Roles of Peroxisome Proliferator-Activated Receptor α in Bitter Melon Seed Oil-Corrected Lipid Disorders and Conversion of α-Eleostearic Acid into Rumenic Acid in C57BL/6J Mice

• Published in: Nutrients Vol. 8; no. 12; p. 805
• Main Authors: Chang, Ya-Yuan, Su, Hui-Min, Chen, Szu-Han, Hsieh, Wen-Tsong, Chyuan, Jong-Ho, Chao, Pei-Min
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.12.2016; MDPI
• Subjects: Acyl-CoA oxidase; Acyl-CoA Oxidase - metabolism; Adipose tissue; Adipose Tissue, White - drug effects; Adipose Tissue, White - metabolism; Adiposity - drug effects; AMP-activated protein kinase; Animals; Apoptosis; bitter melon seed oil; Body fat; Browning; Conversion; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases - metabolism; Diet, High-Fat - adverse effects; Dyslipidemias - drug therapy; Dyslipidemias - metabolism; Eleostearic acid; Enzymes; Fatty Liver - drug therapy; hepatic steatosis; High fat diet; Hydroxylase; Kinases; Linoleic Acids, Conjugated - metabolism; Linolenic Acids - metabolism; Lipid metabolism; Lipids; Liver - metabolism; Mice; Mice, Inbred C57BL; Mice, Knockout; Momordica charantia - chemistry; obesity; Oils & fats; Oilseeds; Oxidoreductases Acting on CH-CH Group Donors - metabolism; Phagocytosis; Phytotherapy; Plant Oils - administration & dosage; Plant Oils - chemistry; PPAR alpha - genetics; PPAR alpha - metabolism; PPAR alpha - physiology; PPARα; Protein kinase A; Proteins; Rodents; Signal transduction; Signal Transduction - drug effects; Soybean oil; Soybeans; Steatosis; Triglycerides; Triglycerides - metabolism; Tyrosine; Tyrosine 3-monooxygenase; Tyrosine 3-Monooxygenase - metabolism; Uncoupling protein 1; Uncoupling Protein 1 - metabolism; Vitamin A; α-eleostearic acid; α-eleostearic acid; PPARα; obesity; bitter melon seed oil; hepatic steatosis
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu8120805

We previously reported that bitter melon seed oil (BMSO) was an effective anti-steatosis and antiobesity agent. Since the major fatty acid α-eleostearic acid (α-ESA) in BMSO is a peroxisome proliferator-activated receptor α (PPARα) activator, the objective was to investigate the role of PPARα in BMSO-modulated lipid disorders and α-ESA metabolism. C57BL/6J wild (WD) and PPARα knockout (KO) mice were fed a high-fat diet containing BMSO (15% soybean oil + 15% BMSO, HB) or not (30% soybean oil, HS) for 5 weeks. The HB diet significantly reduced hepatic triglyceride concentrations and increased acyl-CoA oxidase activity in WD, but not in KO mice. However, regardless of genotype, body fat percentage was lowered along with upregulated protein levels of uncoupling protein 1 (UCP1) and tyrosine hydroxylase, as well as signaling pathway of cAMP-dependent protein kinase and AMP-activated protein kinase in the white adipose tissue of HB-treated groups compared to HS cohorts. In WD-HB and KO-HB groups, white adipose tissue had autophagy, apoptosis, inflammation, and browning characteristics. Without PPARα, in vivo reduction of α-ESA into rumenic acid was slightly but significantly lowered, along with remarkable reduction of hepatic retinol saturase ( ) expression. We concluded that BMSO-mediated anti-steatosis depended on PPARα, whereas the anti-adiposity effect was PPARα-independent. In addition, PPARα-dependent enzymes may participate in α-ESA conversion, but only have a minor role.