Carboxytherapy-Induced Fat loss is Associated with VEGF-Mediated Vascularization

Background Carboxytherapy is the transcutaneous administration of CO2 gas for therapeutic purposes. Although this non-surgical procedure has been widely used for reducing localized adiposity, its effectiveness on fat loss in obese patients and its underlying mechanisms remain unclear. Methods C57BL/6 mice were fed with a high-fat diet for 8 weeks to generate obese animal models. Obese mice were randomly assigned to two groups: One group was administered air to both inguinal fat pads (air/air), and the other group was treated with air to the left inguinal fat pad and with CO2 to the right inguinal fat pad (air/CO2). Each group was treated every other day for 2 weeks. Morphological changes and expression levels of genes associated with lipogenesis and vascularization in fat were determined by histological and qRT-PCR analyses. Results Mice treated with air/CO2 showed lower body weights and blood glucose levels compared to air/air-treated mice. Paired comparison analysis revealed that CO2 administration significantly decreased adipose tissue weights and adipocyte sizes compared to air treatment. Additionally, CO2 treatment markedly increased vessel numbers and expressions of Vegfa and Fgf1 genes in adipose tissues. The expressions of Fasn and Fabp4 genes were also modestly reduced in CO2-treated adipose tissue. Moreover, Ucp1 expression, the target gene of VEGF and a key regulator in energy expenditure, was significantly increased in CO2-treated adipose tissue. Conclusions Carboxytherapy is effective in the reduction of localized fat in obese patients which is mechanistically associated with alteration of the vasculature involved in VEGF. No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.