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katherine-medina

Frontiers | Dietary Polyphenols and Their Role in Oxidative Stress-Induced Human Diseas... - 1 views

  • phenolic acids, flavonoids, catechins, tannins, lignans, stilbenes and anthocyanidins
  • They possess antioxidant, chemopreventive and a wide range of pharmacological properties (
  • Over 8,000 polyphenols have been reported from plants, out of several hundreds of polyphenols exist in human diets
  • ...25 more annotations...
  • Organic compounds bearing an aromatic ring with at least one hydroxyl group are termed as “phenolics”. In case, a compound possesses one or more aromatic rings having more than one hydroxyl group are called polyphenols (or polyphenolic compounds).
  • As per the C1-C6 or C3-C6 backbone, they are usually referred to as derivatives of benzoic acid or cinnamic acid
  • However, the role of the dietary polyphenols of their antioxidant abilities is still unclear.
    • katherine-medina
       
      How exactly is the role of antioxidants unclear?
  • Increased intake of foods containing polyphenols (for example, quercetin, epigallocatechin-3-gallate, resveratrol, cyanidin etc.) has been claimed to lower the incidence of a majority of chronic oxidative cellular damage, DNA damage, tissue inflammations, various cancers, viral/bacterial infections, and neurodegenerative diseases
    • katherine-medina
       
      So an increase of foods with natural extracts, so just plain vegetables that are not processed.
  • γ rays
    • katherine-medina
       
      I had no idea these were a thing.
  • This review specifically focuses a current understanding on the dietary sources of polyphenols and their protective effects including mechanisms of action against various major human diseases.
  • ROS when increased or excessively produced can cause oxidative changes/damages to all cellular macromolecules
  • Several antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) aid in the removal of free radicals
  • Peroxynitrite can also destroy lipoproteins and causes lipid peroxidation of cell membranes
  • ROS can also affect protein synthesis and protein functions. Protein oxidation can result in amino acid modifications
  • Flavonoids are further classified into different subgroups based on their structures such as flavan-3-ols (examples: catechin, epicatechin, epigallocatechin), isoflavones (examples: genistein, genistin, daidzenin, daidzin, biochanin A, formononetin), flavones (examples: luteolin, apigenin, chrysin), flavonones (examples: hesperetin, naringenin), flavonols (examples: quercetin, kaempferol, galangin, fisetin, myricetin), flavononol (example: taxifolin), flavylium salts (examples: cyanidin, cyanin, pelargonidin), and flavanones (examples: hesperetin, naringenin, eriodictyol, isosakuranetin)
    • katherine-medina
       
      WOW so flavonoids have a large variety and classes.
  • urther, OS exerts deleterious effects on DNA leading to the formation of DNA lesions, which can result in genomic instability and consequently lead to cell death.
  • Polyphenols are found naturally in fruits and vegetables such as cereals, pulses, dried legumes, spinach, tomatoes, beans, nuts, peppermint, cinnamon, pears, cherries, oranges, apples, red wine, tea, cocoa, coffee and so on (Arts and Hollman, 2005; Scalbert et al., 2005). Polyphenols are classified into different groups depending on the number of aromatic (phenolic) rings they contain and the structural elements that connect these rings. They are broadly grouped into phenolic acids, flavonoids, stilbenes and lignans
    • katherine-medina
       
      SO each polyphenol has a different number of phenolic rings. What is the difference between the different polyphenols such as phenolic acid, flavonoids, stilbenes and lignans. I think that I should look at which of these groups are more effective when working with antibiotics as a way to aid them in the fight against resistant bacterias.
  • In plant derived polyphenolic compounds, flavonoids comprise the largest group with an approximately 10,000 natural analogues
  • Dietary supplements containing elevated amounts of flavonoids from strawberries, lettuce, or blueberries aid in the reversal of age-related discrepancies in the brain and behavioral control in aged rats
  • Tea catechins
    • katherine-medina
       
      I ha e looked into these a bit, but I did not know that they can help with neurodegenerative diseases.
  • reduced glutathione (GSH), and on membrane sulphydryl (-SH) group in humans has been reported by Maurya and Rizvi (2009).
  • OS can be the primary or secondary reason for various CVDs. Preclinical evidence support that OS is linked to a variety of CVDs, including atherosclerosis, ischemia, stroke, cardiomyopathy, cardiac hypertrophy, and hypertension, as well as congestive heart failure
  • Dietary flavonoids may reduce endothelial disorders linked with various risk factors for atherosclerosis before plaque creation
  • The polyphenols of Hibiscus sabdariffa weaken diabetic nephropathy in terms of serum lipid profile and kidney oxidative markers
  • . Studies suggest that a diet that includes regular consumption of fruits and vegetables (rich in polyphenols such as catechins, resveratrol, ellagic acid, naringenin, quercetin etc.) significantly lowers the risk of developing many cancers.
  • Black tea polyphenols like EGCG, theaflavins and thearubigins have potent anticancer properties
  • Anti-carcinogenic effects of resveratrol are due to the antioxidant function, which inhibits hydroperoxidase, Akt (PI3K-Akt) signaling pathway, matrix metalloprotease-9, NF-kB, protein kinase C, cyclooxygenase, focal adhesion kinase and Bcl-2 (B cell lymphoma 2) biomarkers/enzymes (Athar et al., 2007)
  • Increased OS may lead to the vulnerability of the infection and also triggers the malfunctioning of cellular metabolism
  • Resveratrol shows its anti-rheumatoid arthritis properties with reduced RA patients’ swelling, tenderness, and disease activity by lowering the biochemical indicators of inflammation like MMP-3, IL-6, ESR, C-reactive protein, and undercarboxylated osteocalcin
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    A good overview about polyphenols.
katherine-medina

IJMS | Free Full-Text | Antioxidant Versus Pro-Apoptotic Effects of Mushroom-Enriched D... - 0 views

  • In addition, the gut microbiota has also been described to be modulated by mushroom bioactive molecules, with implications in reducing liver inflammation during NAFLD progression.
  • non-alcoholic steatohepatitis (NASH)
    • katherine-medina
       
      I like the abbreviation
  • NASH is currently the third most common indication for liver transplantation in the United States and accounts for 10% of all HCC cases in Europe
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  • The increase in nutrient availability causes systemic metabolic alterations that lead to an increase in hepatic mitochondrial respiration as well as changes in the mitochondrial lipid membrane composition.
  • They are also rich in phenolic acids, such as hydroxybenzoic and hydroxycinnamic acid, flavonoids, tocopherols, ascorbic acid and carotenoids that are known for their antioxidant activity
    • katherine-medina
       
      They are high in polyphenols, just like I had thought, I do wonder if they have tried to single out a certain flavonoid or stilbene in order to determine whether or not it was the mechanism that caused the positive reaction.
  • Of note, indeed NAFLD patients present a “metabolic inflexibility”, that is, a reduced capacity to switch back from
    • katherine-medina
       
      I did not know that
  • The increased levels of β-oxidation seem to result in an increase in citrate within the mitochondrial matrix that can be transported to the cytosol via the citrate-malate shuttle and converted to acetyl-CoA and oxaloacetate by the enzyme ATP-citrate lyase [90,106]. Indeed, NAFLD patients present increased citrate levels in plasma
  • An alternative explanation for the deficient mitochondrial respiration might be the alterations in the mitochondria lipid composition, which are already present in steatosis.
  • As defined by mitohormesis, ROS production is physiological at low levels, acting as a crucial effector in proliferation, expression of antioxidant enzymes and insulin signalling. However, high levels of ROS formation causes oxidative stress and cell damage by reacting with its different components [90,114,115]. Oxidative stress occurs when the antioxidant capacity of the cell is not sufficient to neutralize the overproduction of ROS. ROS generation causes the peroxidation of phospholipids and cardiolipin at the mitochondrial membrane
  • All these mechanisms seem to be involved in the progression from NAFL to NASH. Indeed, NASH patients present increased ROS production, DNA damage, as measured by 8-Oxo-2’-deoxyguanosine (8OHdG) levels, and hepatic lipid peroxidation coupled with decreased expression of ETC Com
    • katherine-medina
       
      So essentially NASH patients have a higher level of ROS which damages their DNA. increase of ROS = DNA damage
  • In parallel, the negative regulation on the inhibitor of apoptosis proteins (IAPs) mediated by the translocation of a series of IAP antagonists such as Smac, HTRA2/Omi and apoptosis-related protein in the TGF-ß signalling pathway (ARTS) to the cytosol, results in the release and activation of caspases
  • Aiming at weight loss, calorie-restricted diets and regular physical activity can improve hepatic mitochondria dysfunction by decreasing FFA liver input and alleviating oxidative stress.
  • New therapies need to be developed to target NAFLD and NASH,
    • katherine-medina
       
      Are there any new therapies to treat NASH and NAFLD
  • showed lipid metabolism-modulating properties in the liver
  • This may lead to a decrease in lipogenesis and a concomitant increase in β-oxidation that could explain the reduction in IHTG content [203]. Similarly, the supplementation with a 1% aqueous extract of A. cinnamomea for 8 weeks reduced the expression of leptin and increased the expression of adiponectin, which was accompanied by an increase of AMPK and PGC-1α and a reduced expression of ACC, FAS and SREBP
  • IHTG content that was similar to the positive control group, treated with rosiglitazone, a PPAR-agonist antidiabetic drug
    • katherine-medina
       
      Interesting, I wonder if there is more that can be done with this extract with these types of effects.
  • herefore, these studies suggest a pivotal capacity of mushroom extracts to counteract the detrimental oxidative damage of mitochondria in NAFLD.
  • which seems to exacerbate NASH. H2O2 over-production may open the mPTP, while its transmembrane diffusion to the cytoplasm may even result in highly detrimental OH• formation. [93,131,132]. In contrast, the capacity of mushroom extracts from species such as Pleurotus ostreatus (Jacq.) P. Kumm. (oyster mushroom) or G. lucidum to elevate the entire antioxidant defence system of hepatocytes, seems a more promising therapeutic effect against the oxidative stress in NASH.
  • . Such evidence further supports the potential of G. lucidum extracts in reversing mitochondrial dysfunction in NAFLD.
  • In this line of research, novel therapies aim to target apoptosis via mitochondria, using molecules that mimic BH3 proteins and disrupt the interactions of pro-apoptotic and anti-apoptotic proteins.
  • Both aqueous and ethanol extracts, or isolated compounds (GL22 from Ganoderma leucocontextum T.H Li, W.Q. Deng, Dong M. Wang & H.P. Hu) increased the pro-apoptotic Bax to anti-apoptotic Bcl-2/Bcl-xL ratio
  • The antitumorigenic effects of mushroom extracts and isolated compounds have also been demonstrated in in-vivo xenograft models, resulting in tumour size reduction and increased animal survival rates (Table 2). Furthermore, in the HCC Huh7 xenograft mice model, fatty acid binding proteins
  • Therefore, the mechanisms by which mushroom extracts or isolated compounds induce mitochondrial-related apoptosis pathways are diverse and may be related with specific bioactive compounds. Modulation of pathways crucial for cell survival and alterations in lipid homeostasis seem to be related with the pro-apoptotic effects observed in HCC cell lines and in in-vivo xenograft models.
    • katherine-medina
       
      Cool
  • To sum up, mitochondria play a central role in the pathophysiology and progression of NAFLD as well as in the development of HCC, which can be a late-stage consequence of NASH. Hepatic mitochondria undergo bioenergetic remodelling to face the metabolic burden imposed by the increased FFAs load secondary to systemic IR. In turn, a decompensation of these processes may result in ROS formation and mitochondrial dysfunction, contributing to the development of NASH. Lastly, hepatic mitochondria also seem to be involved in anti-apoptotic oncogenic processes driving HCC. Targeting mitochondrial dysfunction is thus a promising approach for the treatment of the NAFLD continuum. The following section describes some of the in-vitro and in-vivo studies on the beneficial effects of mushroom-enriched diets or mushroom-derived compounds/extracts (Box 2) in preventing/reverting such liver damage.
  • This distinct property of mushroom-based therapy or -containing diet is especially relevant in the multifactorial context of NAFLD and especially NASH, where systemic synergistic metabolic alterations need to be addressed.
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    An article detailing a bit of the effects that mushrooms can have on the liver's mitochondrial cells.
Sean Nash

SciDraw | Scientific Drawings - 0 views

  •  
    This is a great source for constructing diagrams you will need for your display, presentation, & manuscript
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