Cholesterol and the cell membrane
Recent studies concerning cholesterol, its behavior and its roles in cell growth provide important new clues to the role of this fascinating molecule in normal and pathological states.
Red cell membrane: past, present, and future
As a result of natural selection driven by severe forms of malaria, 1 in 6 humans in the world, more than 1 billion people, are affected by red cell abnormalities, making them the most common of the inherited disorders. The non-nucleated red cell is unique among human cell type in that the plasma membrane, its only structural component, accounts for all of its diverse antigenic, transport, and mechanical characteristics. Our current concept of the red cell membrane envisions it as a composite structure in which a membrane envelope composed of cholesterol and phospholipids is secured to an elastic network of skeletal proteins via transmembrane proteins. Structural and functional characterization of the many constituents of the red cell membrane, in conjunction with biophysical and physiologic studies, has led to detailed description of the way in which the remarkable mechanical properties and other important characteristics of the red cells arise, and of the manner in which they fail in disease states. Current studies in this very active and exciting field are continuing to produce new and unexpected revelations on the function of the red cell membrane and thus of the cell in health and disease, and shed new light on membrane function in other diverse cell types.
Membrane curvature and mechanisms of dynamic cell membrane remodeling
Membrane curvature is no longer seen as a passive consequence of cellular activity but an active means to create membrane domains and to organize centres for membrane trafficking. Curvature can be dynamically modulated by changes in lipid composition, the oligomerization of curvature scaffolding proteins and the reversible insertion of protein regions that act like wedges in membranes. There is an interplay between curvature-generating and curvature-sensing proteins during vesicle budding. This is seen during vesicle budding and in the formation of microenvironments. On a larger scale, membrane curvature is a prime player in growth, division and movement.
Lantana camara L. Aqueous-methanolic Extract Provides Potent Red Blood Cell Membrane Fortification against Plasmodial Attack
Aim: The aim of our study was evaluation of the possible anti-plasmodial efficacy of Lantana camara L. extracts, with specific emphasis on its role in stabilization of the RBC membrane.
Place and Duration of Study: Department of Zoology, BMT and Human Genetics, Gujarat University, Gujarat, India, between December-2014 to May- 2015.
Methodology: In the present study, we have tested the In vitro anti-plasmodial activity of aqueous-methanolic extract (fraction VIII) of leaves of Lantana camara L. against MRC-2 (CQ-sensitive) and RKL-9 (CQ-resistant) strains of Plasmodium falciparum. The cytotoxicity test on HeLa cell line was evaluated using the 3-[4, 5-dimethylthyazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) test in order to determine the selectivity index.
Results: According to the results, the aqueous-methanolic and aqueous extracts of leaves of Lantana camara L. manifested potent anti-oxidant activity. The fraction VIII of aqueous-methanolic extract showed 48.0±0.12% and 35.0±021% (MRC-2 and RKL-9 respectively) inhibition of entry of parasite in the RBCs at 7.81 µg concentration. Qualitative tests revealed the presence of various phytocomponents in the leaves of Lantana camara L. that may be responsible for the In-vitro activity of the plant.
Conclusion: On the basis of the study it can be concluded that leaves of L. camara L. are rich sources of a vast quanta of secondary metabolites/ phytocomponents which can provide leads to a potent prophylactic drug against malaria.
In vitro Assessment of the Antibacterial Activity of Matricaria chamomile Alcoholic Extract against Pathogenic Bacterial Strains
An alarming increasing in the occurrences of antimicrobial resistance inside the existing clinical use and so the recent appearance of multidrug resistant bacteria that attempts the treatment of infections necessities to find out novel antimicrobial agents. In the attendance of Chamomile there is quite a lot of information on various studies concerning the antibacterial effects of this herb and fractioned bioassay conducted with the consent of energetic standards. Chamomile powder (Matricaria chamomilla L.) was purchased from private pharmacies. Fifty grams of chamomile powder was extracted with 250 ml 10% ethanol by soxhelt device at 45ÄŠ. In vitro determination of antibacterial activity of alcoholic extract of Matricaria chamomilla was done. The chamomile alcoholic extract showed higher action against Klebsiella pneumoniae (35±1.57 mm) inhibition zone and lower effect alongside Enterococcus faecalis (10±1.43 mm), but all the results were significant because inhibition values were near the result of active control. MIC values of chamomile alcoholic extract near values of tetracycline mainly against Klebsiella pneumoniae, Escherichia coli and Staphylococcus aureus. While MBC values of the chamomile alcoholic extract were in corresponding with tetracycline values similar to MIC, except that chamomile produced less corresponding values with tetracycline against Enterococcus faecalis and Pseudomonas aeruginosa. Conclusion Chamomile possesses significant and potent antibacterial activity against various bacterial strains like Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae.
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 Mohandas, N. and Gallagher, P.G., 2008. Red cell membrane: past, present, and future. Blood, The Journal of the American Society of Hematology, 112(10), pp.3939-3948.
 McMahon, H.T. and Gallop, J.L., 2005. Membrane curvature and mechanisms of dynamic cell membrane remodelling. Nature, 438(7068), pp.590-596.
 George, L.B., Joshi, U.U., Jani, D.V., Guleria, S.D. and Highland, H.N., 2016. Lantana camara L. aqueous-methanolic extract provides potent red blood cell membrane fortification against plasmodial attack. European Journal of Medicinal Plants, pp.1-10.
 Alkuraishy, H.M., Al-Gareeb, A.I., Albuhadilly, A.K. and Alwindy, S., 2015. In vitro assessment of the antibacterial activity of Matricaria chamomile alcoholic extract against pathogenic bacterial strains. Microbiology Research Journal International, pp.55-61.