European Journal of Nutrition

, Volume 51, Issue 8, pp 1011–1019

Silk and silkworm pupa peptides suppress adipogenesis in preadipocytes and fat accumulation in rats fed a high-fat diet

  • Sun Hee Lee
  • Dongsun Park
  • Goeun Yang
  • Dae-Kwon Bae
  • Yun-Hui Yang
  • Tae Kyun Kim
  • Dajeong Kim
  • Jangbeen Kyung
  • Sungho Yeon
  • Kyo Chul Koo
  • Jeong-Yong Lee
  • Seock-Yeon Hwang
  • Seong Soo Joo
  • Yun-Bae Kim
Original Contribution

DOI: 10.1007/s00394-011-0280-6

Cite this article as:
Lee, S.H., Park, D., Yang, G. et al. Eur J Nutr (2012) 51: 1011. doi:10.1007/s00394-011-0280-6

Abstract

Purpose

The objective was to confirm the anti-obesity activity of a silk peptide (SP) and a silkworm pupa peptide (SPP) in rats fed a high-fat diet (HFD) and to elucidate their action mechanism(s) in a preadipocyte culture system.

Methods

In an in vitro mechanistic study, the differentiation and maturation of 3T3-L1 preadipocytes were stimulated with insulin (5 μg/mL), and effects of SP and SPP on the adipogenesis of mature adipocytes were assessed. In an in vivo anti-obesity study, male C57BL/6 mice were fed an HFD containing SP or SPP (0.3, 1.0, or 3.0%) for 8 weeks, and blood and tissue parameters of obesity were analyzed.

Results

Hormonal stimulation of preadipocytes led to a 50–70% increase in adipogenesis. Polymerase chain reaction and Western blot analyses revealed increases in adipogenesis-specific genes (leptin and Acrp30) and proteins (peroxisome proliferator-activated receptor-γ and Acrp30). The hormone-induced adipogenesis and activated gene expression was substantially inhibited by treatment with SP and SPP (1–50 μg/mL). The HFD markedly increased body weight gain by increasing the weight of epididymal and mesenteric fat. Body and fat weights were significantly reduced by SP and SPP, in which decreases in the area of abdominal adipose tissue and the size of epididymal adipocytes were confirmed by magnetic resonance imaging and microscopic examination, respectively. Long-term HFD caused hepatic lipid accumulation and increased blood triglycerides and cholesterol, in addition to their regulatory factors Acrp30 and leptin. However, SP and SPP recovered the concentrations of Acrp30 and leptin, and attenuated steatosis.

Conclusions

SP and SPP inhibit the differentiation of preadipocytes and adipogenesis by modulating signal transduction pathways and improve HFD-induced obesity by reducing lipid accumulation and the size of adipocytes.

Keywords

Silk peptideSilkworm pupa peptideAdipogenesisObesityHyperlipidemiaSteatosis

Supplementary material

394_2011_280_MOESM1_ESM.doc (4 mb)
Supplementary material 1 (DOC 4063 kb)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Sun Hee Lee
    • 1
  • Dongsun Park
    • 1
  • Goeun Yang
    • 1
  • Dae-Kwon Bae
    • 1
  • Yun-Hui Yang
    • 1
  • Tae Kyun Kim
    • 1
  • Dajeong Kim
    • 1
  • Jangbeen Kyung
    • 1
  • Sungho Yeon
    • 2
  • Kyo Chul Koo
    • 3
  • Jeong-Yong Lee
    • 3
  • Seock-Yeon Hwang
    • 4
  • Seong Soo Joo
    • 5
  • Yun-Bae Kim
    • 1
  1. 1.College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National UniversityCheongjuKorea
  2. 2.Department of Food Science and TechnologyChungbuk National UniversityCheongjuKorea
  3. 3.Worldway Co., Ltd.JeoneuiKorea
  4. 4.Department of Biomedical Laboratory ScienceDaejeon UniversityDaejeonKorea
  5. 5.Division of Marine Molecular BiotechnologyGangneung-Wonju National UniversityGangneungKorea