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PAiN
03-19-2014, 05:01 PM
High dose of biotin sabotages fat cell growth





Large – but not absurdly so – doses of the vitamin biotin reduce the amount of triglycerides in the blood and they reduce fat mass too.

Molecular researchers at the Universidad Nacional Autonoma de Mexico discovered this when they did tests on mice. Might biotin be a useful slimming supplement?


Large – but not absurdly so – doses of the vitamin biotin reduce the amount of triglycerides in the blood and they reduce fat mass too. Molecular researchers at the Universidad Nacional Autonoma de Mexico discovered this when they did tests on mice. Might biotin be a useful slimming supplement?


Cardiologists discovered in the 1970s that if you give humans high doses of biotin you reduce the amount of lipids in their blood. [Kardiologiia. 1972 Dec;12(12):113.] [Artery. 1980;7(4):330-51.] This is appealing because triglycerides are a risk factor for cardiovascular disease.


The Mexicans revived this study in the hope that they might discover a way of helping people with high levels of cholesterol or triglycerides in their blood.


The researchers gave male mice feed containing either just enough biotin or feed containing extra biotin, for a period of eight weeks. The human equivalent of the biotin dose in the supplementation group was about 1 – 1.5 mg per day.


Supplying extra biotin reduced the triglyceride concentration in the blood by 35 percent.


The figure below shows the effect of biotin supplementation on the production of a number of proteins that cells use to store fat: glucose transporter-2 (GLUT2), glucokinase (GK), phosphofructokinase (PFK1), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PDH), acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD1), sterol regulatory element binding protein 1-c (SREBP1c), forkhead box O1 (FoxO1) and peroxisome proliferator receptor gamma (PPAR-gamma).


The first figure shows the production of lipogenic proteins in fat tissue; the second shows the production of lipogenic proteins in the liver. In fat cells, the administration of biotin reduced the production of all lipogenic proteins; in liver cells it reduced the production of most proteins.



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The idea of using vitamins for medicinal purposes is not new. Doctors prescribe vitamin B3 to reduce excessive quantities of triglycerides in the bloodstream. Pharmacologists have also developed analogues of vitamin A and D for use as medicines.


So, goes the Mexicans’ reasoning, maybe doctors will also find medicinal applications for pharmacological doses of biotin, even though the pharmacological doses are not actually terribly high.


“The biotin content in commercial supplements for humans is 40- to 166-fold higher than the reference dietary intake of 30 microg/day”, the researchers write. “The data in the present study showed that, in mice, a 55-fold increase in biotin concentration in the diet decreases serum triglycerides and the expression of lipogenic enzymes, providing molecular support to the effects of pharmacological concentrations of biotin on lipemia.”


Might biotin work as a slimming supplement? The research results suggest this may be the case. At the end of the eight-week experiment the mice in the control group had 14.9 percent fat in their bodies. The mice in the biotin group had 12.6 percent.
Pharmacological concentrations of biotin reduce serum triglycerides and the expression of lipogenic genes.

Larrieta E, Velasco F, Vital P, López-Aceves T, Lazo-de-la-Vega-Monroy ML, Rojas A, Fernandez-Mejia C.


Abstract
Besides its role as a carboxylase prosthetic group, biotin regulates gene expression and has a wide repertoire of effects on systemic processes. Several studies have shown that pharmacological concentrations of biotin reduce hypertriglyceridemia. The molecular mechanisms by which pharmacological concentrations of biotin affect lipid metabolism are largely unknown. The present study analyzed the effects of pharmacological doses of biotin on triglyceridemia, insulin sensitivity and on mRNA expression of various lipogenic genes. Three-week-old male BALB/cAnN Hsd mice were fed a biotin-control or a biotin-supplemented diet (1.76 or 97.7mg of free biotin/kg diet, respectively) over a period of eight weeks. Serum triglyceride concentrations, insulin and glucose tolerance and mRNA abundance of various lipogenic genes were investigated. The biotin-supplemented group showed 35% less serum triglycerides than control mice. In the liver, we found a significant (P<0.05) reduction of mRNA levels of SREBP1-c, glucose transporter-2, phosphofructokinase-1, pyruvate kinase, acetyl-CoA carboxylase and fatty acid synthase, while glucose-6-phosphate dehydrogenase expression increased. No changes in glucokinase, stearoyl-CoA desaturase-1, FoxO1 or PPAR-gamma expression were observed. In adipose tissue, we found a decreased expression of SREBP1c, glucose-6-phosphate deshydrogenase, acetyl-CoA carboxylase, fatty acid synthase, stearoyl-CoA desaturase-1, phosphofructokinase-1 and PPAR-gamma, but no changes in FoxO1 expression. Moreover, the group fed a biotin-supplemented diet showed a significant decrease in adipose tissue weight. No differences in insulin sensitivity or serum insulin concentrations were observed between groups. Our results indicate that pharmacological concentrations of biotin decrease serum tryglyceride concentrations and lipogenic gene expression in liver and adipose tissues.
Copyright 2010 Elsevier B.V. All rights reserved.


PMID: 20655901 [PubMed - indexed for MEDLINE]
Source: http://www.ncbi.nlm.nih.gov/pubmed/20655901