Autophagy in vascular dementia and natural products with autophagy regulating activity

Didang decoction improves gut microbiota and cognitive function in TDACD rats: Combined proteomics and 16S rRNA sequencing

BACKGROUND

Type 2 diabetes mellitus (T2DM) significantly elevates the risk of cognitive impairment. Didang Decoction (DDD), a classical Traditional Chinese Medicine (TCM) formula, has shown promise in alleviating diabetic symptoms and improving cognitive performance. Although historical TCM records suggest neuroprotective properties, ​the mechanistic basis for DDD's therapeutic effects on T2DM-associated cognitive dysfunction (TDACD) remains unexplored.

PURPOSE

This work sought to clarify the chemical composition and mechanisms of action of DDD by pursuing three primary objectives: (1) identification of the major active constituents of DDD; (2) validating of the hypothesis that DDD ameliorates TDACD via regulation of the gut microbiota; and (3) investigating DDD's regulatory effects on hippocampal lipid metabolism and autophagy pathways.

METHODS

Ultra-high performance liquid chromatography-Q exactive mass spectrometry (UHPLC-QE-MS/MS) was employed to analyze the chemical composition of DDD. Cognitive function was assessed through behavioral tests. Histopathological examinations and western blotting (WB) were conducted to assess the effects of DDD on the hippocampus of TDACD rats. 16S ribosomal RNA (16S rRNA) sequencing was conducted to characterize gut microbiota, composition, and proteomics was used to evaluate hippocampal proteins expression.

RESULTS

The major bioactive components of DDD were identified, including dihydrotanshinone I, aloe-emodin, chrysophanol, calycosin, sakuranetin, gallic acid, kaempferol, and rhein, emodin, etc. DDD increased neuronal density and synaptic function in the hippocampus of TDACD rats, hereby improving working memory and long-term memory. DDD boosted the relative abundance of beneficial bacteria, including Roseburia, [Eubacterium] coprostanoligenes group, Christensenellaceae R-7 group, and Alistipes, which were diminished in the TDACD group. Proteomics analysis indicated that DDD enhanced hippocampal energy metabolism and reduced neuronal damage in TDACD rats via pathways related to cholesterol and fatty acid metabolism, as well as autophagy.

CONCLUSIONS

DDD demonstrates potential as an adjuvant therapeutic agent for TDACD, with dual benefits in ameliorating glucose metabolism and cognitive impairments. Mechanistically, the neuroprotective effects of DDD are attributed to the regulation of hippocampal lipid energy metabolism and autophagic homeostasis, as well as the enhancement of beneficial gut microbes.

Danggui-Shaoyao-San (DSS) ameliorating cognitive impairment in ischemia-reperfusion vascular dementia mice through miR-124 regulating PI3K/Akt signaling pathway

Vascular dementia (VD) is a disease characterized by cognitive impairment and memory loss due to brain cell damage caused by cerebral vascular ischemia. Danggui-Shaoyao-San (DSS) has been used clinically to treat diseases for centuries. The VD model was established by bilateral common carotid artery (BCCA) repeated ischemia-reperfusion (I/R) and caudal bleeding. Target prediction of DSS and miR-124 in PI3K/Akt signaling pathway by network pharmacology. The effect of DSS on cognitive dysfunction were evaluated through methods such as behavioral experiments, cerebral blood flow monitoring, HE and Nissl staining, western blot, and q-PCR. Prediction result showed that both DSS and miR-124 could target Akt1. DSS treatment significantly reduced hippocampal cell damage, improved learning and memory ability. Mechanically, DSS treatment up-regulated the expression levels of PI3K and Akt protein, and its gene. Bcl-2/Bax index is up-regulated and cell apoptosis reduced. LC3II/LC3I index decreased and autophagy of brain cells increased. Moreover, DSS down-regulated the expression level of miR-124. And inhibition of miR-124 up-regulate the expression of PI3K, Akt. These results suggested that DSS can reduce the content of miR-124 in the hippocampus of VD mice, thus regulating the PI3K/Akt signaling pathway and improving the learning and memory ability of VD mice.

Tong-Qiao-Huo-Xue Decoction promotes synaptic remodeling via cAMP/PKA/CREB pathway in vascular dementia rats

BACKGROUND

Tong-Qiao-Huo-Xue Decoction (TQHXD) is a traditional Chinese medicinal formula widely used in the treatment of vascular dementia (VD). Although it has demonstrated good clinical efficacy, the specific molecular mechanisms underlying its therapeutic effects on VD remain unclear.

OBJECTIVE

This study aimed to elucidate the neuroprotective mechanisms of TQHXD to provide a scientific basis for the clinical treatment of VD.

METHODS

The chemical components of TQHXD were qualitatively analyzed using ultra-performance liquid chromatography (UPLC) and gas chromatography (GC). Network pharmacology predicted the potential protective mechanisms of TQHXD against VD. A rat model of VD was established through bilateral vessel occlusion (2-VO), and an oxygen-glucose deprivation/reperfusion (OGD/R) model was used to induce damage to neuronal cells of the hippocampus. In vivo experiments assessed changes in cerebral blood flow, learning and memory capabilities, hippocampal neuronal morphology, dendritic length, dendritic spine density, and synapse number in rats. We examined the expression of synaptic remodeling-related proteins and pathway proteins in the hippocampal region. In vitro assays evaluated cell viability, apoptosis, reactive oxygen species (ROS) levels, and expression of synaptic remodeling-related proteins and signaling pathway.

RESULTS

Multiple active components were identified in TQHXD. KEGG enrichment analysis suggested that the therapeutic effects of TQHXD on VD may be related to the cAMP signaling pathway. Treatment with TQHXD significantly improved learning and memory performance in VD rats, improved hippocampus morphology, and increased dendritic length, dendritic spine density, and number of synapses. Furthermore, TQHXD improved cell viability, reduced apoptosis, and decreased intracellular ROS levels in vitro. Western blotting, immunofluorescence, and enzyme-linked immunosorbent assay results collectively demonstrated that TQHXD upregulated the expression of synaptic remodeling-related proteins and pathway-related proteins both in vivo and in vitro.

CONCLUSIONS

TQHXD treated VD by promoting synaptic remodeling in hippocampal neurons, likely through activation of the cAMP/PKA/CREB pathway.

Identifying shared diagnostic genes and mechanisms in vascular dementia and Alzheimer's disease via bioinformatics and machine learning

Background

Alzheimer's disease (AD) and vascular dementia (VaD) share overlapping pathophysiological characteristics, yet comparative genetic studies are rare. Understanding these overlaps may aid in identifying common diagnostic markers and therapeutic targets.

Objective

This study identifies shared diagnostic genes and mechanisms linking AD and VaD.

Methods

Datasets GSE5281 and GSE122063 from the GEO database were used to identify differentially expressed genes (DEGs). Intersection DEGs were analyzed using KEGG and GO enrichment to explore signaling pathways. A PPI network was constructed, and LASSO and SVM-RFE were applied to identify core genes. CIBERSORT assessed immune cell composition and their relationship with core genes. Diagnostic efficacy was evaluated using ROC curves, nomogram, and Decision Curve Analysis (DCA). Core genes were used to identify characteristic genes in various brain regions of AD patients.

Results

The analysis identified 9021 DEGs for AD and 373 DEGs for VaD, with 74 co-expressed genes and 8 core genes. ROC curves, nomogram, and DCA indicated high diagnostic accuracy. Core gene analysis revealed differential expression of characteristic genes in various brain regions of AD patients.

Conclusions

This research identified 74 co-expressed genes and 8 pivotal diagnostic genes. These genes likely play roles in signal transduction, neuroinflammation, and autophagy in both AD and VaD. The findings offer potential targets for future research and clinical interventions. Further research should use larger, more diverse datasets and incorporate custom NGS panels to identify novel genetic variants, enhancing precise diagnostic and therapeutic strategies.

Exploring the therapeutic implications of natural compounds modulating apoptosis in vascular dementia

Vascular dementia (VaD) is a prevalent form of dementia stemming from cerebrovascular disease, manifesting in memory impairment and executive dysfunction, thereby imposing a substantial societal burden. Unfortunately, no drugs have been approved for the treatment of VaD due to its intricate pathogenesis, and the development of innovative and efficacious medications is urgently needed. Apoptosis, a programmed cell death process crucial for eliminating damaged or unwanted cells within an organism, assumes pivotal roles in embryonic development and tissue homeostasis maintenance. An increasing body of evidence indicates that apoptosis may significantly influence the onset and progression of VaD, and numerous natural compounds have demonstrated significant therapeutic potential. Here, we discuss the molecular mechanisms underlying apoptosis and its correlation with VaD. We also provide a crucial reference for developing innovative pharmaceuticals by systematically reviewing the latest research progress concerning the neuroprotective effects of natural compounds on VaD by regulating apoptosis. Further high-quality clinical studies are imperative to firmly ascertain these natural compounds' clinical efficacy and safety profiles in the treatment of VaD.

Nicotinamide riboside alleviates brain dysfunction induced by chronic cerebral hypoperfusion via protecting mitochondria

Chronic cerebral hypoperfusion (CCH) is an enduring inadequate blood flow to the brain, resulting in vascular dementia (VaD). However, the effective treatment strategies are lacking. Supplementing with nicotinamide adenine dinucleotide (NAD+) has shown neuroprotective benefits in other neurodegenerative disorders. Nicotinamide riboside (NR), as a precursor of NAD+, is believed to hold promise in improving mitochondrial health, autophagy, and cognitive function. Meanwhile, NR has unique oral bioavailability, good tolerability, and minimal side effects, and it is the most promising for clinical translation. However, the effectiveness of NR in treating CCH-related VaD is still uncertain. The present study examined the neuroprotective effects of NR supplementation and its underlying mechanisms in a CCH rat model. The rats with CCH were given NR at a daily dosage of 400 mg/kg for 3 months. NR supplementation increased blood and brain NAD+ levels and improved brain function in CCH rats, including cognitive function and oxygenation capacity. It also reduced hippocampal neuronal loss and abnormalities and mitigated the decrease in dendritic spine density. The analysis of RNA sequencing in hippocampal tissue supports these findings. Electron microscopy and protein detection results suggest that NR may maintain mitochondrial structural integrity and exert a protective role by attenuating mitochondrial fission and impaired autophagy flux caused by CCH. In conclusion, these findings offer evidence for the neuroprotective potential of NR supplementation in ameliorating cognitive impairment induced by CCH.

Latest advances and clinical application prospects of resveratrol therapy for neurocognitive disorders

Neurocognitive disorders, such as Alzheimer's disease, vascular dementia, and postoperative cognitive dysfunction, are non-psychiatric brain syndromes in which a significant decline in cognitive function causes great trauma to the mental status of the patient. The lack of effective treatments for neurocognitive disorders imposes a considerable burden on society, including a substantial economic impact. Over the past few decades, the identification of resveratrol, a natural plant compound, has provided researchers with an opportunity to formulate novel strategies for the treatment of neurocognitive disorders. This is because resveratrol effectively protects the brain of those with neurocognitive disorders by targeting some mechanisms such as inflammation and oxidative stress. This article reviews the status of recent research investigating the use of resveratrol for the treatment of different neurocognitive disorders. By examining the possible mechanisms of action of resveratrol and the shared mechanisms of different neurocognitive disorders, treatments for neurocognitive disorders may be further clarified.

Baicalin alleviates angiotensin II-induced cardiomyocyte apoptosis and autophagy and modulates the AMPK/mTOR pathway

As a main extraction compound from Scutellaria baicalensis Georgi, Baicalin exhibits various biological activities. However, the underlying mechanism of Baicalin on hypertension-induced heart injury remains unclear. In vivo, mice were infused with angiotensin II (Ang II; 500 ng/kg/min) or saline using osmotic pumps, followed by intragastrically administrated with Baicalin (5 mg/kg/day) for 4 weeks. In vitro, H9C2 cells were stimulated with Ang II (1 μM) and treated with Baicalin (12.5, 25 and 50 μM). Baicalin treatment significantly attenuated the decrease in left ventricular ejection fraction and left ventricular fractional shortening, increase in left ventricular mass, left ventricular systolic volume and left ventricular diastolic volume of Ang II infused mice. Moreover, Baicalin treatment reversed 314 differentially expressed transcripts in the cardiac tissues of Ang II infused mice, and enriched multiple enriched signalling pathways (including apoptosis, autophagy, AMPK/mTOR signalling pathway). Consistently, Baicalin treatment significantly alleviated Ang II-induced cell apoptosis in vivo and in vitro. Baicalin treatment reversed the up-regulation of Bax, cleaved-caspase 3, cleaved-caspase 9, and the down-regulation of Bcl-2. Meanwhile, Baicalin treatment alleviated Ang II-induced increase of autophagosomes, restored autophagic flux, and down-regulated LC3II, Beclin 1, as well as up-regulated SQSTM1/p62 expression. Furthermore, autophagy inhibitor 3-methyladenine treatment alleviated the increase of autophagosomes and the up-regulation of Beclin 1, LC3II, Bax, cleaved-caspase 3, cleaved-caspase 9, down-regulation of SQSTM1/p62 and Bcl-2 expression after Ang II treated, which similar to co-treatment with Baicalin. Baicalin treatment reduced the ratio of p-AMPK/AMPK, while increased the ratio of p-mTOR/mTOR. Baicalin alleviated Ang II-induced cardiomyocyte apoptosis and autophagy, which might be related to the inhibition of the AMPK/mTOR pathway.

Enriched environment ameliorates fear memory impairments induced by sleep deprivation via inhibiting PIEZO1/calpain/autophagy signaling pathway in the basal forebrain

AIMS

To verify the hypothesis that an enriched environment (EE) alleviates sleep deprivation-induced fear memory impairment by modulating the basal forebrain (BF) PIEZO1/calpain/autophagy pathway.

METHODS

Eight-week-old male mice were housed in a closed, isolated environment (CE) or an EE, before 6-h total sleep deprivation. Changes in fear memory after sleep deprivation were observed using an inhibitory avoidance test. Alterations in BF PIEZO1/calpain/autophagy signaling were detected. The PIEZO1 agonist Yoda1 or inhibitor GsMTx4, the calpain inhibitor PD151746, and the autophagy inducer rapamycin or inhibitor 3-MA were injected into the bilateral BF to investigate the pathways involved in the memory-maintaining role of EE in sleep-deprived mice.

RESULTS

Mice housed in EE performed better than CE mice in short- and long-term fear memory tests after sleep deprivation. Sleep deprivation resulted in increased PIEZO1 expression, full-length tropomyosin receptor kinase B (TrkB-FL) degradation, and autophagy, as reflected by increased LC3 II/I ratio, enhanced p62 degradation, increased TFEB expression and nuclear translocation, and decreased TFEB phosphorylation. These molecular changes were partially reversed by EE treatment. Microinjection of Yoda1 or rapamycin into the bilateral basal forebrain induced excessive autophagy and eliminated the cognition-protective effects of EE. Bilateral basal forebrain microinjection of GsMTx4, PD151746, or 3-MA mimicked the cognitive protective and autophagy inhibitory effects of EE in sleep-deprived mice.

CONCLUSIONS

EE combats sleep deprivation-induced fear memory impairments by inhibiting the BF PIEZO1/calpain/autophagy pathway.

β-asarone improves cognitive impairment and alleviates autophagy in mice with vascular dementia via the cAMP/PKA/CREB pathway

BACKGROUND

Vascular dementia (VD) is the second most common type of dementia after Alzheimer's disease. β-asarone, a major component of Acorus tatarinowii Schott, is important in neurodegenerative and neurovascular diseases. Studies have confirmed that β-asarone can mitigate autophagy and reduce damage in hypoxic cells. We also reported that β-asarone improves learning and memory. This study further clarifies whether β-asarone attenuates cerebral ischaemic injury by acting through the cAMP/PKA/CREB pathway in VD model mice.

METHODS

Here, genes and potential pathways that may be targeted by β-asarone for the treatment of transient cerebral ischaemia (TCI) and cognitive impairment (CI) were obtained using network pharmacology. The two-vessel occlusion method was used to establish the VD model. The Morris water maze test was used to evaluate the effects on memory. Then, the protein levels of mitofusin-2 (Mfn2), brain-derived neurotrophic factor (BDNF), optic atrophy 1 (OPA1), cyclic adenosine monophosphate (cAMP), myelin basic protein (MBP), matrix metalloproteinase-9 (MMP9) and neuron specific enolase (NSE) were determined by ELISA. The levels of superoxide dismutase (SOD) and malonaldehyde (MDA) were measured using commercial kits. Then, qRT-PCR was employed to investigate the expression of the candidate genes screened from the protein-protein interaction (PPI) network. Furthermore, the expression of the autophagy-related proteins Beclin-1, (microtubule-associated protein light chain 3) LC3, p62, postsynaptic density protein 95 (PSD95), protein kinase A (PKA), pPKA, cyclic-AMP response binding protein (CREB), and pCREB was determined by western blotting. The expression of autophagy-related proteins, PSD95 and translocase of outer mitochondrial membrane 20 (TOM20) was determined by immunofluorescence analyses.

RESULTS

The network pharmacological analysis showed 234 targets related to β-asarone, 1,118 genes related to TCI and 2,039 genes associated with CI. Our results confirm that β-asarone treatment not only alleviated brain damage in the VD model by improving mitochondrial and synaptic function, reducing neuronal injury and upregulating the expression of antioxidants but also effectively improved the cognitive behaviour of VD model mice. Moreover, β-asarone downregulated VD-induced RELA and CCND1 mRNA expression. In addition, we validated that β-asarone increased the phosphorylation of PKA and CREB and upregulated cAMP protein expression. The results showed that the cAMP/PKA/CREB signalling pathway was upregulated. Moreover, β-asarone administration decreased the protein expression levels of Beclin-1 and LC3 and increased the expression levels of p62 in VD model mice.

CONCLUSIONS

β-asarone inhibits Beclin-1-dependent autophagy and upregulates the cAMP/PKA/CREB signalling pathway to attenuate mitochondrial and synaptic damage from cerebral ischaemia and improve learning and cognitive abilities in VD model mice.

Combined VEGF and bFGF loaded nanofiber membrane protects against neuronal injury and hypomyelination in a rat model of chronic cerebral hypoperfusion

Currently, there are no effective therapeutic targets for the treatment of chronic cerebral hypoperfusion(CCH)-induced cerebral ischemic injury. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are discovered as the inducers of neurogenesis and angiogenesis. We previously made a nanofiber membrane (NFM), maintaining a long-term release of VEGF and bFGF up to 35 days, which might make VEGF and bFGF NFM as the potential protective agents against cerebral ischemic insult. In this study, the effects of VEGF and bFGF delivered by NFM into brain were investigated as well as their underlying mechanismsin a rat model of CCH. VEGF + bFGF NFM application increased the expressions of tight junction proteins, maintained BBB integrity, and alleviated vasogenic cerebral edema. Furthermore, VEGF + bFGF NFM sticking enhanced angiogenesis and elevated CBF. Besides, VEGF + bFGF NFM treatment inhibited neuronal apoptosis and decreased neuronal loss. Moreover, roofing of VEGF + bFGF NFM attenuated microglial activation and blocked the launch of NLRP3/caspase-1/IL-1β pathway. In addition, VEGF + bFGF NFM administration prevented disruption to the pre/postsynaptic membranes and loss of myelin sheath, relieving synaptic injury and demyelination. Oligodendrogenesis, neurogenesis and PI3K/AKT/mTOR pathway were involved in the treatment of VEGF + bFGF NFM against CCH-induced neuronal injury and hypomyelination. These findings supported that VEGF + bFGF NFM application constitutes a neuroprotective strategy for the treatment of CCH, which may be worth further clinical translational research as a novel neuroprotective approach, benifiting indirect surgical revascularization.

Gastrodin relieves cognitive impairment by regulating autophagy via PI3K/AKT signaling pathway in vascular dementia

Vascular dementia (VaD), the second most common type of dementia, is attributed to lower cerebral blood flow. To date, there is still no available clinical treatment for VaD. The phenolic glucoside gastrodin (GAS) is known for its neuroprotective effects, but the role and mechanisms of action on VD remains unclear. In this study, we aim to investigate the neuroprotective role and underlying mechanisms of GAS on chronic cerebral hypoperfusion (CCH)-mediated VaD rats and hypoxia-induced injury of HT22 cells. The study showed that GAS relieved learning and memory deficits, ameliorated hippocampus histological lesions in VaD rats. Additionally, GAS down-regulated LC3II/I, Beclin-1 levels and up-regulated P62 level in VaD rats and hypoxia-injured HT22 cells. Notably, GAS rescued the phosphorylation of PI3K/AKT pathway-related proteins expression, which regulates autophagy. Mechanistic studies verify that YP-740, a PI3K agonist, significantly resulted in inhibition of excessive autophagy and apoptosis with no significant differences were observed in the YP-740 and GAS co-treatment. Meantime, we found that LY294002, a PI3K inhibitor, substantially abolished GAS-mediated neuroprotection. These results revealed that the effects of GAS on VaD are related to stimulating PI3K/AKT pathway-mediated autophagy, suggesting a potentially beneficial therapeutic strategy for VaD.

Neuroprotective Strategies for Stroke by Natural Products: Advances and Perspectives

Cerebral ischemic stroke is a disease with high prevalence and incidence. Its management focuses on rapid reperfusion with intravenous thrombolysis and endovascular thrombectomy. Both therapeutic strategies reduce disability, but the therapy time window is short, and the risk of bleeding is high. Natural products (NPs) have played a key role in drug discovery, especially for cancer and infectious diseases. However, they have made little progress in clinical translation and pose challenges to the treatment of stroke. Recently, with the investigation of precise mechanisms in cerebral ischemic stroke and the technological development of NP-based drug discovery, NPs are addressing these challenges and opening up new opportunities in cerebral stroke. Thus, in this review, we first summarize the structure and function of diverse NPs, including flavonoids, phenols, terpenes, lactones, quinones, alkaloids, and glycosides. Then we propose the comprehensive neuroprotective mechanism of NPs in cerebral ischemic stroke, which involves complex cascade processes of oxidative stress, mitochondrial damage, apoptosis or ferroptosis-related cell death, inflammatory response, and disruption of the blood-brain barrier (BBB). Overall, we stress the neuroprotective effect of NPs and their mechanism on cerebral ischemic stroke for a better understanding of the advances and perspective in NPs application that may provide a rationale for the development of innovative therapeutic regimens in ischemic stroke.

A New Therapeutic Trend: Natural Medicine for Ameliorating Ischemic Stroke via PI3K/Akt Signaling Pathway

Ischemic stroke (IS) is an acute cerebrovascular disease caused by sudden arterial occlusion, which is characterized by a high morbidity, mortality, and disability rate. It is one of the most important causes of nervous system morbidity and mortality in the world. In recent years, the search for new medicine for the treatment of IS has become an attractive research focus. Due to the extremely limited time window of traditional medicine treatment, some side effects may occur, and accompanied by the occurrence of adverse reactions, the frequency of exploration with natural medicine is significantly increased. Phosphatidylinositol-3-kinase/Protein kinase B (PI3K/Akt) signaling pathway is a classical pathway for cell metabolism, growth, apoptosis, and other physiological activities. There is considerable research on medicine that treats various diseases through this pathway. This review focuses on how natural medicines (including herbs and insects) regulate important pathophysiological processes such as inflammation, oxidative stress, apoptosis, and autophagy through the PI3K/Akt signaling pathway, and the role it plays in improving IS. We found that many kinds of herbal medicine and insect medicine can alleviate the damage caused by IS through the PI3K/Akt signaling pathway. Moreover, the prescription after their combination can also achieve certain results. Therefore, this review provides a new candidate category for medicine development in the treatment of IS.

Progress in the Mechanism of Autophagy and Traditional Chinese Medicine Herb Involved in Dementia

Dementias is a kind of neurodegenerative disease, which occurs among the aging population. Current therapeutic outcome for dementia is limited. The medical use of herbal plant has a rich history in traditional Chinese medicine practice for thousands of years. Herbal medicine (HM) may provide a positive effect for prevention and treatment in dementia. As an alternative treatment to dementia, there has been a growing interest in HM extracts in scientific community as a result of its promising study results, mainly in animal experiment. At the molecular level, HM extracts trigger autophagy and reduce generation of reactive oxygen species (ROS) while inhibiting inflammation and reduce neurotoxicity. Experiments both in vivo and in vitro have identified certain potential of HM extracts and natural products as an important regulator factor in mediating autophagy, which might contribute to the improvement of dementia. This brief review not only summarizes the mechanism of autophagy in dementia but also offers a general understanding of the therapeutic mechanism of HM extracts in treating dementia and evaluates the potential clinical practice of HM in general.

Dynamic observation of 5-fluorouracil-induced myocardial injury and mitochondrial autophagy in aging rats

Patients treated with 5-fluorouracil (5-FU) can develop rare but potentially severe cardiac effects, including cardiomyopathy, angina pectoris, heart failure and cardiogenic shock. The specific pathologies and underlying mechanisms are yet to be fully understood. The results of previous studies have indicated that mitochondrial autophagy is widely detected in many angiocardiopathies. In the present study, the dynamic changes in the homeostasis of mitochondrial injury and autophagy were observed in rats treated with 5-FU for different durations. A corresponding control group and a 5-FU model group were established in groups of Sprague-Dawley rats aged 2 and 18 months, and the myocardial enzyme levels were determined at different time points. At 2 weeks post-model establishment, cardiac ultrasound and myocardial histological staining were performed, cardiomyocyte apoptosis and myocardial mitochondrial function were assessed, and mitochondrial ultrastructure was examined. In addition, the expression levels of autophagy-related proteins were evaluated in the 18-month-old rats on days 7 and 14 of 5-FU administration. The experimental results demonstrated that 5-FU induced an elevation in the levels of myocardial enzymes, as well as changes in the cardiac structure and function, and that these changes were more prominent over longer drug durations. In addition, 5-FU decreased the levels of myocardial mitochondrial ATP and mitochondrial membrane potential, and aggravated myocardial fibrosis and cardiomyocyte apoptosis compared with those observed in the untreated control group, treated with the same volume of saline as 5-FU in the 5-FU group. These injuries were particularly evident in aging rats. Notably, 5-FU increased the expression levels of myocardial mitochondrial autophagy-related proteins, and electron microscopy revealed a more severe autophagic state in the model groups compared with that in the control groups. In conclusion, 5-FU induced myocardial mitochondrial damage, the degree of which was more severe in aging rats compared with that in young rats. The mitochondrial autophagy induced by 5-FU was excessive, and the degree of autophagy was aggravated with increased 5-FU administration time.