Whole sorghum flour improves glucose tolerance, insulin resistance and preserved pancreatic islets function in obesity diet-induced rats

Sorghum phytonutrients and their health benefits: A systematic review from cell to clinical trials

Sorghum is key for global food security due to its genetic variability, resilience, and rich phytonutrient content, which are linked to numerous health benefits. A systematic review assessed the health effects of sorghum by analyzing cell (n = 22), animal (n = 20), and human (n = 7) studies across antioxidant, anti-inflammatory, obesity, cancer, cardiovascular, and diabetes outcomes. This review, involving 42 papers and 177 researchers from 12 countries, collected data from sorghum accessions (acc) and significant effects. Studies used 68 identified and 8 unidentified sorghums, 57% red (n = 20), brown (n = 5), and black (n = 17) pericarp colors, and evaluated whole (n = 31), brans (n = 11), and decorticated grains (n = 2). Colored sorghum, richer in phenolic compounds, especially 3-deoxyanthocyanins and tannins, inhibited cancer cell activities, including proliferation, tumor growth, and ROS activity, and promoted cell cycle arrest and apoptosis. Sorghum elevated HO1 and eNOS expression for cardiovascular, health-reduced platelet aggregation, and modulated platelet microparticles. They also suppressed inflammation markers and decreased lipid accumulation. Animal studies indicated sorghum's potential across antioxidant capacity, cancer and inflammation mitigation, and lipid and glucose metabolism. Translating these findings to human scenarios requires caution, especially considering cell studies do not fully represent polyphenol metabolism. Human studies provided mixed results, indicating antioxidant and potential anti-inflammatory benefits and nuanced effects on glucose and lipid metabolism. The main risks of bias highlighted challenges in quantifying phytonutrients, identifying sorghum acc features, and lack of assessors blinding. Nonetheless, sorghum emerges as a promising functional food for countering chronic diseases in Western diets.

Baking Process Effects and Combined Cowpea Flour and Sorghum Bran on Functional Properties of Gluten-Free Cookies

Gluten-related disorders, including celiac disease and non-celiac gluten sensitivity, are growing worldwide. The only treatment for both disorders is a lifelong gluten-free diet. However, gluten-free foods are generally poorer in nutrients, less healthy, and have a high cost. Sorghum and cowpea are gluten-free grains with high levels of phenolic compounds (PC) and a low cost. Their phenolic profile is structurally different; thus, the blend of both can provide synergistic/complementary health benefits to the final product. This study analyzed the effect of baking process and the blend of cowpea flour (CP) and sorghum bran (SB) on the levels of PC, resistant starch (RS), neutral detergent fiber (NDF), and antioxidant capacity (AC) of gluten-free cookies. Eleven rice or cowpea cookie formulations were made with or without white sorghum bran (WSB) or black sorghum bran (BSB). Baking increased the extractability of PC, AC, and the NDF of almost all formulations. The PC and AC were, respectively, about twice and 3-5 times higher in cookies containing BSB compared to the others. There was a minor effect of WSB on the PC and AC. Although there were losses, the retention of RS of cookies after the baking process was between 49.8 and 92.7%. Sorghum bran has excellent potential for use as a functional ingredient in healthy food production. The combined CP and SB have great potential to improve the nutritional and functional properties of gluten-free products, especially the PC, RS, and NDF contents.

Effect of sorghum and barley-containing bread on plasma total polyphenols, antioxidant status and inflammation in healthy subjects

The aim of this study was to investigate the effect of bread incorporated with whole-grain red sorghum and barley flours on biomarkers of oxidative stress and inflammation in humans. In a randomized cross-over study, 20 healthy subjects consumed either control bread made of all-purpose wheat flour only or bread containing 40% whole-grain red sorghum and barley flours (20% each), with a washout period of 1-2 week. The test breads were fed at breakfast after 12 h fast. Blood samples were collected at baseline (fasting) and 2 h after intake of breads. Plasma total polyphenols, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, thiobarbituric acid reactive substances (TBARS) and highly sensitive C-reactive protein were assessed. Compared to fasting values, the 2 h postprandial levels of plasma total polyphenols (P = 0.001), T-AOC (P = 0.031) and SOD activity (P = 0.026) were significantly higher following consumption of sorghum and barley-containing bread (SBB). Moreover, net changes in plasma total polyphenols (P = 0.001), T-AOC (P = 0.047) and SOD activity (P = 0.035) were significantly higher following consumption of SBB. In conclusion, bread containing whole-grain red sorghum and barely flours enhanced plasma total polyphenols and antioxidant status and hence its consumption would modulate biomarkers of cardio-metabolic health.

Protective Effect of Butanolic Fraction of Delphinium brunonianum on Fructose-Mediated Metabolic Alterations in Rats

The present study was conducted with an intent to evaluate the protective effect of butanolic fraction of Delphinium brunonianum on fructose mediated metabolic abnormalities in rats. Rats in all groups except control group were fed on 10% fructose for 6 weeks; however, rats in the treated group also received butanolic fraction for the last 3 weeks, along with the fructose. Moreover, phytoconstituents present in butanolic fraction were analyzed using LC-MS. All doses of butanolic fraction profoundly reduce the fructose-induced blood pressure, sympathetic over-activity, and weight gain. Furthermore, butanolic fraction prominently reduces the glucose intolerance and hyperinsulinemia in fructose-fed rats. On treatment with butanolic fraction, oxidative enzymes and the functionality of the aorta was also restored. Phytochemical analysis revealed the presence of several active constituents including bergenin, scopolin, rutinoside, kaempferol, coumaric acid, apigenin, and gingerol. In conclusion, butanolic fraction of Delphinium brunonianum has the potential to prevent and recover the fructose-induced metabolic perturbations.

Potential of Sorghum Polyphenols to Prevent and Treat Alzheimer's Disease: A Review Article

Alzheimer's disease (AD) is characterized by the excessive deposition of extracellular amyloid-beta peptide (Aβ) and the build-up of intracellular neurofibrillary tangles containing hyperphosphorylated tau proteins. This leads to neuronal damage, cell death and consequently results in memory and learning impairments leading to dementia. Although the exact cause of AD is not yet clear, numerous studies indicate that oxidative stress, inflammation, and mitochondrial dysfunction significantly contribute to its onset and progression. There is no effective therapeutic approach to stop the progression of AD and its associated symptoms. Thus, early intervention, preferably, pre-clinically when the brain is not significantly affected, is a better option for effective treatment. Natural polyphenols (PP) target multiple AD-related pathways such as protecting the brain from Aβ and tau neurotoxicity, ameliorating oxidative damage and mitochondrial dysfunction. Among natural products, the cereal crop sorghum has some unique features. It is one of the major global grain crops but in the developed world, it is primarily used as feed for farm animals. A broad range of PP, including phenolic acids, flavonoids, and condensed tannins are present in sorghum grain including some classes such as proanthocyanidins that are rarely found in others plants. Pigmented varieties of sorghum have the highest polyphenolic content and antioxidant activity which potentially makes their consumption beneficial for human health through different pathways such as oxidative stress reduction and thus the prevention and treatment of neurodegenerative diseases. This review summarizes the potential of sorghum PP to beneficially affect the neuropathology of AD.

The use of alternative food sources to improve health and guarantee access and food intake

To feed and provide Food Security to all people in the world is a big challenge to be achieved with the 2030 Agenda. Undernutrition and obesity are to the opposite of a healthy nutritional status. Both conditions are associated with unbalanced nutrition, absence of food or excess of non-nutritive foods intake. These two nutritional conditions associated with food production are closely related to some goals highlighted by the United Nations in the 2030 Agenda to achieve sustainable world development. In this context, the search for alternative foods whose sustainable production and high nutritional quality guarantee regular access to food for the population must be encouraged. Alternative foods can contribute to Food Security in many ways as they contribute to the local economy and income generation. Popularizing and demystifying the uses of unconventional food plants, ancestral grains, flowers, meliponiculture products, and edible insects as sources of nutrients and non-nutrients is another challenge. Herein, we present an overview of alternative foods - some of them cultivated mostly in Brazil - that can be explored as sources of nutrients to fight hunger and malnutrition, improve food production and the economic growth of nations.

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.

Effects of sorghum rice and black rice on genes associated with cholesterol metabolism in hypercholesterolemic mice liver and intestine

The effects of different proportions of dietary sorghum rice and black rice on the expression of genes related to cholesterol metabolism in mice liver, intestine, and the characteristics of the small intestinal microbiota were investigated. Six types of diets were used to feed C57BL/6 mice: AIN-93M standard diet, high-cholesterol model diet, high-cholesterol and low-dose sorghum grain or black rice diet, and high-cholesterol and high-dose sorghum grain or black rice diet. The results showed that black rice or sorghum grain diets had no effect on the serum TC, LDL-C levels in the hypercholesterolemic mice, whereas these diets decreased serum TG level, and black rice diets increased serum HDL-C level. The diets containing black rice and sorghum grain had no effect on liver TC, TG, HDL-C levels. However, these diets decreased LDL-C levels significantly except high dose of black rice. The black rice or sorghum grain diets reduced the expression of the genes encoding liver 3-hydroxyl-3-methyl-glutarate monoacyl coenzyme A reductase (HMG-CoA-R) and increased the expression of SREBP-2, thereby partially inhibiting the synthesis of cholesterol in liver. The diets containing different proportions of black rice and a low proportion of sorghum grain reduced the expression level of Niemann-Pick type C 1 like 1 (NPC1L1) mRNA and increased the mRNA level of the ATP-binding cassette transporters, ABCG5/ABCG8, in the small intestine, thereby reducing cholesterol absorption. A diet containing a low proportion of black rice promoted the expression of ABCA1 mRNA and increased the expression of high-density lipoprotein (HDL) mRNA, thereby promoting reverse cholesterol transport. Black rice diets significantly increased the relative abundances of microbiota in the small intestine and maintained biodiversity, while sorghum grain had no positive effect on the abundance of microbiota.

Sorghum (Sorghum bicolor L.) as a potential source of bioactive substances and their biological properties

Sorghum is the fifth cereal most produced in the world after wheat, rice, maize, and barley. In some regions, this crop is replacing maize, due to its high yield, resistance to drought and heat. There are several varieties of sorghum, whose coloration varies from cream, lemon-yellow, red, and even black. Pigmented sorghum grain is a rich source of antioxidants like polyphenols, mainly tannins, which have multiple benefits on human health such as, antiproliferative properties associated with the prevention of certain cancers, antioxidant activities related to the prevention of associated diseases to oxidative stress, antimicrobial and anti-inflammatory effects, it also improves glucose metabolism. Despite having these types of compounds, it is not possible to assimilate them, their use in the food industry has been limited, since sorghum is considered a food of low nutritional value, due to the presence of anti-nutritional factors such as strong tannins which form complexes with proteins and iron, thus reducing their digestibility. Based on these restrictions that this product has had as food for humans, the analysis of this review emphasizes the valorization of sorghum as a source of bioactive substances and the importance they confer on human health because of the biological potential it has.

Effects of extruded whole-grain sorghum (Sorghum bicolor (L.) Moench) based diets on calcium absorption and bone health of growing Wistar rats

Apparent calcium absorption, total bone mineral content and density, and mineral contents of the right femur were studied using a growing rat model. Twenty-four male Wistar rats were fed with diets based on extruded whole grain red (RSD) or white sorghum (WSD), and control diet (CD) up to 60 days. The animals fed with sorghum diets consumed less and gained less weight compared to those fed with CD, but the efficiency of all diets was similar. Calcium intake was lower in animals fed with sorghum diets, related to the lower total intake of these animals. Apparent calcium absorption in animals fed with RSD was lower than in those fed with CD (CD: 72.7%, RSD: 51.0%, WSD: 64.8%). No significant differences in bone mineral density of total body, spin, femur, distal femur, tibia and proximal tibia were observed among the groups. However, Ca and P contents in the right femur of the rats consuming RSD were lower, indicating a certain imbalance in the metabolism of these minerals.

Evaluation of the efficacy of toasted white and tannin sorghum flours to improve oxidative stress and lipid profile in vivo

The objective of the present work was to evaluate and compare the effect of toasted white and tannin sorghum flours on lipid metabolism and antioxidant potential in vivo. Male spontaneously hypertensive rats (SHR) were induced to oxidative stress with paracetamol and fed a normal diet (AIN-93M) and diets containing toasted tannin sorghum flour and toasted white sorghum flour (without tannins), replacing 100% cellulose, during 29 days. Hepatotoxicity was assessed by biochemical tests and by quantifying oxidative stress markers. Groups that received toasted sorghum flour with and without tannins showed reduction of alanine aminotransferase (ALT) concentration and improvement of lipid profile, with increase of high-density lipoprotein (HDL) compared to paracetamol control, and did not differ statistically from the AIN-93M control. Moreover, toasted white sorghum flour presented similar efficacy in reducing oxidative stress in liver tissue compared to toasted tannin sorghum flour, although the former had lower total phenolic content and antioxidant capacity, suggesting a greater effect of small phenolic compounds, such as phenolic acids, in the prevention of oxidative stress. Therefore, toasted white and tannin sorghum flours had similar efficacy to improve the lipid profile and oxidative stress in rats treated with paracetamol, constituting potential sources of antioxidants, which can be used as promising ready-to-eat foods and as ingredients for the development of sorghum-based products. PRACTICAL APPLICATION: The health benefits of sorghum coupled with the growing interest of the food industry in producing healthier food products have motivated the development of toasted sorghum flours as potential sources of antioxidants and dietary fiber. We have demonstrated that consumption of toasted white and tannin sorghum flours by rats treated with paracetamol had similar efficacy to improve oxidative stress and lipid profile. Thus, these toasted sorghum flours have great potential to be used by the food industry as ready-to-eat foods or as ingredients in the development of various food products.

Flavonoids in Decorticated Sorghum Grains Exert Antioxidant, Antidiabetic and Antiobesity Activities

Eight new genotypes of brown sorghum grain were decorticated and assessed for their antioxidant, antidiabetic and antiobesity activities in vitro. The DPPH and ABTS radical scavenging assays of the soluble fractions were evaluated, followed by digestive enzymes and advanced glycation end-products (AGEs) formation inhibition assays. DSOR 33 and DSOR 11 exhibited the highest DPPH (IC50 = 236.0 ± 1.98 µg/mL and 292.05 ± 2.19 µg/mL, respectively) and ABTS radical scavenging activity (IC50 = 302.50 ± 1.84 µg/mL and 317.05 ± 1.06 µg/mL, respectively). DSOR 17, DSOR 11 and DSOR 33 showed significantly higher inhibitory activity of both α-glucosidase and α-amylase (IC50 = 31.86, 35.10 and 49.40 µg/mL; and 15.87, 22.79 and 37.66 µg/mL, respectively) compared to acarbose (IC50 = 59.34 and 27.73 µg/mL, respectively). Similarly, DSOR 33, DSOR 11 and DSOR 17 showed potent inhibition of both AGEs and lipase with IC50 values of 18.25, 19.03 and 38.70 µg/mL; and 5.01, 5.09 and 4.94 µg/mL, respectively, compared to aminoguanidine (52.30 µg/mL) and orlistat (5.82 µg/mL). Flavonoids were the predominant compounds identified, with flavones being the major subclass in these three extracts. Our findings suggest that decorticated sorghum grains contain substantial amounts of flavonoids and could be promising candidates for the prevention and treatment of diabetes and obesity.

Sorghum Phytochemicals and Their Potential Impact on Human Health

Sorghum contains a wide array of phytochemicals and their levels are affected by the genotype. Phytochemicals identified in sorghum include phenolic acids, flavonoids, condensed tannins, polycosanols, phytosterols, stilbenes, and phenolamides. Most of these phytochemicals are concentrated in the bran fraction and have been shown to have several potential health benefits, which include antidiabetic, cholesterol-lowering, anti-inflammatory, and anticancer properties. This chapter gives an overview of sorghum genetics relevant to phytochemicals, phytochemicals identified in sorghum grain, and their potential health benefits.