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Pharmaceutical Applications of Chondroitin
Published in Amit Kumar Nayak, Md Saquib Hasnain, Dilipkumar Pal, Natural Polymers for Pharmaceutical Applications, 2019
Dilipkumar Pal, Amit Kumar Nayak, Supriyo Saha, Md Saquib Hasnain
Reduction-sensitive conjugation of chondroitin sulfate A (CS A) and deoxycholic acid using disulfide bonding was developed. This biologically reduced formulation was formed micelles in the aqueous environment (Hongxia et al., 2017). Critical micelle concentration of CS A-ss- deoxycholic acid conjugate was showed 0.047 mg/mL of critical micelle concentration with 387 nm of mean diameter. Drug loading capacity was done by encapsulated doxorubicin and release behavior was examined in 7.4 phosphates buffered saline; whereas the similar release characteristics were observed with the reduction-sensitive micelles and reduction-insensitive control micelles. In vitro releasing of doxorubicin from the responsive micelles was accelerated in 20 mM glutathione-phosphate buffer saline. Furthermore, the confocal laser scanning microscopy was confirmed that doxorubicin-loaded CS A-ss-deoxycholic acid conjugate micelles were observed with greater efficiency against human gastric cancer cell line (HGC-27). The results of this research revealed that reduction sensitive doxorubicin-loaded CS A-ss-deoxycholic acid conjugate micelles behaved as potent intracellular carriers of anticancer drugs (Hongxia et al., 2017).
Thin-Layer Chromatography in Clinical Chemistry
Published in Bernard Fried, Joseph Sherma, Practical Thin-Layer Chromatography, 2017
The determination of bile acids is done in various biological specimens,32 e.g., bile, serum, duodenal contents, and crude fecal extracts. Thin-layer chromatography (TLC) has been used extensively for the separation of bile acids. Prior to TLC analysis of bile acid, purification of the specimen is essential. Sample cleanup steps would, however, depend upon the type of biological specimens being analyzed. Isolation of individual free bile acids in serum involves protein separation, alkaline hydrolysis, solvolysis of conjugated bile acids, and purification of lipids. Kindel et al.33 published a very useful paper in 1989 for separation of bile acids by TLC. These authors separated five predominant bile acids (cholic, chenodeoxycholic acid, deoxycholic acid, lithocholic acid, and ursodeoxycholic acid) in human stool specimens on a silica gel plate using two different solvent systems. The plate was first developed in isooctane-2-propanol–acetic acid (30:10:1, v/v) for 40 min, dried, and developed again with isooctane–ethyl acetate–acetic acid (10:10:2, v/v) for 65 min. For quantitative analysis, the plate was dipped in 0.2% 2,7-dichlorofluorescein ethanolic solution, and bile acid fluorescence was measured by TLC with direct scanning fluorometry (TLC–DSF). In clinical practice, this TLC procedure constitutes a reliable, simple, and time-saving alternative to gas chromatography.
Steroids: Arthritis, Fertility, Heart Attacks, And Home Run Records
Published in Richard J. Sundberg, The Chemical Century, 2017
Cholesterol is an important constituent of biological membranes, but at elevated levels, it contributes to arterial plaque and is also the major constituent of gall stones. Deoxycholic acid and cholic acid are liver metabolites of cholesterol and are called bile acids. Estrone and testosterone are the primary female and male sex hormones, respectively. The sex hormones are involved in many aspects of the reproductive cycle, including onset of puberty, fertility, and pregnancy. Progesterone is involved in the female reproductive cycle and inhibits ovulation during pregnancy. The steroids function through binding to various receptors called androgen, estrogen, and progesterone, etc. receptors. These receptors in turn function to control activation of genes. Some of the systems appear to be controlled on the basis of a balance between particular steroids. From a pharmacological point of view, it is of interest to have both agonist and antagonists that can either activate or inhibit a specific receptor and its function. Structures such as cortisone are called corticosteroids and are produced by the adrenal glands. They are characterized by an oxygen substituent at C-11 and the hydroxyacetyl group at C-17. The corticosteroids are involved in the hypothalamus–pituitary–adrenal axis and are critical messenger in the endocrine system. The corticosteroids influence metabolism, cell differentiation and function of the immune system. Aldosterone is an important mediator of blood pressure and salt and water retention (see Section 14.1).
Process optimization in ginseng fermentation by Monascus ruber and study on bile acid-binding ability of fermentation products in vitro
Published in Preparative Biochemistry & Biotechnology, 2021
Chongyan Zhao, Fang Yang, Feng Lin, Qingsong Qu, Zhixun Li, Xing Liu, Lu Han, Xinyuan Shi
Cholesterol is a precursor to the synthesis of bile acids. About 80% of the cholesterol is metabolized by liver tissue and converted to bile acid, which is involved in the enterohepatic circulation. Finally, part of bile acid is reabsorbed by the body.[36,37] de Aguiar Vallim[38] reported that bile acids can bind some food ingredients and then excrete with the digestion of food. Therefore, Cholesterol will be continuously converted to bile acids to maintain the homeostasis of the bile acid pool, thereby reducing the cholesterol content in the blood. In the human body, bile acids are classified into free bile acids (cholic acid, deoxycholic acid, etc.) and conjugated bile acid (cholic acid, deoxycholic acid, etc. combined with glycine and taurine).[39] The conjugated bile acids are generally present in the form of sodium salts, which is more common in the human body. Therefore, in this study, it is applicable that sodium taurocholate and sodium cholate were selected as representative of the conjugated bile acids.