Glucose as a Major Antioxidant: When, What for and Why It Fails?

Antioxidants

Andriy Cherkas¹  Serhii Holota²  Tamaz Mdzinarashvili³  Neven Zarkovic⁴  Rosita Gabbianelli⁵ 

[1] Department of Internal Medicine1, Lviv National Medical University, 79010 Lviv, Ukraine;Department of Pharmaceutical, Organic and Bioorganic Chemistry, Lviv National Medical University, 79010 Lviv, Ukraine;Institute of Medical and Applied Biophysics, I. Javakhishvili Tbilisi State University, 0128 Tbilisi, Georgia;Laboratory for Oxidative Stress (LabOS), Institute “Rudjer Boskovic”, HR-10000 Zagreb, Croatia;Unit of Molecular Biology, School of Pharmacy, University of Camerino, 62032 Camerino, Italy;

关键词: glucose;    pentose phosphate pathway;    nadph;    redox balance;    glycogen;    glycolysis;    stress resistance;    insulin resistance;   

DOI  :  10.3390/antiox9020140

来源: DOAJ

【 摘 要 】

A human organism depends on stable glucose blood levels in order to maintain its metabolic needs. Glucose is considered to be the most important energy source, and glycolysis is postulated as a backbone pathway. However, when the glucose supply is limited, ketone bodies and amino acids can be used to produce enough ATP. In contrast, for the functioning of the pentose phosphate pathway (PPP) glucose is essential and cannot be substituted by other metabolites. The PPP generates and maintains the levels of nicotinamide adenine dinucleotide phosphate (NADPH) needed for the reduction in oxidized glutathione and protein thiols, the synthesis of lipids and DNA as well as for xenobiotic detoxification, regulatory redox signaling and counteracting infections. The flux of glucose into a PPP—particularly under extreme oxidative and toxic challenges—is critical for survival, whereas the glycolytic pathway is primarily activated when glucose is abundant, and there is lack of NADP⁺ that is required for the activation of glucose-6 phosphate dehydrogenase. An important role of glycogen stores in resistance to oxidative challenges is discussed. Current evidences explain the disruptive metabolic effects and detrimental health consequences of chronic nutritional carbohydrate overload, and provide new insights into the positive metabolic effects of intermittent fasting, caloric restriction, exercise, and ketogenic diet through modulation of redox homeostasis.

【 授权许可】

Unknown