Anti-Ageing Effect of Physalis alkekengi Ethyl Acetate Layer on a d-galactose-Induced Mouse Model through the Reduction of Cellular Senescence and Oxidative Stress

Cow placenta extract ameliorates d-galactose-induced liver damage by regulating BAX/CASP3 and p53/p21/p16 pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Placenta is a kind of traditional Chinese medicine, known as "Ziheche", which has the function of tonifying qi and blood, nourishing liver and kidney. Placenta extract (PE) has been used for delaying organismal aging and treating various liver diseases. Cow placenta is a rich natural resource with large mass. Its composition is similar to that of human placenta, but it has not been effectively utilized. However, little is known about the effect of CPE on the liver of aging mice.

AIM OF THE STUDY

The aim of this study is to explore the protective effect and mechanism of CPE on the liver of d-galactose (D-gal) induced aging mice.

MATERIALS AND METHODS

Statistical methods were used to calculate mouse body weight and liver index. Hematoxylin-eosin (H&E) and transmission electron microscopy (TEM) were used to detect the morphological structure of the liver. Automatic biochemical analyzer was used to measure serum biochemical indicators. Three special staining methods were used to observe hepatocytes apoptosis, senescence and proliferation respectively. Relative kits were used to detect oxidative, inflammatory, and aging markers in the liver. Finally, real-time quantitative polymerase chain reaction and western-blot were used to detect aging related signaling pathways.

RESULTS

CPE significantly improved the morphological damage and dysfunction of liver, restored the activities of liver enzymes in serum, and alleviated liver oxidative stress and inflammatory response in D-gal induced aging mice. Furthermore, CPE inhibited hepatocyte apoptosis and senescence, and promoted hepatocyte proliferation by regulating BAX/CASP3 and p53/p21/p16 signaling pathways, ultimately reduced the effects of aging on the liver.

CONCLUSION

CPE effectively ameliorated the impact of aging on the liver by inhibiting free radical production or scavenging excessive free radicals, and its mechanism is associated to the regulation of apoptosis and proliferation-related factors.

Chemical components and against alzheimer's disease effects of the calyxes of Physalis alkekengi L. var. franchetii (Mast.) Makino

Physalis alkekengi L. var. franchetii (Mast.) Makino (PA), a traditional Chinese medicine, is utilised for treating dermatitis, sore throat, dysuria, and cough. This research aimed to identify the main constituents in the four extracted portions from the calyces of PA (PAC) utilising ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The Alzheimer's disease (AD) mice model was induced by D-galactose (D-gal) combined with aluminium chloride (AlCl3). Subsequent investigation into the underlying mechanisms involved behavioural and histopathological observations. The results demonstrated that four extracted portions of PAC (PACE) significantly enhanced memory and learning abilities in the Morris water maze. The concentrations of Aβ, tau and p-tau in brain tissue exhibited a significant decrease relative to the model group. Moreover, the four PACE treatment groups increased the glutathione (GSH) and superoxide dismutase (SOD) levels, while concurrently reducing malondialdehyde (MDA), interleukin-1β (IL-1β) and interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) levels. In summary, the current study demonstrates that the four PACE formulations exhibit beneficial anti-AD properties, with the most pronounced efficacy observed in the EA group. Additionally, PAC shows potential in mitigating neuroinflammation and oxidative damage by inhibiting the TLR4/NF-κB signalling pathway. This research lays a theoretical groundwork for the future clinical development and utilisation of PAC in treating AD.

Evaluation of the Impact of Alternanthera philoxeroides (Mart.) Griseb. Extract on Memory Impairment in D-Galactose-Induced Brain Aging in Mice through Its Effects on Antioxidant Enzymes, Neuroinflammation, and Telomere Shortening

Aging is a well-known factor that accelerates brain deterioration, resulting in impaired learning and memory functions. This current study evaluated the potential of an extract of Alternanthera philoxeroides (AP), an edible flavonoid-rich plant, to ameliorate D-galactose-induced brain aging in male mice. Chronic administration of D-galactose (150 mg/kg/day) in mice mimicked the characteristics of aging by accelerating senescence via downregulation of the following telomere-regulating factors: mouse telomerase reverse transcriptase (mTERT) and mouse telomeric repeat-binding factors 1 (mTRF1) and 2 (mTRF2). D-galactose also decreased the activities of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), while increasing expression of neuroinflammatory cytokines in the frontal cortex and hippocampus. Daily treatment of D-galactose-induced aging mice with AP at 250 and 500 mg/kg/day or vitamin E (100 mg/kg/day) significantly increased the activities of SOD and CAT, as well as expression of mTERT, mTRF1, and mTRF2, which are involved in telomere stabilization, but decreased the levels of proinflammatory cytokines IL-1β, IL-6, and TNF-α. In the behavioral portion of the study, AP improved aging-related cognitive deficits in short-term memory as shown by the Y-maze task and the novel object recognition test (NORT) and long-term memory as shown by the Morris water maze test (MWMT). The flavones kaempferol-O-glucoside (1), quercetin (2), alternanthin B (3), demethyltorosaflavone D (4), and chrysoeriol-7-O-rhamnoside (5), which could be responsible for the observed effects of AP in the D-galactose-induced aging mice, were identified by HPLC analysis.

Research on the Chemical Constituents against Alzheimer's Disease of the Fruits of Physalis alkekengi L. var. franchetii (Mast.) Makino

Physalis alkekengi L. var. franchetii (Mast.) Makino (PA) is a natural plant which is utilised as a traditional herbal medicine. It has properties that make it effective against inflammation and free radical damage. In the present study, the major constituents of four extraction parts of the fruits of PA (PAF) were investigated by combining ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The mice model of Alzheimer's disease (AD) induced by aluminum chloride (AlCl3 ) combined with D-galactose (D-gal) was established to comprehend the mechanism behind PAF's anti-AD activity from both behavioural and pathological perspectives. The results showed that four extraction parts of PAF (PAFE) had favorable anti-AD effects and the ethyl acetate (EA) group showed the best activity. UPLC-Q-TOF-MS analysis identified Physalin B, Nobiletin and Caffeic acid as the main anti-AD active constituents in EA extract. This study reveals that PAF can reduce neuroinflammatory damage by inhibiting p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway, which is the theoretical basis for clinical development and utilization of PAF in AD therapy.

Stevioside Improves Antioxidant Capacity and Intestinal Barrier Function while Attenuating Inflammation and Apoptosis by Regulating the NF-κB/MAPK Pathways in Diquat-Induced Oxidative Stress of IPEC-J2 Cells

As a natural sweetener, stevioside is extracted from Stevia rebaudiana Bertoni and possesses potent antioxidant activity. However, little information is known about its protective role in maintaining the intestinal epithelial cells health under oxidative stress. The aim of this study was to investigate the protective effects and underlying mechanisms of stevioside on alleviating inflammation, apoptosis, and improving antioxidant capacity in intestinal porcine epithelial cells (IPEC-J2) under oxidative stress by diquat. The results demonstrated that the pretreatment with stevioside (250 μM) for 6 h increased cell viability and proliferation and prevented apoptosis induced by diquat at 1000 μM for 6 h in IPEC-J2 cells, compared with the diquat alone-treated cells. Importantly, stevioside pretreatment significantly reduced ROS and MDA production as well as upregulated T-SOD, CAT, and GSH-Px activity. Moreover, it also decreased cell permeability and improved intestinal barrier functions by significantly upregulating the tight junction protein abundances of claudin-1, occludin, and ZO-1. At the same time, stevioside significantly down-regulated the secretion and gene expression of IL-6, IL-8, and TNF-α and decreased the phosphorylation levels of NF-κB, IκB, and ERK1/2 compared with the diquat alone group. Taken together, this study demonstrated that stevioside alleviated diquat-stimulated cytotoxicity, inflammation, and apoptosis in IPEC-J2 cells, protecting cellular barrier integrity and mitigating oxidative stress by interfering with the NF-κB and MAPK signaling pathways.

Bazi Bushen capsule attenuates cognitive deficits by inhibiting microglia activation and cellular senescence

CONTEXT

Bazi Bushen capsule (BZBS) has anti-ageing properties and is effective in enhancing memory.

OBJECTIVE

To find evidence supporting the mechanisms and biomarkers by which BZBS functions.

MATERIALS AND METHODS

Male C57BL/6J mice were randomly divided into five groups: normal, ageing, β-nicotinamide mononucleotide capsule (NMN), BZBS low-dose (LD-BZ) and BZBS high-dose (HD-BZ). The last four groups were subcutaneously injected with d-galactose (d-gal, 100 mg/kg/d) to induce the ageing process. At the same time, the LD-BZ, HD-BZ and NMN groups were intragastrically injected with BZBS (1 and 2 g/kg/d) and NMN (100 mg/kg/d) for treatment, respectively. After 60 days, the changes in overall ageing status, brain neuron morphology, expression of p16^INK4a, proliferating cell nuclear antigen (PCNA), ionized calcium-binding adapter molecule 1 (Iba1), postsynaptic density protein 95 (PSD95), CD11b, Arg1, CD206, Trem2, Ym1 and Fizz1, and the senescence-associated secretory phenotype (SASP) factors were observed.

RESULTS

Compared with the mice in the ageing group, the HD-BZ mice exhibited obvious improvements in strength, endurance, motor coordination, cognitive function and neuron injury. The results showed a decrease in p16^INK4a, Iba1 and the upregulation of PCNA, PSD95 among brain proteins. The brain mRNA exhibited downregulation of Iba1 (p < 0.001), CD11b (p < 0.001), and upregulation of Arg1 (p < 0.01), CD206 (p < 0.05), Trem2 (p < 0.001), Ym1 (p < 0.01), Fizz1 (p < 0.05) and PSD95 (p < 0.01), as well as improvement of SASP factors.

CONCLUSIONS

BZBS improves cognitive deficits via inhibition of cellular senescence and microglia activation. This study provides experimental evidence for the wide application of BZBS in clinical practice for cognitive deficits.

Anti-oxidative and anti-inflammatory activities of the ethanol extract of edible flower from Chimonanthus praecox

Chimonanthi Praecocis Flos, namely wintersweet flower, is the edible flower or flower bud of Chimonanthus praecox (L.) Link which is a deciduous shrub plant originated from China and is widely cultivated as a garden or ornamental plant all over the world. However, few studies focused on its anti-inflammatory property. In the present study, we explored the anti-inflammatory and anti-oxidative activities of ethanol extract of Chimonanthi Praecocis Flos (CPE) which contained 7.980% ± 0.176% total flavonoids and 1.461% ± 0.041% total alkaloids. In LPS-stimulated RAW264.7 macrophages, CPE significantly decreased the production of NO and prostaglandin E₂ (PGE₂) through reducing the expressions of their synthases—inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). It also suppressed the transcription and translation of pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-6 (IL-6). Further research revealed that CPE impeded the phosphorylation and degradation of IκBα, thus restraining the nuclear translocation of p65, and consequently dampening NF-κB signaling. In endotoxemia mice, several pro-inflammatory cytokines in serum were also decreased after CPE treatment. Besides anti-inflammatory activity, anti-oxidative activity is another important capacity of wintersweet flower. Indeed, CPE reduced LPS-elevated intracellular total reactive oxygen species (ROS) level by weakening NADPH oxidase activity in cell system. Moreover, it directly scavenged DPPH radical and superoxide anion, and exerted ferric reducing ability in cell-free system. Our findings demonstrate that wintersweet flower can be used as a beneficial natural product or an additive by virtue of its anti-oxidative and anti-inflammatory properties.

Anti-aging effects and mechanisms of anthocyanins and their intestinal microflora metabolites

Aging, a natural and inevitable physiological process, is the primary risk factor for all age-related diseases; it severely threatens the health of individuals and places a heavy burden on the public health-care system. Thus, strategies to extend the lifespan and prevent and treat age-related diseases have been gaining increasing scientific interest. Anthocyanins (ACNs) are a subclass of flavonoids widely distributed in fruits and vegetables. Growing evidence suggests that ACNs delay aging and relieve age-related diseases. However, owing to the low bioavailability of ACNs, their gut metabolites have been proposed to play a critical role in mediating health benefits. In this review, we introduce the biological fate of ACNs after consumption and highlight ACNs metabolites (phenolic acids) from intestinal microorganisms. Additionally, ACNs and gut metabolites exhibit outstanding anti-aging ability in Caenorhabditis elegans, Drosophila melanogaster, and mouse models, probably associated with increasing antioxidation, anti-inflammation, protein homeostasis, antiglycation, mitochondrial function, and inhibition of insulin/IGF-1 signaling (IIS). ACNs and gut metabolites have great application prospects as functional foods and drugs to delay aging and manage age-related diseases. Further investigation should focus on the interaction between ACNs and gut microbiota, including clarifying the complex metabolic pathway and maximizing the health effects of ACNs.

Ganoderic acid D prevents oxidative stress-induced senescence by targeting 14-3-3ε to activate CaM/CaMKII/NRF2 signaling pathway in mesenchymal stem cells

Stem cell senescence is an important cause of aging. Delaying senescence may present a novel way to combat aging and age-associated diseases. This study provided a mechanistic insight into the protective effect of ganoderic acid D (GA-D) against human amniotic mesenchymal stem cell (hAMSCs) senescence. GA-D, a Ganoderma lucidum-derived triterpenoid, markedly prevented hAMSCs senescence via activating the Ca²⁺ calmodulin (CaM)/CaM-dependent protein kinase II (CaMKII)/nuclear erythroid 2-related factor 2 (Nrf2) axis, and 14-3-3ε was identified as a target of GA-D. 14-3-3ε-encoding gene (YWHAE) knockdown in hAMSCs reversed the activation of the CaM/CaMKII/Nrf2 signals to attenuate the GA-D anti-aging effect and increase senescence-associated β-galactosidase (SA-β-gal), p16 and p21 expression levels, including reactive oxygen species (ROS) production, thereby promoting cell cycle arrest and decreasing differentiation potential. YWHAE overexpression maintained or slightly enhanced the GA-D anti-aging effect. GA-D prevented d-galactose-caused aging in mice by significantly increasing the total antioxidant capacity, as well as superoxide dismutase and glutathione peroxidase activity, and reducing the formation of malondialdehyde, advanced glycation end products, and receptor of advanced glycation end products. Consistent with the protective mechanism of GA-D against hAMSCs senescence, GA-D delayed the senescence of bone-marrow mesenchymal stem cells in this aging model in vivo, reduced SA-β-gal and ROS production, alleviated cell cycle arrest, and enhanced cell viability and differentiation via regulating 14-3-3ε and CaM/CaMKII/Nrf2 axis. Therefore, GA-D retards hAMSCs senescence by targeting 14-3-3ε to activate the CaM/CaMKII/Nrf2 signaling pathway. Furthermore, the in vivo GA-D anti-aging effect may involve the regulation of stem cell senescence via the same signal axis.

γ-Glutamylcysteine ameliorates D-gal-induced senescence in PC12 cells and mice via activating AMPK and SIRT1

Aging is a natural process accompanied by inflammation and oxidative stress and is closely associated with age-related diseases. As a direct precursor of glutathione, γ-glutamylcysteine (γ-GC) possesses antioxidant and anti-inflammatory properties; however, whether γ-GC plays an important role in anti-aging remains unknown. Here, we investigated the protective effects and mechanisms of γ-GC in D-galactose (D-gal)-induced senescence in PC12 cells and aging mice. Our results showed that γ-GC treatment significantly reduced the percentage of senescence-associated-β-galactosidase (SA-β-Gal)-positive cells and inhibited D-gal-induced cell cycle arrest in PC12 cells. The results of Nissl and hematoxylin and eosin (H&E) staining in mouse brain showed that γ-GC treatment markedly reversed the damage in the hippocampus of D-gal-induced aging mice. Moreover, γ-GC increased the phosphorylation of AMP-activated protein kinase (AMPK) to promote the nuclear translocation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) while inhibiting the nuclear translocation of deleted in breast cancer 1 (DBC1), which leads to the activation of sirtuin 1 (SIRT1) and deacetylation of p53 in the nucleus. Therefore, γ-GC may be a potential therapeutic candidate compound for the prevention and treatment of age-related diseases.

Mulberry polyphenol extracts attenuated senescence through inhibition of Ras/ERK via promoting Ras degradation in VSMC

Ageing is one of the major risk factors of human diseases, including cancer, diabetes, and cardiovascular disease. Mulberry exhibits a wide range of functions, such as anti-oxidant, anti-inflammation, and anti-diabetes. In this study, we investigated the role of mulberry polyphenol extract (MPE) in K-Ras-induced senescence of smooth muscle cells. Forced expression of K-Ras enhanced senescence of smooth muscle A7r5 cells as shown by the elevation of β-galactosidase activity. Treatment with MPE significantly repressed the Ras, phosphorylated ERK, and β-galactosidase level. MPE triggered the association of cyclins with their corresponding cyclin-dependent protein kinases and hyperphosphorylated retinoblastoma (RB). MPE also down-regulated the levels of K-Ras-induced CDK inhibitors. MPE enhanced the phosphorylated AMP-dependent protein kinase (AMPK) and inducible nitric oxide synthase (iNOS) level in the presence of K-Ras. Pretreatment with either L-NAME or AMPK inhibitor reversed the effects of MPE. In addition, L-NAME and AMPK inhibitor repressed the MPE-induced total and phosphorylated 3-hydroxy-3-methylglutaryl coenzyme A (HMG-Co A) level. MPE repressed K-Ras-induced G0/G1 arrest, whereas L-NAME and AMPK inhibitor blocked the effects of MPE. Our results indicated that MPE recovered the K-Ras-induced senescence of vascular smooth muscle cells through iNOS and AMPK-dependent pathway. Our findings suggested that MPE may prevent ageing-induced atherosclerosis.

Licochalcone D Ameliorates Oxidative Stress-Induced Senescence via AMPK Activation

Increased oxidative stress is a crucial factor for the progression of cellular senescence and aging. The present study aimed to investigate the effects of licochalcone D (Lico D) on oxidative stress-induced senescence, both in vitro and in vivo, and explore its potential mechanisms. Hydrogen peroxide (200 µM for double time) and D-galactose (D-Gal) (150 mg/kg) were used to induce oxidative stress in human bone marrow-mesenchymal stem cells (hBM-MSCs) and mice, respectively. We performed the SA-β-gal assay and evaluated the senescence markers, activation of AMPK, and autophagy. Lico D potentially reduced oxidative stress-induced senescence by upregulating AMPK-mediated activation of autophagy in hBM-MSCs. D-Gal treatment significantly increased the expression levels of senescence markers, such as p53 and p21, in the heart and hippocampal tissues, while this effect was reversed in the Lico D-treated animals. Furthermore, a significant increase in AMPK activation was observed in both tissues, while the activation of autophagy was only observed in the heart tissue. Interestingly, we found that Lico D significantly reduced the expression levels of the receptors for advanced glycation end products (RAGE) in the hippocampal tissue. Taken together, our findings highlight the antioxidant, anti-senescent, and cardioprotective effects of Lico D and suggest that the activation of AMPK and autophagy ameliorates the oxidative stress-induced senescence.

D-galactose-induced liver aging model: Its underlying mechanisms and potential therapeutic interventions

Aging is associated with a variety of morphological and functional changes in the liver. Oxidative stress and inflammation are now widely accepted as the main mechanisms involved in the aging process that may subsequently cause severe injury to mitochondrial DNA which leads to apoptosis. As aging may increase the risks for various liver diseases and plays as an adverse prognostic factor increasing the mortality rate, knowledge regarding the mechanisms of age-related liver susceptibility and the possible therapeutic interventions is imperative. Due to cost and time constraints, a mimetic aging model is generally preferred to naturally aged animals to study the underlying mechanisms of aging liver. The use of D-galactose in aging research is dated back to 1962 and has since been used widely. This review aims to comprehensively summarize the effects of D-galactose-induced aging on the liver and the underlying mechanisms involved. Its potential therapeutic interventions are also discussed. It is hoped that this invaluable information may facilitate researchers in choosing the appropriate aging model and provide a valuable platform for testing potential therapeutic strategies for the prevention and treatment of age-related liver diseases.

Skeletal Aging and Osteoporosis: Mechanisms and Therapeutics

Bone is a dynamic organ maintained by tightly regulated mechanisms. With old age, bone homeostasis, which is maintained by an intricate balance between bone formation and bone resorption, undergoes deregulation. Oxidative stress-induced DNA damage, cellular apoptosis, and cellular senescence are all responsible for this tissue dysfunction and the imbalance in the bone homeostasis. These cellular mechanisms have become a target for therapeutics to treat age-related osteoporosis. Genetic mouse models have shown the importance of senescent cell clearance in alleviating age-related osteoporosis. Furthermore, we and others have shown that targeting cellular senescence pharmacologically was an effective tool to alleviate age- and radiation-induced osteoporosis. Senescent cells also have an altered secretome known as the senescence associated secretory phenotype (SASP), which may have autocrine, paracrine, or endocrine function. The current review discusses the current and potential pathways which lead to a senescence profile in an aged skeleton and how bone homeostasis is affected during age-related osteoporosis. The review has also discussed existing therapeutics for the treatment of osteoporosis and rationalizes for novel therapeutic options based on cellular senescence and the SASP as an underlying pathogenesis of an aging bone.

Impaired Cognitive Flexibility Induced by Chronic Cerebral Hypoperfusion in the 5XFAD Transgenic Mouse Model of Mixed Dementia

Cerebrovascular lesions are widely prevalent in patients with Alzheimer’s disease (AD), but their relationship to the pathophysiology of AD remains poorly understood. An improved understanding of the interaction of cerebrovascular damage with AD is crucial for the development of therapeutic approaches. Herein, we investigated the effects of chronic cerebral hypoperfusion (CCH) in a 5XFAD transgenic (Tg) mouse model of AD. We established CCH conditions in both Tg and non-Tg mice by inducing unilateral common carotid artery occlusion (UCCAO). Cognitive performance in mice was evaluated, and their brain tissue was examined for amyloid-beta (Aβ) pathology to elucidate possible mechanisms. We found that UCCAO-operated Tg mice showed impaired cognitive flexibility in the reversal phase of the hidden-platform water maze task compared to sham-operated Tg mice. Interestingly, UCCAO-operated Tg mice used fewer spatial cognitive strategies than sham-operated Tg mice during reversal learning. These cognitive deficits were accompanied by increased Aβ plaque burden and Aβ42 levels in the hippocampus and prefrontal cortex, 2 regions that play essential roles in the regulation of cognitive flexibility. Furthermore, changes in cognitive flexibility are strongly correlated with the expression levels of enzymes related to Aβ clearance, such as neprilysin and insulin-degrading enzymes. These findings suggest that, in 5XFAD mice, impaired cognitive flexibility is related to CCH, and that Aβ clearance might be involved in this process.