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Functional Benefits of Ficus Hispida L.
Published in Hafiz Ansar Rasul Suleria, Megh R. Goyal, Health Benefits of Secondary Phytocompounds from Plant and Marine Sources, 2021
D. Suma, A. Vysakh, R. N. Raji, Ninan Jisha, M. S. Latha
Oleanolic acid, hispidin, bergapten, and β-sitosterol are the phytoconstituents present in FH and these act as antioxidants/anti-lipid peroxidants. Their function is to protect membrane lipids from generating oxidative damage. It is done through cessation of peroxyl radical dependent reactions. SOD, CAT, GPx, and GST are the enzymes of antioxidant nature, which have vital function in the removal of reactive oxygen species. GSH, vitamin C, and vitamin E are intimately related non-enzymatic antioxidants and play an important role in defending the cell from damage due to oxidation. F. hispida extracts possess some bioactive antioxidant phytoconstituents, which afforded the antioxidant activity and lessened the utilization of endogenous antioxidants, which could be accountable for the decline of AZA activated oxidative stress probably through hepatic GSH reparative effect. Recently it has recognized that tylophorine counterpart as definite action compared to the available anticancer agents. Repressive action on NF-KB binding arbitrated transcription, guiding to apoptosis is one of its actions.
Cell Components and Function
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
The cell membrane is a matrix of the phospholipid bilayer with mobile and randomly distributed integral proteins (fluid mosaic model of Singer and Nicholson). This accounts for the cytoskeletal and extracellular interactions between membrane lipids and proteins which restrict the mobility of membrane structures. The cell membrane can be thought of as a layer of insulation covered on both sides by conducting material. This structure is traversed by protein channels that determine ionic permeability and the resultant electrical potential across the membrane. The functions of the cell membrane include signal transduction, enzymatic activity, transport and immunity.
Structures and Properties of Self-Assembled Phospholipids in Excess Water
Published in E. Nigel Harris, Thomas Exner, Graham R. V. Hughes, Ronald A. Asherson, Phospholipid-Binding Antibodies, 2020
The integral membrane proteins or glycoproteins usually have one or more segments of hydrophobic amino acid residues penetrating the lipid bilayer.6 Within the lipid bilayer, these residues are almost exclusively arranged as a-helices with an orientation nearly perpendicular to the bilayer surface. The dynamics and mobility of these bilayer-spanning proteins or glycoproteins must, therefore, be subject to modulation by the organization and polymorphism of the lipid bilayer. Consequently, the functional states of bilayer-spanning proteins or glycoproteins in biological membranes may be correlated with the physical state of the lipid bilayer. The function of lipid bilayers should, therefore, be considered not only to serve as a barrier separating two aqueous compartments, but also to modulate the activity of membrane proteins. Hence, studies of phospholipids and other membrane lipids in the form of a bilayer are of great importance in understanding the functional control of bilayer-spanning proteins in biological membranes and for providing basic information explaining the dynamic regulation of membrane activities in general.
A novel WFS1 variant associated with severe diabetic retinopathy in Wolfram syndrome type 1
Published in Ophthalmic Genetics, 2023
Rym Maamouri, Syrine Hizem, Ines Kammoun, Yasmina Elaribi, Imen Rejeb, Molka Sebai, Houweyda Jilani, Cécile Rouzier, Monia Cheour, Véronique Paquis-Flucklinger, Lamia Ben Jemaa
Sanger sequencing in the proband revealed the homozygous c.1901A>T variant in exon 8 of the WFS1 gene (supplementary figure). This missense variant is responsible for the substitution of lysine (positive charge) by methionine (neutral charge) at amino acid 634 of the wolframin protein (p.Lys634Met). The lysine residue is located in the transmembrane domain of the protein (https://www.uniprot.org/). According to the Hope prediction program (http://www3.cmbi.umcn.nl/hope/), the mutant residue would be smaller and more hydrophobic than the wild-type residue. This difference in size and hydrophobicity could affect the contacts and interactions with the membrane lipids. Furthermore, the substitution induces a loss of charge of the wild-type residue, which could be responsible for the loss of interactions with other molecules or residues. The variant was classified as damaging according to 10 computational prediction tools vs 2 benign predictions (https://varsome.com/). According to the ACMG, this variant was classified as likely pathogenic given to the following criteria: the variant was absent from controls in the genome aggregation database (gnomAD https://gnomad.broadinstitute.org), an alternative variant in the same residue was described and classified as pathogenic (19), missense variants are a common mechanism of the disease, in addition to multiple lines of computational evidence supporting the deleterious effect of the variant.
Modulating the lipid profile of blastocyst cell membrane with DPPC multilamellar vesicles
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2022
Hugo De Rossi, Camila Bortoliero Costa, Luana Teixeira Rodrigues-Rossi, Giovana Barros Nunes, Dóris Spinosa Chéles, Isabella Maran Pereira, Daniele F. O. Rocha, Eloi Feitosa, Ana Valéria Colnaghi Simionato, Gisele Zoccal Mingoti, Pedro Henrique Benites Aoki, Marcelo Fábio Gouveia Nogueira
The plasma membrane may rupture and undergo severe changes in volume due to the entry and exit of cryoprotectants and intracellular water. Cell membranes that exhibit higher fluidity, permeability, and thermal phase properties suffer less damage during cryopreservation [4,5]. The main membrane lipids are glycerophospholipids (GPs), sphingolipids, and sterols (usually cholesterol in mammals). Phospholipids (PLs) may be present as different molecular species, such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), sphingomyelin (SM), and phosphatidylserine (PS) [6–8]. Depending on the level of lipid saturation, the interaction between PLs and cholesterol molecules in the cell membrane can affect bilayer organisation and biophysical [7] and physicochemical [9–11] properties, including phase fluidity and permeability.
Fisetin, a potential caloric restriction mimetic, modulates ionic homeostasis in senescence induced and naturally aged rats
Published in Archives of Physiology and Biochemistry, 2022
Sandeep Singh, Geetika Garg, Abhishek Kumar Singh, Shambhoo Sharan Tripathi, Syed Ibrahim Rizvi
Membrane lipid is an important factor to maintain membrane fluidity, integrity, permeability and activity of membrane-bound transporters. An alteration in the lipid level disturbs the equilibrium of erythrocytes membrane and this affects the maintenance of asymmetric ionic concentration between intra- and extracellular matrix (Owen et al.1981, Suda et al.2002). Lipid peroxidation during aging is attributed to structural and functional deformability of the membrane (Rajasekaran et al.2004). Age-dependent increase in lipid hydroperoxides has previously been reported and substantiates our results (Singh et al.2016, Garg et al.2018). Antioxidants have potential protective role against age-dependent increase in membrane lipid hydroperoxides. Our results showed a significant decrease in the level of D-gal induced lipid hydroperoxides after the supplementation of fisetin. This decrease in lipid hydroperoxides level might be due to anti-lipid peroxidative nature of fisetin.