Nutr Res Pract.  2014 Feb;8(1):33-39.

Pear pomace water extract inhibits adipogenesis and induces apoptosis in 3T3-L1 adipocytes

• Rhyu J
• Kim MS
• You MK
• Bang MA
• Kim HA

Abstract

Obesity occurs when a person's calorie intake exceeds the amount of energy burns, which may lead to pathologic growth of adipocytes and the accumulation of fat in the tissues. In this study, the effect and mechanism of pear pomace extracts on 3T3-L1 adipocyte differentiation and apoptosis of mature adipocytes were investigated. The effects of pear pomace extract on cell viability and the anti-adipogenic and proapoptotic effects were investigated via MTT assay, Oil red O staining, western blot analysis and apoptosis assay. 3T3-L1 preadipocytes were stimulated with DMEM containing 10% FBS, 0.5 mM 3-isobutyl-1-methylxanthine (IBMX), 5 microg/ml insulin and 1 microM dexamethasone for differentiation to adipocytes. 3T3-L1 cells were cultured with PBS or water extract of pear pomace. Water extract of pear pomace effectively inhibited lipid accumulations and expressions of PPAR-gamma and C/EBPalpha in 3T3-L1 cells. It also increased expression of p-AMPK and decreased the expression of SREBP-1c and FAS in 3T3-L1 cells. The induction of apoptosis was observed in 3T3-L1 cells treated with pear pomace. These results indicate that pear pomace water extract inhibits adipogenesis and induces apoptosis of adipocytes and thus can be used as a potential therapeutic substance as part of prevention or treatment strategy for obesity.

Keyword

Pear pomace water extract; 3T3-L1 cells; adipogenesis; apoptosis

MeSH Terms

1-Methyl-3-isobutylxanthine
3T3-L1 Cells
Adipocytes*
Adipogenesis*
Apoptosis*
Blotting, Western
Burns
Cell Survival
Dexamethasone
Insulin
Obesity
Pyrus*
Sterol Regulatory Element Binding Protein 1
Water*
1-Methyl-3-isobutylxanthine
Dexamethasone
Insulin
Sterol Regulatory Element Binding Protein 1
Water

Figure

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  Fig. 1 Effects of pear pomace water extract on the proliferation of 3T3-L1 preadipocytes as measured by MTT assay. 3T3-L1 cells were treated with different concentrations of pear pomace extract. After incubation for 24 hours MTT assay was performed. The results represent means ± SD of the data in triplicated experiments.

• 

  Fig. 2 Effect of pear pomace water extract on 3T3-L1 adipocyte differentiation. 3T3-L1 cells differentiated with hormonal cocktail for eight days in absence or presence of pear pomace extract. (A) Intracelluar lipids were stained with Oil Red-O. (B) Stained triglyceride content was quantified by measuring absorbance. Means with the same letter are not significantly different by Duncan's multiple range test (P < 0.05)

• 

  Fig. 3 Effect of pear pomace water extract on PPAR-γ (A) and C/EBPα (B) expression in 3T3-L1 adipocytes. 3T3-L1 preadipocytes were stimulated to differentiated in the presence of pear pomace water extract (100 and 250 µg/ml). Cell lysates were prepared and subjected to Western blotting to detect C/EBPα and PPARγ. Means with the same letter are not significantly different by Duncan's multiple range test (P < 0.05)

• 

  Fig. 4 Effect of pear pomace water extract on AMPK activation in 3T3-L1 adipocytes. 3T3-L1 preadipocytes were stimulated to differentiated in the presence of pear pomace water extract (100 and 250 µg/ml). Cell lysates were prepared and subjected to Western blotting to detect p-AMPK. Means with the same letter are not significantly different by Duncan's multiple range test (P < 0.05)

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  Fig. 5 Effect of pear pomace water extract on SREBP-1c(A) and FAS(B) expression in 3T3-L1 adipocytes. 3T3-L1 preadipocyte were stimulated to differentiate the presence of pear pomace water extracts (100 and 250 (µg/ml). Cell lysates were prepared and subjected to Western blotting to detect SREBP-1c and FAS. Means with the same letter are not significantly different by Duncan's multiple range test (P < 0.05)

• 

  Fig. 6 Flow cytometric analysis of pear pomace extract induced apoptosis in mature adipocytes. Pear pomace water extract (100 and 250 µg/ml) induced apoptosis in mature adipocytes. Mature 3T3-L1 adipocytes were incubated for 24 hours and 48 hours. Cell apoptosis was evaluated by Muse Cell Analyzer. Means with the same letter are not significantly different by Duncan's multiple range test (P < 0.05)

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