Oral supplement study with in vivo obesity model

Forty 6-week old male C57BL/6J mice (Jackson Laboratories, Bar Harbor, ME) were fed a high fat diet (HFD, 60% kilocalories fat, D12492 Research Diets Inc., New Brunswick, NJ) for eight weeks. Animals were randomly assigned to one of the following four study groups (10 per group) on Day -1 based on body weight: Group 1 (HFD non-supplemented controls), Group 2 (daily oral 5 mg/kg heptadecanoic acid, C17:0), Group 3 (daily oral 35 mg/kg heptadecanoic acid, C17:0), and Group 4 (daily oral 5 mg/kg pentadecanoic acid, C15:0). Group sizes for this pilot study were based on numerous published studies initially evaluating the effects of other natural small molecules on similar metabolic indices in the same model. Animals were provided the vehicle (1x PBS) or test articles daily via gastric gavage for 12 weeks. Animals were fed the HFD throughout the study. The study was conducted by Charles River Laboratories (Shrewsbury, MA), where animals were housed singly in solid bottom polycarbonate cages with Beta-chip contact bedding and enviro-dri nesting material, with temperature and humidity ranges of 18° to 26 °C and 30 to 70%, respectively. A 12 hr light cycle was used, and water and food were provided ad libitum. The following blood-based variables were measured after 12 weeks of supplementation: glucose, insulin, triglycerides, cholesterol (total, HDL, LDL), IL-18, IL-6, monocyte chemoattractant protein 1 (MCP-1), plasminogen activation inhibitor 1 (PAI-1), tumor necrosis factor (TNF)α, free fatty acids, and ferritin. Body weights and body weight changes were recorded weekly throughout the study. Due to low sample sizes and inability to assume normal distributions, Wilcoxon tests were used to compare blood-based and body weight values between supplemented and non-supplemented controls; a two-sided P value ≤ 0.05 was defined as significant.