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Ability of Great Northern and Pinto Beans to Prevent High Cholesterol Caused by a Diet Rich In Saturated Fat in a Hamster Model
Great northern and pinto beans have been shown to possess a variety of bioactive components that potentially provide cholesterol lowering properties. In this research project, three animal studies were carried out to investigate the ability and possible underlying mechanism of raw great northern and pinto beans as well as steamed pinto beans to mitigate the high cholesterol caused by a diet rich in saturated fat. In each study, hamsters were randomly assigned into four different groups (n = 11), each received either a normal fat diet (NF), a diet rich in saturated fat (HSF) or HSF diets supplemented with 5 % (w/w) whole beans or 0.5 % (w/w) bean hulls over a period of four weeks. The results showed that the supplementation of the raw and steamed whole beans to the HSF diet significantly reduced plasma and liver cholesterol in experimental animals. The decrease in plasma and / or hepatic cholesterol occurred concurrently with the increased excretion of cholesterol in the feces, indicating that the supplements promoted the elimination of cholesterol out of body. The analyses of several important genes involved in cholesterol homeostasis revealed that the supplements primarily inhibited the absorption of cholesterol from the intestinal lumen. Apart from acting on the cholesterol absorption pathway, the raw pinto beans were also able to inhibit hepatic cholesterol synthesis by suppressing the gene responsible for this activity. In contrast, the cholesterol synthesis in the liver actually increased in great northern bean supplemented animals, which might help prevent the depletion of cholesterol due to high excretion. The results also demonstrated that heat treatment during steaming negatively affected the efficacy of pinto beans in reducing cholesterol. Among the hull supplements, only raw pinto bean hulls added at 0.5 % (w/w) was able to lower cholesterol, which might be attributed to its high level of phenolic compounds. Nevertheless, the hulls played an important role in the overall capability of the beans to prevent high cholesterol caused by a diet rich in saturated fat, as demonstrated by their effects in molecular regulation of cholesterol homeostasis.
Nguyen, An Tien, "Ability of Great Northern and Pinto Beans to Prevent High Cholesterol Caused by a Diet Rich In Saturated Fat in a Hamster Model" (2018). ETD collection for University of Nebraska - Lincoln. AAI10844640.