27 research outputs found

    The isolation and characterization of heat shock protein Hsp12 in Lipomyces starkeyi

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    Bibliography: leaves 60-72.The stress response protein Hsp 12 is induced in S. cerevisiae cells upon exposure to salt stress, heat shock, ethanol, and upon entry to stationary phase (Mtwisha et aI., 1998). In this study, the occurrence of proteins related to Hsp12 was investigated in a number of yeasts (namely, Saccharomyces cerevisiae S288C, Schizosaccharomyces pombe, Debaromyces hansenii, Lipomyces starkeyi Y-2024, Saccharomyces cerevisiae IFO 23X7 (Kaokai), Zygosaccharomyces rouxii and Pichia sorbitophila. This was performed by selective protein extraction followed by SDS-P AGE and western blotting using a S. cerevisiae anti-Hsp 12 antibody. The results showed that almost all the yeasts investigated possessed a protein that had an identical migration to that of Hsp 12 with the exception of S. pombe, which contained a 9 kDa protein. Western blotting using the antiHsp 12 antibody cross-reacted only with the two S. cerevisiae species in addition to the 12 kDa protein from Lipomyces starkeyi of all the species investigated. MALDI-TOF peptide mass analysis after tryptic digestion of the L. starkeyi 12 kDa protein showed that a close sequence similarity existed to that of S. cerevisiae Hsp 12 and none to rest of the 12 kDa proteins isolated from all the other species investigated. In order to determine the sequence of the Hsp 12 protein, the L. starkeyi Hsp 12 gene was amplified using S. cerevisiae Hsp 12 primers. Gene sequencing of both S. cerevisiae and L. starkeyi Hsp 12 genes revealed three nucleotide differences existed between them. L. starkeyi Hsp 12 was found to be present in relatively small amounts during early growth stages but increased during log phase with a slight further increase during stationary phase. Increasing the salt concentration in the growth medium was found to induce Hsp 12. Increased levels of Hsp 12 appeared to confer a degree of protection during desiccation and subsequent rehydration of both L. starkeyi and S. cerevisiae

    Regulation of Glut-4 Expression in Skeletal Muscle cells: The Roles of Nuclear Respiratory Factor-1 and calcium/calmodulin dependent protein Kinase

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    GLUT4 protein is the major glucose transporter in skeletal muscle and is vital in the maintenance of euglycemia (17; 108). Underexpression of GLUT4 or impairement of its translocation from intracellular compartments to the cell surface, are linked to diminished glucose transport, hyperglycemia and type II diabetes (59; 61; 153). Type II diabetes can be alleviated by increasing GLUT4 expression (223). Previous reports have shown that overexpression of NRF-1 and activation of CaMKII increases GLUT4 expression but the mechanisms involved have not be characterized (10; 173). Therefore, the objective of this thesis was to investigate the molecular mechanisms by which NRF-1 and CaMK II regulate GLUT4 expression in C2C12 myocytes. We engineered C2C12 cells that overexpressed NRF-1 in response to doxycycline (Dox) using a Tet-On gene expression system and assessed the effects of NRF-1 overexpression on: a) MEF2A, GLUT4 and δALAS proteins by western blot, and b) the binding of NRF-1 to mef2a and δalas genes and MEF2A to the glut4 gene, by chromatin immunoprecipitation assay (ChIP). The importance of MEF2A in NRF-1-induced increase in GLUT4 expression was investigated by silencing MEF2A expression using small interference RNA (siRNA). CaMK II was activated in wild-type C2C12 myocytes using 10 mM caffeine and was inhibited by 25 μ M KN93. Acetylation of histones in the vicinity of NRF-1 and MEF2A binding sites on the mef2a and glut4 genes, respectively, were assessed by ChIP assay. HDAC5 nuclear export was assessed by immunocytochemistry and mRNA levels by qRT-PCR. Overexpression of NRF-1 resulted in ~3-fold increases in mef2a-bound NRF-1 and glut4 -bound MEF2A at 6 h and 8 h post Dox treatment, respectively. MEF2A and GLUT4 proteins were both increased ~1.6-fold at 6 h and 18 h post Dox treatment. Silencing of MEF2A caused a marked downregulation of GLUT4 expression in NRF-1-overexpressing cells

    A review of therapeutic potentials of sweet potato: Pharmacological activities and influence of the cultivar

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    Sweet potato (Ipomoea batatas) is a global food crop, now being recognized as a functional food due to several of its nutraceutical components. Several experimental studies have reported that sweet potato can generally be beneficial in the prevention or treatment of chronic diseases through its antioxidant, anti-inflammatory, immunomodulatory, anticancer/antitumour, antimicrobial and antiulcer activities. Studies on the haematinic effect of potato leaves and their ability to enhance some haemotological parameters are reviewed in this paper. Furthermore, the review provides an overview of the significance and influence of cultivar on the composition and pharmacological activities of sweet potato. Sweet potato contains a lot of beneficial phytochemicals, some of which are peculiar to certain varieties. There is, therefore, a need for the continuous evaluation and selection of cultivars with the appropriate phytochemical composition and bioactivities to be able to fully explore the medicinal value of sweet potato. Studies aimed at the isolation, characterization and toxicological evaluation of its bioactive compounds may help to strengthen and confirm the possible role of sweet potato as a health promoting food and an alternative remedy for chronic diseases. This review highlights the pharmacological reports on different forms of sweet potato and their potential medicinal values.Keywords: Sweet potato, Cultivar influence, Chronic diseases, Ipomoea batatas, Diabetes, Anticancer, Haematological effec

    Natural antioxidant vitamins: A review of their beneficial roles in management of diabetes mellitus and its complications

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    Diabetes mellitus is a complex and progressive metabolic disease which is associated with multiple complications. Chronic  hyperglycaemia is the defining characteristic of diabetes mellitus. Hyperglycaemia leads to generation of free radicals and  induces oxidative stress, which has become the chief factor that leads to diabetic complications. This review supports the use of antioxidant vitamins as therapeutic agents in the management of diabetes mellitus and its complications, and also provides an insight into the potential pharmacological effects of natural antioxidant vitamins in diabetic conditions. These antioxidant  vitamins can be used as safe supplements to manage the occurrence and complications of the disease. Selected studies have  reported on the beneficial effects of antioxidant vitamins in experimental models. The involvement of oxidative stress in diabetes and its complications has made the use of natural antioxidant vitamins (free radical scavengers) from plants inevitable as they may be very effective and safer in the management of diabetes.Keywords: Antioxidant, Oxidative stress, Vitamins, Diabetes mellitu

    A study on neonatal intake of oleanolic acid and metformin in rats (rattus norvegicus) with metabolic dysfunction : implications on lipid metabolism and glucose transport

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    Abstract: Metabolic syndrome, a cluster of different disorders which include diabetes, obesity and cardiovascular diseases, is a global epidemic that is growing at an alarming rate. The origins of disease can be traced back to early developmental stages of life. This has increased mortalities and continues to reduce life expectancies of individuals across the globe. The aim of this study was to investigate the sub-acute and long term effects of neonatal oral administration of oleanolic acid and metformin on lipids (free fatty acids, FFAs) and genes associated with lipid metabolism and glucose transport using a neonatal rat experimental model. In the first study, seven days old pups were randomly grouped into control—distilled water (DW); oleanolic acid (60 mg/kg), metformin (500 mg/kg), high fructose diet (20% w/v, HF), oleanolic acid (OA) + high fructose diet (OA + HF), and Metformin + high fructose diet (MET + HF) groups. The pups were treated for 7 days, and then terminated on postnatal day (PD) 14. In the second study, rat pups were initially treated similarly to study 1 and weaned onto normal rat chow and plain drinking water on PD 21 till they reached adulthood (PD112). Tissue and blood samples were collected for further analyses..

    Long-Term Impact of Neonatal Intake of Oleanolic Acid on the Expression of AMP-Activated Protein Kinase, Adiponectin and Inflammatory Cytokines in Rats Fed with a High Fructose Diet

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    Abstract: AMP-activated protein kinase (AMPK) is known to regulate both glucose and lipid metabolism, which play vital roles in the development of metabolic syndrome. One way of regulating AMPK is through hormonal activation using adiponectin. Patients diagnosed with type-2 diabetes (T2D) and obesity exhibit low adiponectin concentration levels in their blood. Moreover, studies have also shown that inflammatory processes play a significant role in the etiology of these metabolic diseases. In this study, the long-term effects of neonatal intake of oleanolic acid (OA) on the AMPK gene, genes associated with glucose transport and lipid metabolism, adiponectin levels, and inflammatory biomarkers in rats fed with a high fructose diet were investigated. Seven day old pups were randomly divided into five groups and treated as follows; 0.5% dimethylsulphoxide v/v in distilled water vehicle control (CON), oleanolic acid (OA, 60 mg/kg), high fructose diet (HF, 20% w/v), high fructose diet combined with oleanolic acid (HF+OA), and high fructose diet combined with metformin (HF+MET, 500 mg/kg)..

    Metabolomics: A Scoping Review of Its Role as a Tool for Disease Biomarker Discovery in Selected Non-Communicable Diseases

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    From MDPI via Jisc Publications RouterHistory: accepted 2021-06-23, pub-electronic 2021-06-25Publication status: PublishedMetabolomics is a branch of ‘omics’ sciences that utilises a couple of analytical tools for the identification of small molecules (metabolites) in a given sample. The overarching goal of metabolomics is to assess these metabolites quantitatively and qualitatively for their diagnostic, therapeutic, and prognostic potentials. Its use in various aspects of life has been documented. We have also published, howbeit in animal models, a few papers where metabolomic approaches were used in the study of metabolic disorders, such as metabolic syndrome, diabetes, and obesity. As the goal of every research is to benefit humankind, the purpose of this review is to provide insights into the applicability of metabolomics in medicine vis-à-vis its role in biomarker discovery for disease diagnosis and management. Here, important biomarkers with proven diagnostic and therapeutic relevance in the management of disease conditions, such as Alzheimer’s disease, dementia, Parkinson’s disease, inborn errors of metabolism (IEM), diabetic retinopathy, and cardiovascular disease, are noted. The paper also discusses a few reasons why most metabolomics-based laboratory discoveries are not readily translated to the clinic and how these could be addressed going forward

    Administration of S-allyl cysteine to neonatal rats modulates inflammatory biomarkers in high-fructose-fed rats in adulthood

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    PURPOSE : To investigate the potential prophylactic effect of S-allyl cysteine (SAC), found in garlic (Allium sativum), against the development of apro-inflammatory status induced by diet in neonatal rats later on in adulthood. METHODS : Suckling Wistar rat pups (4-day-old; male = 21 and female = 21) were randomly allocated to either of 3 groups and orally gavaged daily with the following treatments from postnatal day (PND) 6 – 20: group 1 (control) - 10 mL/kg distilled water; group 2 - 10 mL/kg of 20 % w/v fructose solution (FS) and group 3 - 10 mL/kg FS + SAC. The rat pups were weaned on PND 21, and given ad libitum access to standard rat chow and plain drinking up to PND 115. The rats were euthanized on PND 116 and plasma was collected for the determination of interleukins (IL-1β, IL-4, IL-5, IL-10), vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1)] using Bio-Plex Pro magnetic beadbased assays on Bio-Plex platform. RESULTS : Oral administration of FS during suckling increased significantly (p < 0.05) plasma concentrations of IL-5, MCP-1 and VEGF in adult male rats, and plasma MCP-1 in adult female rats. Neonatal oral administration of SAC prevented FS-programmed increase in pro-inflammatory cytokines (p < 0.05) later on in adulthood. CONCLUSION : Oral administration of SAC during the neonatal period protected against FS-induced proinflammatory status and thus, could possibly be exploited as a prophylactic or intervention agent against a pro-inflammatory status induced by a high fructose diet.https://www.tjpr.org/homeam2021Physiolog

    Modulatory effects of oleanolic acid on cardiac anti-oxidant status and inflammatory response in high fructose-fed neonatal Sprague-Dawley rats

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    This present study investigated the antioxidant and inflammatory properties of oleanolic acid (OA) on neonatal rats administered with high fructose diet (HFD). Neonatal rats (24) were assigned at random to four (4) groups namely: Group A (control) which had distilled water only; Group B was administered with OA only; Group C was administered with HFD; Group D received HFD and OA. Animals were administered orally using orogastric gavage at a dosage of 10 ml/kg for 7 days (postnatal day 7-14. The antioxidant status of the hearts such as TEAC, Ferric Reducing Anti-oxidant Power, FRAP, Trolox Equivalence Antioxidant Capacity and oxidative stress biomarkers (MDA, Malondialdehyde and GSH, Glutathione) were evaluated using standard procedures. The levels of inflammatory cytokines in the hearts were determined using magnetic bead-based assays procedure. The TEAC values were significantly decreased in HFD+OA treatment (p < 0.05) in comparison with HFD group. Glutathione concentration in the HFD group had significant increase (p < 0.05) following treatment with oleanolic acid. FRAP values and MDA level were significantly (p < 0.01) elevated post exposure to HFD and treatment with oleanolic acid insignificantly decreased MDA level when compared with HFD group. The pro-inflammatory cytokines (IL-1β, IL-6, IL-12, IFN-γ, TNF-a and MCP-1) were significantly (p < 0.05) increased HFD group when compared to the control. Oleanolic acid administration significantly reduced inflammation in postexposure to HFD. Neonatal intake of oleanolic acid may help to prevent inflammation and oxidative damage in the progression of cardiovascular related diseases.https://www.tjnpr.orgam2023Physiolog
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