Chlorella vulgaris improves insulin signaling in tissues of diet- induced obesity mice

Program: Late-Breaking Abstracts
Session: MON-LB-Late-Breaking Poster Session 3
Bench to Bedside
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-LB-09
Juliana Falcato Vecina*, Alexandre Gabarra Oliveira, PhD, Tiago Gomes Araujo, Mario J Saad and Mary L. S. Queiroz
State University of Campinas, Campinas, Brazil
Obesity is a worldwide epidemic problem with high morbidity and mortality. It is associated with a chronic systemic low-grade inflammation that promotes insulin resistance, which predicts type 2 diabetes. Insulin resistance is associated with a complex network of signaling pathways, including reduced insulin-stimulated tyrosine phosphorylation of insulin receptor (IR) and its substrate (IRS) as well as the Akt serine phosphorylation in its main target tissues. The search for natural agents that minimize the obesity-associated disorders is receiving special attention from the scientific community. Accordingly, Chlorella vulgaris (CV), a microscopic single celled freshwater alga rich in nutrients, emerges as an alternative treatment and prophylaxis of obesity-related complications. Considering theses aspects, we aimed to evaluate the prophylactic action of CV in body weight, lipid metabolism, blood glucose, insulin sensitivity and its signaling in liver, skeletal muscle and adipose tissue of diet-induced obese (DIO) mice. Animals were randomly assigned to 4 groups: standard rodent chow or high-fat diet treated or non-treated (i.e, control (CTL), CTL+CV, DIO, DIO+CV). The expression and phosphorylation of IRβ, IRS-1 and Akt were determined by Western blot analyses. DIO and DIO+CV groups showed a significant increase in blood glucose compared to CTL, however, the values of the DIO+CV were significantly lower than DIO group. Regarding body weight, all DIO animals were not significantly different from their peers, despite the treatment. The administration of CV did not change the insulin and leptin levels in DIO mice, when compared to CTL. However, DIO+CV mice presented an expressive improvement in their ITT and GTT, which reflects improved insulin sensitivity in these animals. For the first time, our results demonstrated the influence of CV administration on insulin signaling pathway by increasing phosphorylation levels of mainly proteins, such as IR, IRS-1 and Akt in its main target tissue. In parallel, we also observed lower phosphorylation levels of IRS-1ser307. The lipid profile showed cholesterol total and triglycerides levels impressive elevated in DIO group when compared to CTL. The administration of CV was able to maintain them under physiologic levels. Taken together, these data support the idea that CV acts preventing the deleterious effect in DIO mice, thus CV emerges as a prophylactic and therapeutic alternative to related-obesity complications.

Nothing to Disclose: JFV, AGO, TGA, MJS, MLSQ

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Sources of Research Support: São Paulo Research Foundation (FAPESP) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)