Refined sorghum flours precooked by extrusion enhance the integrity of the colonic mucosa barrier and promote a hepatic antioxidant environment in growing Wistar rats

The effects of precooked-refined sorghum flour consumption on antioxidant status, lipid profile, and colonic and bone health were evaluated. Twenty-four male Wistar rats were fed with control diet (C), or red or white precooked-refined sorghum based diets (SD) for 60 days. The intake of SD was lower than that of C, but the efficiency of all diets was similar. Rats fed with SD showed lower feces excretion, cecal pH and enzyme activities (β-glucosidase, β-glucuronidase and mucinase) than C. White SD improved intestinal architecture, cell proliferation and apoptosis, upregulated ZO1 and occludin tight junction proteins and stimulated goblet cell differentiation, enhancing the integrity of the mucosa barrier in both proximal and distal colonic mucosa in a better way than red SD. Consumption of SD significantly decreased serum triglyceride levels compared with the C diet. The mineral content of the right femur was not different among diets. The liver enzyme activities (superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase) did not show differences among diets. Liver reducing power and reduced glutathione/oxidize glutathione ratio were higher for animals consuming SD than C. It can be concluded that the consumption of precooked refined sorghum flours still has beneficial effects for health, mainly at the colonic level, despite the lower phenolics and fibre contents of refined flours with respect to whole grain flours.