Effects of neomycin on absorption, synthesis, and/or flux of cholesterol in man.

Abstract

A B S T R A C T The mode of action of the hypocholesteremic drug neomycin (2 g/day) was studied in four patients. All showed a significant reduction in plasma cholesterol concentrations (mean 25%, range (1), and since then it has been demonstrated that a few other antibacterial drugs have similar properties. Of these kanamycin (2) and paromomycin (3) are similar in structure to neomycin, but chlortetracycline (2), chloramphenicol (4), and para-aminosalicylic acid (2) have markedly different molecular conDr. Sedaghat's present address is:

Effects of Neomycin Alone and in Combination with Cholestyramine on Serum Cholesterol and Fecal Steroids in Hypercholesterolemic Subjects

“…It is not, however, known whether large neomycin doses could also increase fecal bile acid output; whether the neomycin-induced increase in fecal steroids is long-standing, as the serum cholesterol lowering is; whether the decrease in serum cholesterol is related to changes in cholesterol elimination; and whether cholesterol synthesis is compensatorily increased by the drug. Cholesterol turnover studies off and on neomycin did not reveal any significant changes in the half time of the serum cholesterol radioactivity decay curve (14), and the unchanged slope of this curve during the neomycininduced fall in serum cholesterol was interpreted to be a result of the combined action of reduced absorption, enhanced mobilization oftissue cholesterol and stimulated cholesterol synthesis (13).…”

“…However, analysis of intestinal contents after administration of neomycin with a test meal revealed that the drug precipitated fatty acids and cholesterol, and only to a small extent bile acids from intraluminal micelles in man (11). Small neomycin doses actually reduced serum cholesterol by enhancing cholesterol elimination into feces as neutral sterols, having no consistent effect on fecal bile acids (12,13). It is not, however, known whether large neomycin doses could also increase fecal bile acid output; whether the neomycin-induced increase in fecal steroids is long-standing, as the serum cholesterol lowering is; whether the decrease in serum cholesterol is related to changes in cholesterol elimination; and whether cholesterol synthesis is compensatorily increased by the drug.…”

Antihyperlipidemic Activity of Commiphora Mukul Against Atherogenic Diet-Induced Hyperlipidemia in Experimental Rats

“…India is well known for its rich traditional systems of medicine, that is, Ayurveda, Siddha, and Unani besides a vast reservoir of living traditions of ethnomedicine. Several modern drugs in use such as statins, fibrates, nicotinic acid and resins [3], lower blood cholesterol level, either by inhibiting endogenous synthesis and/or by lowering cholesterol absorption from the intestine [4]. Due to their side effects, people are looking for safer alternatives, and the search for new drugs capable of reducing and regulating serum cholesterol level has gained interest resulting in numerous reports on significant activities of natural agents.…”

Correlation of neomycin, faecal neutral and acid sterols with colon carcinogenesis in rats

“…Studies with clofibrate, cholestyramine (Steiner et al, 1991), neomycin (Broitman et al, 1960;Sedaghat  , 1975;Kesaniemi and Miettinen, 1991) etc. have been suggestive enough to promote concern regarding the effects of lowering serum cholesterol with drugs to the development of gastrointestinal tract neoplasms.…”

“…Neomycin, which is known to have a significant effect upon sterol metabolism in gut and their faecal concentration (Sedaghat et al, 1975), has been administered orally to rats fed polyunsaturated fat (safflower oil) and cholesterol diets. The influence of neomycin on the location, incidence and number of large and small bowel tumorigenesis in rats induced by DMH, and subsequent changes in faecal excretion of neutral and acid sterols have been investigated.…”