Nutr Res Pract.  2014 Dec;8(6):613-617. 10.4162/nrp.2014.8.6.613.

Anti-adipogenic effect of mulberry leaf ethanol extract in 3T3-L1 adipocytes

• Yang SJ
• Park NY
• Lim Y

• KMID: 2313786
• DOI: http://doi.org/10.4162/nrp.2014.8.6.613

Abstract

BACKGROUND/OBJECTIVES
Adipogenesis is part of the cell differentiation process in which undifferentiated fibroblasts (pre-adipocytes) become mature adipocytes with the accumulation of lipid droplets and subsequent cell morphological changes. Several transcription factors and food components have been suggested to be involved in adipogenesis. The aim of this study was to determine whether mulberry leaf ethanol extract (MLEE) affects adipogenesis in 3T3-L1 adipocytes.
MATERIALS/METHODS
The 3T3-L1 adipocytes were treated with different doses of MLEE for 8 days starting 2 days post-confluence. Cell viability, fat accumulation, and adipogenesis-related factors including CCAAT-enhancer-binding protein alpha (C/EBPalpha), peroxisome proliferator-activated receptor gamma (PPARgamma), PPARgamma coactivator 1 alpha (PGC-1alpha), fatty acid synthase (FAS), and adiponectin were analyzed.
RESULTS
Results showed that MLEE treatments at 10, 25, 50, and 100 microg/ml had no effect on cell morphology and viability. Without evident toxicity, all MLEE treated cells had lower fat accumulation compared with control as shown by lower absorbances of Oil Red O stain. MLEE at 50 and 100 microg/ml significantly reduced protein levels of PPARgamma, PGC-1alpha, FAS, and adiponectin in differentiated adipocytes. Furthermore, protein level of C/EBPalpha was significantly decreased by the treatment of 100 microg/ml MLEE.
CONCLUSION
These results demonstrate that MLEE treatment has an anti-adipogenic effect in differentiated adipocytes without toxicity, suggesting its potential as an anti-obesity therapeutic.

Keyword

Adipocytes; adipogenesis; anti-obesity; mulberry leaf extract

MeSH Terms

Adipocytes*
Adipogenesis
Adiponectin
CCAAT-Enhancer-Binding Proteins
Cell Differentiation
Cell Survival
Ethanol*
Fibroblasts
Morus*
PPAR gamma
Transcription Factors
Adiponectin
CCAAT-Enhancer-Binding Proteins
Ethanol
PPAR gamma
Transcription Factors

Figure

• 

  Fig. 1 Effect of mulberry leaf ethanol extract (MLEE) on the cell viability in 3T3-L1 adipocytes. Cells were incubated with MLEE at the indicated concentrations (0-100 µg/ml) for 48 h; growth rate was assessed by MTT (3-4,5-dimethylthiazol-2-yl-2, 3-diphenyl tetrazolium bromide) assay. All values are mean ± SD.

• 

  Fig. 2 Mulberry leaf ethanol extract (MLEE) treatment inhibits lipid accumulation in 3T3-L1 adipocytes. At 2 days after confluence, differentiation was induced in 3T3-L1 adipocytes, and different concentrations of MLEE (0-100 µg/ml) were treated for 8 days. Eight days after differentiation and MLEE treatment, fat contents were analyzed by oil red O staining. (A-B) Representative images of Oil Red O staining. (C) Quantification of lipid accumulation based on the optical density values at 520 nm of destained Oil Red O extracted from the adipocytes. All values are mean ± SD. Mean values with different letters are significantly different at P < 0.05.

• 

  Fig. 3 The effects of mulberry leaf ethanol extract (MLEE) on the protein expression of adipogenesis-related factors in 3T3-L1 adipocytes. Representative western blots and densitometric analysis for (A) CCAAT-enhancer-binding protein alpha (C/EBPα), (B) peroxisome proliferator-activated receptor gamma (PPARγ), (C) PPARγ coactivator 1 alpha (PGC-1α), (D) fatty acid synthase (FAS), and (E) adiponectin were shown and the expression of beta-actin was analyzed to confirm an equal protein loading control. All values are mean ± SD. Mean values with different letters are significantly different at P < 0.05.

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