Journal of Biomedical Science

, Volume 13, Issue 6, pp 763–772

Fractionation and identification of 9c, 11t, 13t-conjugated linolenic acid as an activator of PPARα in bitter gourd (Momordica charantia L.)

Authors

  • Chia-Ying Chuang
    • Nutritional Biochemistry Laboratory, Institute of Microbiology and BiochemistryNational Taiwan University
  • Chin Hsu
    • Nutritional Biochemistry Laboratory, Institute of Microbiology and BiochemistryNational Taiwan University
  • Che-Yi Chao
    • Nutritional Biochemistry Laboratory, Institute of Microbiology and BiochemistryNational Taiwan University
    • Department of Applied Life ScienceAsia University
  • Yung-Shung Wein
    • Department of ChemistryNational Taiwan University
  • Yueh-Hsiung Kuo
    • Department of ChemistryNational Taiwan University
    • Institute of BioAgricultural Science, Academia Sinica
    • Nutritional Biochemistry Laboratory, Institute of Microbiology and BiochemistryNational Taiwan University
    • Department of Biochemical Science and TechnologyNational Taiwan University
Original Paper

DOI: 10.1007/s11373-006-9109-3

Cite this article as:
Chuang, C., Hsu, C., Chao, C. et al. J Biomed Sci (2006) 13: 763. doi:10.1007/s11373-006-9109-3

Summary

Bitter gourd (Momordica charantia L.) is a common vegetable in Asia that has been used in traditional medicine for the treatment of Diabetes. PPARs are ligand-dependent transcription factors that belong to the steroid hormone nuclear receptor family and control lipid and glucose homeostasis in the body. We previously reported that the ethyl acetate (EA) extract of bitter gourd activated peroxisome proliferator receptors (PPARs) α and γ. To identify the active compound that activated PPARα, wild bitter gourd EA extract was partitioned between n-hexane and 90% methanol/10% H2O, and the n-hexane soluble fraction was further separated by silica gel column chromatography and finally by preparative HPLC. A transactivation assay employing a clone of CHOK1 cells stably transfected with a (UAS)4-tk-alkaline phosphatase reporter and a chimeric receptor of GAL4-rPPARα LBD was used to track the active component. Based on Mass, NMR, and IR spectroscopy, 9cis, 11trans, 13trans-conjugated linolenic acid (9c, 11t, 13t-CLN) was identified as a PPARα activator in wild bitter gourd. The isolated 9c, 11t, 13t-CLN rich fraction also significantly induced acyl CoA oxidase (ACO) activity in a peroxisome proliferator-responsive murine hepatoma cell line, H4IIEC3, implying that 9c, 11t, 13t-CLN was able to act on a natural PPARα signaling pathway as well. The content of 9c, 11t, 13t-CLN was estimated to be about 7.1 g/kg of our dried wild bitter gourd sample. The concentration of 9c, 11t, 13t-CLN and activation activity in the hydrolyzed EA extract of the seeds was higher than that of the flesh. The potential health benefits of 9c, 11t, 13t-CLN through the PPARα regulated mechanism are worthy to be further characterized in in vivo studies.

Keywords

PPARα9cis11trans13trans-conjugated linolenic acidwild bitter gourdtransactivation assayAcyl CoA Oxidase

Abbreviations

ACO

Acyl CoA oxidase

AP

Alkaline phosphatase

CLA

Conjugated linoleic acid

CLN

Conjugated linolenic acid

LBD

Ligand-binding domain

PPAR

Peroxisome proliferators activated receptor

PP

Peroxisome proliferators

PPRE

Peroxisome proliferators responsive elements

RXR

Retinoic X receptor

TLC

Thin layer chromatography

TZD

Thiazolidinedione

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Copyright information

© National Science Council Taipei 2006