Stimulation of cytosolic and mitochondrial calcium mobilization by indomethacin in Caco-2 cells: Modulation by the polyphenols quercetin, resveratrol and rutin

An Integrated Approach to Skeletal Muscle Health in Aging

A decline in muscle mass and function represents one of the most problematic changes associated with aging, and has dramatic effects on autonomy and quality of life. Several factors contribute to the inexorable process of sarcopenia, such as mitochondrial and autophagy dysfunction, and the lack of regeneration capacity of satellite cells. The physiologic decline in muscle mass and in motoneuron functionality associated with aging is exacerbated by the sedentary lifestyle that accompanies elderly people. Regular physical activity is beneficial to most people, but the elderly need well-designed and carefully administered training programs that improve muscle mass and, consequently, both functional ability and quality of life. Aging also causes alteration in the gut microbiota composition associated with sarcopenia, and some advances in research have elucidated that interventions via the gut microbiota-muscle axis have the potential to ameliorate the sarcopenic phenotype. Several mechanisms are involved in vitamin D muscle atrophy protection, as demonstrated by the decreased muscular function related to vitamin D deficiency. Malnutrition, chronic inflammation, vitamin deficiencies, and an imbalance in the muscle-gut axis are just a few of the factors that can lead to sarcopenia. Supplementing the diet with antioxidants, polyunsaturated fatty acids, vitamins, probiotics, prebiotics, proteins, kefir, and short-chain fatty acids could be potential nutritional therapies against sarcopenia. Finally, a personalized integrated strategy to counteract sarcopenia and maintain the health of skeletal muscles is suggested in this review.

The multifaceted roles of natural products in mitochondrial dysfunction

Mitochondria are the primary source of energy production in cells, supporting the metabolic demand of tissue. The dysfunctional mitochondria are implicated in various diseases ranging from neurodegeneration to cancer. Therefore, regulating dysfunctional mitochondria offers a new therapeutic opportunity for diseases with mitochondrial dysfunction. Natural products are pleiotropic and readily obtainable sources of therapeutic agents, which have broad prospects in new drug discovery. Recently, many mitochondria-targeting natural products have been extensively studied and have shown promising pharmacological activity in regulating mitochondrial dysfunction. Hence, we summarize recent advances in natural products in targeting mitochondria and regulating mitochondrial dysfunction in this review. We discuss natural products in terms of their mechanisms on mitochondrial dysfunction, including modulating mitochondrial quality control system and regulating mitochondrial functions. In addition, we describe the future perspective and challenges in the development of mitochondria-targeting natural products, emphasizing the potential value of natural products in mitochondrial dysfunction.

Endoplasmic reticulum as a target in cardiovascular diseases: Is there a role for flavonoids?

Flavonoids are found in natural health products and plant-based foods. The flavonoid molecules contain a 15-carbon skeleton with the particular structural construction of subclasses. The most flavonoid's critical subclasses with improved health properties are the catechins or flavonols (e.g., epigallocatechin 3-gallate from green tea), the flavones (e.g., apigenin from celery), the flavanones (e.g., naringenin from citrus), the flavanols (e.g., quercetin glycosides from berries, onion, and apples), the isoflavones (e.g., genistein from soya beans) and the anthocyanins (e.g., cyanidin-3-O-glucoside from berries). Scientific data conclusively demonstrates that frequent intake of efficient amounts of dietary flavonoids decreases chronic inflammation and the chance of oxidative stress expressing the pathogenesis of human diseases like cardiovascular diseases (CVDs). The endoplasmic reticulum (ER) is a critical organelle that plays a role in protein folding, post-transcriptional conversion, and transportation, which plays a critical part in maintaining cell homeostasis. Various stimuli can lead to the creation of unfolded or misfolded proteins in the endoplasmic reticulum and then arise in endoplasmic reticulum stress. Constant endoplasmic reticulum stress triggers unfolded protein response (UPR), which ultimately causes apoptosis. Research has shown that endoplasmic reticulum stress plays a critical part in the pathogenesis of several cardiovascular diseases, including diabetic cardiomyopathy, ischemic heart disease, heart failure, aortic aneurysm, and hypertension. Endoplasmic reticulum stress could be one of the crucial points in treating multiple cardiovascular diseases. In this review, we summarized findings on flavonoids' effects on the endoplasmic reticulum and their role in the prevention and treatment of cardiovascular diseases.

The role of cholesterol and mitochondrial bioenergetics in activation of the inflammasome in IBD

Inflammatory Bowel Disease (IBD) is characterized by a loss of intestinal barrier function caused by an aberrant interaction between the immune response and the gut microbiota. In IBD, imbalance in cholesterol homeostasis and mitochondrial bioenergetics have been identified as essential events for activating the inflammasome-mediated response. Mitochondrial alterations, such as reduced respiratory complex activities and reduced production of tricarboxylic acid (TCA) cycle intermediates (e.g., citric acid, fumarate, isocitric acid, malate, pyruvate, and succinate) have been described in in vitro and clinical studies. Under inflammatory conditions, mitochondrial architecture in intestinal epithelial cells is dysmorphic, with cristae destruction and high dynamin-related protein 1 (DRP1)-dependent fission. Likewise, these alterations in mitochondrial morphology and bioenergetics promote metabolic shifts towards glycolysis and down-regulation of antioxidant Nuclear erythroid 2-related factor 2 (Nrf2)/Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) signaling. Although the mechanisms underlying the mitochondrial dysfunction during mucosal inflammation are not fully understood at present, metabolic intermediates and cholesterol may act as signals activating the NLRP3 inflammasome in IBD. Notably, dietary phytochemicals exhibit protective effects against cholesterol imbalance and mitochondrial function alterations to maintain gastrointestinal mucosal renewal in vitro and in vivo conditions. Here, we discuss the role of cholesterol and mitochondrial metabolism in IBD, highlighting the therapeutic potential of dietary phytochemicals, restoring intestinal metabolism and function.

NSAIDs and Cancer Resolution: New Paradigms beyond Cyclooxygenase

Acute inflammation or resolved inflammation is an adaptive host defense mechanism and is self-limiting, which returns the body to a state of homeostasis. However, unresolved, uncontrolled, or chronic inflammation may lead to various maladies, including cancer. Important evidence that links inflammation and cancer is that nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, reduce the risk and mortality from many cancers. The fact that NSAIDs inhibit the eicosanoid pathway prompted mechanistic drug developmental work focusing on cyclooxygenase (COX) and its products. The increased prostaglandin E2 levels and the overexpression of COX-2 in the colon and many other cancers provided the rationale for clinical trials with COX-2 inhibitors for cancer prevention or treatment. However, NSAIDs do not require the presence of COX-2 to prevent cancer. In this review, we highlight the effects of NSAIDs and selective COX-2 inhibitors (COXIBs) on targets beyond COX-2 that have shown to be important against many cancers. Finally, we hone in on specialized pro-resolving mediators (SPMs) that are biosynthesized locally and, in a time, -dependent manner to promote the resolution of inflammation and subsequent tissue healing. Different classes of SPMs are reviewed, highlighting aspirin's potential in triggering the production of these resolution-promoting mediators (resolvins, lipoxins, protectins, and maresins), which show promise in inhibiting cancer growth and metastasis.

Positive Lusitropic Effect of Quercetin on Isolated Ventricular Myocardia from Normal and Streptozotocin-Induced Diabetic Mice

The lusitropic effect of quercetin was examined on isolated ventricular myocardial tissue preparations from normal and streptozotocin-induced diabetic mice. The time required for 90% relaxation of the myocardium, which was prolonged in the diabetic mice, was shortened by quercetin in both normal and diabetic myocardia. This effect of quercetin was completely inhibited by cyclopiazonic acid but not by SEA0400. These results indicated that quercetin accelerates myocardial relaxation through activation of the sarco-endoplasmic reticulum Ca²⁺-ATPase.

Effect of Quercetin on Injury to Indomethacin-Treated Human Embryonic Kidney 293 Cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammation and pain and even to prevent the progression of cardiovascular disease. They have become widely used because of their effectiveness, especially among athletes performing high-intensity training. Indomethacin is used for pain management in sports medicine and is highly effective and versatile. However, several clinical studies have reported that indomethacin induces acute renal damage. In the present study, we determined that indomethacin reduced human embryonic kidney 293 (HEK293) cell viability in a concentration-dependent manner by triggering apoptosis. In addition, we demonstrated the effect of quercetin on indomethacin-treated HEK293 cells by inactivating the caspase-3 and caspase-9 signals. Furthermore, quercetin reduced ROS production and increased mitochondrial membrane potential (ΔΨm) in indomethacin-treated HEK293 cells. Our results indicate that quercetin can interrupt the activated caspase and mitochondrial pathway induced by indomethacin in HEK293 cells and affect apoptotic mRNA expression. Quercetin can protect against indomethacin-induced HEK293 cell apoptosis by regulating abnormal ΔΨm and apoptotic mRNA expression.

The antioxidant Rutin counteracts the pathological impact of α-synuclein on the enteric nervous system in vitro

Motoric disturbances in Parkinson's disease (PD) derive from the loss of dopaminergic neurons in the substantia nigra. Intestinal dysfunctions often appear long before manifestation of neuronal symptoms, suggesting a strong correlation between gut and brain in PD. Oxidative stress is a key player in neurodegeneration causing neuronal cell death. Using natural antioxidative flavonoids like Rutin, might provide intervening strategies to improve PD pathogenesis. To explore the potential effects of micro (mRutin) compared to nano Rutin (nRutin) upon the brain and the gut during PD, its neuroprotective effects were assessed using an in vitro PD model. Our results demonstrated that Rutin inhibited the neurotoxicity induced by A53T α-synuclein (Syn) administration by decreasing oxidized lipids and increasing cell viability in both, mesencephalic and enteric cells. For enteric cells, neurite outgrowth, number of synaptic vesicles, and tyrosine hydroxylase positive cells were significantly reduced when treated with Syn. This could be reversed by the addition of Rutin. nRutin revealed a more pronounced result in all experiments. In conclusion, our study shows that Rutin, especially the nanocrystals, are promising natural compounds to protect neurons from cell death and oxidative stress during PD. Early intake of Rutin may provide a realizable option to prevent or slow PD pathogenesis.

Flavonoids and cellular stress: a complex interplay affecting human health

Flavonoid consumption has beneficial effects on human health, however, clinical evidence remains often inconclusive due to high interindividual variability. Although this high interindividual variability has been consistently observed in flavonoid research, the potential underlying reasons are still poorly studied. Especially the knowledge on the impact of health status on flavonoid responsiveness is limited and merits more investigation. Here, we aim to highlight the bidirectional interplay between flavonoids and cellular stress. First, the state-of-the-art concerning inflammatory stress and mitochondrial dysfunction is reviewed and a comprehensive overview of recent in vitro studies investigating the impact of flavonoids on cellular stress, induced by tumor necrosis factor α, lipopolysaccharide and mitochondrial stressors, is given. Second, we critically discuss the influence of cellular stress on flavonoid uptake, accumulation, metabolism and cell responses, which has, to our knowledge, never been extensively reviewed before. Next, we advocate the innovative insight that stratification of the general population based on health status can reveal subpopulations that benefit more from flavonoid consumption. Finally, suggestions are given for the development of future cell models that simulate the physiological micro-environment, including interindividual variability, since more mechanistic research is needed to establish scientific-based personalized food recommendations for specific subpopulations.

Differential inhibitory effects of resveratrol on excitotoxicity and synaptic plasticity: involvement of NMDA receptor subtypes

Objectives: The neuroprotective effects of resveratrol against excitatory neurotoxicity have been associated with N-methyl-D-aspartate receptor (NMDAR) inhibition. This study examined the differential inhibitory effects of resveratrol on NMDAR-mediated responses in neuronal cells with different NMDAR subtype composition.Methods: The effects of resveratrol on NMDA-induced cell death and calcium influx in immature and mature rat primary cortical neurons were determined and compared. Moreover, the potencies and efficacies of resveratrol to inhibit NR1/NR2A, NR1/NR2B, NR1/NR2C, and NR1/NR2D NMDAR expressed in HEK 293 cells were evaluated.Results: Resveratrol significantly attenuated NMDA-induced cell death in mature neurons, but not in immature neurons. Resveratrol also concentration-dependently reduced NMDA-induced calcium influx among all NMDAR subtypes, but displayed NR2 subunit selectivity, with a potency rank order of NR2B = NR2D > NR2A = NR2C and an efficacy rank order of NR2B = NR2C > NR2A = NR2D. Data show the stronger inhibitory effects of resveratrol on NR1/NR2B than other subtypes. Moreover, resveratrol did not affect hippocampal long-term potentiation (LTP), but impaired long-term depression (LTD).Discussion: These findings reveal the specific NMDAR modulating profile of resveratrol, providing further insight into potential mechanisms underlying the protective effects of resveratrol on neurological disorders.

Protective Effect of TRPM8 against Indomethacin-Induced Small Intestinal Injury via the Release of Calcitonin Gene-Related Peptide in Mice

Transient receptor potential melastatin 8 (TRPM8) is a non-selective cation channel activated by mild cooling and chemical agents including menthol. Nonsteroidal anti-inflammatory drugs have antipyretic, analgesic effects, and they can cause stomach and small intestinal injury. The current study investigated the role of TRPM8 in the pathogenesis of indomethacin-induced small intestinal injury. In male TRPM8-deficient (TRPM8KO) and wild-type (WT) mice, intestinal injury was induced via the subcutaneous administration of indomethacin. In addition, the effect of WS-12, a specific TRPM8 agonist, was examined in TRPM8KO and WT mice with indomethacin-induced intestinal injury. TRPM8KO mice had a significantly higher intestinal ulcerogenic response to indomethacin than WT mice. The repeated administration of WS-12 significantly attenuated the severity of intestinal injury in WT mice. However, this response was abrogated in TRPM8KO mice. Furthermore, in TRPM8-enhanced green fluorescent protein (EGFP) transgenic mice, which express EGFP under the direction of TRPM8 promoter, the EGFP signals in the indomethacin-treated intestinal mucosa were upregulated. Further, the EGFP signals were commonly found in calcitonin gene-related peptide (CGRP)-positive sensory afferent neurons and partly colocalized with substance P (SP)-positive neurons in the small intestine. The intestinal CGRP-positive neurons were significantly upregulated after the administration of indomethacin in WT mice. Nevertheless, this response was abrogated in TRPM8KO mice. In contrast, indomethacin increased the expression of intestinal SP-positive neurons in not only WT mice but also TRPM8KO mice. Thus, TRPM8 has a protective effect against indomethacin-induced small intestinal injury. This response may be mediated by the upregulation of CGRP, rather than SP.

Quercetin alleviates styrene oxide-induced cytotoxicity in cortical neurons in vitro via modulation of oxidative stress and apoptosis

Styrene 7,8-oxide (SO) is the principal metabolite of styrene, an industrial neurotoxic compound which causes various neurodegenerative disorders. The present study aimed to explore the mechanisms of SO cytotoxicity (0.5 - 4 mM) in primary cortical neurons and to evaluate the neuroprotective potential of quercetin (QUER). Our results showed that exposure to SO decreased viability of cortical neurons in a concentration-dependent manner. In the presence of QUER, cell viability was increased significantly. The neuroprotective effects of QUER were associated with the reduction of intracellular Reactive Oxygen Species (ROS), the decrease in calcium overload and the restoration of mitochondrial membrane depolarization caused by SO. Additionally, to evaluate neuronal death mechanisms triggered by SO, cells were incubated with Ac-DEVD-CHO, Calpeptin and Necrostatin-1, pharmacological inhibitors of caspase-3, calpains and necroptosis respectively. The data showed that the three inhibitors reduced cell death induced by SO and suggested the implication of apoptotic, necrotic and necroptotic pathways. However, western blot analysis showed that QUER attenuated the activation of caspase-3 but did not prevent calpain activity. Taken together, these data indicated that the cytotoxicity of SO was mediated by oxidative stress and apoptosis, necrosis and necroptosis mechanisms, while the neuroprotection provided by QUER against SO depended mainly on its anti-apoptotic activity.

Heterodimeric Insecticidal Peptide Provides New Insights into the Molecular and Functional Diversity of Ant Venoms

Ants use venom for predation, defense, and communication; however, the molecular diversity, function, and potential applications of ant venom remains understudied compared to other venomous lineages such as arachnids, snakes and cone snails. In this work, we used a multidisciplinary approach that encompassed field work, proteomics, sequencing, chemical synthesis, structural analysis, molecular modeling, stability studies, and in vitro and in vivo bioassays to investigate the molecular diversity of the venom of the Amazonian Pseudomyrmex penetrator ants. We isolated a potent insecticidal heterodimeric peptide Δ-pseudomyrmecitoxin-Pp1a (Δ-PSDTX-Pp1a) composed of a 27-residue long A-chain and a 33-residue long B-chain cross-linked by two disulfide bonds in an antiparallel orientation. We chemically synthesized Δ-PSDTX-Pp1a, its corresponding parallel AA and BB homodimers, and its monomeric chains and demonstrated that Δ-PSDTX-Pp1a had the most potent insecticidal effects in blowfly assays (LD₅₀ = 3 nmol/g). Molecular modeling and circular dichroism studies revealed strong α-helical features, indicating its cytotoxic effects could derive from cell membrane pore formation or disruption. The native heterodimer was substantially more stable against proteolytic degradation (t _1/2 = 13 h) than its homodimers or monomers (t _1/2 < 20 min), indicating an evolutionary advantage of the more complex structure. The proteomic analysis of Pseudomyrmex penetrator venom and in-depth characterization of Δ-PSDTX-Pp1a provide novel insights in the structural complexity of ant venom and further exemplifies how nature exploits disulfide-bond formation and dimerization to gain an evolutionary advantage via improved stability, a concept that is highly relevant for the design and development of peptide therapeutics, molecular probes, and bioinsecticides.

A Bioactive Olive Pomace Extract Prevents the Death of Murine Cortical Neurons Triggered by NMDAR Over-Activation

We have recently demonstrated that bioactive molecules, extracted by high pressure and temperature from olive pomace, counteract calcium-induced cell damage to different cell lines. Here, our aim was to study the effect of the same extract on murine cortical neurons, since the preservation of the intracellular Ca²⁺-homeostasis is essential for neuronal function and survival. Accordingly, we treated neurons with different stimuli in order to evoke cytotoxic glutamatergic activation. In these conditions, the high-pressure and temperature extract from olive pomace (HPTOPE) only abolished the effects of N-methyl-d-aspartate (NMDA). Particularly, we observed that HPTOPE was able to promote the neuron rescue from NMDA-induced cell death. Moreover, we demonstrated that HPTOPE is endowed with the ability to maintain the intracellular Ca²⁺-homeostasis following NMDA receptor overactivation, protecting neurons from Ca²⁺-induced adverse effects, including aberrant calpain proteolytic activity. Moreover, we highlight the importance of the extraction conditions used that, without producing toxic molecules, allow us to obtain protecting molecules belonging to proanthocyanidin derivatives like procyanidin B2. In conclusion, we can hypothesize that HPTOPE, due to its functional and nontoxic properties on neuronal primary culture, can be utilized for future therapeutic interventions for neurodegeneration.

Quercetin supplemented casein-based extender improves the post-thaw quality of rooster semen

The advantageous influence of quercetin (Q) supplementation in an extender has not yet been evaluated for rooster semen cryopreservation. This research was purposely conducted in order to assess the effect of different quercetin concentrations added into an extender on the sperm quality of the rooster subsequent to a freezing-thawing process. After the freezing-thawing process, spermatozoa quality parameters (membrane functionality, acrosome integrity, motility, viability, and abnormal morphology), endogenous enzymes (SOD, CAT, and GPx), mitochondrial activity, DNA fragmentation index, lipid peroxidation (MDA), and ROS were all evaluated. A total of 75 neat pooled ejaculates (3 ejaculates/rooster) were collected from 25 arbor acres roosters (24 wks) twice a week using abdominal massage technique, then divided into five equal aliquots and diluted with an extender containing different doses of Q (CS-Q) as follows: casein extender without Q (control only), casein extender containing 0.040 mg/mL quercetin (CS-Q 0.040), 0.020 mg/mL quercetin (CS-Q 0.020), 0.010 mg/mL quercetin (CS-Q 0.010), and 0.005 mg/mL quercetin (CS-Q 0.005). Our results depicted that adding to the extender with a 0.010 mg/mL Q enhanced (P < 0.01) sperm motility, membrane function, viability, mitochondrial activity, intact acrosome (P < 0.05), SOD (P < 0.001), CAT, and GPx (P < 0.01) compared to the control group at post-thaw. Compared to the control group and other treatment groups after the freeze-thawing process, the addition of 0.005 mg/mL Q into the extender also showed higher (P < 0.05) improvement in the quality of sperm parameters and a higher (P < 0.01) SOD and CAT but did not improve mitochondrial activity and sperm viability. In addition, there was a lower degree of DNA fragmentation index, lower (P < 0.05) lipid peroxidation and ROS in frozen-thawed sperm treated with 0.010 mg/mL and 0.005 mg/mL Q than in control and the other treatment groups. In addition, 0.020 mg/mL Q supplementation into the extender also reduced DNA fragmentation and improved GPx activity compared to the control group at post-thaw. Different concentrations of Q 0.010 and 0.005 mg/mL added to the extender reduced the percentage of abnormal spermatozoa compared to the other groups. The results of this study showed for the first time that the inclusion of an extender with a suitable quercetin concentration of 0.010 mg/mL improved the post-thawed quality of rooster semen.

Pre-treatment with a combination of Shenmai and Danshen injection protects cardiomyocytes against hypoxia/reoxygenation- and H2O2-induced injury by inhibiting mitochondrial permeability transition pore opening

Increasing evidence has indicated that opening of the mitochondrial permeability transition pore (mPTP) has a vital role in myocardial ischemia/reperfusion (I/R) injury. Shenmai injection (SMI) plus Danshen injection (DSI) combination, termed Yiqi Yangyin Huoxue (YYH) therapy is used in the clinic to treat cardiovascular diseases, including myocardial I/R injury. Previous studies by our group have demonstrated the protective effect of pretreatment with YYH against myocardial I/R injury in isolated rat hearts. The present study aimed to examine the protective effect of YYH against hypoxia/reoxygenation (H/R)- and H₂O₂-induced cardiomyocyte injury, and to determine whether this effect is produced by inhibition of mPTP opening. Primary cardiomyocytes isolated from neonatal rats were cultured and randomly grouped into a control group, injury group and pretreatment group, with six duplicated wells in each group during each assay. Cardiomyocytes in the injury group were subjected to H/R to simulate I/R or exposed to H₂O₂ for 2 h to induce oxidative injury. Cellular injury was assessed via release of creatine kinase (CK) and lactate dehydrogenase (LDH), and cell viability was measured by an MTT assay. The mitochondrial membrane potential (ΔΨm) and cytosolic reactive oxygen species (ROS) were detected using the fluorescent probes rhodamine123 (Rh123) and chloromethyl-2,7-dichlorodihydrofluorescein diacetate (CM-H₂DCFDA), respectively. Intracellular Ca²⁺, mitochondrial Ca²⁺ and mPTP opening were measured using fluo-4 acetoxymethyl (Fluo-4/AM), rhodamine-2 acetoxymethyl (Rhod-2/AM) and calcein acetoxymethyl (Calcein/AM) probes, respectively. The results indicated that pretreatment with YYH enhanced cell viability, increased ΔΨm, reduced CK and LDH release, and decreased intracellular ROS and Ca²⁺, thus reducing cardiomyocyte injury induced by H/R or H₂O₂. LY294002, a specific phosphoinositide 3-kinase (PI3K) inhibitor, and PD98059, a specific inhibitor of the extracellular signal-regulated kinase 1/2 (Erk1/2) pathway, eliminated the protective effects of the combination therapy on cell viability and the change in the ΔΨm in cardiomyocytes. In conclusion, pre-treatment with YYH has cardioprotective effects against H/R injury and oxidative stress via activation of the PI3K/Akt and Erk1/2 signaling pathways, which reduces mPTP opening, overproduction of ROS and calcium overload.

The effects of vitamins and selenium mixture or ranitidine against small intestinal injury induced by indomethacin in adult rats

This study was aimed at investigating morphological and biochemical efficacies of antioxidants on indomethacin-induced small intestinal damage in rats. Group I: control animals (negative control) given only placebo, Group II: (positive control) are animals orally given combination of antioxidants [vitamin C (Vit C), vitamin E (Vit E), β-carotene and sodium selenite (Se)] daily for 3 days, Group III: Rats were given only indomethacin, Group IV: animals were given of antioxidants combination for 3 days, last dose was given 2 hr before the administration of indomethacin. Group V: Animals receiving ranitidine for 3 days (second positive control). Group VI: Animals received ranitidine for 3 days, last dose was given 2 hr before to indomethacin administration. Indomethacin caused degenerative morphological and biochemical changes, which were reversed on antioxidants administration. As a result, we propose that antioxidants combination would be therapeutically beneficial for treating indomethacin-induced lesions of small intestine. PRACTICAL APPLICATIONS: Indomethacin is a widely preferred nonsteroidal anti-inflammatory drug (NSAID) but its side effects on gastrointestinal system are well known. Indomethacin also causes production of reactive oxygen species. Antioxidants and selenium has protective effects. According to the results of this study, antioxidants and selenium can be used as a food supplement for preventing NSAID-induced side effects and toxicity.

Dimethyl sulfoxide and quercetin prolong the survival, motility, and fertility of cold-stored mouse sperm for 10 days

Technology for preserving sperm is useful for disseminating valuable male genetic traits. Cold storage is suitable for easily transporting sperm as an alternative to the shipment of live animals. However, there is a technical limitation in that the fertility of cold-stored sperm declines within 3 days. To overcome this problem, we examined the protective effects of quercetin and dimethyl sulfoxide (DMSO). DMSO and quercetin maintained the fertility and motility of cold-stored sperm for 10 days. In addition, quercetin attenuated the reduction of mitochondrial membrane potential of cold-stored sperm during sperm preincubation, allowing the induction of capacitation, and it localized to the midpiece of sperm. Furthermore, DMSO and quercetin enhanced the level of tyrosine phosphorylation of cold-stored sperm. DMSO and quercetin have life-prolonging effects on sperm during cold storage. Cold storage using DMSO and quercetin will provide a robust system for internationally transporting valuable sperm samples.

Physicochemical, pharmacokinetics, and histological evaluation of new naproxen-quercetin co-lyophilizate to diminish drug-induced gastric irritations in rats

Quercetin (QUE) is a flavonoid found in several plants and commonly distributed in edible vegetables and fruits. To evaluate the effect of co-lyophilization of naproxen (NPX) with QUE at different weight ratios on physicochemical characteristics induced gastric irritation, and drug pharmacokinetics. NPX binary systems with QUE in different weight ratios were prepared by freeze-drying alkalinized solutions, and were characterized in terms of physicochemical properties as well as NPX dissolution rate in acidic pH. NPX-induced gastric inflammation studies were carried out in rats for 7 days. The pharmacokinetics of the two formulations were assessed to evaluate the bioavailability of NPX-QUE 1:2 co-lyophilizate. Westar rats were administered oral doses equivalent to 40 mg kg⁻¹ of NPX and blood samples were taken from the retro-orbital vein of rats at 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0 12.0, and 24.0 h post dosing. Co-lyophilization of NPX with QUE enhanced drug dissolution rate in the acidic medium, which was correlated with an increased QUE weight ratio in the co-lyophilizates. Rat stomachs from group V (NPX-QUE 1:2 co-lyophilizate) showed non-significant changes, and biopsies from this group showed no significant leukocyte infiltration and edema in the mucosa. The bioavailability of NPX-QUE 1: 2 co-lyophilizate was similar to the control sample. NPX-QUE 1: 2 co-lyophilizate could be an alternative to NPX in the treatment of arthritis as it minimizes the potential for gastric irritation and enhances safety while retaining the same efficacy and bioavailability.

Calcium-induced chloride secretion is decreased by Resveratrol in ileal porcine tissue

Objective

Chloride (Cl⁻) secretion is crucial for intestinal fluid secretion. Therefore, effects of the polyphenol Resveratrol (RSV) on Cl⁻ secretion have been investigated. In a previous study, we observed effects of RSV on forskolin-induced Cl⁻ secretion in the porcine jejunum but not the ileum although RSV itself induced a transepithelial ion current that may represent Cl⁻ secretion in the ileum. The aim of this study was to gain further insights regarding the effects of RSV on characteristics of Cl⁻ secretion in the porcine ileum using the Ussing chamber technique (recording of short circuit currents (I_sc) as a measure for epithelial net ion transfer).

Results

RSV increased the I_sc in the porcine ileum but not in the porcine jejunum as is already known. This increase was absent in a Cl⁻-free buffer system, indicating that RSV indeed induces Cl⁻ secretion. However, the carbachol-induced I_sc was significantly inhibited by RSV indicating an inhibition of Ca²⁺-induced Cl⁻ secretion. The cellular basis for these contradictory, segment specific results of RSV on Cl⁻ secretion has to be subjected to further studies. The results also underline, that is difficult to generalize effects of RSV between different intestinal locations, organs, cell culture models or species.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3825-4) contains supplementary material, which is available to authorized users.

Quercetin Prevents Diastolic Dysfunction Induced by a High-Cholesterol Diet: Role of Oxidative Stress and Bioenergetics in Hyperglycemic Rats

Alterations in cardiac energy metabolism play a key role in the pathogenesis of diabetic cardiomyopathy. Hypercholesterolemia associated with bioenergetic impairment and oxidative stress has not been well characterized in the cardiac function under glycemic control deficiency conditions. This work aimed to determine the cardioprotective effects of quercetin (QUE) against the damage induced by a high-cholesterol (HC) diet in hyperglycemic rats, addressing intracellular antioxidant mechanisms and bioenergetics. Quercetin reduced HC-induced alterations in the lipid profile and glycemia in rats. In addition, QUE attenuated cardiac diastolic dysfunction (increased E:A ratio), prevented cardiac cholesterol accumulation, and reduced the increase in HC-induced myocyte density. Moreover, QUE reduced HC-induced oxidative stress by preventing the decrease in GSH/GSSG ratio, Nrf2 nuclear translocation, HO-1 expression, and antioxidant enzymatic activity. Quercetin also counteracted HC-induced bioenergetic impairment, preventing a reduction in ATP levels and alterations in PGC-1α, UCP2, and PPARγ expression. In conclusion, the mechanisms that support the cardioprotective effect of QUE in rats with HC might be mediated by the upregulation of antioxidant mechanisms and improved bioenergetics on the heart. Targeting bioenergetics with QUE can be used as a pharmacological approach to modulate structural and functional changes of the heart under hypercholesterolemic and hyperglycemic conditions.

Cell protection from Ca2+-overloading by bioactive molecules extracted from olive pomace

We are reporting in the present study that molecules extracted from olive pomace prevent cell death induced by Ca²⁺-overloading in different cell types. Exposure of cells to these molecules counteracts the Ca²⁺-induced cell damages by reducing the activation of the Ca²⁺-dependent protease calpain, acting possibly through the modification of the permeability to Ca²⁺ of the plasma membrane. The purification step by RP-HPLC suggests that effective compound(s), differing from the main biophenols known to be present in the olive pomace extract, could be responsible for this effect. Our observations suggest that bioactive molecules present in the olive pomace could be potential candidates for therapeutic applications in pathologies characterised by alterations of intracellular Ca²⁺ homeostasis.

Resveratrol and inflammatory bowel disease: the evidence so far

Despite the fact that inflammatory bowel disease (IBD) has still no recognised therapy, treatments which have proven at least mildly successful in improving IBD symptoms include anti-inflammatory drugs and monoclonal antibodies targeting pro-inflammatory cytokines. Resveratrol, a natural (poly)phenol found in grapes, red wine, grape juice and several species of berries, has been shown to prevent and ameliorate intestinal inflammation. Here, we discuss the role of resveratrol in the improvement of inflammatory disorders involving the intestinal mucosa. The present review covers three specific aspects of resveratrol in the framework of inflammation: (i) its content in food; (ii) its intestinal absorption and metabolism; and (iii) its anti-inflammatory effects in the intestinal mucosa in vitro and in the very few in vivo studies present to date. Actually, if several studies have shown that resveratrol may down-regulate mediators of intestinal immunity in rodent models, only two groups have performed intervention studies in human subjects using resveratrol as an agent to improve IBD conditions. The effects of resveratrol should be further investigated by conducting well-designed clinical trials, also taking into account different formulations for the delivery of the bioactive compound.

Inhibition of the TRPM2 and TRPV1 Channels through Hypericum perforatum in Sciatic Nerve Injury-induced Rats Demonstrates their Key Role in Apoptosis and Mitochondrial Oxidative Stress of Sciatic Nerve and Dorsal Root Ganglion

Sciatic nerve injury (SNI) results in neuropathic pain, which is characterized by the excessive Ca²⁺ entry, reactive oxygen species (ROS) and apoptosis processes although involvement of antioxidant Hypericum perforatum (HP) through TRPM2 and TRPV1 activation has not been clarified on the processes in SNI-induced rat, yet. We investigated the protective property of HP on the processes in the sciatic nerve and dorsal root ganglion neuron (DRGN) of SNI-induced rats. The rats were divided into five groups as control, sham, sham+HP, SNI, and SNI+HP. The HP groups received 30 mg/kg HP for 4 weeks after SNI induction. TRPM2 and TRPV1 channels were activated in the neurons by ADP-ribose or cumene peroxide and capsaicin, respectively. The SNI-induced TRPM2 and TRPV1 currents and intracellular free Ca²⁺ and ROS concentrations were reduced by HP, N-(p-amylcinnamoyl) anthranilic acid (ACA), and capsazepine (CapZ). SNI-induced increase in apoptosis and mitochondrial depolarization in sciatic nerve and DRGN of SNI group were decreased by HP, ACA, and CapZ treatments. PARP-1, caspase 3 and 9 expressions in the sciatic nerve, DRGN, skin, and musculus piriformis of SNI group were also attenuated by HP treatment. In conclusion, increase of mitochondrial ROS, apoptosis, and Ca²⁺ entry through inhibition of TRPM2 and TRPV1 in the sciatic nerve and DRGN neurons were decreased by HP treatment. The results may be relevant to the etiology and treatment of SNI by HP.

Aedes aegypti Larvicidal Sesquiterpene Alkaloids from Maytenus oblongata

Four new sesquiterpene alkaloids (1-4) with a β-dihydroagrofuran skeleton and a new triterpenoid (5) were isolated from an ethyl acetate extract of Maytenus oblongata stems. Their structures were elucidated using 1D and 2D NMR spectroscopy as well as MS and ECD experiments. The M. oblongata stem EtOAc extract and the pure compounds isolated were tested for larvicidal activity against Aedes aegypti under laboratory conditions, and compounds 2 and 3 were found to be active.

The deleterious effect of cholesterol and protection by quercetin on mitochondrial bioenergetics of pancreatic β-cells, glycemic control and inflammation: In vitro and in vivo studies

Studying rats fed high cholesterol diet and a pancreatic β-cell line (Min6), we aimed to determine the mechanisms by which quercetin protects against cholesterol-induced pancreatic β-cell dysfunction and impairments in glycemic control. Quercetin prevented the increase in total plasma cholesterol, but only partially prevented the high cholesterol diet-induced alterations in lipid profile. Quercetin prevented cholesterol-induced decreases in pancreatic ATP levels and mitochondrial bioenergetic dysfunction in Min6 cells, including decreases in mitochondrial membrane potentials and coupling efficiency in the mitochondrial respiration (basal and maximal oxygen consumption rate (OCR), ATP-linked OCR and reserve capacity). Quercetin protected against cholesterol-induced apoptosis of Min6 cells by inhibiting caspase-3 and -9 activation and cytochrome c release. Quercetin prevented the cholesterol-induced decrease in antioxidant defence enzymes from pancreas (cytosolic and mitochondrial homogenates) and Min6 cells and the cholesterol-induced increase of cellular and mitochondrial oxidative status and lipid peroxidation. Quercetin counteracted the cholesterol-induced activation of the NFκB pathway in the pancreas and Min6 cells, normalizing the expression of pro-inflammatory cytokines. Quercetin inhibited the cholesterol-induced decrease in sirtuin 1 expression in the pancreas and pancreatic β-cells. Taken together, the anti-apoptotic, antioxidant and anti-inflammatory properties of quercetin, and its ability to protect and improve mitochondrial bioenergetic function are likely to contribute to its protective action against cholesterol-induced pancreatic β-cell dysfunction, thereby preserving glucose-stimulated insulin secretion (GSIS) and glycemic control. Specifically, the improvement of ATP-linked OCR and the reserve capacity are important mechanisms for protection of quercetin. In addition, the inhibition of the NFκB pathway is an important mechanism for the protection of quercetin against cytokine mediated cholesterol-induced glycemic control impairment. In summary, our data highlight cellular, molecular and bioenergetic mechanisms underlying quercetin's protective effects on β-cells in vitro and in vivo, and provide a scientifically tested foundation upon which quercetin can be developed as a nutraceutical to preserve β-cell function.

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Quercetin prevents the impairment in glycemic control induced by cholesterol.

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Quercetin prevents cholesterol-impaired insulin secretion in pancreatic β-cells.

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Quercetin improves mitochondrial bioenergetics impaired by cholesterol.

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Quercetin prevents the decrease in SIRT1 expression induced by cholesterol.

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Quercetin prevents NF-kB activation and prevents cholesterol-induced inflammation.

Quercetin and the mitochondria: A mechanistic view

Quercetin is an important flavonoid that is ubiquitously present in the diet in a variety of fruits and vegetables. It has been traditionally viewed as a potent antioxidant and anti-inflammatory molecule. However, recent studies have suggested that quercetin may exert its beneficial effects independent of its free radical-scavenging properties. Attention has been placed on the effect of quercetin on an array of mitochondrial processes. Quercetin is now recognized as a phytochemical that can modulate pathways associated with mitochondrial biogenesis, mitochondrial membrane potential, oxidative respiration and ATP anabolism, intra-mitochondrial redox status, and subsequently, mitochondria-induced apoptosis. The present review evaluates recent evidence on the ability of quercetin to interact with the abovementioned pathways, and critically analyses how, such interactions can exert protection against mitochondrial damage in response to toxicity induced by several exogenously and endogenously-produced cellular stressors, and oxidative stress in particular.

Danhong injection protects cardiomyocytes against hypoxia/reoxygenation- and H2O2-induced injury by inhibiting mitochondrial permeability transition pore opening

ETHNOPHARMACOLOGICAL RELEVANCE

Danhong injection (DHI), a Chinese medical product extracted from Radix et Rhizoma Salviae Miltiorrhizae (Salvia miltiorrhiza Bge., Labiatae, Danshen in Chinese) and Flos Carthami (Carthamus tinctorius L., Compositae, Honghua in Chinese), has been widely used for the treatment of ischemic heart disease, and clinical and experimental studies have demonstrated the protective effects against myocardial ischemia/reperfusion injury. Nevertheless, the underlying cellular mechanisms responsible for this protective effect are poorly understood.

AIM OF THE STUDY

The present study aimed to examine the mechanism of DHI in regulating hypoxia/reoxygenation- and H2O2-induced cardiomyocytes injury.

MATERIALS AND METHODS

Neonatal rat cardiomyocytes were subjected to hypoxia (9h)-reoxygenation (2h) or H2O2 (100 μM) in the presence or absence of DHI (2.5, 5, 10 μg/mL). Intracellular reactive oxygen species (ROS), cytosolic and mitochondrial Ca(2+) concentrations, mitochondrial membrane potential (ΔΨm) and mitochondrial permeability transition pore (mPTP) opening were monitored using CMH2DCFDA, Fluo-4 and rhod-2, JC-1 and calcein, respectively. Cell survival was evaluated using the 2-(4,5-dimethylthiazol-2-yl)-2,5 -diphenyltetrazolium bromide (MTT) assay and apoptosis was detected by Annexin V/propidium iodide (PI) staining.

RESULTS

DHI improved cell survival following H/R and H2O2 injury and reduced H/R-induced cytochrome c release and apoptosis when compared with non-DHI treated cells. In addition, DHI attenuated H/R-induced ROS generation, H2O2-induced cytosolic and mitochondrial Ca(2+) overload, and cellular ROS generation when compared with H/R- and H2O2-only groups. Moreover, DHI significantly inhibited both mPTP opening and ΔΨm depolarization.

CONCLUSION

These data demonstrate that the protective mechanism of DHI against H/R- and H2O2-induced injury is mediated by the inhibition of mPTP opening via mitigating Ca(2+) overload and ROS generation.

Changes of intracellular Ca2+ in quercetin-induced autophagy progression

Quercetin was previously reported to exhibit significant anti-proliferative activities, and its major effect on tumors was to induce cell apoptosis or autophagy. However, the specific mechanism remains controversial. In this study, autophagy induced by quercetin was determined with various methods. Intracellular Ca2+ ([Ca2+]i) was measured after being incubated with Fluo-3 acetoxymethyl (AM). At the same time, the relationship between the intracellular Ca2+ and autophagy induced by quercetin was further analyzed. These results showed that autophagy induced by quercetin (0-50 µg/ml) in HepG2 cells was in a dose-dependent manner. Meanwhile, when autophagy was induced by quercetin, [Ca2+]i was significantly increased. And after being incubated with calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N-tetraacetic acid-AM, autophagy was suppressed, which implied that [Ca2+]i elevation appeared to be the cause for autophagy induction. These results suggested that calcium from intracellular calcium storage may play an important role in quercetin-induced autophagy.

Prevention of oxidative stress, inflammation and mitochondrial dysfunction in the intestine by different cranberry phenolic fractions

Cranberry fruit has been reported to have high antioxidant effectiveness that is potentially linked to its richness in diversified polyphenolic content. The aim of the present study was to determine the role of cranberry polyphenolic fractions in oxidative stress (OxS), inflammation and mitochondrial functions using intestinal Caco-2/15 cells. The combination of HPLC and UltraPerformance LC®-tandem quadrupole (UPLC-TQD) techniques allowed us to characterize the profile of low, medium and high molecular mass polyphenolic compounds in cranberry extracts. The medium molecular mass fraction was enriched with flavonoids and procyanidin dimers whereas procyanidin oligomers (DP > 4) were the dominant class of polyphenols in the high molecular mass fraction. Pre-incubation of Caco-2/15 cells with these cranberry extracts prevented iron/ascorbate-mediated lipid peroxidation and counteracted lipopolysaccharide-mediated inflammation as evidenced by the decrease in pro-inflammatory cytokines (TNF-α and interleukin-6), cyclo-oxygenase-2 and prostaglandin E2. Cranberry polyphenols (CP) fractions limited both nuclear factor κB activation and Nrf2 down-regulation. Consistently, cranberry procyanidins alleviated OxS-dependent mitochondrial dysfunctions as shown by the rise in ATP production and the up-regulation of Bcl-2, as well as the decline of protein expression of cytochrome c and apoptotic-inducing factor. These mitochondrial effects were associated with a significant stimulation of peroxisome-proliferator-activated receptor γ co-activator-1-α, a central inducing factor of mitochondrial biogenesis and transcriptional co-activator of numerous downstream mediators. Finally, cranberry procyanidins forestalled the effect of iron/ascorbate on the protein expression of mitochondrial transcription factors (mtTFA, mtTFB1, mtTFB2). Our findings provide evidence for the capacity of CP to reduce intestinal OxS and inflammation while improving mitochondrial dysfunction.

Nonsteroidal anti-inflammatory drug induces proinflammatory damage in gastric mucosa through NF-κB activation and neutrophil infiltration: anti-inflammatory role of heme oxygenase-1 against nonsteroidal anti-inflammatory drug

Nonsteroidal anti-inflammatory drug (NSAID)-induced mitochondrial oxidative stress (MOS) is an important prostaglandin (PG)-independent pathway of the induction of gastric mucosal injury. However, the molecular mechanism behind MOS-mediated gastric pathology is still obscure. In various pathological conditions of tissue injury oxidative stress is often linked with inflammation. Here we report that MOS induced by indomethacin (an NSAID) induces gastric mucosal inflammation leading to proinflammatory damage. Indomethacin, time dependently stimulated the expression of proinflammatory molecules such as intercellular adhesion molecule 1(ICAM-1), vascular cell adhesion molecule 1(VCAM-1), interleukin1β (IL-1β), and monocyte chemotactic protein-1 (MCP-1) in gastric mucosa in parallel with the increase of neutrophil infiltration and injury of gastric mucosa in rat. Western immunoblotting and confocal microscopic studies revealed that indomethacin induced nuclear translocation of nuclear factor kappa-B (NF-κB) in gastric mucosal cells, which resulted in proinflammatory signaling. The prevention of MOS by antioxidant tryptamine-gallic acid hybrid (SEGA) inhibited indomethacin-induced expression of ICAM-1, VCAM-1, IL-1β, and MCP-1. SEGA also prevented indomethacin-induced NF-κB activation and neutrophil infiltration as documented by chromatin immunoprecipitation studies and neutrophil migration assay, respectively. Heme oxygenase-1 (HO-1), a cytoprotective enzyme associated with tissue repair mechanisms is stimulated in response to oxidative stress. We have investigated the role of HO-1 against MOS and MOS-mediated inflammation in recovering from gastropathy. Indomethacin stimulated the expression of HO-1 and indomethacin-stimulated HO-1 expression was reduced by SEGA, an antioxidant, which could prevent MOS. Thus, the data suggested that the induction of HO-1 was a protective response against MOS developed by indomethacin. Moreover, the induction of HO-1 by cobalt protoporphyrin inhibited inflammation and chemical silencing of HO-1 by zinc protoporphyrin aggravated the inflammation by indomethacin. Thus, NSAID by promoting MOS-induced proinflammatory response damaged gastric mucosa and HO-1 protected NSAID-induced gastric mucosal damage by preventing NF-κB activation and proinflammatory activity.

Polyphenols protect the epithelial barrier function of Caco-2 cells exposed to indomethacin through the modulation of occludin and zonula occludens-1 expression

The aim of this study was to determine the protective effect of quercetin, epigallocatechingallate, resveratrol, and rutin against the disruption of epithelial integrity induced by indomethacin in Caco-2 cell monolayers. Indomethacin decreased the transepithelial electrical resistance and increased the permeability of the monolayers to fluorescein-dextran. These alterations were abolished by all the tested polyphenols but rutin, with quercetin being the most efficient. The protective effect of quercetin was associated with its capacity to inhibit the redistribution of ZO-1 protein induced in the tight junction by indomethacin or rotenone, a mitochondrial complex-I inhibitor, and to prevent the decrease of ZO-1 and occludin expression induced by indomethacin. The fact that the antioxidant polyphenols assayed in this study differ in their protective capacity against the epithelial damage induced by indomethacin suggests that this damage is due to the ability of this agent to induce not only oxidative stress but also mitochondrial dysfunction.

Indomethacin inhibits cancer cell migration via attenuation of cellular calcium mobilization

Non-steroidal anti-inflammatory drugs (NSAIDs) were shown to reduce the risk of colorectal cancer recurrence and are widely used to modulate inflammatory responses. Indomethacin is an NSAID. Herein, we reported that indomethacin can suppress cancer cell migration through its influence on the focal complexes formation. Furthermore, endothelial growth factor (EGF)-mediated Ca²⁺ influx was attenuated by indomethacin in a dose dependent manner. Our results identified a new mechanism of action for indomethacin: inhibition of calcium influx that is a key determinant of cancer cell migration.