Astaxanthin prevents loss of insulin signaling and improves glucose metabolism in liver of insulin resistant mice.

Abstract

This study investigates the effects of astaxanthin (ASX) on insulin signaling and glucose metabolism in the liver of mice fed a high fat and high fructose diet (HFFD). Adult male Mus musculus mice of body mass 25-30 g were fed either normal chow or the HFFD. After 15 days, mice in each group were subdivided among 2 smaller groups and treated with ASX (2 mg·(kg body mass)⁻¹) in olive oil for 45 days. At the end of 60 days, HFFD-fed mice displayed insulin resistance while ASX-treated HFFD animals showed marked improvement in insulin sensitivity parameters. ASX treatment normalized the activities of hexokinase, pyruvate kinase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, glycogen phosphorylase, and increased glycogen reserves in the liver. Liver tissue from ASX-treated HFFD-fed animals showed increased tyrosine phosphorylation and decreased serine phosphorylation of insulin receptor substrates (IRS)-1 and -2. ASX increased IRS 1/2 and phosphatidylinositol 3-kinase (PI3K) association and serine phosphorylation of Akt. In addition, ASX decreased HFFD-induced serine kinases (c-jun N-terminal kinase-1 and extracellular signal-regulated kinase-1). The results suggest that ASX treatment promotes the IRS-PI3K-Akt pathway of insulin signaling by decreasing serine phosphorylation of IRS proteins, and improves glucose metabolism by modulating metabolic enzymes.

• Authors: Saravanan Bhuvaneswari, Carani Venkatraman Anuradha
• Journal: Canadian journal of physiology and pharmacology (Can J Physiol Pharmacol) Vol. 90 Issue 11 Pg. 1544-52 (Nov 2012) ISSN: 1205-7541 [Electronic] Canada
• PMID: 23181282 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antioxidants
• Hypoglycemic Agents
• Insulin Receptor Substrate Proteins
• Irs1 protein, mouse
• Irs2 protein, mouse
• Liver Glycogen
• Xanthophylls
• Tyrosine
• Serine
• astaxanthine
• Phosphatidylinositol 3-Kinase
• Akt1 protein, mouse
• Proto-Oncogene Proteins c-akt

Topics

• Animals
• Antioxidants (therapeutic use)
• Dietary Supplements
• Hyperglycemia (diet therapy, etiology)
• Hypoglycemic Agents (therapeutic use)
• Insulin Receptor Substrate Proteins (agonists, metabolism)
• Insulin Resistance
• Liver (drug effects, enzymology, metabolism)
• Liver Glycogen (metabolism)
• Male
• Mice
• Phosphatidylinositol 3-Kinase (chemistry, metabolism)
• Phosphorylation (drug effects)
• Protein Processing, Post-Translational
• Proto-Oncogene Proteins c-akt (agonists, metabolism)
• Random Allocation
• Serine (metabolism)
• Signal Transduction (drug effects)
• Tyrosine (metabolism)
• Xanthophylls (therapeutic use)