Quercetin, but not rutin and quercitrin, prevention of H2O2-induced apoptosis via anti-oxidant activity and heme oxygenase 1 gene expression in macrophages

Effects of Mediterranean diets and nutrigenomics on cardiovascular health

The field of nutrigenomics studies the interaction between nutrition and genetics, and how certain dietary patterns can impact gene expression and overall health. The Mediterranean diet (MedDiet), characterized by a high intake of fruits, vegetables, whole grains, and healthy fats, has been linked to better cardiovascular health (CVH) outcomes. This review summarizes the current state of research on the effects of nutrigenomics and MedDiet on cardiovascular health. Results suggest that MedDiet, through its impact on gene expression, can positively influence CVH markers such as blood pressure, lipid profile, and inflammation. However, more research is needed to fully understand the complex interactions between genetics, nutrition, and CVH, and to determine the optimal dietary patterns for individualized care. The aim of this scientific review is to evaluate the current evidence on the effects of nutrigenomics and MedDiet on cardiovascular health. The review summarizes the available studies that have investigated the relationship between nutrition, genetics, and cardiovascular health, and explores the mechanisms by which certain dietary patterns can impact CVH outcomes. The review focuses on the effects of MedDiet, a dietary pattern that is rich in whole foods and healthy fats, and its potential to positively influence CVH through its impact on gene expression. The review highlights the limitations of current research and the need for further studies to fully understand the complex interplay between nutrition, genetics, and cardiovascular health.

Enhancing effect of the coexisting alpha-tocopherol on quercetin absorption and metabolism

The aim of this study is to investigate the modulating effect of coexisting food components on the absorption and metabolism of quercetin and blood plasma antioxidant potentials. The combination of quercetin with α-tocopherol (αT), cellulose, or a commercially available vegetable beverage containing αT and dietary fiber was orally administered to mice. Compared to the single administration of quercetin aglycone, the coadministration of αT with quercetin significantly increased the plasma quercetin concentration at 0.5 h, whereas the combination of quercetin and cellulose decreased it. Interestingly, the administration of quercetin mixed with the vegetable beverage showed no significant change in the quercetin concentration in the mice plasma. The treatment of the cells with the blood plasma after the coadministration of αT with quercetin significantly upregulated the gene expression of the antioxidant enzyme (heme oxygenase-1), whereas the quercetin and cellulose combination did not. In the plasma of the quercetin-administered mice, eight types of quercetin metabolites were detected, and their quantities were affected by the combination with αT. The potentials of the heme oxygenase-1 gene expression by these metabolites were very limited, although several metabolites showed radical scavenging activities comparable to aglycone in the in vitro assays. These results suggested that the combination of αT potentiates the quercetin absorption and metabolism and thus the plasma antioxidant potentials, at least in part, by the quantitative changes in the quercetin metabolites.

Quercetin nano phytosome: as a novel anti-leishmania and anti-malarial natural product

Leishmaniasis is a vector-borne disease that affects several populations worldwide with the clinical manifestations in skin, mucous membranes, and internal organs and there are not any effective and available vaccines and conventional treatments are highly toxic. Quercetin is a kind of flavonoid with different biological effects including free radical scavenging and anti-microbial activity and this study is aimed to assess the anti-leishmania and anti-malarial effects of quercetin loaded phytosome and quercetin alone. In this experimental study, the in vitro activity of above drugs were measured using microscopically examinations and for evaluation the anti-leishmanial efficacy, the size of lesions were measured. Moreover the cytotoxicity of the treatments was evaluated on WI38 and J774 cell lines. Our results indicated that quercetin loaded phytosome and quercetin alone have acceptable anti-parasitic activity mostly at concentration of 400 µg/ml on both P. falciparium and L. major. The results of cytotoxicity revealed that the mentioned drugs have no effects on human cell lines and also have no hemolytic activity. The drug of choice for the treatment of leishmaniasis, in addition to killing the parasite, should not have a toxic effect on human cells and our results indicated that quercetin can be a valuable candidate for treatment of different kinds of leishmaniasis.

A Comprehensive Analysis and Anti-Cancer Activities of Quercetin in ROS-Mediated Cancer and Cancer Stem Cells

Reactive oxygen species (ROS) induce carcinogenesis by causing genetic mutations, activating oncogenes, and increasing oxidative stress, all of which affect cell proliferation, survival, and apoptosis. When compared to normal cells, cancer cells have higher levels of ROS, and they are responsible for the maintenance of the cancer phenotype; this unique feature in cancer cells may, therefore, be exploited for targeted therapy. Quercetin (QC), a plant-derived bioflavonoid, is known for its ROS scavenging properties and was recently discovered to have various antitumor properties in a variety of solid tumors. Adaptive stress responses may be induced by persistent ROS stress, allowing cancer cells to survive with high levels of ROS while maintaining cellular viability. However, large amounts of ROS make cancer cells extremely susceptible to quercetin, one of the most available dietary flavonoids. Because of the molecular and metabolic distinctions between malignant and normal cells, targeting ROS metabolism might help overcome medication resistance and achieve therapeutic selectivity while having little or no effect on normal cells. The powerful bioactivity and modulatory role of quercetin has prompted extensive research into the chemical, which has identified a number of pathways that potentially work together to prevent cancer, alongside, QC has a great number of evidences to use as a therapeutic agent in cancer stem cells. This current study has broadly demonstrated the function-mechanistic relationship of quercetin and how it regulates ROS generation to kill cancer and cancer stem cells. Here, we have revealed the regulation and production of ROS in normal cells and cancer cells with a certain signaling mechanism. We demonstrated the specific molecular mechanisms of quercetin including MAPK/ERK1/2, p53, JAK/STAT and TRAIL, AMPKα1/ASK1/p38, RAGE/PI3K/AKT/mTOR axis, HMGB1 and NF-κB, Nrf2-induced signaling pathways and certain cell cycle arrest in cancer cell death, and how they regulate the specific cancer signaling pathways as long-searched cancer therapeutics.

Different Effects of Quercetin Glycosides and Quercetin on Kidney Mitochondrial Function—Uncoupling, Cytochrome C Reducing and Antioxidant Activity

Flavonols are found in plants as aglycones and as glycosides. Antioxidant activity of flavonols may occur via several mechanisms within the cell, and mitochondria as a target may play an important role. There is a lack of information about the influence of the sugar moiety on biological activity of flavonoid glycosides. The aims of study were to investigate the effects of quercetin and its glycosides on mitochondrial respiration rates at various metabolic states, and to evaluate their antioxidant potential using chemical and biological approaches. Mitochondrial function was measured using an oxygraphic method, cytochrome c reduction spectrophotometrically, H2O2 generation in mitochondria fluorimetrically, and antioxidant activity of flavonoids using an HPLC-post column system. Our data revealed that quercetin and its glycosides isoquercitrin, rutin, and hyperoside uncouple kidney mitochondrial respiration (increasing the State 2 respiration rate) and significantly reduce cytochrome c. Moreover, quercetin, and its glycosides decrease the production of mitochondrial H2O2 and possess radical scavenging and ferric reducing capacities. The highest activity was characteristic for quercetin, showing that the sugar moiety significantly diminishes its activity. In conclusion, our results show the efficient radical scavenging, ferric and cytochrome c reducing capacities, and uncoupling properties of quercetin and its glycosides, as well as the importance of the sugar residue and its structure in the regulation of kidney mitochondrial function.

Rosiridin Attenuates Scopolamine-Induced Cognitive Impairments in Rats via Inhibition of Oxidative and Nitrative Stress Leaded Caspase-3/9 and TNF-α Signaling Pathways

AIM

A monoterpene and bioactive component of the plant Rhodiola rosea (R. rosea), rosiridin has beneficial effects on the human central nervous system and enhances brain function. The goal of this scientific study was to determine if rosiridin might shield rats from neurocognitive problems induced by scopolamine.

METHODS

To track the potential toxicities in rats, the acute toxicity in rats was clarified. Rosiridin at a dose of 10 mg/kg was tested in rats for 14 days. At the conclusion of the investigation, behavioral parameters that were used to identify the rats' cognitive and motor abilities were evaluated. Several biochemical parameters were estimated using the prepared homogenate, including acetylcholine esterase (AChE), choline acetyltransferase (ChAT), radical scavengers produced by the body (Catalase-CAT, superoxide dismutase-SOD, and reduced glutathione-GSH), indicators of oxidative and nitrative burnout, pro-inflammatory (Interleukins- IL-1β, IL-6, interferon gamma IFN-ꝩ, and tumor necrosis factor-TNF-α), and cell apoptosis caspases 3 and 9.

RESULTS AND CONCLUSION

A significant behavioral parameter restoration was seen in the rosiridin-treated group, including reduction in latency time during acquisition and retention trial in the Morris water maze test, and percentage of spontaneous alterations in the y-maze test, when compared to the disease control group that received scopolamine; rosiridin also altered the oxidative stress and neuroinflammatory markers, as well as restoring Ach and ChAT activities and normalizing GSH, SOD, MDA, TNF-α, nitrate, IL-1β, IL-6, IFN-ꝩ, caspases 3 and 9 levels. The results imply that rosiridin limits the effect of scopolamine on rat cognitive function.

Targeting Oxidative Stress as a Therapeutic Approach for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease characterized by an abnormal reepithelialisation, an excessive tissue remodelling and a progressive fibrosis within the alveolar wall that are not due to infection or cancer. Oxidative stress has been proposed as a key molecular process in pulmonary fibrosis development and different components of the redox system are altered in the cellular actors participating in lung fibrosis. To this respect, several activators of the antioxidant machinery and inhibitors of the oxidant species and pathways have been assayed in preclinical in vitro and in vivo models and in different clinical trials. This review discusses the role of oxidative stress in the development and progression of IPF and its underlying mechanisms as well as the evidence of oxidative stress in human IPF. Finally, we analyze the mechanism of action, the efficacy and the current status of different drugs developed to inhibit the oxidative stress as anti-fibrotic therapy in IPF.

Antiamnesic and Neuroprotective Effects of an Aqueous Extract of Ziziphus jujuba Mill. (Rhamnaceae) on Scopolamine-Induced Cognitive Impairments in Rats

Background

Alzheimer's disease is a neurological condition that affects about 44 million people worldwide. The available treatments target symptoms rather than the underlying causes. Ziziphus jujuba (Rhamnaceae) is widely used in traditional Cameroonian medicine to treat diabetes, pain, infections, and dementia. Previous studies reported that Z. jujuba aqueous macerate improves working memory impairment, but no study on the antiamnesic effect of a concoction of Z. jujuba in rats has been performed. Therefore, this study aimed to assess the antiamnesic and neuroprotective effects of an aqueous extract of Z. jujuba on scopolamine-induced cognitive impairments in rats.

Methods

Learning and memory impairments were induced in rats by administering scopolamine (1 mg/kg, i.p.) to 58 rats for 15 days. Rats that developed learning and memory impairments in Morris water maze and Y-maze paradigms were divided into 7 groups (8 rats each) and treated daily for 15 days as follows: the normal control group received distilled water (10 ml/kg, p.o.), the negative control group received distilled water (10 ml/kg, p.o.), positive control groups either received donepezil (1.2 mg/kg, p.o.) or tacrine (10 mg/kg, p.o.), and the three test groups were given the extract (29, 57, and 114 mg/kg, p.o.). At the end of treatments, learning and memory impairments were determined using the same paradigms. Animals were then euthanized, and biochemical parameters of oxidative stress, inflammation, and apoptosis were analyzed in the hippocampus and prefrontal cortex.

Results

On the 4th day of the acquisition phase in the Morris water maze, Z. jujuba (29 and 114 mg/kg) reduced (p < 0.001) the latency to reach the platform, while in the retention phase, Z. jujuba (57 and 114 mg/kg) decreased (p < 0.001) the time to reach the platform and increased the time in the target quadrant (p < 0.05) compared to control. Surprisingly, the extract failed to affect spontaneous alternations in the Y-maze. Furthermore, the extract (29, 57, and 114 mg/kg) reversed (p < 0.001) scopolamine-induced oxidative stress, inflammation, and apoptosis. This was supported by the reduction of neuronal alterations in the hippocampus and prefrontal cortex.

Conclusions

Compared to donepezil, a standard drug against Alzheimer's disease, these findings suggest that Z. jujuba extract possesses antiamnesic and neuroprotective effects, and these effects are mediated in part through antioxidant, anti-inflammatory, and antiapoptotic activities. These findings help to explain its use in treating psychiatric disorders in Cameroon's folk medicine.

Comprehensive investigations for a potential natural prophylaxis-A cellular and murine model for apple cider vinegar against hydrogen peroxide and scopolamine induced oxidative stress

Oxidative stress is the critical marker of neurological complications such as Alzheimer's disease (AD). Apple cider vinegar (ACV) is known to have health benefits due to its antidiabetic, anti-inflammatory, and high antioxidant properties. Therefore, we hypothesized that regular consumption of ACV would protect against AD-like neurological diseases via inhibition of oxidative stress. Authors have compared the efficacy of ACV with that of Chrysin and Rivastigmine in cellular and animal studies. In the cellular study, oxidative stress was induced in Neuro2A cells (1 × 10⁷ ) via H₂ O₂ (50 μM) treatment. Subsequently, acetylcholinesterase (AChE) activity was performed, and cell viability, SOD, GSH, lipid peroxidation (MDA) levels were measured. Similarly, in the animal study, oxidative stress was introduced in Swiss albino mice (10-11 weeks old, 20-25 g, n = 30) via scopolamine (1 mg/kg). Subsequently, histopathological experiments were performed; cognitive ability, AChE activity, and SOD, GSH, and MDA levels were measured. The in vitro results indicated that ACV (2 μM) provided better protection than Chrysin and Rivstigmine in cell viability. ACV has also performed better in restoring the antioxidants markers (SOD, GSH levels) and reducing MDA and AChE levels. In the in vivo study, test compounds (ACV, Chrysin, and Rivastigmine) improved cognitive impairment, increased the SOD and GSH level, reduced the MDA level and AChE activity, and protected the cortex-hippocampal neurons from degeneration. Here also, ACV (0.7%) showed better neuroprotection than the other two compounds. Therefore, these results supported our hypothesis that moderate consumption of ACV might prove to be beneficial prophylaxis against AD-like neurological diseases.

Antioxidant and Anticholinesterase Activities of Extracts and Phytochemicals of Syzygium antisepticum Leaves

Bioassay-guided separation of young leaves extracts of Syzygium antisepticum (Blume) Merr. & L.M. Perry led to the isolation of four triterpenoids (betulinic acid, ursolic acid, jacoumaric acid, corosolic acid) and one sterol glucoside (daucosterol) from the ethyl acetate extract, and three polyphenols (gallic acid, myricitrin, and quercitrin) from the methanol (MeOH) extract. The MeOH extract of S. antisepticum and some isolated compounds, ursolic acid and gallic acid potentially exhibited acetylcholinesterase activity evaluated by Ellman’s method. The MeOH extract and its isolated compounds, gallic acid, myricitrin, and quercitrin, also strongly elicited DPPH radical scavenging activity. In HEK-293 cells, the MeOH extract possessed cellular antioxidant effects by attenuating hydrogen peroxide (H₂O₂)-induced ROS production and increasing catalase, glutathione peroxidase-1 (GPx-1), and glutathione reductase (GRe). Furthermore, myricitrin and quercitrin also suppressed ROS production induced by H₂O₂ and induced GPx-1 and catalase production in HEK-293 cells. These results indicated that the young leaves of S. antisepticum are the potential sources of antioxidant and anticholinesterase agents. Consequently, S. antisepticum leaves are one of indigenous vegetables which advantage to promote the health and prevent diseases related to oxidative stress.

Suppressive effects of quercetin on hydrogen peroxide-induced caveolin-1 phosphorylation in endothelial cells

Caveolin-1 is a major protein of the caveolae structure in vascular endothelial cell membrane. Phosphorylation of caveolin-1 is one of the initial events leading to exacerbation of vascular permeability caused by oxidative stress. Although quercetin is known to be an anti-atherosclerosis factor that acts as a dietary antioxidant, little is known about its role in the regulation of caveolin-1 phosphorylation. In this study, we investigated the inhibitory effect of quercetin on hydrogen peroxide-induced caveolin-1 phosphorylation in human umbilical vein endothelial cells. Quercetin inhibited caveolin-1 phosphorylation in cells pretreated with quercetin for 24 h and then exposed to hydrogen peroxide. However, quercetin 3-O-β-glucuronide, a conjugated metabolite of quercetin, did not exert this inhibitory effect. Exposure to hydrogen peroxide increased vascular permeability and reduced mRNA expression of the intercellular adhesion protein, vascular endothelial cadherin (VE-cadherin). By contrast, pretreatment with quercetin suppressed the increase in vascular permeability and decreased VE-cadherin expression. These results indicate that deconjugated quercetin can play a role in the prevention of altered vascular permeability under oxidative stress by suppressing caveolin-1 phosphorylation. Thus, dietary quercetin may be beneficial for the maintenance of endothelial cell function.

Natural Antioxidant and Anti-Inflammatory Compounds in Foodstuff or Medicinal Herbs Inducing Heme Oxygenase-1 Expression

Heme oxygenase-1 (HO-1) is an inducible antioxidant enzyme that catalyzes heme group degradation. Decreased level of HO-1 is correlated with disease progression, and HO-1 induction suppresses development of metabolic and neurological disorders. Natural compounds with antioxidant activities have emerged as a rich source of HO-1 inducers with marginal toxicity. Here we discuss the therapeutic role of HO-1 in obesity, hypertension, atherosclerosis, Parkinson's disease and hepatic fibrosis, and present important signaling pathway components that lead to HO-1 expression. We provide an updated, comprehensive list of natural HO-1 inducers in foodstuff and medicinal herbs categorized by their chemical structures. Based on the continued research in HO-1 signaling pathways and rapid development of their natural inducers, HO-1 may serve as a preventive and therapeutic target for metabolic and neurological disorders.

Food policy, nutrition and nutraceuticals in the prevention and management of COVID-19: Advice for healthcare professionals

BACKGROUND

The 2019 novel coronavirus (2019-nCoV) represents an ongoing major global health crisis with a potentially unprecedented death toll and socio-economic impact in the modern era. Measures taken to reduce the rate of transmission are too unprecedented, but are deemed necessary. The extensive strain on public health services has meant that individual agency is increasingly called for. To support this, there is a need to review policy and procedure governing the food and commerce industries in particular. Additionally, it is necessary to convey a more comprehensive and nuanced understanding of relevant diet and lifestyle factors to both healthcare practitioners and the general public.

SCOPE AND APPROACH

To our knowledge, a review of possible additional measures for healthcare proffesionals, which includes the possible nutritional management COVID-19 pandemic does not yet exist.Key Findings and Conclusions: This review identifies i) changing trends in consumer awareness and purchasing patterns in response to COVID-19, and their potential future implications for the food and food-commerce industry ii) problematic elements of policy relevant to the outbreak of COVID-19, including the handling of wild-life and food-commerce, ii) newly emergent technologies in food science which represent viable and cost-effective means to reduce the risk of transmission of coronavirus, such as anti-microbial packaging, iii) important nutritional considerations with regard to coronavirus disease prevention and management, including nutrition in early infancy, and the role of select micronutrients (vitamins and minerals), phytochemicals and probiotics in conferring protection against both viral infection and pathogenicity.

Quercetin Inhibited Endothelial Dysfunction and Atherosclerosis in Apolipoprotein E-Deficient Mice: Critical Roles for NADPH Oxidase and Heme Oxygenase-1

NADPH oxidase-dependent superoxide (O₂^·-) production and oxidative stress play important roles in endothelial dysfunction and atherosclerosis. Herein, we investigated the potential effects of dietary quercetin, a flavonoid derived in the diet from vegetables and fruit, on vascular endothelial function and atherosclerosis in the high-fat diet (HFD)-fed apolipoprotein E-deficient (ApoE^-/-) mice. Dietary quercetin treatment significantly suppressed endothelial dysfunction and aortic atherosclerosis in HFD-fed ApoE^-/- mice (P < 0.05, all cases). Mechanistic studies demonstrated that dietary quercetin significantly attenuated p47phox expression and inhibited NADPH oxidase-derived oxidative stress in the aortas of HFD-fed ApoE^-/- mice, while the expression and activity of antioxidant enzyme heme oxygenase-1 (HO-1) was enhanced after quercetin treatment (P < 0.05, all cases). In vitro, it was found that quercetin significantly attenuated NADPH oxidase-derived O₂^·- formation (75 ± 5.6% for quercetin versus 100 ± 6.0% for the control group, P < 0.01) in endothelial cells through induction of HO-1. In addition, the favorable effects of quercetin on oxidant (i.e., H₂O₂)-induced endothelial dysfunction could be eliminated by tin protoporphyrin IX (an HO-1 inhibitor) or HO-1-specific siRNA. Our results demonstrated the critical roles of NADPH oxidase and HO-1 for the indirect antioxidant properties of quercetin in vascular diseases.

Comparison of Different Extraction Methods for the Phenolic Compounds Recovery with the Antioxidant Activity of Bougainvillea x buttiana

Background:

Bougainvillea x buttiana has long been used as a Mexican conventional medicinal drug to cure different sicknesses.

Objective:

In this work, the consequences of ethanol combination and temperature extraction for phenolic compound recovery with the biological activity in Bougainvillea x buttiana extracts were investigated.

Materials and Methods:

The phenolic recovery from Bougainvillea x buttiana was determined by comparing the effects of ethanol 0%, 50-100% (v/v) and extraction temperature (26, 45 and 64°C). The total phenolic content was investigated using spectrophotometric methods. Antioxidant activity from different Bougainvillea x buttiana extracts was evaluated by determining their potential to scavenge the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. The chemical compositions and cytotoxic effect of extracts were determined using GC-MS techniques and the crystal violet technique, respectively.

Results:

Our results confirmed that all extractions with different concentrations and temperatures had significant effects over the total phenolic contents and antioxidant activity (DPPH) of the extracts. The best recuperation of the total phenol content was observed in extracts with 60% ethanol at 26°C (201.08 mgEGA/g dry extract). Extracts with 100% ethanol at 26°C showed the highest antioxidant activity (IC50 was 286.75 μg/mL). GC-MS revealed the presence of various phytochemical contents with polar and non-polar properties. The phenolic compounds were investigated as to the structure, quantity and position of the hydroxyl groups on the benzene ring.

Conclusion:

The ethanolic extract of Bougainvillea x buttiana was confirmed to have high phenolic content and contain pharmacologically active compounds, with potent antioxidant effects and low cytotoxic effects.

In vitro and in vivo antioxidant activity of eucalyptus leaf polyphenols extract and its effect on chicken meat quality and cecum microbiota

While eucalyptus leaf polyphenols extract (EPE) has been evaluated for its various bioactivities, few studies thus far have focused on its systemic antioxidant activity or its effects in chickens in relation to meat quality or the intestinal microbiome. Therefore, the goal of this study was to investigate the antioxidant activity of EPE in vitro and in vivo, and to evaluate its effect on chicken meat quality and cecum microbiota. In this study, EPE scavenged DPPH free radical, ABTS free radical, and superoxide radical, and showed strong reducing power in chemical-based assay. EPE protected RAW264.7 cells from H₂O₂-induced oxidative damage by improving total superoxide dismutase (T-SOD) activity, catalase (CAT) activity and glutathione (GSH) content, decreasing malondialdehyde (MDA) content. Additionally, EPE dietary supplementation was found to increase chicken meat antioxidant levels and quality. Furthermore, chickens fed a diet supplemented with EPE had differentially changed cecal microbial compositions when compared to controls. EPE supplementation notably improved the α-diversity of the cecum. The Firmicutes/Bacteroidetes ratio and the relative abundance of Verrucomicrobia at the phylum level were clearly enhanced in the cecum with EPE supplementation (p < 0.05), with the relative abundance of Subdivision 5 genera incertae sedis and Aminivibrio enriched at genus level (p < 0.05). Therefore, these findings indicate that EPE is a good source of natural antioxidants and could be used as antioxidant supplements in animal feed and other foods, contributing to gut health improvement.

Quercetin Protects Against Lipopolysaccharide-Induced Intestinal Oxidative Stress in Broiler Chickens through Activation of Nrf2 Pathway

We investigated the potential ability of quercetin to protect against lipopolysaccharide (LPS)-induced intestinal oxidative stress in broiler chickens and the potential role of the Nrf2 (nuclear factor erythroid 2-related factor 2) signaling pathway. One-day-old broiler chickens (n = 240) were randomized into four groups: saline-challenged broiler chickens fed a basal diet (Con), LPS-challenged broiler chickens on a basal diet (LPS), and LPS-treated broiler chickens on a basal diet containing either 200 or 500 mg/kg of quercetin (Que200+LPS or Que500+LPS). Quercetin (200 mg/kg) significantly alleviated LPS-induced decreased duodenal, jejunal, and illeal villus height and increased the crypt depth in these regions. Quercetin significantly inhibited LPS-induced jejunal oxidative stress, including downregulated reactive oxygen species (ROS), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, and it upregulated superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels. Quercetin relieved LPS-induced jejunal mitochondria damage and upregulated mitochondrial DNA copy number-related gene expression, including cytochrome c oxidase subunit 1 (COX1), ATP synthase F0 subunit 6 (ATP6), and NADH dehydrogenase subunit 1 (ND1). Quercetin attenuated the LPS-induced inhibition of Nrf2 activation, translocation, and downstream gene expression, including heme oxygenase-1 (HO-1), NAD (P) H dehydrogenase quinone 1 (NQO1), and manganese superoxide dismutase (SOD2). Additionally, quercetin attenuated the LPS-inhibition of c-Jun N-terminal kinase (JNK), Extracellular Regulated protein Kinases (ERK), and p38MAPK (p38) phosphorylation in the MAPK pathway. Thus, quercetin attenuated LPS-induced oxidative stress in the intestines of broiler chickens via the MAPK/Nrf2 signaling pathway.

Andean Prumnopitys Andina (Podocarpacae) Fruit Extracts: Characterization of Secondary Metabolites and Potential Cytoprotective Effect

The fruits from the Chilean Podocarpaceae Prumnopitys andina have been consumed since pre-Hispanic times. Little is known about the composition and biological properties of this fruit. The aim of this work was to identify the secondary metabolites of the edible part of P. andina fruits and to assess their antioxidant activity by means of chemical and cell-based assays. Methanol extracts from P. andina fruits were fractionated on a XAD7 resin and the main compounds were isolated by chromatographic means. Antioxidant activity was determined by means of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing power (FRAP), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. The cytoprotective activity of the extract against oxidative and dicarbonyl stress was evaluated in human gastric epithelial cells (AGS). The total intracellular antioxidant activity (TAA) of the extract was determined in AGS cells. The inhibition of meat lipoperoxidation was evaluated under simulated gastric digestion conditions. Rutin, caffeic acid β-glucoside and 20-hydroxyecdysone were identified as major components of the fruit extract. Additional compounds were identified by high-performance liquid chromatography diode-array detector mass spectrometry (HPLC-DAD-MSⁿ) and/or co-injection with standards. Extracts showed dose-dependent cytoprotective effects against oxidative and dicarbonyl-induced damage in AGS cells. The TAA increased with the pre-incubation of AGS cells with the extract. This is the first report on the composition and biological activity of this Andean fruit.

Effects of quercetin and rosuvastatin each alone or in combination on cyclophosphamide-induced premature ovarian failure in female albino mice

BACKGROUND

Cyclophosphamide (CP) causes premature ovarian failure (POF) due to ovarian toxicity. The toxicity mechanism is attributed to oxidative stress, inflammation, and apoptosis. We assessed whether quercetin and rosuvastatin could promote ovarian protection against CP ovotoxicity.

METHODS

A total of 80 female BALB/c mice were randomly assigned; 10 mice into each of eight groups. Group 1 (control), group 2 (EH), group 3 (CP), group 4 (QH), group 5 (QL), group 6 (RH), group 7 (RL), and group 8 (COM).

RESULTS

Quercetin and rosuvastatin groups (4:8) showed signs of restored ovarian function in the form of a significant, dose-dependent increase in primordial follicles number, serum anti-Mullerian hormone level, and ovarian tissue glutathione level (p < 0.05) versus group 3, and a significant, dose-dependent decrease in atretic follicles number and ovarian tissue level of malondialdehyde (p < 0.05) versus group 3. Immunohistochemistry analysis demonstrated a lower expression of caspase and nuclear factor-kappa B of groups (4:8) versus group 3, although quercetin and rosuvastatin showed a nonsignificant reduction in tumor volume.

CONCLUSIONS

We demonstrated the protective effect of quercetin and rosuvastatin against ovarian toxicity and POF induced by CP without compromising its antitumor effect.

Pro-apoptotic effect of haem oxygenase-1 in human colorectal carcinoma cells via endoplasmic reticular stress

Several biological effects of haem oxygenase (HO)‐1, including anti‐inflammatory, antiapoptotic and antioxidative properties were reported; however, the role of HO‐1 in apoptosis is still unclear. In the presence of stimulation by cobalt protoporphyrin (CoPP), an HO‐1 inducer, apoptotic characteristics were observed, including DNA laddering, hypodiploid cells, and cleavages of caspase (Casp)‐3 and poly(ADP) ribose polymerase (PARP) proteins in human colon carcinoma COLO205, HCT‐15, LOVO and HT‐29 cells in serum‐free (SF) conditions with increased HO‐1, but not heat shock protein 70 (HSP70) or HSP90. The addition of 10% foetal bovine serum (FBS) or 1% bovine serum albumin accordingly inhibited CoPP‐induced apoptosis and HO‐1 protein expression in human colon cancer cells. CoPP‐induced apoptosis of colon cancer cells was prevented by the addition of the pan‐caspase inhibitor, Z‐VAD‐FMK (VAD), and the Casp‐3 inhibitor, Z‐DEVD‐FMK (DEVD). N‐Acetyl cysteine inhibited reactive oxygen species‐generated H₂O₂‐induced cell death with reduced intracellular peroxide production, but did not affect CoPP‐induced apoptosis in human colorectal carcinoma (CRC) cells. Two CoPP analogs, ferric protoporphyrin and tin protoporphyrin, did not affect the viability of human CRC cells or HO‐1 expression by those cells, and knockdown of HO‐1 protein expression by HO‐1 small interfering (si)RNA reversed the cytotoxic effect elicited by CoPP. Furthermore, the carbon monoxide (CO) donor, CORM, but not FeSO₄ or biliverdin, induced DNA ladders, and cleavage of Casp‐3 and PARP proteins in human CRC cells. Increased phosphorylated levels of the endoplasmic reticular (ER) stress proteins, protein kinase R‐like ER kinase (PERK), and eukaryotic initiation factor 2α (eIF2α) by CORM and CoPP were identified, and the addition of the PERK inhibitor, GSK2606414, inhibited CORM‐ and CoPP‐induced apoptosis. Increased GRP78 level and formation of the HO‐1/GRP78 complex were detected in CORM‐ and CoPP‐treated human CRC cells. A pro‐apoptotic role of HO‐1 against the viability of human CRC cells via induction of CO and ER stress was firstly demonstrated herein.

Taurine Have Neuroprotective Activity against Oxidative Damage-Induced HT22 Cell Death through Heme Oxygenase-1 Pathway

Glutamate-induced oxidative neurotoxicity plays a part role in neuronal degeneration on the disorders of central nervous system (CNS). The expression of heme oxygenase (HO)-1 mediated by Inducible nuclear factor-E2-related factor 2 (Nrf2) functions as an anti-oxidants that is able to play an important role in the pathogenesis of several neuronal disorders. In the present study, taurine showed the inhibitory effect against reactive oxygen species (ROS) induction and protective effects against neurotoxicity induced by glutamate- and H2O2 through induction of HO-1 expression in HT22 cells. Moreover, taurine promoted the Nrf2 nuclear translocation in HT22 cells. We also verified the oxidative stress-mediated cell death of HT22 cells was significantly repressed by taurine, using tin protoporphyrin (SnPP) as an HO activity inhibitor. In addition, we found that treatment of the cells with p38 inhibitor (SB203580) suppressed taurine-induced HO-1 expression and cytoprotection, but inhibitors of c-Jun NH2 terminal kinase (JNK) (SP600125) or extracellular signal regulated kinase (ERK) (PD98059) did not. These results suggest that taurine improves the resistance against oxidative damages induced by glutamate in HT22 cells via the p38/Nrf2-dependent HO-1 expression. Our results demonstrated the potential application of taurine as a therapeutic agent for neurodegenerative diseases.

Activity-guided isolation of phase II enzyme inducers from buckwheat flour methanolic extracts

BACKGROUND

Buckwheat is an important alternative crop and a raw material for functional food formulation. Phase II detoxification proteins/enzymes provide cytoprotective roles against oxidative stress and inflammation originating from various stressors. We aimed to identify and characterize potential phase II enzyme inducers from methanolic extracts of buckwheat flour, using an activity-guided fractionation based on the induction of quinone reductase (QR) (EC 1.6.5.2) in Hepa 1c1c7 cells.

RESULTS

We isolated the QR inducers N-trans-feruloyltyramine (I), syringic acid (II), quercetin (III) and myricetin (IV). The relative QR-inducing ability, as well as the concentration required to double QR specific activity (CD values, in parentheses), decreased in the order: quercetin (3.0 µmol L^-1 ) > N-trans-feruloyltyramine (24 µmol L^-1 ) > myricetin (58 µmol L^-1 ) > syringic acid (5.4 mmol L^-1 ). Quercetin and N-trans-feruloyltyramine exhibited the greatest extent of QR induction of an approximately four-fold maximum induction and these compounds also exhibited the greatest values for the ratio of IC₅₀ (i.e. level to reduce viability by 50%): CD values of 11 and > 8.3, respectively, among the four QR inducers isolated. Isobologram analyses for binary combinations of compounds I-IV revealed primarily antagonistic interactions for QR induction.

CONCLUSION

These findings add to our understanding of the nutraceutical potential of buckwheat as a chemoprophylactic dietary component. © 2018 Society of Chemical Industry.

Protective effect of enzymatic hydrolysates from seahorse (Hippocampus abdominalis) against H2O2-mediated human umbilical vein endothelial cell injury

Oxidative stress-mediated endothelial dysfunction and LDL oxidation have been implicated in the pathogenesis of atherosclerosis. Thus, the protection of the endothelial cells against oxidative stress-mediated injury and the inhibition of LDL oxidation by the use of antioxidants are a good strategy against atherosclerosis development. Here, we investigated the protective effect and the inhibition of LDL oxidation of seahorse H. abdominalia hydrolysates by Alcalase (SHAH). SHAH showed higher antioxidant activities by measuring DPPH, ABTS⁺, and ORAC assays than the other hydrolysates. SHAH reduced the formation of thiobarbituric acid reactive substance in Cu²⁺-induced LDL oxidation. In human umbilical vein endothelial cell (HUVEC), SHAH ameliorated H₂O₂-mediated HUVEC injury through the restoration of antioxidant enzyme activities and glutathione. In addition, SHAH inhibited HUVEC apoptosis through the down-regulation of caspase-3 and p53 and the increase bcl-2/bax ratio. These results suggested that seahorse H. abdominalia could be developed as potential agents for atherosclerosis.

Plant-Derived Anticancer Agents: Lessons from the Pharmacology of Geniposide and Its Aglycone, Genipin

For centuries, plants have been exploited by mankind as sources of numerous cancer chemotherapeutic agents. Good examples of anticancer compounds of clinical significance today include the taxanes (e.g., taxol), vincristine, vinblastine, and the podophyllotoxin analogues that all trace their origin to higher plants. While all these drugs, along with the various other available therapeutic options, brought some relief in cancer management, a real breakthrough or cure has not yet been achieved. This critical review is a reflection on the lessons learnt from decades of research on the iridoid glycoside geniposide and its aglycone, genipin, which are currently used as gold standard reference compounds in cancer studies. Their effects on tumour development (carcinogenesis), cancer cell survival, and death, with particular emphasis on their mechanisms of actions, are discussed. Particular attention is also given to mechanisms related to the dual pro-oxidant and antioxidant effects of these compounds, the mitochondrial mechanism of cancer cell killing through reactive oxygen species (ROS), including that generated through the uncoupling protein-2 (UCP-2), the inflammatory mechanism, and cell cycle regulation. The implications of various studies for the evaluation of glycosidic and aglycone forms of natural products in vitro and in vivo through pharmacokinetic scrutiny are also addressed.

Alternative use of Bacillus subtilis spores: protection against environmental oxidative stress in human normal keratinocytes

Inorganic trivalent arsenic is a major environmental pollutant and exposure to human results in many pathologies, including keratosis and carcinoma. Here, we analyzed the effects of B. subtilis spores on human normal keratinocytes in the presence of sodium arsenite oxidative stress. Pre-treatment of cells with spores before inducing oxidative stress was able to keep normal levels of intracellular ROS, GSH and lipid peroxidation, as well as to inhibit the activation of the MAPK cascade. Moreover, spores showed a positive effect on cell proliferation, probably due to their binding on the cell surface and the activation of intracellular catalases. We found that spores exert their protective effect by the nuclear translocation of Nrf-2, involved in the activation of stress response genes. This, in turn, resulted in a protective effect against sodium arsenite stress injury, as oxidative stress markers were reported to physiological levels when cells were stressed before incubating them with spores. Therefore, B. subtilis spores can be considered as a new agent to counteract oxidative stress on normal human keratinocytes.

Flavonoids as detoxifying and pro-survival agents: What's new?

The role of flavonoids in the survival machinery of cells has come in the spotlight due to the recent evidence of their effect on the relationship mitochondria-ER stress-proteasome, including the intracellular mechanisms of autophagy and apoptosis. Numerous experimental animal investigations and even human clinical studies have highlighted the major role of these natural compounds in the economy of life and their deep relationship with autotrophic organisms in the evolutionary space. Their role as anti-oxidant and oxidative stress preventive molecules has to date been investigated extensively in the literature. Despite this great amount of promising evidence, many concerns, however, remain, most of which dealing with biochemistry, bioavailability, pharmacokinetics, and interaction of flavonoids with gut microbiome, issues that make difficult any good attempt to introduce these molecules in the human healthcare systems as possible, encouraging therapeutic substances. This review tries to address and elucidate these items.

Study on Chemical Profile and Neuroprotective Activity of Myrica rubra Leaf Extract

The chemical profile of Myrica rubra (a native species in China) leaf extract was investigated by UPLC-PDA-HRMS, and the neuroprotective activity of two characteristic constituents, myricanol and myricetrin, was evaluated with N2a cells using H₂O₂-inducedoxidative challenge through a series of methods, e.g., MTT assay, ROS assay and [Ca2+]i assay. Among the 188 constituents detected in the extract of Myrica rubra leaf, 116 were identified definitely or tentatively by the comprehensive utilization of precise molecular weight and abundant multistage fragmentation information obtained by quadrupole orbitrap mass spectrometry. In addition, 14 potential new compounds were reported for the first time. This work established an example for the research of microconstituents in a complex analyte and revealed that suppression of H₂O₂-induced cytotoxicity in N2a cells was achieved by the pretreatment with myricanol. The evidence suggested myricanol may potentially serve as a remedy for prevention and therapy of neurodegenerative diseases induced by oxidative stress.

Antibacterial, Anticancer and Neuroprotective Activities of Rare Actinobacteria from Mangrove Forest Soils

Mangrove is a complex ecosystem that contains diverse microbial communities, including rare actinobacteria with great potential to produce bioactive compounds. To date, bioactive compounds extracted from mangrove rare actinobacteria have demonstrated diverse biological activities. The discovery of three novel rare actinobacteria by polyphasic approach, namely Microbacterium mangrovi MUSC 115T, Sinomonas humi MUSC 117T and Monashia flava MUSC 78T from mangrove soils at Tanjung Lumpur, Peninsular Malaysia have led to the screening on antibacterial, anticancer and neuroprotective activities. A total of ten different panels of bacteria such as Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300, ATCC 70069, Pseudomonas aeruginosa NRBC 112582 and others were selected for antibacterial screening. Three different neuroprotective models (hypoxia, oxidative stress, dementia) were done using SHSY5Y neuronal cells while two human cancer cells lines, namely human colon cancer cell lines (HT-29) and human cervical carcinoma cell lines (Ca Ski) were utilized for anticancer activity. The result revealed that all extracts exhibited bacteriostatic effects on the bacteria tested. On the other hand, the neuroprotective studies demonstrated M. mangrovi MUSC 115T extract exhibited significant neuroprotective properties in oxidative stress and dementia model while the extract of strain M. flava MUSC 78T was able to protect the SHSY5Y neuronal cells in hypoxia model. Furthermore, the extracts of M. mangrovi MUSC 115T and M. flava MUSC 78T exhibited anticancer effect against Ca Ski cell line. The chemical analysis of the extracts through GC-MS revealed that the majority of the compounds present in all extracts are heterocyclic organic compound that could explain for the observed bioactivities. Therefore, the results obtained in this study suggested that rare actinobacteria discovered from mangrove environment could be potential sources of antibacterial, anticancer and neuroprotective agents.

Flavonolignan 2,3-dehydrosilydianin activates Nrf2 and upregulates NAD(P)H:quinone oxidoreductase 1 in Hepa1c1c7 cells

Silybum marianum (milk thistle) is a medicinal plant used for the treatment of various liver disorders. This study examined whether the main flavonolignans from S. marianum (i.e. silybin, silychristin, silydianin) and their 2,3-dehydro derivatives (i.e. 2,3-dehydrosilybin, 2,3-dehydrosilychristin, 2,3-dehydrosilydianin) activate the Nrf2 pathway, which regulates the expression of genes encoding many cytoprotective enzymes, including NAD(P)H:quinone oxidoreductase 1 (NQO1). After 48h of exposure, 2,3-dehydrosilydianin at concentrations of 25μM and higher significantly elevated the activity of NQO1 in murine hepatoma Hepa1c1c7 cells. In contrast, other tested compounds at non-cytotoxic concentrations had a mild or negligible effect on the NQO1 activity. Using a luciferase reporter assay, 2,3-dehydrosilydianin was found to significantly activate transcription via the antioxidant response element in stably transfected human AREc32 reporter cells. Moreover, 2,3-dehydrosilydianin caused the accumulation of Nrf2 and significantly induced the expression of the Nqo1 gene at both the mRNA and protein levels in Hepa1c1c7 cells. We found that 2,3-dehydrosilydianin also increased to some extent the expression of other Nrf2 target genes, namely of the heme oxygenase-1 gene (Hmox1) and the glutamate-cysteine ligase modifier subunit gene (Gclm). We conclude that 2,3-dehydrosilydianin activates Nrf2 and induces Nrf2-mediated gene expression in Hepa1c1c7 cells.

Anthoxanthin Polyphenols Attenuate Aβ Oligomer-induced Neuronal Responses Associated with Alzheimer's Disease

AIMS

Epidemiological evidence implicates polyphenols as potential natural therapeutics for Alzheimer's disease (AD). To investigate this prospect, five anthoxanthin polyphenols were characterized for their ability to reduce amyloid-β (Aβ) oligomer-induced neuronal responses by two mechanisms of action, modulation of oligomerization and antioxidant activity, as well as the synergy between these two mechanisms.

METHODS

Anthoxanthin oligomerization modulation and antioxidant capabilities were evaluated and correlated with anthoxanthin attenuation of oligomer-induced intracellular reactive oxygen species (ROS) and caspase activation using human neuroblastoma cell treatments designed to isolate these mechanisms of action and to achieve dual-action.

RESULTS

While modulation of oligomerization resulted in only minor reductions to neuronal responses, anthoxanthin antioxidant action significantly attenuated oligomer-induced intracellular ROS and caspase activation. Kaempferol uniquely exhibited synergism when the two mechanisms functioned in concert, leading to a pronounced reduction in both ROS and caspase activation.

CONCLUSIONS

Together, these findings identify the dominant mechanism by which these anthoxanthins attenuate Aβ oligomer-induced neuronal responses, elucidate their prospective synergy, and demonstrate the potential of anthoxanthin polyphenols as natural AD therapeutics.

Actions of Quercetin, a Polyphenol, on Blood Pressure

Disorder of blood pressure control causes serious diseases in the cardiovascular system. This review focuses on the anti-hypertensive action of quercetin, a flavonoid, which is one of the polyphenols characterized as the compounds containing large multiples of phenol structural units, by varying the values of various blood pressure regulatory factors, such as vascular compliance, peripheral vascular resistance, and total blood volume via anti-inflammatory and anti-oxidant actions. In addition to the anti-inflammatory and anti-oxidant actions of quercetin, we especially describe a novel mechanism of quercetin’s action on the cytosolic Cl⁻ concentration ([Cl⁻]_c) and novel roles of the cytosolic Cl⁻ i.e., (1) quercetin elevates [Cl⁻]_c by activating Na⁺-K⁺-2Cl⁻ cotransporter 1 (NKCC1) in renal epithelial cells contributing to Na⁺ reabsorption via the epithelial Na⁺ channel (ENaC); (2) the quercetin-induced elevation of [Cl⁻]_c in renal epithelial cells diminishes expression of ENaC leading to a decrease in renal Na⁺ reabsorption; and (3) this reduction of ENaC-mediated Na⁺ reabsorption in renal epithelial cells drops volume-dependent elevated blood pressure. In this review, we introduce novel, unique mechanisms of quercetin’s anti-hypertensive action via activation of NKCC1 in detail.

Rutin as a Mediator of Lipid Metabolism and Cellular Signaling Pathways Interactions in Fibroblasts Altered by UVA and UVB Radiation

Background. Rutin is a natural nutraceutical that is a promising compound for the prevention of UV-induced metabolic changes in skin cells. The aim of this study was to examine the effects of rutin on redox and endocannabinoid systems, as well as proinflammatory and proapoptotic processes, in UV-irradiated fibroblasts. Methods. Fibroblasts exposed to UVA and UVB radiation were treated with rutin. The activities and levels of oxidants/antioxidants and endocannabinoid system components, as well as lipid, DNA, and protein oxidation products, and the proinflammatory and pro/antiapoptotic proteins expression were measured. Results. Rutin reduced UV-induced proinflammatory response and ROS generation and enhanced the activity/levels of antioxidants (SOD, GSH-Px, vitamin E, GSH, and Trx). Rutin also normalized UV-induced Nrf2 expression. Its biological activity prevented changes in the levels of the lipid mediators: MDA, 4-HNE, and endocannabinoids, as well as the endocannabinoid receptors CB1/2, VR1, and GPR55 expression. Furthermore, rutin prevented the protein modifications (tyrosine derivatives formation in particular) and decreased the levels of the proapoptotic markers—caspase-3 and cytochrome c. Conclusion. Rutin prevents UV-induced inflammation and redox imbalance at protein and transcriptional level which favors lipid, protein, and DNA protection. In consequence rutin regulates endocannabinoid system and apoptotic balance.

The protective mechanism of QGC in feline esophageal epithelial cells by interleukin-1β treatment

In a previous study, Quercetin-3-O-β-D-glucuronopyranoside (QGC) has anti-oxidative and anti-inflammatory effects in vivo. QGC is a flavonoid glucoside extracted from Rumex Aquaticus. We investigated the downstream target proteins involved in IL-1β-stimulated ROS production and the ability of QGC to inhibit ROS production. Cell viability was determined using the MTT reduction assay. Western blot analysis was performed with antibodies to investigate the activation of three MAPKs, NF-κB, and phosphorylated IκB-α (pIB), and the expression of COX-2. 2',7'-dichlorofluorescin diacetate was used to detect the generation of intracellular ROS species. When the cells were exposed to media containing IL-1β for 18 h, cell viability was not affected. QGC did not reduce the COX-2 expression induced by IL-1β. However; QGC attenuated the production of intracellular ROS induced by IL-1β. IL-1β increased the expression of ERK, p38 MAPK, and pIB, and nuclear translocation of NF-κB were recovered by the ROS scavenger N-acetyl-L-cysteine (NAC) and QGC, but not by the NADPH oxidase inhibitor diphenylene iodonium. Pretreatment of cells with the ERK inhibitor PD98059, the p38 MAPK inhibitor SB202190, NAC, and QGC attenuated nuclear translocation of NF-κB and activation of pIB. QGC has a scavenging effect on cytokine-induced ROS production, thereby preventing its downstream effects, nuclear translocation of NF-κB, and activation of pIB is mediated by activation of ERK and p38 MAPK, although QGC does not inhibit IL-1β-stimulated COX-2 expression in feline esophageal epithelial cells. The data suggest that QGC exerts anti-oxidative effects and inhibitory effects against esophageal epithelial cells signals by the action of IL-1β treatment.

Semisynthetic flavonoid 7-O-galloylquercetin activates Nrf2 and induces Nrf2-dependent gene expression in RAW264.7 and Hepa1c1c7 cells

The natural flavonoid quercetin is known to activate the transcription factor Nrf2, which regulates the expression of cytoprotective enzymes such as heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). In this study, a novel semisynthetic flavonoid 7-O-galloylquercetin (or quercetin-7-gallate, 3) was prepared by direct galloylation of quercetin, and its effect on the Nrf2 pathway was examined. A luciferase reporter assay showed that 7-O-galloylquercetin, like quercetin, significantly activated transcription via the antioxidant response element in a stably transfected human AREc32 reporter cell line. In addition, 7-O-galloylquercetin caused the accumulation of Nrf2 and induced the expression of HO-1 at both the mRNA and protein levels in murine macrophage RAW264.7 cells. The induction of HO-1 by 7-O-galloylquercetin was significantly suppressed by N-acetyl-l-cysteine and SB203580, indicating the involvement of reactive oxygen species and p38 mitogen-activated protein kinase activity, respectively. HPLC/MS analyses also showed that 7-O-galloylquercetin was not degalloylated to quercetin, but it was conjugated with glucuronic acid and/or methylated in RAW264.7 cells. Furthermore, 7-O-galloylquercetin was found to increase the protein levels of Nrf2 and HO-1, and also the activity of NQO1 in murine hepatoma Hepa1c1c7 cells. Taken together, we conclude that 7-O-galloylquercetin increases Nrf2 activity and induces Nrf2-dependent gene expression in RAW264.7 and Hepa1c1c7 cells.

Morinda citrifolia mitigates rotenone-induced striatal neuronal loss in male Sprague-Dawley rats by preventing mitochondrial pathway of intrinsic apoptosis

OBJECTIVES

Parkinson disease (PD) is a neurodegenerative disorder affecting mainly the motor system, as a result of death of dopaminergic neurons in the substantia nigra pars compacta. The present scenario of research in PD is directed to identify novel molecules that can be administered individually or co-administered with L-Dopa to prevent the L-Dopa-Induced Dyskinesia (LID) like states that arise during chronic L-Dopa administration. Hence, in this study, we investigated whether Morinda citrifolia has therapeutic effects in rotenone-induced Parkinson's disease (PD) with special reference to mitochondrial dysfunction mediated intrinsic apoptosis.

METHODS

Male Sprague-Dawley rats were stereotaxically infused with rotenone (3 µg in both SNPc and VTA) and co-treated with the ethyl acetate extract of Morinda citrifolia and levodopa.

RESULTS

The results revealed that rotenone-induced cell death was reduced by MCE treatment as measured by decline in the levels of pro-apoptotic proteins. Moreover, MCE treatment significantly augmented the levels of anti-apoptotic Bcl2 and blocks the release of cytochrome c, thereby alleviating the rotenone-induced dopaminergic neuronal loss, as evidenced by tyrosine hydroxylase (TH) immunostaining in the striatum.

DISCUSSION

Taken together, the results suggest that Morinda citrifolia may be beneficial for the treatment of neurodegenerative diseases like PD.