Management of hypercholesterolemia through dietary beta glucans in a zebrafish model

Consumption of lipid-rich and highly processed foods can increase the cholesterol content in the blood, leading to unfavourable disease conditions. beta-glucans are known to have hypocholesterolemic effect, however, subtle changes in their molecular branching can influence their bioactivity. Therefore, a comparative investigation of the cholesterol lowering potential of dietary beta-glucans from oats and a microalga and simvastatin, a well-known cholesterol lowering drug, was undertaken employing the zebrafish model of hypercholesterolemia.We conducted a twelve-week long feeding experiment employing adult male zebrafish. The fish were allocated to 5 dietary treatments; a control group, a high cholesterol group, two beta-glucan groups and a simvastatin group.The intestinal transcriptome of the zebrafish responded to dietary cholesterol, indicating the possible suppression of endogenous cholesterol biosynthesis pathways, dysfunction of both endoplasmic reticulum and mitochondria, and brought about histological changes in the intestine. The two beta-glucans and simvastatin significantly mitigated the rise in plasma cholesterol levels, restored the expression of several genes and possibly alleviated the endoplasmic reticulum-related effects induced by dietary cholesterol. Oat and microalgal beta-glucan feeding induced distinct patterns of gene expression changes, which revealed antagonistic effect of the two beta-glucans on fatty acid metabolism, protein catabolic processes and nuclear division in the intestine.