Effects of GD pre-administration in diet-induced obese adult zebrafish. GD suppressed an increase in plasma triglyceride (TG) (A) and plasma total cholesterol (TCHO) (B) levels in OF zebrafish. (C) GD reduced the visceral adipose tissue (VAT) volume in OF zebrafish. (D) Representative images to show VAT (red) after 3D micro-CT analysis. Gray color indicates skeletal bone. *p < 0.05, **p < 0.01 vs. OF, n = 5, error bars indicate SD.

Expression levels of UCP1 in zebrafish liver and VAT. (A) Protein expression targets of UCP1 were identified by Pathway Studio comparing altered genes in GD-treated zebrafish with those of OF zebrafish. The red and blue colors denote genes with increased and decreased expression, respectively. The gray color of UCP1 indicates UCP1 was not detected in RNA-Seq analysis. Gene expression level changes of ucp1 in zebrafish liver (B) and VAT (C) were validated by qPCR analysis. *p < 0.05 vs. OF, n = 5, error bars indicate SD. (D) Representative images of AdipoRed staining of differentiated control adipocytes and GD-treated adipocytes. 3T3-L1 cells were differentiated and treated with 10 mg/mL GD for 2 days and processed for AdipoRed staining. Mature adipocytes were photographed at the magnification of 40 × (upper panels) and 200 × (lower panels). The red color indicates lipid accumulation. (E) Effect of 10 mg/mL GD on intracellular lipid accumulation in 3T3-L1 adipocytes. Cellular lipid content was measured by AdipoRed assay. **p < 0.01 vs. control. (F) GD-induced mRNA expression level change of Ucp1 in 3T3-L1 cells. **p < 0.01 vs. control, n = 6, error bars indicate SD.

Effects of GD intake on ICR mice on a high-fat diet (HFD). Change in plasma TG (A), plasma TCHO (B), and VAT volume (C) after 2 weeks of GD administration. (D) Represents micro-CT images of the four groups. The red dotted lines demarcate the area for which VAT volume was measured (from the xiphoid process of the sternum to the hip joint). Yellow indicates the visceral adipose tissue, and orange indicates the subcutaneous adipose tissue. (E) GD-induced Ucp1 expression in mice eWAT. (F) Fluorescent immunohistochemical staining (FIHC) with anti-mouse Ucp1 antibody in eWAT sections. PD, phrase difference images; Scale bar = 50 μm. (G) Average adipocyte size (n = 30) of the four mouse groups in (F). *p < 0.05, **p < 0.01 vs. HFD, n = 10, error bars indicate SD.