The proposed research stems from our previous demonstration that alfalfa meal, as well as an extract of alfalfa meal operationally termed alfalfa saponins, reduces the intestinal absorption of cholesterol, lowers cholesterolemia, and induces the regression of atherosclerosis in cholesterol-fed monkeys. However, because alfalfa saponins are a mixture of substances whose chemical structures are largely unknown, I have synthesized a series of novel saponins, i.e., cellobiose-tigogenin, cellobiose-diosgenin, glucose-diosgenin, and glucose-tigogenin. Preliminary experiments demonstrate that these saponins bind cholesterol in vitro. Other preliminary experiments showed that the first three of these also reduced intestinal absorption of cholesterol in rats. Not all members of the series have been tested yet. In the proposed research, certain synthetic saponins will be given to rats, rabbits, and monkeys. The effects of the saponins on the intestinal absorption of cholesterol will be further studied in rats, and a dose-response curve will be established. The possible absorption of the 14C-saponins will be determined. The mechanism of action of the synthetic saponins will be established through the steroid and bile acid balance technique. The effects of a 6-month period of ingesting survival, body growth rate, multiple hematologic and blood biochemical values, urinalysis results, and gross and microscopic pathological data. The effects of synthetic saponins on atherosclerosis prevention will be studied in rabbits with atheroscelerosis induced by a cholesterol diet or by a cholesterol-free diet. Finally, the effects of the synthetic saponins on cholesterolemia in monkeys will be studied. If the saponins reduce cholesterolemia without toxic effects, they might be used in the treatment of hypercholesterolemic humans.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL016587-10
Application #
3335232
Study Section
Pathology A Study Section (PTHA)
Project Start
1977-05-01
Project End
1986-12-31
Budget Start
1985-01-01
Budget End
1986-12-31
Support Year
10
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Oregon Regional Primate Research Center
Department
Type
DUNS #
City
Beaverton
State
OR
Country
United States
Zip Code
97006
Malinow, M R; Elliott, W H; McLaughlin, P et al. (1987) Effects of synthetic glycosides on steroid balance in Macaca fascicularis. J Lipid Res 28:1-9
Malinow, M R; Gardner, J O; Nelson, J T et al. (1986) Effects of alpha- and beta-tigogenin cellobiosides on cholesterol absorption. Steroids 48:197-211
Malinow, M R; McLaughlin, P; Aigner-Held, R et al. (1986) Absorption of cholesterol and beta-sitosterol from cigarette smoke in Macaca mulatta. Atherosclerosis 60:15-21
Malinow, M R (1986) Regression and resolution in atherosclerosis. Prog Clin Biol Res 219:31-8
Malinow, M R (1985) Effects of synthetic glycosides on cholesterol absorption. Ann N Y Acad Sci 454:23-7