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Development of Ophthalmic Formulations
Published in Sandeep Nema, John D. Ludwig, Parenteral Medications, 2019
Paramita Sarkar, Martin Coffey, Mohannad Shawer
Corticosteroids work by blocking the enzyme phospholipase A2 to inhibit arachidonic acid production, thereby preventing the synthesis and release of prostaglandins, thromboxanes, and eicosanoids. Some concerning side effects of corticosteroid treatment are an increase in IOP, suppression of the immune system response to pathogens, slowed wound healing, and formation of cataracts. Steroids have been used extensively pre- and postsurgery as a result of their broad effects and are generally more potent than NSAIDs for the treatment of severe inflammation. Recently, soft steroids have been introduced in an effort to maintain the potent efficacy of the corticosteroids while reducing the undesirable side effects. One of these soft steroids is loteprednol etabonate, which has less effect on IOP due to its rapid metabolic deactivation. Most of the steroids have low aqueous solubility, and hence, most are formulated as suspensions or emulsions.
Effects of Pressure on Vascular Smooth Muscle Cells
Published in Jiro Nagatomi, Eno Essien Ebong, Mechanobiology Handbook, 2018
Sheila Nagatomi, Harold A. Singer, Rena Bizios
Other molecular-level responses include evidence that exposure of rat smooth muscle cells to pressure induced DNA synthesis via phospholipase C activation.30 Evidence to support this claim was provided by the absence of pressure-induced DNA synthesis in rat aortic smooth muscle cells pretreated with 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate (200 μM), a phospholipase C inhibitor, following exposure to sustained 80 mm Hg pressure.30 Activation of phospholipase C triggers a signal transduction pathway leading to increased intracellular calcium, which, in turn, induces smooth muscle cell contraction.8,30 An overstimulated contractile state of smooth muscle cells induces constriction of blood vessels that may contribute to hypertension.43
Enzymatic Reactions in Microemulsions
Published in Promod Kumar, K. L. Mittal, Handbook of Microemulsion Science and Technology, 2018
Hydrolysis of a phospholipid, phosphatidylcholine, was performed in microemulsions using phospholipase A2 as catalyst [78]. The reaction is fast and gives the lysophospholipid in quantitative yield when the reaction is performed in the presence of at least 10 mM calcium ions in the dispersed aqueous phase, as can be seen in Fig. 13a. The Ca dependence of phospholipase A2 is well known from reactions in aqueous solution. As can be seen from Fig. 13b, the hydrolysis reaction is very pH-sensitive, much more so than is normally seen for lipases.
Expression, purification and biophysical characterization of recombinant Streptomyces violaceoruber phospholipase PLA2 overproduced in Pichia pastoris
Published in Preparative Biochemistry & Biotechnology, 2020
S. Y. Filkin, N. V. Chertova, A. A. Zenin, A. V. Lipkin, A. A. Sichev, D. S. Bityak, E. G. Sadykhov, V. O. Popov, A. N. Fedorov
Phospholipase can hydrolyze ester bonds in different positions of phospholipids. PLA2s (E.C 3.1) are enzymes that hydrolyze the ester bond in the sn-2 position. PLA2s participate in several important physiological processes such as phospholipid digestion, cell signaling, and inflammation.[2] PLA2 can be classified in several groups such as secretory, cellular, calcium-independent, platelet-activating factor acetylhydrolase (PAF-AH).[3] The most important for biotechnological and industrial applications is secretory PLA2. Secretory PLA2 can be found in several sources, for example, bee and snake venoms.[4]
Optimization using response surface methodology of phospholipase C production from Bacillus cereus suitable for soybean oil degumming
Published in Preparative Biochemistry & Biotechnology, 2023
Ines Abdelkader, Sameh Ben Mabrouk, Bilel Hadrich, Mohammed Refai, Ahmed Fendri, Adel Sayari
Phospholipases are worldwide group of enzymes that hydrolyze the ester bonds of phospholipids (PLs) turning out diversity of products. They are distributed as phospholipases A1, A2, C and D according to their site of hydrolysis.[1,2]