aging effects of G. lucidum and its underlying mechanisms.

MATERIALS AND METHODS

We investigated the anti-aging effects of G. lucidum sporoderm-broken spore powder (Gl-SBSP) on Caenorhabditis elegans (C. elegans) lifespan and aging across multiple organs using natural aging, D-galactose (D-gal)-induced aging, and radiation-induced premature senescence mouse models. In C. elegans, we assessed lifespan, reproductive capacity, body length, pharyngeal pumping, body bends, fat and lipofuscin levels, as well as reactive oxygen species (ROS) accumulation. In mice, histopathological staining, complete blood counts, and enzyme-linked immunosorbent assay (ELISA) were used to evaluate tissue damage, while quantitative real-time PCR (RT-qPCR) was employed to access small intestine barrier integrity. Western blot (WB) and immunohistochemistry (IHC) were utilized to analyze the distribution of alpha Klotho (α-Klotho) in the kidney, blood, and urine.

RESULTS

Gl-SBSP significantly extended C. elegans lifespan, improved reproductive capacity and mobility, and reduced lipofuscin and ROS levels. In naturally aged mice, Gl-SBSP enhanced physical appearance and performance. Additionally, Gl-SBSP alleviated aging-related structural and functional decline in multiple organs, including the colon, spleen, kidneys, liver, and small intestine, across all aging models. Biochemical analyses revealed that Gl-SBSP increased transmembrane α-Klotho (mα-Klotho) and soluble α-Klotho (sα-Klotho) levels in kidney tissue and elevated sα-Klotho levels in serum and urine.

CONCLUSION

This study is the first to demonstrate that G. lucidum exerts α-Klotho-associated anti-aging effects in animal models, highlighting its potential as an anti-aging intervention.

Allium Macrostemon Bge. Attenuates the Cognitive Decline of Aging Mice by Enhancing BDNF/TrkB Pathway

Allium macrostemon Bge. (AM) is a widely utilized culinary spice recognized for its numerous health-promoting properties. Aging-related cognitive impairment (ARCI) represents a significant global health concern during the aging process. However, the potential of AM to attenuate ARCI has not been investigated. This work aims to reveal the effects and potential mechanisms of the water extraction of AM (WEAM) in alleviating ARCI, with a particular emphasis on the BDNF/TrkB signaling pathway. The findings showed a significant enhancement in memory function and a reduction in hippocampal neuronal damage in aging mice following treatment with WEAM, manifested by an increased spontaneous alternation rate in the Y-maze, prolonged step-through latency, and decreased number of errors in the PAT test, a shortened escape latency and increased platform swimming time and platform crossing times in the MWM test. Additionally, WEAM reduced oxidative stress, elevated the expression of proteins related to synaptic plasticity (SYN and PSD95), and activated the BDNF/TrkB signaling pathway in D-galactose-induced aging mice. To elucidate the mechanism by which WEAM alleviates ARCI, both a TrkB activator (7,8-DHF) and an inhibitor (ANA-12) were employed. The results demonstrated that the effects of WEAM on synaptic plasticity were potentiated by 7,8-DHF and diminished by ANA-12. Finally, 11 chemical compositions of WEAM were analyzed and quantified using HPLC-MS/MS, including macrostemonoside, sarsasapogenin, diosgenin, timosaponin AIII, N-p-trans-coumaroyltyramine, guanosine, adenosine, phenylalanine, adenine, arginine, and valine. These results suggest that AM may serve as a promising culinary spice for mitigating ARCI by promoting the BDNF/TrkB signaling pathway, thereby enhancing synaptic plasticity.

An Update on Neuroaging on Earth and in Spaceflight

Over 400 articles on the pathophysiology of brain aging, neuroaging, and neurodegeneration were reviewed, with a focus on epigenetic mechanisms and numerous non-coding RNAs. In particular, this review the accent is on microRNAs, the discovery of whose pivotal role in gene regulation was recognized by the 2024 Nobel Prize in Physiology or Medicine. Aging is not a gradual process that can be easily modeled and described. Instead, multiple temporal processes occur during aging, and they can lead to mosaic changes that are not uniform in pace. The rate of change depends on a combination of external and internal factors and can be boosted in accelerated aging. The rate can decrease in decelerated aging due to individual structural and functional reserves created by cognitive, physical training, or pharmacological interventions. Neuroaging can be caused by genetic changes, epigenetic modifications, oxidative stress, inflammation, lifestyle, and environmental factors, which are especially noticeable in space environments where adaptive changes can trigger aging-like processes. Numerous candidate molecular biomarkers specific to neuroaging need to be validated to develop diagnostics and countermeasures.

Research on the mechanism of buyang huanwu decoction in the amelioration of age-associated memory impairment based on the "co-occurrence network regulation of intestinal microecology-host metabolism-immune function"

ETHNOPHARMACOLOGICAL RELEVANCE

Brain aging can promote neuronal damage, contributing to aging-related diseases like memory dysfunction. Buyang Huanwu Decoction (BYHWD), a traditional Chinese medicine formula known for tonifying qi and activating blood circulation, shows neuroprotective properties. Despite this, the specific mechanism by which BYHWD improves age-associated memory impairment (AAMI) has not been explored in existing literature.

AIM OF THE STUDY

This study aimed to investigate the mechanism of BYHWD in the improvement of AAMI based on the "co-occurrence network regulation of intestinal microecology-host metabolism-immune function".

MATERIALS AND METHODS

Firstly, D-galactose was performed to induce a rat model of AAMI. Learning and memory deficits was assessed by the Morris water maze test. H&E and Nissl staining were used to observe the pathological changes in neurons in the hippocampus of rats. Meanwhile, the levels of pro-inflammatory cytokines and the activation of antioxidant enzymes in rat serum were measured using ELISA. Finally, an integrated pharmacological approach was applied to explore the potential mechanism of BYHWD in improving AAMI.

RESULTS

Our results indicated that BYHWD significantly mitigated the pathological structure of the hippocampus, reversed the levels of IL-6, TNF-α, GSH, and CAT in the serum, and improved learning and memory in aging rats. Transcriptomics combined with network pharmacology showed that energy metabolism and the inflammatory response were the key biological pathways for BYHWD to ameliorate AAMI. Integrative analysis of the microbiome and metabolomics revealed that BYHWD has the potential to restore the balance of abundance between probiotics and harmful bacteria, and ameliorate the reprogramming of energy metabolism caused by aging in the brain. The co-occurrence network analysis demonstrated that a strong correlation between the treatment of AAMI and the stability of intestinal microecology, host metabolism, and immune network.

CONCLUSION

The findings of this study collectively support the notion that BYHWD has a superior therapeutic effect in an AAMI rat model. The mechanism involves regulating the "intestinal microecology-metabolism-immune function co-occurrence network" system to restore the composition of gut microbiota and metabolites. This further improves the metabolic phenotype of brain tissue and maintains the homeostasis of central nervous system's immunity, leading to an improvement in AAMI. Consequently, this study offers a unique perspective on the prevention and treatment of AAMI. And, BYHWD is also considered to be a promising preclinical treatment for improving AAMI.

Ellagitannin Component Punicalin Ameliorates Cognitive Dysfunction, Oxidative Stress, and Neuroinflammation via the Inhibition of cGAS-STING Signaling in the Brain of an Aging Mouse Model

Despite remarkable breakthroughs in pharmacotherapy, many potential therapies for aging remain unexplored. Punicalin (PUN), an ellagitannin component, exerts anti-inflammatory, antioxidant, and anti-apoptotic effects. This study investigated the beneficial effects of PUN against age-related brain damage in mice and explored the underlying mechanisms. We validated the protective effects of PUN against D-galactose (D-gal)-induced neuroinflammation and subsequent neuronal damage in BV2 microglia and N2a cells, respectively, in vitro. In vivo experiments were conducted on mice that were administered an 8-week regimen of intraperitoneal injections of D-gal at a dosage of 150 mg/kg/day, concurrently with oral gavage of PUN at the same dose. PUN inhibited the production of D-gal-induced inflammatory cytokines (iNOS, COX2, TNF-α, IL-6, IL-2, and IL-1β) in BV2 cells and conferred protection to N2a cells against synaptic damage mediated by BV2 microglia-induced neuroinflammation. The in vivo findings revealed that PUN considerably improved memory and learning deficits, reduced MDA levels, enhanced GSH-Px, CAT, and SOD activities, and modulated the expression of inflammatory proteins such as iNOS, COX-2, IL-1β, IL-2, IL-6, and TNF-α. Furthermore, PUN inhibited the secretion of SASP factors (ICAM-1, PAI-1, MMP-3, and MMP-9), decreased microglial activation, and reduced astrocytosis. Additionally, PUN suppressed the expression of cGAS, p-STING, p-TBK1, p-p65, and p-IRF3 in aging mouse brains and cultured BV2 microglia. In conclusion, PUN improved cognitive dysfunction in aging mice through antioxidant and anti-inflammatory mechanisms via inhibition of the cGAS-STING pathway, suggesting that it can be a promising therapeutic agent for brain aging and aging-related diseases.

Icariin Ameliorates D-galactose-induced Cell Injury in Neuron-like PC12 Cells by Inhibiting MPTP Opening

OBJECTIVE

Icariin (ICA) has a good neuroprotective effect and can upregulate neuronal basal autophagy in naturally aging rats. Mitochondrial dysfunction is associated with brain aging-related neurodegenerative diseases. Abnormal opening of the mitochondrial permeability transition pore (mPTP) is a crucial factor in mitochondrial dysfunction and is associated with excessive autophagy. This study aimed to explore that ICA protects against neuronal injury by blocking the mPTP opening and down-regulating autophagy levels in a D-galactose (D-gal)-induced cell injury model.

METHODS

A cell model of neuronal injury was established in rat pheochromocytoma cells (PC12 cells) treated with 200 mmol/L D-gal for 48 h. In this cell model, PC12 cells were pre-treated with different concentrations of ICA for 24 h. MTT was used to detect cell viability. Senescence associated β-galactosidase (SA-β-Gal) staining was used to observe cell senescence. Western blot analysis was performed to detect the expression levels of a senescence-related protein (p21), autophagy markers (LC3B, p62, Atg7, Atg5 and Beclin 1), mitochondrial fission and fusion-related proteins (Drp1, Mfn2 and Opa1), and mitophagy markers (Pink1 and Parkin). The changes of autophagic flow were detected by using mRFP-GFP-LC3 adenovirus. The intracellular ultrastructure was observed by transmission electron microscopy. Immunofluorescence was used to detect mPTP, mitochondrial membrane potential (MMP), mitochondrial reactive oxygen species (mtROS) and ROS levels. ROS and apoptosis levels were detected by flow cytometry.

RESULTS

D-gal treatment significantly decreased the viability of PC12 cells, and markedly increased the SA-β-Gal positive cells as compared to the control group. With the D-gal stimulation, the expression of p21 was significantly up-regulated. Furthermore, D-gal stimulation resulted in an elevated LC3B II/I ratio and decreased p62 expression. Meanwhile, autophagosomes and autolysosomes were significantly increased, indicating abnormal activation of autophagy levels. In addition, in this D-gal-induced model of cell injury, the mPTP was abnormally open, the ROS generation was continuously increased, the MMP was gradually decreased, and the apoptosis was increased. ICA effectively improved mitochondrial dysfunction to protect against D-gal-induced cell injury and apoptosis. It strongly inhibited excessive autophagy by blocking the opening of the mPTP. Cotreatment with ICA and an mPTP inhibitor (cyclosporin A) did not ameliorate mitochondrial dysfunction. However, the protective effects were attenuated by cotreatment with ICA and an mPTP activator (lonidamine).

CONCLUSION

ICA inhibits the activation of excessive autophagy and thus improves mitochondrial dysfunction by blocking the mPTP opening.

Effectiveness and mechanisms of combined use of antioxidant nutrients in protecting against oxidative stress-induced neuronal loss and related neurological deficits

BACKGROUND

Oxidative stress is a well-known pathological factor driving neuronal loss and age-related neurodegenerative diseases. Melatonin, coenzyme Q10 and lecithin are three common nutrients with an antioxidative capacity. Here, we examined the effectiveness of them administrated individually and in combination in protecting against oxidative stress-induced neuronal death in vitro, and neurodegenerative conditions such as Alzheimer's disease and associated deficits in vivo.

METHODS

Mouse neuroblastoma Neuro-2a (N2a) cells were exposed with H2O2 for 6 h, and subsequently treated with melatonin, coenzyme Q10, and lecithin alone or in combination for further 24 h. Cell viability was assessed using the CCK-8 assay. Eight-week-old male mice were intraperitoneally injected with D-(+)-galactose for 10 weeks and administrated with melatonin, coenzyme Q10, lecithin, or in combination for 5 weeks starting from the sixth week, followed by behavioral tests to assess the effectiveness in mitigating neurological deficits, and biochemical assays to explore the underlying mechanisms.

RESULTS

Exposure to H2O2 significantly reduced the viability of N2a cells and increased oxidative stress and tau phosphorylation, all of which were alleviated by treatment with melatonin, coenzyme Q10, lecithin alone, and, most noticeably, by combined treatment. Administration of mice with D-(+)-galactose-induced oxidative stress and tau phosphorylation, brain aging, impairments in learning and memory, anxiety- and depression-like behaviors, and such detrimental effects were mitigated by melatonin, coenzyme Q10, lecithin alone, and, most consistently, by combined treatment.

CONCLUSIONS

These results suggest that targeting oxidative stress via supplementation of antioxidant nutrients, particularly in combination, is a better strategy to alleviate oxidative stress-mediated neuronal loss and brain dysfunction due to age-related neurodegenerative conditions.

Effects of endogenous DHA milk and exogenous DHA milk on oxidative stress and cognition in SAMP8 mice

In this study, Senescence Accelerated Mice (SAMP8) were supplemented with exogenous DHA milk, endogenous DHA milk, normal milk, or 0.9 % saline solution. Enzyme-linked immunosorbent assay (ELISA), gas chromatography (GC), ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI MS/MS), and Morris water maze were used to characterize the effects of diet on oxidative stress and cognition in SAMP8 mice. Supplementation endogenous DHA milk or exogenous DHA milk can enhance the antioxidant capacity of mice organs. Endogenous DHA milk increased the superoxide dismutase (SOD) activity of mice brain and serum than normal milk and 0.9 % saline solution (P ≤ 0.05), as well as increased SOD activity of mice liver and glutathione peroxidase (GSH-Px) activity of mice brain than normal milk (P ≤ 0.05). Exogenous DHA milk increased SOD activity of mice brain than normal milk and 0.9 % saline solution, as well as increased SOD activity of mice serum than 0.9 % saline solution (P ≤ 0.05). Several polar lipid relative content, such as 18:0/18:2 PS, 17:0 Ceramide, and 20:4 LPC in mice brain was affected by dietary supplementation with DHA-containing milk. Lipid oxidation metabolites in mice brain were not affected by DHA-containing milk. Endogenous DHA milk increased the number of platform location crossing times of mice in the Morris water maze test, compared with Exogenous DHA milk, normal milk, and 0.9 % saline solution (P ≤ 0.05).

Distinct signatures on d-galactose-induced aging and preventive/protective potency of two low-dose vitamin D supplementation regimens on working memory, muscular damage, cardiac and cerebral oxidative stress, and SIRT1 and calstabin2 downregulation

Chronic administration of d-galactose (d-gal) in rodents reproduces the overproduction of reactive oxygen species of physiological aging. The present research shows for the first time distinct signatures on d-gal-induced aging (500 mg/kg, 6 weeks) and the preventive and protective potential of two vitamin D (50 IU) supplementation regimens (pre-induction and simultaneous, respectively) in two vital organs (heart and brain). d-gal-induced notorious alterations in working memory, a strong increase in brain malondialdehyde (MDA) oxidative levels, and strong downregulation of sirtuin 1 (SIRT1) in the heart and hippocampus and of calstabin2 in the heart. Cardiac and brain superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymatic antioxidant capacities were damaged, brain calstabin2 was downregulated, and neuropathology was observed. Heart damage also included a moderate increase in MDA levels, serologic lactate dehydrogenase (LDH), total creatine kinase (CK) activities, and histopathological alterations. The used dose of vitamin D was enough to prevent cognitive impairment, avoid muscular damage, hamper cardiac and cerebral oxidative stress, and SIRT1 and calstabin2 downregulation. Most importantly, the potencies of the two preventive schedules depended on the tissue and level of study. The pre-induction schedule prevented d-gal-induced aging by 1 order of magnitude higher than simultaneous administration in all the variables studied except for SIRT1, whose strong downregulation induced by d-gal was equally prevented by both schedules. The benefits of vitamin D for oxidative stress were stronger in the brain than in the heart. Brain MDA levels were more sensitive to damage, while SOD and GPx antioxidant enzymatic activities were in the heart. In this order, the magnitude of SOD, MDA, and GPx oxidative stress markers was sensitive to prevention. In summary, the results unveiled distinct aging induction, preventive signatures, and sensitivity of markers depending on different levels of study and tissues, which are relevant from a mechanistic view and in the design of targeted interventions.

Mitigation of behavioral deficits and cognitive impairment by antioxidant and neuromodulatory potential of Mukia madrespatana in D-galactose treated rats

Plants and their parts have been extensively used for the therapeutic purposes such as aging due to their powerful antioxidative belongings. Presently, we intended to examine the consequence of fruit peel of Mukia madrespatana (M.M) on D-galactose (D-Gal) persuaded anxiety and/or depression profile, cognition and serotonin metabolism in rats. Animals were divided in to 4 groups (n = 6). (i) Water treated (ii) D-Gal treated (iii) M.M. treated (iv) D-Gal + M.M. treated. All the animals received their respective treatment for 4 weeks. D-Gal and M.M. fruit peel were given to animals with oral gavage with doses 300 mg/ml/kg/day and 2 g/kg/day respectively. After 4 weeks' behavioral analysis performed to evaluate anxiety and depression profile, cognitive function of animals. After that animals were sacrificed and whole brain removed for biochemical (redox status, degradative enzyme of acetylcholine), and neurochemical (serotonin metabolism) analysis. Results showed that administration of M.M. inhibited D-Gal-instigated anxious and depressive behaviors and improved cognition. Treatment of M.M. decreased MDA levels, AChE activity and increased antioxidant enzyme activity in D-Gal administered and control rats. Enhanced serotonin metabolism also decreased by M.M. in control and D-Gal administered rats. In conclusion, M.M. fruit peel has powerful antioxidative and neuromodulatory properties and due to this effect, it may be a good source of mitigation/treatment for aging induced behavioral and cognitive impairment.

Berberine Rescues D-Ribose-Induced Alzheimer's Pathology via Promoting Mitophagy

Mitochondrial dysfunction is considered an early event of Alzheimer disease (AD). D-ribose is a natural monosaccharide that exists in cells, especially in mitochondria, and can lead to cognitive dysfunction. However, the reason for this is unclear. Berberine (BBR) is an isoquinoline alkaloid that can target mitochondria and has great prospect in the treatment of AD. The methylation of PINK1 reinforces the burden of Alzheimer's pathology. This study explores the role of BBR and D-ribose in the mitophagy and cognitive function of AD related to DNA methylation. APP/PS1 mice and N2a cells were treated with D-ribose, BBR, and mitophagy inhibitor Mdivi-1 to observe their effects on mitochondrial morphology, mitophagy, neuron histology, AD pathology, animal behavior, and PINK1 methylation. The results showed that D-ribose induced mitochondrial dysfunction, mitophagy damage, and cognitive impairment. However, BBR inhibition of PINK1 promoter methylation can reverse the above effects caused by D-ribose, improve mitochondrial function, and restore mitophagy through the PINK1-Parkin pathway, thus reducing cognitive deficits and the burden of AD pathology. This experiment puts a new light on the mechanism of action of D-ribose in cognitive impairment and reveals new insights in the use of BBR for AD treatment.

Chlorogenic acid combined with epigallocatechin-3-gallate mitigates D-galactose-induced gut aging in mice

Chlorogenic acid (CGA) and epigallocatechin-3-gallate (EGCG) are major polyphenolic constituents of coffee and green tea with beneficial health properties. In this study, we evaluated the gut protecting effect of CGA and EGCG, alone or in combination, on D-galactose-induced aging mice. CGA plus EGCG more effectively improved the cognition deficits and protected the gut barrier function, compared with the agents alone. Specifically, CGA plus EGCG prevented the D-galactose mediated reactive oxygen species accumulation by increasing the total antioxidant capacity, reducing the levels of malondialdehyde, and suppressing the activity of the antioxidant enzymes superoxide dismutase and catalase. In addition, supplementation of CGA and EGCG suppressed gut inflammation by reducing the levels of the proinflammatory cytokines TNFα, IFNγ, IL-1β and IL-6. Moreover, CGA and EGCG modulated the gut microbiome altered by D-galactose. For instance, CGA plus EGCG restored the Firmicutes/Bacteroidetes ratio of the aging mice to control levels. Furthermore, CGA plus EGCG decreased the abundance of Lactobacillaceae, Erysipelotrichaceae, and Deferribacteraceae, while increased the abundance of Lachnospiraceae, Muribaculaceae, and Rikenellaceae, at the family level. In conclusion, CGA in combination with EGCG ameliorated the gut alterations induced by aging, in part, through antioxidant and anti-inflammatory effects, along with its gut microbiota modulatory capacity.

Inhibiting mitochondrial inflammation through Drp1/HK1/NLRP3 pathway: A mechanism of alpinetin attenuated aging-associated cognitive impairment

Mitochondrial inflammation triggered by abnormal mitochondrial division and regulated by the Drp1/HK1/NLRP3 pathway is correlated with the progression of aging-associated cognitive impairment (AACI). Alpinetin is a novel flavonoid derived from Zingiberaceae that has many bioactivities such as antiinflammation and anti-oxidation. However, whether alpinetin alleviates AACI by suppressing Drp1/HK1/NLRP3 pathway-inhibited mitochondrial inflammation is still unknown. In the present study, D-galactose (D-gal)-induced aging mice and BV-2 cells were used, and the effects of alpinetin on learning and memory function, neuroprotection and activation of the Drp1/HK1/NLRP3 pathway were investigated. Our data indicated that alpinetin significantly alleviated cognitive dysfunction and neuronal damage in the CA1 and CA3 regions of D-gal-treated mice. Moreover, D-gal-induced microglial activation was markedly reduced by alpinetin by inhibiting the Drp1/HK1/NLRP3 pathway-suppressed mitochondrial inflammation, down-regulating the levels of p-Drp1 (s616), VDAC, NLRP3, ASC, Cleaved-caspase 1, IL-18, and IL-1β, and up-regulating the expression of HK1. Furthermore, after Drp1 inhibition by Mdivi-1 in vitro, the inhibitory effect of alpinetin on Drp1/HK1/NLRP3 pathway was more evident. In summary, the current results implied that alpinetin attenuated aging-related cognitive deficits by inhibiting the Drp1/HK1/NLRP3 pathway and suppressing mitochondrial inflammation, suggesting that the inhibition of the Drp1/HK1/NLRP3 pathway is one of the mechanisms by which alpinetin attenuates AACI.

Boosting amygdaloid GABAergic and neurotrophic machinery via dapagliflozin-enhanced LKB1/AMPK signaling in anxious demented rats

Anxiety is a neuropsychiatric disturbance that is commonly manifested in various dementia forms involving Alzheimer's disease (AD). The mechanisms underlying AD-associated anxiety haven't clearly recognized the role of energy metabolism in anxiety represented by the amygdala's autophagic sensors; liver kinase B1 (LKB1)/adenosine monophosphate kinase (AMPK). Dapagliflozin (DAPA), a SGLT2 inhibitor, acts as an autophagic activator through LKB1 activation in several diseases including AD. Herein, the propitious yet undetected anxiolytic potential of DAPA as an autophagic enhancer was investigated in AD animal model with emphasis on amygdala's GABAergic neurotransmission and brain-derived neurotrophic factor (BDNF). Alzheimer's disease was induced by ovariectomy (OVX) along with seventy-days-D-galactose (D-Gal) administration (150 mg/kg/day, i.p). On the 43rd day of D-Gal injection, OVX/D-Gal-subjected rats received DAPA (1 mg/kg/day, p.o) alone or with dorsomorphin the AMPK inhibitor (DORSO, 25 μg/rat, i.v.). In the amygdala, LKB1/AMPK were activated by DAPA inducing GABA_B2 receptor stimulation; an effect that was abrogated by DORSO. Dapagliflozin also replenished the amygdala GABA, NE, and 5-HT levels along with glutamate suppression. Moreover, DAPA triggered BDNF production with consequent activation of its receptor, TrkB through activating GABA_B2-related downstream phospholipase C/diacylglycerol/protein kinase C (PLC/DAG/PKC) signaling. This may promote GABA_A expression, verifying the crosstalk between GABA_A and GABA_B2. The DAPA's anxiolytic effect was visualized by improved behavioral traits in elevated plus maze together with amendment of amygdala' histopathological abnormalities. Thus, the present study highlighted DAPA's anxiolytic effect which was attributed to GABA_B2 activation and its function to induce BDNF/TrkB and GABA_A expression through PLC/DAG/PKC pathway in AMPK-dependent manner.

Functional chicken-liver hydrolysates ameliorate insulin resistance and cognitive decline in streptozotocin-induced diabetic mice

As part of the slaughtering processing in Taiwan, approximately 10,000 metric tons of broiler livers are produced yearly. However, these livers are regarded as waste. Our team has successfully developed a functional chicken-liver hydrolysate (CLH) with several useful activities. It has been reported that there is a positive relationship between diabetes mellitus (DM) patients and cognitive decline. To maximize broiler-livers' utilization and add value, we investigated the modulative effects of the CLHs on glucose homeostasis and cognitive decline in streptozotocin (STZ) induced diabetic mice. After a 9-wk experiment, CLH supplementation lowered blood glucose by increasing GLUT4 protein expressions in the brains, livers, and muscles of STZ-induced mice (P < 0.05). CLHs also enhanced antioxidant capacities in the livers and brains of STZ-induced mice. Amended memory and alternation behavior were tested by using water and Y-maze assays (P < 0.05). Besides, STZ-induced mice with CLH supplementation had less contracted neuron bodies in the hippocampus and lower (P < 0.05) Aβ depositions in the dentate gyrus area. Less AGE accumulation and apoptosis-related proteins (RAGE, JNK, and activated Caspase 3) in the brains of STZ-induced mice were also detected by supplementing CLHs (P < 0.05). In conclusion, the results from this study offer not only scientific evidence on the amelioration of insulin resistance and cognitive decline in hyperglycemia but also add value to this byproduct.

Gemfibrozil, a lipid-lowering drug, reduces anxiety, enhances memory, and improves brain oxidative stress in d-galactose-induced aging mice

Gemfibrozil (GFZ) is a lipid-lowering drug with several other effects, such as antioxidant and anti-inflammatory activities. In the current study, chronic d-galactose treatment (d-gal, 150 mg/kg/day; i.p., 6 weeks) induced a model of accelerated aging in male mice and was used to study the behavioral, anti-oxidative, and neuroprotective effects of GFZ (100 mg/kg/day; p.o.). Anxiety-like behaviors were assessed using the elevated plus-maze while working memory was measured by spontaneous alternation in a Y-maze. Brain oxidative stress was determined by measuring malondialdehyde (MDA) levels, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities. Neuropathological evaluation of the brain with hematoxylin-eosin and Masson's trichrome staining was also performed. The results demonstrated that the anxious-like phenotype and the cognitive impairments observed in d-gal-treated mice could be prevented in those animals coadministered with GFZ. Besides, the decrease in SOD and GPx antioxidant enzymatic activities and increase of MDA levels were also prevented in the brains of d-gal plus GFZ treated mice. Preliminary hematoxylin-eosin staining also suggested neuroprotective effects of GFZ. The results of Masson's trichrome staining showed no evidence of fibrosis in brain sections of different experimental groups. The current data provide novel insights into GFZ in the d-galactose-induced aging mouse model that open promising future research lines to determine inflammatory mediators and cell signaling underlying these effects.

Atorvastatin modulates the expression of aging-related genes in the brain of aging induced by D-galactose in mice

OBJECTIVES

Atorvastatin (AT), a competitive inhibitor of 3-hydroxymethyl-3-glutaryl-coenzyme-A reductase, is a cholesterol-lowering drug. AT has been shown to have neuroprotective, antioxidant, and anti-inflammatory properties. Previously, we have reported that AT could attenuate the behavioral, renal, and hepatic manifestations of aging. To clarify further the mechanisms involved, the present study was designed to evaluate the effect of AT on the expression of some aging-related genes in the brain of aging mice induced by D-galactose (DG).

MATERIALS AND METHODS

For this purpose, AT (0.1 and 1 mg/kg/p.o.) was administrated daily in DG-received (500 mg/kg/p.o.) mice model of aging for six weeks. At the end of the experiment, mice were decapitated to remove the brains. Then, the expression profiles of sirtuin 1 (Sirt1), P53, P21, Bcl-2, Bax, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), interleukin 1 beta (IL1β), tumor necrosis factor-alpha (TNFα), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and brain-derived neurotrophic factor (BDNF) were assessed using the real-time PCR method.

RESULTS

The present study shows that DG decreases the expression of Sirt1, Bcl-2, CAT, GPx, and BDNF while increasing the expression of P53, P21, Bax, IL-1β, iNOS, COX-2, and TNF-α. According to the findings of the present study, AT (more potentially at the dose of 1 mg/kg) modulates the expression of these aging-related genes in the brain of aging mice.

CONCLUSION

The results of the present study confirmed our previous reports on the anti-aging effects of AT at the gene level, the precise mechanisms and underlying pathways need further studies.