ABSTRACT
Sorghum grain contains high levels and a diverse profile of polyphenols (PPs), which are antioxidants known to reduce oxidative stress when consumed in the diet. Oxidative stress leading to amyloid-ß (Aß) aggregation, neurotoxicity, and mitochondrial dysfunction is implicated in the pathogenesis of Alzheimer's disease (AD). Thus, PPs have gained attention as possible therapeutic agents for combating AD. This study aimed to (a) quantify the phenolic compounds (PP) and antioxidant capacities in extracts from six different varieties of sorghum grain and (b) investigate whether these PP extracts exhibit any protective effects on human neuroblastoma (BE(2)-M17) cells against Aß- and tau-induced toxicity, Aß aggregation, mitochondrial dysfunction, and reactive oxygen species (ROS) induced by Aß and tert-butyl hydroperoxide (TBHP). PP and antioxidant capacity were quantified using chemical assays. Aß- and tau-induced toxicity was determined using the 3-(4,5-dimenthylthiazol-2-yl)-2,5-dimethyltetrazolium bromide (MTS) assay. The thioflavin T (Th-T) assay assessed anti-Aß aggregation. The dichlorodihydrofluorescein diacetate (DCFDA) assay determined the levels of general ROS and the MitoSOX assay determined the levels of mitochondrial superoxide. Sorghum varieties Shawaya short black-1 and IS1311C possessed the highest levels of total phenolics, total flavonoids, and antioxidant capacity, and sorghum varieties differed significantly in their profile of individual PPs. All extracts significantly increased cell viability compared to the control (minus extract). Variety QL33 (at 2000 µg sorghum flour equivalents/mL) showed the strongest protective effect with a 28% reduction in Aß-toxicity cell death. The extracts of all sorghum varieties significantly reduced Aß aggregation. All extracts except that from variety B923296 demonstrated a significant (p ≤ 0.05) downregulation of Aß-induced and TBHP-induced ROS and mitochondrial superoxide relative to the control (minus extract) in a dose- and variety-dependent manner. We have demonstrated for the first time that sorghum polyphenolic extracts show promising neuroprotective effects against AD, which indicates the potential of sorghum foods to exert a similar beneficial property in the human diet. However, further analysis in other cellular models and in vivo is needed to confirm these effects.
ABSTRACT
Livestock blood is a protein-rich waste byproduct produced during meat production processes in slaughterhouses. Its utilization through conversion into value-added products is an intriguing management strategy. In this study, bovine blood was used to obtain the protein hydrolysate for use as a peptone for microbial growth medium. Lyophilized bovine blood was heat treated to make it susceptible to enzymic hydrolysis, and then enzymatically treated with trypsin (bovine pancreas protease) to produce protein hydrolysate. Physico-chemical features were determined for protein hydrolysate and compared to commercial Merck peptone from meat. Amino acid compositions of bovine blood and commercial peptones were subjected to multivariate analysis based on Euclidean similarity matrix using software PAST. Strains of Staphylococcus aureus 25,923, Pseudomonas aeruginosa 27,853, Staphylococcus aureus 6538 P, Enterococcus faecalis 11,700, Escherichia coli 8739, Klebsiella pneumoniae 13,883, Salmonella typhimurium 14,028 and Listeria monocytogenes 13,932 were used as test microbial strains. Growth of bacteria in culture media based on the peptone from bovine protein hydrolysate was compared to that in corresponding reference media based on commercial peptone. The results of these growth tests were comparable. Growth data were depicted and statistically analyzed using R packages ggplot2 and growthcurver, respectively, providing data fitting a standard form of logistic equation.
Subject(s)
Peptones , Protein Hydrolysates , Animals , Cattle , Peptones/metabolism , Protein Hydrolysates/chemistry , Culture Media/chemistry , Bacteria/metabolism , Trypsin , Escherichia coli/metabolismABSTRACT
Alzheimer's disease (AD) is characterized by the excessive deposition of extracellular amyloid-beta peptide (Aß) 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 Aß 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.
ABSTRACT
Differentiation of stem cells and functionality of target cells are regulated by microenvironmental stimuli to which the cells are exposed. Chemical agents such as growth factors and physical parameters including mechanical loadings are among major stimuli. In this study, equiaxial cyclic strain with two amplitudes was applied on rat adipose-derived mesenchymal stem cells (rAMSCs) with or without 5-azacytidine. The mRNA expression of cardiac-related genes was investigated through RT-PCR (polymerase chain reaction) method. Moreover, morphological features and the actin structure of the cells were studied. Results were indications of significant increase in mRNA expression among four target genes, which marked the increase in two principal cardiac markers of GATA4 and α-cardiac actin, and lesser increase in two other genes (NKX2-5, ßMHC) in all experimental groups treated chemically and/or mechanically. Such effect was maximal when both treatments were applied describing the synergistic effect of combined stimuli. All treatments caused significant increase in cell area and cell shape index. The well spreading of cells was accompanied by enhanced actin structure, especially among samples subjected to mechanical stimulus. Both effects were among required features for functional muscle cells such as cardiac cells. It was concluded that the cyclic equiaxial strain enhanced cardiomyogenic induction among rat adipose-derived mesenchymal stem cells and such effect was strengthened when it was accompanied by application of chemical factor. Results can be considered among strategies for cardiomyogenic differentiation and can be employed in cardiac tissue engineering for production of functional cardiomyocytes to repair of damaged myocardium.