The aim of this work was to evaluate the cytotoxicity of Arthrospira platensis Extracellular Polymeric Substances (EPS) for colon cancer and kidney cell lines. Results showed that EPS were free from cytotoxic effects. A variety of solvents were assessed for their ability to extract the bioactive ingredients from EPS. Methanol gave the highest yield (75.75%) than other solvents. The extracts were tested for activities against a collection of Gram+/- bacteria. The methanol extract exhibited a more potent activity than the other organic extracts, whereas the aqueous extract was active against Staphylococcus epidermis (Gram+) and Salmonella typhimurium (Gram-). Finally, The extracts were also tested for the antioxidant activity, using the Trolox Equivalent Antioxidant Activity assay. The methanol extract displayed a moderate antioxidant activity (TEAC = 0.027 mg/ml). The HPLC analysis of this extract revealed two distinct peaks: 8.1 kDa (8.31 min) and 4.1 kDa (8.54 min)
The kinetic study of Arthrospira platensis extracellular polymeric substances (EPS) production under different trophic modes-photoautotrophy (100 μmol photons m(-2) s(-1)), heterotrophy (1.5 g/L glucose), and mixotrophy (100 μmol photons m(-2) s(-1) and 1.5 g/L glucose)-was investigated. Under photoautotrophic and heterotrophic conditions, the maximum EPS production 219.61 ± 4.73 and 30.30 ± 1.97 mg/L, respectively, occurred during the stationary phase. Under a mixotrophic condition, the maximum EPS production (290.50 ± 2.21 mg/L) was observed during the early stationary phase. The highest specific EPS productivity (433.62 mg/g per day) was obtained under a photoautotrophic culture. The lowest specific EPS productivity (38.33 mg/g per day) was observed for the heterotrophic culture. The effects of glucose concentration, light intensity, and their interaction in mixotrophic culture on A. platensis EPS production were evaluated by means of 32 factorial design and response surface methodology. This design was carried out with a glucose concentration of 0.5, 1.5, and 2.5 g/L and at light levels of 50, 100, and 150 μmol photons m(-2) s(-1). Statistical analysis of the model demonstrated that EPS concentration and EPS yield were mainly influenced by glucose concentration and that conditions optimizing EPS concentration were dissimilar from those optimizing EPS yield. The highest maximum predicted EPS concentration (369.3 mg/L) was found at 150 μmol photons m(-2) s(-1) light intensity and 2.4 g/L glucose concentration, while the highest maximum predicted EPS yield (364.3 mg/g) was recorded at 115 μmol photons m(-2) s(-1) light intensity and 1.8 g/L glucose concentration.
Objective: To investigate the significance of circulating adhesion molecules associated with leucocyteendothelial cell interactions in asthma, serum levels of soluble E (sE)-selectin, soluble P (sP)-selectin, soluble L (sL)-selectin, and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured in mild, moderate and severe asthma. Method: Serum levels of sE-selectin, sP-selectin, sLselectin, and sVCAM-1 were measured in 32 women with asthma and 30 healthy donors using an enzymelinked immunosorbent assay method. Twenty patients were suffering from severe asthma, and 12 from mild/moderate asthma. Results: Serum sE-selectin and sVCAM-1 levels from patients with asthma were significantly higher than those observed in healthy donors (p < 0.01). The levels of sP-selectin were the same as those of controls. The level of sE-selectin exhibited an important increase in the severe asthmatic patients compared with mild/moderate asthma (p < 0.01). The sVCAM-1 level was increased in severe asthma when compared with healthy controls. There was no correlation between the levels of soluble selectins and the age of the patients. A significant correlation was found between sE-selectin and sVCAM-1 levels. Conclusion: These data indicate that circulating soluble forms of the selectins may have different kinetics during the clinical course of asthma, suggesting that they may reflect different inflammatory pathways in severe asthma. Both sVCAM-1 and sE-selectin may be useful immunological markers for monitoring disease activity in asthma.Key words: Asthma, Inflammation, Selectins IntroductionAdherence of leucocytes to endothelial cells (EC) is a primordial event in the sequence of inflammatory response. Specific cell adhesion molecules, expressed on the surface of leucocytes and/or EC, have been identified. As an initial event during inflammation, leucocytes in the blood stream roll along EC with loose contact, mediated by E-selectin, P-selectin and L-selectin. 1 In the inflammation phase, activation of leucocyte integrins occurs with expression of immunoglobulin-like adhesion proteins on EC, including intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 (VCAM-1). The leucocytes that are tightly bound to EC then migrate into the subendothelial tissue. Soluble forms of these adhesion molecules are released in circulation. Serum levels may be increased in several inflammatory diseases, and particularly in asthma. These circulating forms may be biologically active. 2 Asthma is known as a bronchial chronic inflammatory disorder. 3 Immunological abnormalities during asthma are characterized by marked activation of the immune system, leading to increased cytokine production by activated effector cells and the induction of antigen expression on EC. 4 The factors modulating the activation and recruitment of circulating inflammatory cells to the lung remain partially unknown, but an early step in this process is the interaction of adhesion molecules on circulating cells with those on EC. 5 Severe asthma is supposed t...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.