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.)

  • Chia-Ying Chuang
  • Chin Hsu
  • Che-Yi Chao
  • Yung-Shung Wein
  • Yueh-Hsiung Kuo
  • Ching-jang Huang
Original Paper


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.


PPARα 9cis 11trans 13trans-conjugated linolenic acid wild bitter gourd transactivation assay Acyl CoA Oxidase 



Acyl CoA oxidase


Alkaline phosphatase


Conjugated linoleic acid


Conjugated linolenic acid


Ligand-binding domain


Peroxisome proliferators activated receptor


Peroxisome proliferators


Peroxisome proliferators responsive elements


Retinoic X receptor


Thin layer chromatography



Copyright information

© National Science Council Taipei 2006

Authors and Affiliations

  • Chia-Ying Chuang
    • 1
  • Chin Hsu
    • 1
  • Che-Yi Chao
    • 1
    • 2
  • Yung-Shung Wein
    • 3
  • Yueh-Hsiung Kuo
    • 3
    • 5
  • Ching-jang Huang
    • 1
    • 4
  1. 1.Nutritional Biochemistry Laboratory, Institute of Microbiology and BiochemistryNational Taiwan UniversityTapeiTaiwan
  2. 2.Department of Applied Life ScienceAsia UniversityTaichung CountyTaiwan
  3. 3.Department of ChemistryNational Taiwan UniversityTaipeiTaiwan
  4. 4.Department of Biochemical Science and TechnologyNational Taiwan UniversityTaipeiTaiwan
  5. 5.Institute of BioAgricultural Science, Academia SinicaTaipeiTaiwan

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