The effect of alfalfa‐corn diets on cholesterol metabolism and gallstones in prairie dogs

Abstract

Cholesterol gallstones were present in prairie dogs fed alfalfa plus corn with and without exogenous cholesterol (0.4%). The diets fed to the animals for eight weeks contained alfalfa plus corn in fixed proportions of 50:50, 85:15 and 15:85 (w/w). At sacrifice, all animals were healthy but had not gained weight; no deaths occurred during the experiment. Cholesterol gallstones were present in all groups. In the absence of exogenous cholesterol, the highest stone incidence was found in the animals which received the lowest fiber (highest corn) diets (alfalfa plus corn, 50:50, 67%; alfalfa plus corn, 15:85, 83%). Cholesterol gallstone incidence was 100% when exogenous cholesterol was added to the alfalfa plus corn diets (50:50 and 15:85). No pigment gallstones were detected in any animal. Liver and plasma cholesterol concentrations were highest in the animals receiving alfalfa plus corn (15:85) plus 0.4% cholesterol (4.29 mg/g, and 356 mg/dl, respectively). These values were lowest in animals receiving 85% alfalfa plus 15% corn without cholesterol (2.19 mg/g and 88 mg/dl, respectively). Lithogenic indices were below 1.00 in all groups. Biliary bile acids were mainly amidates of cholic acid and chenodeoxycholic acid, with the former predominating. Thus, gallstones can be formed in prairie dogs in the absence of exogenous cholesterol; gallstone incidence is reduced by dietary fiber.

Phytochemical and pharmacological potential ofMedicago sativa: A review

“…Several studies indicate that the ingestion of M. sativa reduces cholesterol absorption and atherosclerotic plaque formation in animals (Wilcox & Galloway, 1961;Malinow et al, 1977aMalinow et al, , 1981aCohen et al, 1990). M. sativa top (stem and leaves) saponins have been reported to decrease plasma cholesterol concentrations without changing high-density lipoprotein cholesterol concentrations, decrease intestinal absorption of cholesterol, increase excretion of neutral steroids and bile acids, prevent atherosclerosis and induce the regression of atherosclerosis (Malinow et al, 1982a).…”

“…Therefore, M. sativa saponins appear to play an important role in neutral steroid excretion, but are not essential for increasing bile acid excretion (Story et al, 1984). In an experiment with prairie dogs, the lowest incidence of cholesterol gallstones was served with the diet of the higher fiber content (85% alfalfa) (Cohen et al, 1990).…”

Evaluation of Antioxidant and Cerebroprotective Effect of Medicago sativa Linn. against Ischemia and Reperfusion Insult

“…Phytochemical reports on MS indicate that the plant contains flavonoids [20], alkaloids [21, 22], phytoestrogens, coumarins, digestive enzymes, triterpenes [23], saponins [24] and phytosterols [23, 25]. Several clinical and animal studies indicate that the ingestion of MS reduces cholesterol absorption and atherosclerotic plaque formation in the arteries [26, 27]. MS is beneficial in cardiovascular complaints [23], convalescence and debility [22], diabetes [28] and also when used as a tonic after blood loss and during anemia [22].…”

Replacement of cholesterol gallstones by murideoxycholyl taurine gallstones in prairie dogs fed murideoxycholic acid

“…In the prairie dog model of cholesterol cholelithiasis, a high-cholesterol (1.2%) diet induced biliary cholesterol crystals within a few days and cholesterol gallstones within a few weeks or months (14,15,30). The reliability invariably displayed cholesterol clefts in their intrahepatic bile ducts.…”

“…Cholesterol crystal clefts were not observed in any of the livers from prairie dogs in the induction phase (group 1 ) or the 12-wk regression phase when the diet was supplemented with MDCA (group 7). and reproducibility of this animal model can be improved by preconditioning the prairie dogs with an alfalfahorn diet, with the result that stones are obtained in all animals maintained with a lithogenic (highcholesterol) chow diet for 75 days (15).…”