Luteolin protects PC-12 cells from H2O2-induced injury by up-regulation of microRNA-21

UHPLC-MS/MS analysis and protective effects on neurodegenerative diseases of phenolic compounds in different parts of Diospyros kaki L. cv. Mopan

Persimmon (Diospyros kaki L. cv. Mopan.), an important commercial crop belonging to the genus of Diospyros in the Ebenaceae family, is rich in bioactive phenolic compounds. In this study, the phenolic compounds from fruits, leaves, and calyces of persimmon were qualitatively and quantitatively determined by UPLC-Q-Exactive-Orbitrap/MS and UPLC-QqQ-MS/MS, respectively. Furthermore, the role of phenolic extract from different parts of persimmon on neuroprotective activity in vitro, through against oxidative stress and anti-neuroinflammation effect was firstly evaluated. The results showed that 75 phenolic compounds, and 3 other kinds of compounds were identified, among which 44 of phenolic compounds were quantified from different parts of persimmon. It is the first time that epicatechin-epigallocatechin, catechin-epigallocatechin, catechin-epigallocatechin (A-type), and glycoside derivatives of laricitrin were identified in persimmon extract. The dominated phenolic compounds in three parts of persimmon were significantly different. All phenolic extracts from each part of persimmon showed strong neuroprotective activities against H2O2-induced oxidative stress in PC-12 cells and LPS-induced BV2 cells. The fruit extract presented the strongest activity, followed by calyx and leaf extract. The systematic knowledge on the phytochemical composition along with activity evaluation of different parts of persimmon could contribute to their targeted selection and development.

Enhancement of porcine in vitro embryonic development through luteolin-mediated activation of the Nrf2/Keap1 signaling pathway

BACKGROUND

Oxidative stress, caused by an imbalance in the production and elimination of intracellular reactive oxygen species (ROS), has been recognized for its detrimental effects on mammalian embryonic development. Luteolin (Lut) has been documented for its protective effects against oxidative stress in various studies. However, its specific role in embryonic development remains unexplored. This study aims to investigate the influence of Lut on porcine embryonic development and to elucidate the underlying mechanism.

RESULTS

After undergoing parthenogenetic activation (PA) or in vitro fertilization, embryos supplemented with 0.5 µmol/L Lut displayed a significant enhancement in cleavage and blastocyst formation rates, with an increase in total cell numbers and a decrease in the apoptosis rate compared to the control. Measurements on D2 and D6 revealed that embryos with Lut supplementation had lower ROS levels and higher glutathione levels compared to the control. Moreover, Lut supplementation significantly augmented mitochondrial content and membrane potential. Intriguingly, activation of the Nrf2/Keap1 signaling pathway was observed in embryos supplemented with Lut, leading to the upregulation of antioxidant-related gene transcription levels. To further validate the relationship between the Nrf2/Keap1 signaling pathway and effects of Lut in porcine embryonic development, we cultured PA embryos in a medium supplemented with brusatol, with or without the inclusion of Lut. The positive effects of Lut on developmental competence were negated by brusatol treatment.

CONCLUSIONS

Our findings indicate that Lut-mediated activation of the Nrf2/Keap1 signaling pathway contributes to the enhanced production of porcine embryos with high developmental competence, and offers insight into the mechanisms regulating early embryonic development.

Ursolic acid ameliorates traumatic brain injury in mice by regulating microRNA-141-mediated PDCD4/PI3K/AKT signaling pathway

BACKGROUND

Neuronal apoptosis and inflammation are the key pathogenic features of secondary brain injury, which results in the neurological impairment that traumatic brain injury (TBI) patients experience. Ursolic Acid (UA) has been shown to have neuroprotective properties against brain damage, however, detailed mechanisms have not been fully disclosed. Research on brain-related microRNAs (miRNAs) has opened up new possibilities for the neuroprotective treatment of UA by manipulating miRNAs. The present study was designed to investigate the impact of UA on neuronal apoptosis and the inflammatory response in TBI mice.

METHODS

The mice's neurologic condition was assessed using the modified neurological severity score (mNSS) and the learning and memory abilities were assessed using the Morris water maze (MWM). Cell apoptosis, oxidative stress, and inflammation were utilized to examine the impact of UA on neuronal pathological damage. miR-141-3p was selected to evaluate whether UA influences miRNAs in a way that has neuroprotective benefits.

RESULTS

The results showed that UA markedly decreased brain edema and neuronal mortality through oxidative stress and neuroinflammation in TBI mice. Using data from the GEO database, we found that miR-141-3p was considerably downregulated in TBI mice and that this downregulation was reversed by UA treatment. Further studies have shown that UA regulates miR-141-3p expression to exhibit its neuroprotective effect in mouse models and cell injury models. Then, miR-141-3p was discovered to directly target PDCD4 in TBI mice and neurons, a well-known PI3K/AKT pathway regulator in the neurons. Most importantly, the upregulation of phosphorylated (p)-AKT and p-PI3K provided the most compelling evidence that UA reactivated the PI3K/AKT pathway in the TBI mouse model, which was through regulating miR-141-3p.

CONCLUSION

Our findings support the notion that UA can improve TBI by modulating miR-141 mediated PDCD4/PI3K/AKT signaling pathway.

Two new alkaloids from Dendrobium nobile Lindl. exhibited neuroprotective activity, and dendrobine alleviated Aβ1-42 -induced apoptosis by inhibiting CDK5 activation in PC12 cells

Dendrobium nobile Lindl. is registered in the Chinese Pharmacopoeia as a traditional medicine. Phytochemical investigation of the ethanol extract of D. nobile Lindl. stems yielded three alkaloid compounds, including two new compounds dendroxine B (2) and denrine B (3) as well as one known compound dendrobine (1). Here, we identified the structure of these compounds using spectroscopic analyses and compared them with those described in previous studies. Compounds 1-3 were found to show protective effect against amyloid-β 1-42 (Aβ_1-42 )-induced neurotoxicity in rat pheochromocytoma (PC12) cells, among which dendrobine exhibited the most significant neuroprotective effect. Hoechst 33342/propidium iodide staining indicated that dendrobine ameliorated Aβ_1-42 -induced apoptosis. Moreover, quantitative real-time polymerase chain reaction and western blot analysis analysis demonstrated that dendrobine suppressed the activation of cyclin-dependent kinase 5 (CDK5), upregulated Bcl-2 expression, and downregulated Bax, cyto-c, and caspase-3 expression. Molecular docking analysis and surface plasmon resonance assay suggested that dendrobine directly bound to CDK5 protein with a KD value of 2.05 × 10^-4  M. In summary, alkaloids are the neuroprotective constituents of D. nobile Lindl., and dendrobine protected PC12 cells against Aβ_1-42 -induced apoptosis by inhibiting CDK5 activation.

Gentamycin Rationally Repositioned to Inhibit miR-34a Ameliorates Oxidative Injury to PC12 Cells

Ischemic stroke accompanies oxidative stress and cell death in the cerebral tissue. The microRNA miR-34a plays a pivotal role in this molecular pathology. This study presents the rational repositioning of aminoglycosidic antibiotics as miR-34a antagonists in order to assess their efficiency in protecting the PC12 stroke model cells from oxidative stress occurring under cerebral ischemic conditions. A library of 29 amino-sugar compounds were screened against anticipated structural models of miR-34a through molecular docking. MiR-ligand interactions were mechanistically studied by molecular dynamics simulations and free-energy calculations. Cultured PC12 cells were treated by H₂O₂ alone or in combination with gentamycin and neomycin as selected drugs. Cell viability and apoptosis were detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) and annexin V-FITC/propidium iodate (PI) double staining assays, respectively. The expression levels of key factors involved in cell proliferation, oxidative stress, and apoptosis in treated PC12 cells were measured through a quantitative real-time polymerase chain reaction and flow cytometric annexin V-FITC/PI double staining assays. A stable and energetically favorable binding was observed for miR-34a with gentamycin and neomycin. Gentamycin pretreatments followed by H₂O₂ oxidative injury led to increased cell viability and protected PC12 cells against H₂O₂-induced apoptotic events. This study will help in further understanding how the suppression of miR-34a in neural tissue affects the cell viability upon stroke.

WWP2 ameliorates oxidative stress and inflammation in atherosclerotic mice through regulation of PDCD4/HO-1 pathway

WWP2 is a HECT-type E3 ubiquitin ligase that regulates various physiological and pathological activities by binding to different substrates, but its role in atherosclerosis (AS) remains largely unknown. The objective of the present study is to investigate the role and underlying molecular mechanisms of WWP2 in endothelial injury. We found that WWP2 expression is significantly decreased in Apolipoprotein E (ApoE) ^-/- mice. Overexpression of WWP2 attenuates oxidative stress and inflammation in AS mice, while knockdown of WWP2 has opposite effects. WWP2 overexpression alleviates oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cell (HUVEC) injury, evidenced by the decreased oxidative stress levels and the secretion of inflammatory cytokines. Programmed cell death 4 (PDCD4) is identified as a potential substrate of WWP2. Co-immunoprecipitation (Co-IP) further demonstrates that WWP2 interacts with PDCD4, which is enhanced by ox-LDL treatment. Furthermore, the level of PDCD4 ubiquitination is significantly increased by WWP2 overexpression under the condition of MG132 treatment, while WWP2 knockdown shows opposite results. Subsequently, rescue experiments demonstrate that WWP2 knockdown further aggravates oxidative stress and inflammation in ox-LDL-treated HUVECs, while knockdown of PDCD4 alleviates this effect. Moreover, the use of sn-protoporphyrin (SnPP), an inhibitor of HO-1 pathway, confirms that PDCD4 enhances endothelial injury induced by ox-LDL through inhibiting HO-1 pathway. In conclusion, our results suggest that WWP2 protects against atherosclerosis progression via the PDCD4/HO-1 pathway, which may provide a novel treatment strategy for atherosclerosis.

Detecting Key Functional Components Group and Speculating the Potential Mechanism of Xiao-Xu-Ming Decoction in Treating Stroke

Stroke is a cerebrovascular event with cerebral blood flow interruption which is caused by occlusion or bursting of cerebral vessels. At present, the main methods in treating stroke are surgical treatment, statins, and recombinant tissue-type plasminogen activator (rt-PA). Relatively, traditional Chinese medicine (TCM) has widely been used at clinical level in China and some countries in Asia. Xiao-Xu-Ming decoction (XXMD) is a classical and widely used prescription in treating stroke in China. However, the material basis of effect and the action principle of XXMD are still not clear. To solve this issue, we designed a new system pharmacology strategy that combined targets of XXMD and the pathogenetic genes of stroke to construct a functional response space (FRS). The effective proteins from this space were determined by using a novel node importance calculation method, and then the key functional components group (KFCG) that could mediate the effective proteins was selected based on the dynamic programming strategy. The results showed that enriched pathways of effective proteins selected from FRS could cover 99.10% of enriched pathways of reference targets, which were defined by overlapping of component targets and pathogenetic genes. Targets of optimized KFCG with 56 components can be enriched into 166 pathways that covered 80.43% of 138 pathways of 1,012 pathogenetic genes. A component potential effect score (PES) calculation model was constructed to calculate the comprehensive effective score of components in the components-targets-pathways (C-T-P) network of KFCGs, and showed that ferulic acid, zingerone, and vanillic acid had the highest PESs. Prediction and docking simulations show that these components can affect stroke synergistically through genes such as MEK, NFκB, and PI3K in PI3K-Akt, cAMP, and MAPK cascade signals. Finally, ferulic acid, zingerone, and vanillic acid were tested to be protective for PC12 cells and HT22 cells in increasing cell viabilities after oxygen and glucose deprivation (OGD). Our proposed strategy could improve the accuracy on decoding KFCGs of XXMD and provide a methodologic reference for the optimization, mechanism analysis, and secondary development of the formula in TCM.

Luteolin attenuated cisplatin-induced cardiac dysfunction and oxidative stress via modulation of Keap1/Nrf2 signaling pathway

Cardiovascular complications are a well-documented limitation of cancer chemotherapy. Cisplatin-induced cardiotoxicity threatens the health and life of patients, and limits the application of cisplatin. Oxidative stress is the main mechanism underlying cisplatin-induced cardiac toxicity. Luteolin (Lut) has been reported to possess cardioprotective properties by activating nuclear factor-E2-related factor 2 (Nrf2) -mediated antioxidant response. However, the effect of Lut on cisplatin-induced cardiac damage remains unclear. In this study, we revealed that Lut exerted a protective effect against cisplatin-induced cardiac dysfunction and injury in vivo. In HL-1 cells, Lut was observed to dramatically reduce cisplatin-induced apoptosis and oxidative stress by modulating the Kelch-like epichlorohydrin-associated protein 1 (Keap1)/Nrf2 pathway. Altogether, these findings suggested that Lut showed promise in attenuating cisplatin-induced cardiac injury and might be considered a protective drug candidate for chemotherapy-associated cardiovascular complications.

[Luteolin has a significant protective effect against cadmium-induced injury in lung epithelial Beas-2B cells]

OBJECTIVE

To investigate the protective effect of luteolin against cadmium (Cd)-induced injury in human lung epithelial Beas-2B cells.

OBJECTIVE

Beas-2B cells were treated with different concentrations of luteolin (0-160 μmol/L) or Cd (0-40 μmol/L) for 24 h, and the cell viability was examined using MTT assay. After treatment with luteolin (0.25, 0.5 and 0.75 μmol/L) with or without Cd (5 μmol/L) for 24 h, the cells were examined for viability, lactate dehydrogenase (LDH) activity and morphological changes of the cell nuclei using Hoechst fluorescent staining. The levels of ROS, SOD, GSH and MDA in the treated cells were detected, and the expression levels of Akt, p-Akt and nuclear factor E2-related factor 2 (Nrf2) proteins were determined using Western blotting.

OBJECTIVE

Luteolin within the concentration range of 0-80 μmol/L did not significantly affect the survival rate of Beas-2B cells (P>0.05), but Cd at 5 μmol/L significantly decreased the cell viability (P < 0.05) with an IC₅₀ of 24.6 μmol/L. In Cd-treated cells, treatment with luteolin significantly mitigated the decrease of cell viability, reduced LDH release and cell apoptosis, enhanced SOD activity and GSH content, and inhibited the production of MDA and ROS (all P < 0.05). Luteolin also significantly up-regulated the expression levels of p-Akt and Nrf2 protein in Cd-treated Beas-2B cells (P < 0.05).

OBJECTIVE

Luteolin has a significant protective effect against Cd-induced injury in Beas-2B cells, and the effects are probably mediated, at least in part, by promoting the activation of Akt and Nrf2.

Protective effects of Lavandula stoechas L. methanol extract against 6-OHDA-induced apoptosis in PC12 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Parkinson's disease (PD) is a neurodegenerative disorder associated with oxidative stress-induced neuronal damage and death. In European and Persian Traditional Medicine, aerial parts (leaves, stems, and flowers) of Lavandula stoechas L. have been widely used for treating neurodegenerative disorders including PD.

AIM OF THE STUDY

Herein, the protective effects of L. stoechas methanol extract were investigated on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity and oxidative damage in PC12 cells.

MATERIALS AND METHODS

The cells were pretreated with a standardized L. stoechas methanol extract (2.5-20 μg/mL) for 24 h and exposed to 6-OHDA (200 μM) thereafter. The cell viability percentage was determined by AlamarBlue test. Intracellular reactive oxygen species (ROS) production was determined by a fluorimetric method using 2',7'-dichlorodihydrofluorescein diacetate and cellular apoptosis was assessed by the fluorescent probe propidium iodide test. Finally, the expression of proteins involved in apoptosis pathway (Phospho SAPK/JNK, SAPK/JNK, p44/42 MAPK (ERK1/2) and Poly ADP ribose polymerase (PARP)) was measured via Western blot analysis.

RESULTS

Treatment of PC12 cells with 6-OHDA could significantly increase cytotoxicity, ROS level, and cell apoptosis. Pretreatment of PC12 cells with the extract could significantly decrease 6-OHDA cytotoxicity, ROS production, (2.5 and 5 μg/mL) and cell apoptosis (5 μg/mL). Western blot analysis showed that 6-OHDA exposure could increase the expression of proteins involved in apoptosis signaling, while pretreatment with L. stoechas (5 μg/mL) reduced apoptotic proteins.

CONCLUSIONS

The present study demonstrated that L. stoechas, which has been traditionally used in Persian Medicine for treating CNS diseases, is a valuable source of active compounds with neuroprotective, anti-oxidant, and anti-apoptotic activity.

Luteolin attenuates doxorubicin-induced derangements of liver and kidney by reducing oxidative and inflammatory stress to suppress apoptosis

Doxorubicin is an effective anti-neoplastic agent; the reported toxicities of DOX limit its use. Luteolin is a polyphenolic phytochemical that exhibits beneficial biological effects via several mechanisms. We investigate luteolin protective effects on hepatorenal toxicity associated with doxorubicin treatment in rats. For 2 weeks, randomly assigned rat cohorts were treated as follows: control, luteolin (100 mg/kg; per os), doxorubicin alone (2mg/kg; by intraperitoneal injection), co-treated cohorts received luteolin (50 and 100 mg/kg) in addition to doxorubicin. Treatment with doxorubicin alone significantly (p < 0.05) increased biomarkers of hepatorenal toxicities in the serum. Doxorubicin also reduced relative organ weights, antioxidant capacity, and anti-inflammatory cytokine interleukine-10. Doxorubicin also increased reactive oxygen and nitrogen species, lipid peroxidation, pro-inflammatory-interleukin-1β and tumour necrosis factor-α-cytokine, and apoptotic caspases-3 and -9). Morphological damage accompanied these biochemical alterations in the rat's liver and kidney treated with doxorubicin alone. Luteolin co-treatment dose-dependently abated doxorubicin-mediated toxic responses, improved antioxidant capacity and interleukine-10 level. Luteolin reduced (p < 0.05) lipid peroxidation, caspases-3 and -9 activities and marginally improved rats' survivability. Similarly, luteolin co-treated rats exhibited improvement in hepatorenal pathological lesions observed in rats treated with doxorubicin alone. In summary, luteolin co-treatment blocked doxorubicin-mediated hepatorenal injuries linked with pro-oxidative, inflammatory, and apoptotic mechanisms. Therefore, luteolin can act as a chemoprotective agent in abating toxicities associated with doxorubicin usage and improve its therapeutic efficacy.

Protection against Alzheimer's disease by luteolin: Role of brain glucose regulation, anti-inflammatory activity, and the gut microbiota-liver-brain axis

Luteolin is a widely distributed flavone herbs and vegetables. It has anti-oxidant and anti-inflammatory activities and improves glucose metabolism by potentiating insulin sensitivity and improving β-cell function and mass. Alzheimer's disease (AD) is induced by the deposition of amyloid-beta (Aβ) in the hippocampus and the formation of neurotoxic Aβ plaques. The Aβ deposition is associated with increased formation of Aβ from amyloid precursor protein by up-regulation of β-secretase and β-site amyloid precursor protein-cleaving enzyme 1 (BACE1). Furthermore, Aβ accumulation is increased by brain insulin resistance. The impairment of insulin/IGF-1 signaling mainly in the hippocampus and brain insulin resistance is connected to signals originating in the liver and gut microbiota, known as the gut microbiota-liver-brain axis. This indicates that the changes in the production of short-chain fatty acids by the gut microbiota and pro-inflammatory cytokines can alter insulin resistance in the liver and brain. Luteolin is detected in the brain tissues after passing through the blood-brain barrier, where it can directly influence neuroinflammation and brain insulin resistance and modulate Aβ deposition. Luteolin (10-70 mg/kg bw for rodents) can modulate the systemic and brain insulin resistance, and it suppresses AD development directly, and it influences Aβ deposition by activation of the gut microbiota-liver-brain axis. In this review, we evaluate the potential of luteolin to mitigate two potential causes of AD, neuroinflammatory processes, and disruption of glucose metabolism in the brain. This review suggests that luteolin intake can enhance brain insulin resistance and neuroinflammation, directly and indirectly, to protect against the development of Alzheimer's-like disease, and the gut microbiota-liver-brain axis is mainly involved in the indirect pathway. However, most studies have been conducted in animal studies, and human clinical trials are needed.

Luteolin attenuates Fipronil-induced neurotoxicity through reduction of the ROS-mediated oxidative stress in rat brain mitochondria

Luteolin (LUT) as a natural compound found in vegetables and fruits has various pharmacological effects. Fipronil (FPN), as a pesticide, has been considered for its effect on the antioxidant system and induction of oxidative stress. This study was designed to investigate the protective effects of LUT against the oxidative stress and mitochondrial toxicity induced by FPN on the rat brain. Several parameters such as mitochondrial reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP) collapse, mitochondrial swelling, cytochrome c release, mitochondrial glutathione (GSH), lipid peroxidation (LPO) and Adenosine triphosphate (ATP) levels were assessed. Results indicated that the administration of LUT (25 μM) significantly improved oxidative stress and mitochondrial damages induced via FPN (6, 12 and 24 μM) in isolated mitochondria from the brain. These results show that LUT exerted protective effects against FPN-induced neurotoxicity in vitro through improving oxidative stress and mitochondrial damages.

Improvement of sensory neuron growth and survival via negatively regulating PTEN by miR-21-5p-contained small extracellular vesicles from skin precursor-derived Schwann cells

Background

Patients with peripheral nerve injury (PNI) often suffer from hypoxic ischemic impairments, in particular when combined with vascular damage, causing neuronal dysfunction and death. Increasing attention has been paid on skin precursor-derived Schwann cells (SKP-SCs), and previous study has shown that SKP-SCs could promote sensory recovery after cell therapy for PNI, resembling the effect of naive SCs, and SKP-SC-derived extracellular vesicles (SKP-SC-EVs) are putatively supposed to be promising therapeutic agents for neural regeneration.

Methods

SKPs were induced to differentiate towards SCs with cocktail factors (N2, neuregulin-1β, and forskolin) in vitro. SKP-SC-EVs were isolated by exoEasy Maxi Kit and characterized by morphology and phenotypic markers of EVs. Rat sensory neurons from dorsal root ganglions (DRGs) were primarily cultured in regular condition or exposed to oxygen-glucose-deprivation (OGD) condition. SKP-SC-EVs were applied to DRGs or sensory neurons, with LY294002 (a PI3K inhibitor) added; the effect on neurite outgrowth and cell survival was observed. Moreover, microRNA (miR) candidate contained in SKP-SC-EVs was screened out, and miR-mimics were transfected into DRG neurons; meanwhile, the negative regulation of PTEN/PI3K/Akt axis and downstream signaling molecules were determined.

Results

It was shown that SKP-SC-EVs could improve the neurite outgrowth of DRGs and sensory neurons. Furthermore, SKP-SC-EVs enhanced the survival of sensory neurons after OGD exposure by alleviating neuronal apoptosis and strengthening cell viability, and the expression of GAP43 (a neuron functional protein) in neurons was upregulated. Moreover, the neuro-reparative role of SKP-SC-EVs was implicated in the activation of PI3K/Akt, mTOR, and p70S6k, as well as the reduction of Bax/Bcl-2 ratio, that was compromised by LY294002 to some extent. In addition, transferring miR-21-5p mimics into sensory neurons could partly protect them from OGD-induced impairment.

Conclusions

Sum up, SKP-SC-EVs could improve neurite outgrowth of DRG sensory neurons in physiological and pathological condition. Moreover, the in vitro therapeutic potential of SKP-SC-EVs on the survival and restoration of OGD-injured sensory neurons was evidenced to be associated with miR-21-5p contained in the small EVs and miR-21-5p/PTEN/PI3K/Akt axis.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-020-02125-4.

Luteolin abates reproductive toxicity mediated by the oxido-inflammatory response in Doxorubicin-treated rats

The anti-neoplastic use of Doxorubicin (DOX) is hampered by several limitations, including reproductive toxicity. Luteolin (LUT)–a phytochemical-biological benefits include antioxidative and anti-inflammatory actions. Here we examined the protective effect of LUT against DOX-induced reproductive toxicity in an in vivo model—male albino Wistar rats—randomly assigned to five groups and treated as follows: Control (corn oil 2 mL/kg; per os), LUT (100 mg/kg; per os), DOX (2 mg/kg) by intraperitoneal injections, co-treated groups received LUT (50 and 100 mg/kg) with DOX. Treatment with DOX alone, significantly (p > 0.05), reduced biomarkers of testicular function, reproductive hormone levels, testicular and epididymal antioxidant, and anti-inflammatory cytokine. DOX increased (p > 0.05) sperm morphological abnormalities, as well as reactive oxygen and nitrogen species, lipid peroxidation, xanthine oxidase, a pro-inflammatory cytokine, and apoptotic biomarkers. Furthermore, testicular and epididymal histological lesion complemented the observed biochemical changes in treated rats. LUT co-treatment resulted in a dosage-dependent improvement in rats’ survivability, antioxidants capacity, reduction in biomarkers of oxidative stress, pro-inflammatory cytokines, and apoptosis in rat’s testis and epididymis. Also, LUT treatment resulted in improved histological features in the testis and epididymis, relative to DOX alone treated rats. LUT co-treatment abated DOX-mediated reproductive organ injuries associated with pro-oxidative, inflammatory, and apoptotic mechanisms. LUT supplementation may serve as a phyto-protective agent in alleviating male reproductive organ toxic injuries associated with Doxorubicin therapy.

Protective Effect of Quercetin against H2O2-Induced Oxidative Damage in PC-12 Cells: Comprehensive Analysis of a lncRNA-Associated ceRNA Network

Quercetin is a bioflavonoid with potential antioxidant properties. However, the mechanisms underlying its effects remain unclear. Herein, we focused on integrating long noncoding RNA (lncRNA), microRNA (miRNA), and messenger RNA (mRNA) sequencing of PC-12 cells treated with quercetin. We treated PC-12 cells with hydrogen peroxide to generate a validated oxidative damage model. We evaluated the effects of quercetin on PC-12 cells and established the lncRNA, miRNA, and mRNA profiles of these cells. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses of these RNAs were conducted to identify the key pathways. Quercetin significantly protected PC-12 neuronal cells from hydrogen peroxide-induced death. We identified 297, 194, and 14 significantly dysregulated lncRNAs, miRNAs, and mRNAs, respectively, associated with the antioxidant effect of quercetin. Furthermore, the phosphatidylinositol-3-kinase/protein kinase B pathway was identified as the crucial signalling pathway. Finally, we constructed a lncRNA-associated competing endogenous RNA (ceRNA) network by utilizing oxidative damage mechanism-matched miRNA, lncRNA, and mRNA expression profiles and those changed by quercetin. In conclusion, quercetin exerted a protective effect against oxidative stress-induced damage in PC-12 cells. Our study provides novel insight into ceRNA-mediated gene regulation in the progression of oxidative damage and the action mechanisms of quercetin.

Silencing MEG3 protects PC12 cells from hypoxic injury by targeting miR-21

Increasing number of literatures highlighted lncRNA maternally expressed gene 3 (MEG3) as an emerging target for hypoxic-ischaemic brain damage (HIBD). This study attempted to assess the role of MEG3 in a cell model of HIBD. Expression of MEG3 in PC12 cells was suppressed by siRNA-mediated transfection, after which the cells were subjected to hypoxia. Cell viability, apoptosis, migration and the expression of related proteins were assessed. Furthermore, the downstream gene of MEG3 and its downstream signalling pathways were explored. We found that, down-regulation of MEG3 prevented hypoxic injury in PC12 cells, as hypoxia induced viability loss, apoptosis and migration repression were attenuated by transfection with MEG3 siRNA. Meanwhile, MEG3 acted as a miR-21 sponge. The neuroprotective functions of MEG3 silence were flattened when miR-21 was suppressed. Moreover, the deactivation of PI3K/AKT pathway and the activation of NF-κB pathway induced by hypoxia were attenuated by MEG3 silence. As expected, the effects of MEG3 silence on these two signalling were via miR-21. In conclusion, the neuroprotective effects of MEG3 silence on PC12 cells injured by hypoxia were observed in this study. Mechanistically, the neuroprotective effects of MEG3 silence on PC12 cells were via sponging miR-21 and thus regulating PI3K/AKT and NF-κB pathways.HIGHLIGHTSMEG3 is highly expressed in PC12 cells following hypoxic injury;Silence of MEG3 prevents hypoxia-induced cell damage in PC12 cells;MEG3 acts as a miR-21 sponge;MEG3 sponges miR-21 to regulate PI3K/AKT and NF-κB pathways.

Programmed cell death factor 4 (PDCD4), a novel therapy target for metabolic diseases besides cancer

Programmed cell death factor 4 (PDCD4) is originally described as a tumor suppressor gene that exerts antineoplastic effects by promoting apoptosis and inhibiting tumor cell proliferation, invasion, and metastasis. Several investigations have probed the aberrant expression of PDCD4 with the progression of metabolic diseases, such as polycystic ovary syndrome (PCOS), obesity, diabetes, and atherosclerosis. It has been ascertained that PDCD4 causes glucose and lipid metabolism disorders, insulin resistance, oxidative stress, chronic inflammatory response, and gut flora disorders to regulate the progression of metabolic diseases. This review aims to summarize the latest researches to uncover the structure, expression regulation, and biological functions of PDCD4 and to elucidate the regulatory mechanism of the development of tumors and metabolic diseases. This review has emphasized the understanding of the PDCD4 role and to provide new ideas for the research, diagnosis, and treatment of tumors and metabolic diseases.

A Chinese Herbal Formula Suppresses Colorectal Cancer Migration and Vasculogenic Mimicry Through ROS/HIF-1α/MMP2 Pathway in Hypoxic Microenvironment

Various malignant tumors, including colorectal cancer, have the ability to form functional blood vessels for tumor growth and metastasis. Vasculogenic mimicry (VM) refers to the ability of highly invasive tumor cells to link each other to form vessels, which is associated with poor cancer prognosis. However, the antitumor VM agents are still lacking in the clinic. Astragalus Atractylodes mixture (AAM), a traditional Chinese medicine, has shown to inhibit VM formation; however the exact mechanism is not completely clarified. In this study, we found that HCT-116 and LoVo could form a VM network. Additionally, hypoxia increases the intracellular reactive oxygen species (ROS) level and accelerates migration, VM formation in colorectal cancer cells, while N-Acetylcysteine (NAC) could reverse these phenomena. Notably, further mechanical exploration confirmed that the matrix metalloprotease 2 (MMP2) induction is ROS dependent under hypoxic condition. On the basis, we found that AAM could effectively inhibit hypoxia-induced ROS generation, migration, VM formation as well as HIF-1α and MMP2 expression. In vivo, AAM significantly inhibits metastasis of colorectal cancer in murine lung-metastasis model. Taken together, these results verified that AAM effectively inhibits migration and VM formation by suppressing ROS/HIF-1α/MMP2 pathway in colorectal cancer under hypoxic condition, suggesting AAM could serve as a therapeutic agent to inhibit VM formation in human colorectal cancer.

Phenolic Compounds Exerting Lipid-Regulatory, Anti-Inflammatory and Epigenetic Effects as Complementary Treatments in Cardiovascular Diseases

Atherosclerosis is the main process behind cardiovascular diseases (CVD), maladies which continue to be responsible for up to 70% of death worldwide. Despite the ongoing development of new and potent drugs, their incomplete efficacy, partial intolerance and numerous side effects make the search for new alternatives worthwhile. The focus of the scientific world turned to the potential of natural active compounds to prevent and treat CVD. Essential for effective prevention or treatment based on phytochemicals is to know their mechanisms of action according to their bioavailability and dosage. The present review is focused on the latest data about phenolic compounds and aims to collect and correlate the reliable existing knowledge concerning their molecular mechanisms of action to counteract important risk factors that contribute to the initiation and development of atherosclerosis: dyslipidemia, and oxidative and inflammatory-stress. The selection of phenolic compounds was made to prove their multiple benefic effects and endorse them as CVD remedies, complementary to allopathic drugs. The review also highlights some aspects that still need clear scientific explanations and draws up some new molecular approaches to validate phenolic compounds for CVD complementary therapy in the near future.

Luteolin exhibits anti-breast cancer property through up-regulating miR-203

Luteolin is a representative of natural flavonoid that has anti-tumour properties. This study designed to check its impact on breast cancer and the underlying mechanisms. MDA-MB-453 and MCF-7 cells were administrated with luteolin and the following techniques were carried out: CCK-8 assay, FITC-PI double-staining and Western blot. qRT-PCR analysis was utilized to see the effects of luteolin on miR-203 expression. Besides, miR-203 expression was silenced by transfection with specific inhibitor. Luteolin remarkably declined MDA-MB-453 and MCF-7 cells viability and accelerated apoptosis which accompanied by Bax up-regulation, Bcl-2 down-regulation and Caspase-3 cleavage. Also, luteolin impeded TGFβ1-induced EMT, as evidenced by the decreased levels of Vimentin, Zeb1 and N-cadherin, as well as the increased level of E-cadherin. miR-203 was highly expressed in 22 pair of breast cancer tissues than the matched paracancerous tissues. Luteolin could elevate miR-203 level. Besides, luteolin's anti-tumour effects were partially eliminated by miR-203 silence. Further, luteolin inhibited Ras/Raf/MEK/ERK signalling, while the inhibitory effects were flattened by miR-203 silence. Luteolin significantly reduced breast cancer cells growth and EMT. Luteolin exerted its anti-tumour effects possibly involved the elevated expression of miR-203 and the inhibited Ras/Raf/MEK/ERK signalling.

Luteolin Attenuates Atherosclerosis Via Modulating Signal Transducer And Activator Of Transcription 3-Mediated Inflammatory Response

Background

Inflammatory factors play a crucial role throughout the development and progression of atherosclerosis, which has been considered as a chronic vascular inflammatory disease. Luteolin, a natural flavonoid which exists in many natural medicinal materials, has anti-inflammatory, anti-fibrotic and other pharmacological effects. Recently, the protective effects of luteolin on the cardiovascular disease have been reported. However, there is a paucity of studies on anti-atherosclerosis. Therefore, the anti-atherosclerosis potential of luteolin remains to be elucidated.

Method

ApoE^-/- mice were fed with a high-fat diet to induce atherosclerosis in an animal model, where they were treated with oral administration of luteolin for 12 weeks. Primary mouse peritoneal macrophages challenged with oxidized low-density lipoprotein (oxLDL) were used for in vitro mechanistic study. The effectiveness of luteolin in the ApoE^-/- mouse model of atherosclerosis was estimated in the aortic sinus and enface, and the underlying mechanisms were explored by molecular modeling study and siRNA-induced gene silencing.

Results

Our results showed that luteolin remarkably attenuated atherosclerosis in high-fat diet-induced ApoE^-/- mouse via alleviating inflammation. We further found that luteolin decreased oxLDL-induced inflammation by inhibiting signal transducer and activator of transcription 3 (STAT3) in vitro, respectively. Further molecular modeling analysis indicated that luteolin interacted with STAT3 primarily through hydrogen bond interaction.

Conclusion

Luteolin could be a promising candidate molecule for atherosclerosis, and STAT3 may be a potential therapeutic target that could prevent the development of atherosclerosis.

The Role of Mast Cells in Stroke

Mast cells (MCs) are densely granulated perivascular resident cells of hematopoietic origin. Through the release of preformed mediators stored in their granules and newly synthesized molecules, they are able to initiate, modulate, and prolong the immune response upon activation. Their presence in the central nervous system (CNS) has been documented for more than a century. Over the years, MCs have been associated with various neuroinflammatory conditions of CNS, including stroke. They can exacerbate CNS damage in models of ischemic and hemorrhagic stroke by amplifying the inflammatory responses and promoting brain–blood barrier disruption, brain edema, extravasation, and hemorrhage. Here, we review the role of these peculiar cells in the pathophysiology of stroke, in both immature and adult brain. Further, we discuss the role of MCs as potential targets for the treatment of stroke and the compounds potentially active as MCs modulators.