scholarly journals Health Effects of Coffee: Mechanism Unraveled?

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1842 ◽  
Author(s):  
Hubert Kolb ◽  
Kerstin Kempf ◽  
Stephan Martin

The association of habitual coffee consumption with a lower risk of diseases, like type 2 diabetes mellitus, chronic liver disease, certain cancer types, or with reduced all-cause mortality, has been confirmed in prospective cohort studies in many regions of the world. The molecular mechanism is still unresolved. The radical-scavenging and anti-inflammatory activity of coffee constituents is too weak to account for such effects. We argue here that coffee as a plant food has similar beneficial properties to many vegetables and fruits. Recent studies have identified a health promoting mechanism common to coffee, vegetables and fruits, i.e., the activation of an adaptive cellular response characterized by the upregulation of proteins involved in cell protection, notably antioxidant, detoxifying and repair enzymes. Key to this response is the activation of the Nrf2 (Nuclear factor erythroid 2-related factor-2) system by phenolic phytochemicals, which induces the expression of cell defense genes. Coffee plays a dominant role in that regard because it is the major dietary source of phenolic acids and polyphenols in the developed world. A possible supportive action may be the modulation of the gut microbiota by non-digested prebiotic constituents of coffee, but the available data are still scarce. We conclude that coffee employs similar pathways of promoting health as assumed for other vegetables and fruits. Coffee beans may be viewed as healthy vegetable food and a main supplier of dietary phenolic phytochemicals.

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1144
Author(s):  
Hubert Kolb ◽  
Stephan Martin ◽  
Kerstin Kempf

Prospective epidemiological studies concur in an association between habitual coffee consumption and a lower risk of type 2 diabetes. Several aspects of these studies support a cause–effect relationship. There is a dependency on daily coffee dose. Study outcomes are similar in different regions of the world, show no differences between sexes, between obese versus lean, young versus old, smokers versus nonsmokers, regardless of the number of confounders adjusted for. Randomized controlled intervention trials did not find a consistent impact of drinking coffee on acute metabolic control, except for effects of caffeine. Therefore, lowering of diabetes risk by coffee consumption does not involve an acute effect on the post-meal course of blood glucose, insulin or insulin resistance. Several studies in animals and humans find that the ingestion of coffee phytochemicals induces an adaptive cellular response characterized by upregulation and de novo synthesis of enzymes involved in cell defense and repair. A key regulator is the nuclear factor erythroid 2-related factor 2 (Nrf2) in association with the aryl hydrocarbon receptor, AMP-activated kinase and sirtuins. One major site of coffee actions appears to be the liver, causing improved fat oxidation and lower risk of steatosis. Another major effect of coffee intake is preservation of functional beta cell mass via enhanced mitochondrial function, lower endoplasmic reticulum stress and prevention or clearance of aggregates of misfolded proinsulin or amylin. Long-term preservation of proper liver and beta cell function may account for the association of habitual coffee drinking with a lower risk of type 2 diabetes, rather than acute improvement of metabolic control.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 614
Author(s):  
Martyna Zagórska-Dziok ◽  
Aleksandra Ziemlewska ◽  
Tomasz Bujak ◽  
Zofia Nizioł-Łukaszewska ◽  
Zofia Hordyjewicz-Baran

Due to the constantly growing interest in ingredients of natural origin, this study attempts to evaluate the possibility of using extracts from three Ayurvedic plants in preparations for the care and treatment of skin diseases. Therefore, studies of antioxidant properties were carried out using DPPH and ABTS radicals, obtaining 76% and 88% of these radical scavenging, respectively. A significant decrease in the intracellular level of free radicals and an increase in the activity of the antioxidant enzyme-superoxide dismutase by almost 60% were also observed. In addition, the extracts were assessed for anti-inflammatory and anti-aging properties, obtaining over 70% inhibition of lipoxygenase activity and almost 40% of collagenase. Additionally, the cytoprotective properties of the obtained extracts on skin cells, keratinocytes and fibroblasts, were demonstrated. To assess the content of biologically active compounds, HPLC-electrospray ionization (ESI)-MS/MS multiple reaction monitoring (MRM) analyses were performed. The obtained results show that all three analyzed plants are a valuable source of biologically active substances with desired properties in the context of skin cell protection. Particularly noteworthy is the extract of Epilobium angustifolium L., for which the most promising results were obtained.


Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1033 ◽  
Author(s):  
Yoonsu Kim ◽  
Jisun Oh ◽  
Chan Ho Jang ◽  
Ji Sun Lim ◽  
Jeong Soon Lee ◽  
...  

The fruit of Ziziphus jujuba, commonly called jujube, has long been consumed for its health benefits. The aim of this study was to examine the protective effect of dietary supplementation of enzymatically hydrolyzed jujube against lung inflammation in mice. The macerated flesh of jujube was extracted with aqueous ethanol before and after Viscozyme treatment. The extract of enzyme-treated jujube, called herein hydrolyzed jujube extract (HJE), contained higher levels of quercetin, total phenolics, and flavonoids, and exhibited more effective radical-scavenging abilities in comparison to non-hydrolyzed jujube extract (NHJE). HJE treatment decreased production of inflammation-associated molecules, including nitric oxide and pro-inflammatory cytokines from activated Raw 264.7 or differentiated THP-1 cells. HJE treatment also reduced expression of nuclear factor-κB and its downstream proteins in A549 human lung epithelial cells. Moreover, oral supplementation of 1.5 g of HJE per kg of body weight (BW) attenuated histological lung damage, decreased plasma cytokines, and inhibited expression of inflammatory proteins and oxidative stress mediators in the lungs of mice exposed to benzo(a)pyrene at 50 mg/kg BW. Expression levels of antioxidant and cytoprotective factors, such as nuclear factor erythroid-derived 2-related factor 2 and heme oxygenase-1, were increased in lung and liver tissues from mice treated with HJE, compared to mice fed NHJE. These findings indicate that dietary HJE can reduce benzo(a)pyrene-induced lung inflammation by inhibiting cytokine release from macrophages and promoting antioxidant defenses in vivo.


2020 ◽  
Vol 21 (16) ◽  
pp. 5825 ◽  
Author(s):  
Amanda Kristiansson ◽  
Sara Davidsson ◽  
Maria E. Johansson ◽  
Sarah Piel ◽  
Eskil Elmér ◽  
...  

Oxidative stress is associated with many renal disorders, both acute and chronic, and has also been described to contribute to the disease progression. Therefore, oxidative stress is a potential therapeutic target. The human antioxidant α1-microglobulin (A1M) is a plasma and tissue protein with heme-binding, radical-scavenging and reductase activities. A1M can be internalized by cells, localized to the mitochondria and protect mitochondrial function. Due to its small size, A1M is filtered from the blood into the glomeruli, and taken up by the renal tubular epithelial cells. A1M has previously been described to reduce renal damage in animal models of preeclampsia, radiotherapy and rhabdomyolysis, and is proposed as a pharmacological agent for the treatment of kidney damage. In this paper, we examined the in vitro protective effects of recombinant human A1M (rA1M) in human proximal tubule epithelial cells. Moreover, rA1M was found to protect against heme-induced cell-death both in primary cells (RPTEC) and in a cell-line (HK-2). Expression of stress-related genes was upregulated in both cell cultures in response to heme exposure, as measured by qPCR and confirmed with in situ hybridization in HK-2 cells, whereas co-treatment with rA1M counteracted the upregulation. Mitochondrial respiration, analyzed with the Seahorse extracellular flux analyzer, was compromised following exposure to heme, but preserved by co-treatment with rA1M. Finally, heme addition to RPTE cells induced an upregulation of the endogenous cellular expression of A1M, via activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)-pathway. Overall, data suggest that A1M/rA1M protects against stress-induced damage to tubule epithelial cells that, at least partly, can be attributed to maintaining mitochondrial function.


2013 ◽  
Vol 64 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Huangyuan Li ◽  
Siying Wu ◽  
Junnian Chen ◽  
Bo Wang ◽  
Nian Shi

Transcription factor NF-E2-related factor 2 (Nrf2) is important for cell protection against chemical-induced oxidative stress. Previously, we have reported that in PC12 cells, Nrf2 can be triggered by deltamethrin (DM), a commonly used pyrethroid insecticide. Molecular mechanisms behind Nrf2 activation by DM are still unclear. Here we studied the effects of cell glutathione (GSH) depletion on Nrf2 activation by DM. We found that DM enhanced Nrf2 expression at the mRNA and protein levels and increased nuclear Nrf2 levels. Activation of Nrf2 was associated with activation of its downstream targets, such as heme oxygenase-1 (HO-1) and glutamate cysteine ligase catalytic subunit (GCLC). In contrast, DL-buthionine-[S,R]- sulfoximine (BSO), a known GSH-depleting agent, did not increase Nrf2 protein expression or cause its nuclear accumulation. However, pre-treatment with BSO triggered mRNA expression of HO-1 and GCLC. Furthermore, BSO pre-treatment suppressed DM-induced Nrf2 upregulation and activation and lowered mRNA expression of HO-1 and GCLC upon DM treatment. These data demonstrate that GSH depletion is not necessary for the activation of Nrf2/ARE by DM in PC12 cells, and that GCLC and HO-1 expression can increase through other signalling pathways.


2017 ◽  
Vol 7 (4) ◽  
pp. 20160113 ◽  
Author(s):  
Yuru Deng ◽  
Edlyn Li-Hui Lee ◽  
Ketpin Chong ◽  
Zakaria A. Almsherqi

The frequent appearance of non-lamellar membrane arrangements such as cubic membranes (CMs) in cells under stressed or pathological conditions points to an intrinsic cellular response mechanism. CM represents highly curved, three-dimensional nano-periodic structures that correspond to mathematically well-defined triply periodic minimal surfaces. Specifically, cellular membrane may transform into CM organization in response to pathological, inflammatory and oxidative stress conditions. CM organization, thus, may provide an advantage to cope with various types of stress. The identification of inducible membrane systems, such as in the mitochondrial inner membranes to cubic morphology upon starvation, opens new avenues for understanding the molecular mechanisms of cellular responses to oxidative stress. In this study, we compared the cellular responses of starved and fed amoeba Chaos carolinense to oxidative stress. Food deprivation from C. carolinense induces a significant increase in prooxidants such as superoxide and hydrogen peroxide. Surprisingly, we observed a significant lower rate of biomolecular damage in starved cells (with higher free radicals generation) when compared with fed cells. Specifically, lipid and RNA damages were significantly less in starved cells compared with fed cells. This observation was not due to the upregulation of intracellular antioxidants, as starved amoeba show reduced antioxidant enzymatic activities; however, it could be attributed to CM formation. CM could uptake and retain short segments of nucleic acids (resembles cellular RNA) in vivo and in vitro. Previous results showed that nucleic acids retained within CM sustain a minimal oxidative damage in vitro upon exposure to high level of superoxide. We thus propose that CM may act as a ‘protective’ shelter to minimize the oxidation of biologically essential macromolecules such as RNA. In summary, we examined enzymatic antioxidant activities as well as oxidative damage biomarkers in starved amoeba C. carolinense in correlation with the potential role of CM as an optimal intracellular membrane organization for the protection of biological macromolecules against oxidative damage.


2012 ◽  
Vol 11 (04) ◽  
pp. 871-893 ◽  
Author(s):  
K. SADASIVAM ◽  
R. JAYAPRAKASAM ◽  
R. KUMARESAN

The molecular properties of robinetin and melanoxetin which are the two naturally occurring flavonoid compounds have been studied theoretically by means of density functional theory approach (DFT) at the level of B3LYP/6-311G(d,p). The analysis of computed bond dissociation enthalpy (BDE), proton dissociation enthalpy (PDE), proton affinity (PA), electron transfer enthalpy (ETE) values for both the flavonoid compounds indicate the role of B-ring for the significant antioxidant characteristics and the instability of the A-ring. It also concerns the dominant role of BDE mechanism for antioxidant activity than PDE, PA and ETE mechanisms. Ionization potential (IP) is also found to be trustworthy in the study of antioxidant activity and the computed IP magnitudes are in agreement with the values of synthetic food additives. Further, the various molecular descriptors along with the plot of frontier molecular orbitals and Mulliken spin population analysis have been obtained and the validity of Koopmans' theorem is also verified with reference to antioxidant behavior.


2018 ◽  
Vol 77 (9) ◽  
pp. 2174-2183 ◽  
Author(s):  
Rongkui Su ◽  
Liyuan Chai ◽  
Chongjian Tang ◽  
Bo Li ◽  
Zhihui Yang

Abstract The advanced oxidation technologies based on •OH can effectively degrade the pharmaceutical and personal care products under operating conditions of normal temperature and pressure. In this study, direct photolysis of ibuprofen (IBU) is slow due to the relatively low molar extinction coefficient and quantum yield. Compared to direct photolysis, the degradation kinetics of IBU was significantly enhanced in the UV/H2O2 system, mainly by •OH radical mediated oxidation. In the UV/H2O2 system, the degradation rate of ionic IBU was slightly faster than that of the molecular form. Kinetic analysis showed that the second-order reaction rate constant of ionic IBU (5.51 × 109 M−1 s−1) was higher than that of the molecular form (3.43 × 109 M−1 s−1). The pseudo first-order rate constant for IBU degradation (kobs) increased with increasing H2O2 dosage. kobs can be significantly decreased in the presence of natural organic matter (NOM), which is due to (i) NOM radical scavenging effects (dominant role) and (ii) UV absorption. The degradation of IBU was inhibited by HCO3–, which was attributed to its scavenging effect. Interestingly, when NO3– was present in aqueous solution, a slight increase in the degradation rate was observed, which was due to NO3– absorbing photons to generate •OH at a low quantum yield. No obvious effects were observed when SO42 and Cl− were present.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Kathrin Pallauf ◽  
Nils Duckstein ◽  
Mario Hasler ◽  
Lars-Oliver Klotz ◽  
Gerald Rimbach

Dietary flavonoids have been shown to extend the lifespan of some model organisms and may delay the onset of chronic ageing-related diseases. Mechanistically, the effects could be explained by the compounds scavenging free radicals or modulating signalling pathways. Transcription factors Nrf2, FoxO, and PPARγpossibly affect ageing by regulating stress response, adipogenesis, and insulin sensitivity. Using Hek-293 cells transfected with luciferase reporter constructs, we tested the potency of flavonoids from different subclasses (flavonols, flavones, flavanols, and isoflavones) to activate these transcription factors. Under cell-free conditions (ABTS and FRAP assays), we tested their free radical scavenging activities and usedα-tocopherol and ascorbic acid as positive controls. Most of the tested flavonoids, but not the antioxidant vitamins, stimulated Nrf2-, FoxO-, and PPARγ-dependent promoter activities. Flavonoids activating Nrf2 also tended to induce a FoxO and PPARγresponse. Interestingly, activation patterns of cellular stress response by flavonoids were not mirrored by their activities in ABTS and FRAP assays, which depended mostly on hydroxylation in the flavonoid B ring and, in some cases, extended that of the vitamins. In conclusion, the free radical scavenging properties of flavonoids do not predict whether these molecules can stimulate a cellular response linked to activation of longevity-associated transcription factors.


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1608
Author(s):  
Lixin Jia ◽  
Xingwang Pei ◽  
Fei Yang

Manganese-catalyzed sulfite activation (i.e., Mn(II)/sulfite) has emerged as an advanced oxidation process to produce sulfate radical (SO4•−) for water treatment. However, to maintain the catalytic activity of Mn(II) ion, solution acidity has to be kept below pH 4, which is difficult to maintain in practice. Moreover, Mn(II)/sulfite reaction is a strongly oxygen-dependent process, and purging air into reaction solution is another extra cost. To solve the above issues, we devised to implement electrolysis into Mn(II)/sulfite (i.e., electro/Mn(II)/sulfite process) for organic compound (bisphenol A, BPA) oxidation. It was revealed that, under near-neutral conditions (pH 6), the removal rate of 10 μM BPA was increased from 46.3%, by Mn(II)/sulfite process, to 94.2% by electro/Mn(II)/sulfite process. The enhancement of BPA removal after implementation of electrolysis to Mn(II)/sulfite process was investigated, and concluded to be a result of several pathways. In detail, the produced oxygen from water electrolysis, direct sulfite oxidation on anode, and local acidic pH at anode vicinity together play a role in promoting SO4•− production and, therefore, contaminant removal. Radical-scavenging assays confirmed the dominant role of SO4•− in electro/Mn(II)/sulfite process.


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