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Herbal Product Development and Characteristics
Published in Anil K. Sharma, Raj K. Keservani, Surya Prakash Gautam, Herbal Product Development, 2020
Mirian Pateiro, Rubén Domínguez, Predrag Putnik, Danijela Bursać Kovačević, Francisco J. Barba, Paulo S. E. Munekata, Elena Movilla Fierro, José M. Lorenzo
The mode of action of the BACs present in the extracts and in essential oils is the same as the synthetic antioxidants, commonly used in foods, such as BHA, BHT, and TBHQ. They act as free-radical scavengers, blocking free radicals by donating a hydrogen atom (Embuscado, 2015; Tongnuanchan and Bejakul, 2014). As with clinical properties, phenolic compounds are the antioxidants and effective free-radical scavengers, able to impede initiation and cascade of lipid oxidation (Hyldgaard et al., 2012). They are primary antioxidants that act in three steps against lipid oxidation: initiation, propagation, and termination. Their capacity to donate an electron to the free radical prevents the oxidation of other compounds (Yanishlieva-Maslarova, 2001). They react with free (lipid) radicals leading to nonradical species and the inactivation of peroxyl radicals, therefore inhibiting the cascade reactions leading to termination (Jayasena and Jo, 2014). Similar mechanism of action is characteristic for protein oxidation where phenolic compounds avoid protein carbonylation by joining with the proteins (Siebert et al., 1996).
Measuring Oxidative Damage and Redox Signalling
Published in James N. Cobley, Gareth W. Davison, Oxidative Eustress in Exercise Physiology, 2022
James N. Cobley, Gareth W. Davison
Measuring reactive species, oxidative damage, and redox signalling presents several formidable challenges. For example, measuring superoxide using dihydroethidium (DHE) poses kinetic challenges (see below). Further, interpreting DHE fluorescence is complex (i.e., several non-selective reactions contribute) and appropriate controls are difficult (i.e., superoxide dismutase (SOD) mimetics are chemically promiscuous) (Sawyer and Valentine, 1981; Zielonka and Kalyanaraman, 2010; Batinic-Haberle et al., 2014). In exercise physiology, most studies attempt to chemically footprint oxidative damage and/or redox signalling. Too often overtly flawed assays like the thiobarbituric acid-reactive substance (TBARS) assay for lipid peroxidation are used (see Table 2.1). Taking the previous example, using TBARS to determine whether vitamin C and/or E decrease lipid peroxidation to blunt exercise adaptations is inappropriate (Cobley et al., 2017). Insufficient specificity allied to assay-induced lipid peroxidation invalidates TBARS (Forman et al., 2015). Even when a valid assay is used (e.g., an OxyBlot to measure protein carbonylation), it is usually confined to the global scale (i.e., the identity of the carbonylated proteins remains unknown). More broadly, the literature has focused on a narrow subset of oxidative damage biomarkers and has largely neglected chemical surrogates of redox signalling. After briefly reviewing direct strategies, we critique how to measure oxidative damage and redox signalling in humans. The present chapter is delimited to thiol-based redox signalling and oxidative damage to proteins and lipids.
Bioengineering of Inorganic Nanoparticle Using Plant Materials to Fight Extensively Drug-Resistant Tuberculosis
Published in Richard L. K. Glover, Daniel Nyanganyura, Rofhiwa Bridget Mulaudzi, Maluta Steven Mufamadi, Green Synthesis in Nanomedicine and Human Health, 2021
Mpho Phehello Ngoepe, Maluta Steven Mufamadi
This is prevalent in cases where microbes are exposed to the drug but are not eradicated either by the microbicidal effects of the drug itself or by the microbiostatic effects (inhibit but do not kill microbes) of the drug, where the host immune system plays a key role in killing the microbes (Teixeira et al., 2018). As a result of these acquisitions of antimicrobial resistance, nanoparticles have been proposed as alternative antibiotics because they are capable of overcoming existing antibiotic resistance mechanisms by various means, such as disruption of bacterial membranes and inhibition of biofilm formation (Wang et al., 2017). The mechanism of antimicrobial action of metal oxide nanoparticles is due to (a) electrostatic interaction between the particle and the microbe cell surface causing cell membrane damage; while cell uptake leads to (b) leakage of the proton due to disruption of the chemiosmosis process (dissipation of the proton motive force); (c) damage of organic biomolecules (carbohydrates, lipids, proteins and nucleic acids) due to the generation of reactive oxygen species (ROS) having a microbicidal effect; (d) altering cellular respiration, cell division and DNA replication due to mesosome binding; (e) inhibition of signal transduction and bacterial growth by dephosphorylation of the phosphotyrosine residue and (f) degradation of protein due to protein carbonylation leading to loss of catalytic activity of the enzyme (Fig 7.1) (Mahira et al., 2019).Antimicrobial mechanism of NPs and their ions.
Date seeds alleviate behavioural and neuronal complications of metabolic syndrome in rats
Published in Archives of Physiology and Biochemistry, 2023
Yosra Dallagi, Dalila Rahali, Morgane Perrotte, Houssem Dkhili, Asma Korsan, Michele Veronique El May, Saloua El Fazaa, Charles Ramassamy, Narges El Golli
We identified a significant increase of protein carbonylation and lipid peroxidation (increase of 4-HNe level) in the hippocampus of MS rats. Similar results were observed in Wistar rats (Amri et al.2017) and in mice (Morrison et al.2010, Kang et al.2015). Interestingly, protein carbonylation is highly associated with cognitive decline and cellular dysfunction (Smith et al.1991, Forster et al.1996, Sohal 2002) and 4-HNe could play particular sinister roles in MS and associated disease process (Mattson 2009). Recently, it has been demonstrated that phosphorylated Tau could change its conformation becoming reactive with AlZ50 antibody, then react with 4-HNe resulting from oxidative stress (Takeda et al.2000). These observations suggest that oxidative damage could play a synergic role with Tau phosphorylation to generate the conformational changes required for paired helical filaments (PHF) formation (Takeda et al.2000). Thus, 4-HNe could constitute an important link between Tau phosphorylation and PHF formation. Interestingly, 4-HNe investigation with western blot showed that the hippocampal proteins most affected by lipid peroxidation in MS group are located approximately at 48 kDa. Is it phosphorylated Tau protein? Further studies are needed in order to verify this hypothesis.
Tucumã (Astrocaryum aculeatum) extract: phytochemical characterization, acute and subacute oral toxicity studies in Wistar rats
Published in Drug and Chemical Toxicology, 2022
Camille Gaube Guex, Gabriela Buzatti Cassanego, Rafaela Castro Dornelles, Rosana Casoti, Ana Martiele Engelmann, Sabrina Somacal, Roberto Marinho Maciel, Thiago Duarte, Warley de Souza Borges, Cínthia Melazzo de Andrade, Tatiana Emanuelli, Cristiane Cademartori Danesi, Euler Esteves Ribeiro, Liliane de Freitas Bauermann
The development of chronic diseases is associated with oxidative stress, which is characterized by an imbalance between the antioxidant system and reactive species production. Malondialdehyde (MDA) is one of the final products generated by lipid peroxidation and is an important biological marker of oxidative damage (Mansour et al. 2008). Furthermore, protein carbonylation can lead to alteration in protein functions, which may result in the etiology or progression of various diseases (Levine 2002). Enzymes like CAT and SOD are part of an enzymatic defense strategy, which is responsible for neutralizing reactive species, therefore preventing oxidative damage. In this study, CETP was shown to decrease MDA levels in the renal tissue of females and increase SOD activity in the hepatic tissue of males, suggesting that the tucumã fruit may play an important role in preventing oxidative damage. These results may be attributed to the phenolic compounds found in the extract, which are known to possess high antioxidant capacity. Therefore, our results indicate that lower doses of tucumã extract are safe and have possible biological activities that may benefit the prevention and/or treatment of disorders.
Molecular and epigenetic modes of Fumonisin B1 mediated toxicity and carcinogenesis and detoxification strategies
Published in Critical Reviews in Toxicology, 2021
Thilona Arumugam, Terisha Ghazi, Anil A. Chuturgoon
A strong correlation between elevated ROS levels and structural damage to proteins in the form of protein carbonyls have also been made in the presence of FB1 (Domijan et al. 2007; Mary et al. 2012; Arumugam et al. 2019). HepG2 cells were extremely sensitive to FB1 as indicated by the 11.9-fold increase in protein carbonyls (Arumugam et al. 2019). The carbonylation of proteins alters polypeptide confirmation which can impair protein functioning. This may have various downstream consequences such as disrupting signalling pathways, modifying enzyme activity, and impairing other protein functions including binding of transcription factors to DNA (Gonos et al. 2018). Moreover, protein carbonyls can inhibit proteasomal activity which is necessary for the degradation of carbonylated proteins. Thus, protein carbonylation can result in cellular dysfunction and eventually contribute to the aetiology and progression of disease states (Dalle-Donne et al. 2006).