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Case 3
Published in Andrew Solomon, Julia Anstey, Liora Wittner, Priti Dutta, Clinical Cases, 2021
Andrew Solomon, Julia Anstey, Liora Wittner, Priti Dutta
Transketolase is an enzyme in the pentose–phosphate pathway, with thiamine and magnesium as its cofactors. Thiamine is vital to cellular energy production, and therefore any deficiency tends to affect the most active tissues first – brain, nervous system and heart
Medicinal Plants in Natural Health Care as Phytopharmaceuticals
Published in Anil K. Sharma, Raj K. Keservani, Surya Prakash Gautam, Herbal Product Development, 2020
Studies have demonstrated the hypoglycaemic action and effects of coriander on carbohydrate metabolism. The effect of coriander seeds on carbohydrate metabolism was studied in rats that were fed with a fat-rich cholesterol diet. The spice exhibited noteworthy hypoglycemic action. There was an increase in the concentration of hepatic glycogen as was evident from the increased activity of glycogen synthase. Activities of glycogen phosphorylase and gluconeogenic enzymes revealed decreased rates of glycogenolysis and gluconeogenesis. The increased activities of glucose-6-phosphate dehydrogenase and glycolytic enzymes suggest the utilization of glucose by the pentose phosphate pathway and glycolysis. These observations clearly indicated that coriander seeds demonstrate good hypoglycemic activity through enhanced glycogenesis, glycolysis and decreased glycogenolysis and gluconeogenesis (Aissaoui et al., 2011).
The vitamins
Published in Geoffrey P. Webb, Nutrition, 2019
Thiamin is the precursor of the important coenzyme TPP. TPP is formed by the addition of pyrophosphate (two phosphate groups) at the position marked by an asterisk in Figure 15.6. TPP is an essential coenzyme in several key reactions in metabolism including the following. The conversion of pyruvate to acetyl CoA in carbohydrate metabolism. The conversion of α-ketoglutarate to succinyl CoA in the Krebs cycle. The reactions catalysed by transketolase in the pentose phosphate pathway.
Xiaojianzhong decoction attenuates aspirin-induced gastric mucosal injury via the PI3K/AKT/mTOR/ULK1 and AMPK/ULK1 pathways
Published in Pharmaceutical Biology, 2023
Ting Chen, Shengchuan Bao, Juan Chen, Jiaxiang Zhang, Hailiang Wei, Xin Hu, Yan Liang, Jingtao Li, Shuguang Yan
Accumulation of oxidative stress causes oxidization and damage to cells, which turns on the autophagic process (Scherz-Shouval and Elazar 2011). Long-term use of aspirin can elevate oxidative stress levels and aggravate gastric mucosal injury (Mahmoud and Abd El-Ghffar 2019). The pentose phosphate pathway can improve the ability of cells to resist oxidative stress and reduce damage (Cao et al. 2017). G6PD, as the first enzyme in the initial stage of the pentose phosphate pathway, can promote the entry of glucose into this pathway, generate NADPH, scavenge peroxides, maintain redox homeostasis, and prevent oxidative damage (Joshi et al. 2020). We examined the expression levels of G6PD and NADPH, and the results showed that XJZD increased both, confirming that XJZD can maintain redox homeostasis by activating the pentose phosphate pathway, thereby reducing gastric mucosal injury.
The study of metabolism and metabolomics in a mouse model of silica pulmonary fibrosis based on UHPLC-QE-MS
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2022
Min Qiu, Ling Qin, Yonghe Dong, Junbing Ma, Zheng Yang, Zhixiang Gao
The pentose phosphate pathway, a form of glucose oxidative decomposition, is the main pathway for the synthesis of phosphoribose and reduced nicotinamide adenine dinucleotide phosphate, which plays an important antioxidant role in the body [16]. Abnormal pentose phosphate metabolism may indicate a disorder in the normal antioxidant stress function, and the levels of deoxyribose 5-phosphate, d-ribose and gluconic acid involved in this pathway were increased to different degrees. Deoxyribose 5-phosphate and d-ribose jointly synthesize d-ribose 5-phosphate, which plays an important role in energy production, and gluconic acid is a glucose-related metabolite [16,17]. Elevated levels of deoxyribose 5-phosphate, d-ribose and gluconic acid indicate a dysregulated pentose phosphate pathway that leads to impaired antioxidant function [18].
Therapeutic perspectives on the metabolism of lymphocytes in patients with rheumatoid arthritis and systemic lupus erythematosus
Published in Expert Review of Clinical Immunology, 2021
Glucose is transported into the cell and catalyzed into glucose-6-phosphate (G6P) by hexokinase (HK). G6P then either undergoes glycolytic degradation to produce pyruvate or enters the pentose phosphate pathway to produce NADPH and nucleotide precursors. The key to glycolytic degradation is the phosphorylation of fructose 6-phosphate to fructose-1, 6-bisphosphate by 6-phosphofructo-1-kinase (PFK1), an irreversible reaction that transfers glucose to glycolysis. The activity of PFK1 is regulated by fructose-2, 6-bisphosphate (F2, 6BP) produced by 6-phosphofructo-2-kinase/ fructose-2, 6-bisphosphase-3 (PFKFB3). Thus, PFKFB3 is the key regulatory enzyme that determines the efficiency of glucose utilization in the cytoplasm. In the T cells derived from patients with RA, PFKFB3 is not enhanced upon activation, glycolysis is suppressed, and pyruvate/lactate production is reduced [76,77]. Conversely, G6PD is enhanced, and there is a shift to the pentose phosphate pathway (PPP). The imbalance in the PFK/G6PD ratio leads to the overproduction of NADPH and accumulation of reduced glutathione, leading to a reductive intracellular environment [78,79].