Reference

Mitotic aneuploidy as a possible mechanism for tumor promoting activity in bile acids

Mitotic aneuploidy as a possible mechanism for tumor promoting activity in bile acids. Ferguson, Lynette R.; Parry, James M. (Med. Sch., Univ. Auckland, Auckland, N. Z.). Carcinogenesis (London), 5(4), 447-51 (English) 1984. CODEN: CRNGDP. ISSN: 0143-3334. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) A range of conjugated and free bile acids were assayed for their ability to induce a variety of genetic endpoints in growing cells of yeast Saccharomyces cerevisiae. None of the bile acids showed activity in assays for the induction of mitotic crossing-over and mutation whereas the free bile acids lithocholic acid (I) [434-13-9], chenodeoxycholic acid [474-25-9], deoxycholic acid [83-44-3] and cholic acid [81-25-4] were potent inducers of mitotic chromosome aneuploidy. In contrast, both conjugated bile acids, taurodeoxycholic acid [516-50-7] and glycodeoxycholic acid [360-65-6] lacked the ability to induce mitotic aneuploidy. When the potencies of the free bile acids were compared, I and chenodeoxycholic acid showed higher levels of induction of mitotic aneuploidy/lethal event compared with cholic and deoxycholic acids. In view of the previously obsd. correlation between the ability of a chem. to induce chromosome aneuploidy and tumor promotional activity, the results indicate that the levels of free bile acids in the colon may be significant factors in the etiol. of colonic cancer.

Application of proton NMR to the design of liposomes for oral use

Application of proton NMR to the design of liposomes for oral use. Synergistic activity of bile salts and pancreatic phospholipase A2 in the induced permeability of small unilamellar phospholipid vesicles. Hunt, G. R. A.; Jones, I. C. (Dep. Sci., Polytech. Wales, Pontypridd CF37 1DL, UK). J. Microencapsulation, 1(2), 113-22 (English) 1984. CODEN: JOMIEF. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) NMR spectroscopy of small unilamellar phospholipid vesicles in the presence of the lanthanide probe ion Dy3+ was used to study the permeability of these liposomes induced by the bile salts, Na glycocholate [863-57-0] and glycodeoxycholate [360-65-6]) and pancreatic phospholipase A2 [9001-84-7]. A marked synergism is demonstrated in the combined effects of these digestive agents in producing permeability of the vesicles to Dy3+. Changes in the NMR spectrum of the vesicular phospholipid head-groups before permeability is induced, indicate that the products of the enzymic hydrolysis (lyso lipids and fatty acids) and transmembrane lipid exchange are involved in the permeability mechanism. The results are discussed in terms of the advantages of the use of NMR techniques in the future design of liposomes for oral use.