Uncoupled protein 3 and p38 signal pathways are involved in anti-obesity activity of Solanum tuberosum L. cv. Bora Valley.
OBJECTIVE
This study was undertaken to elucidate the anti-obesity mechanism of a new purple potato variety that has been used for the prevention of metabolic diseases as a folk remedy in Korea.


METHODS
Proliferation assay, differentiation assay, Western blotting, were performed in 3T3-L1 adipocytes, while blood chemistry for hyperlipidemic parameters, measurement of body weight and abdominal fats, reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, magnetic resonance image (MRI) scanning were carried out in high fat diet fed Sprague-Dawley rats with ethanol extract of Solanum tuberosum L. cv. Bora Valley (ESTBV).


RESULTS
ESTBV significantly inhibited the proliferation and differentiation of 3T3-L1 cells as well as reduced the cellular leptin level. ESTBV also significantly attenuated the levels of insulin and leptin at 500mg/kg in high fat diet fed rats. In addition, ESTBV significantly reduced total fat and whole body lipid in a therapeutic experiment, which was confirmed by MRI scanning and also significantly inhibited the retroperitoneal and epididymal fats in a preventive experiment compared with control. Similarly, the levels of total cholesterol, triglyceride and low density lipoprotein (LDL) were significantly reduced at a lower dose 200mg/kg of ESTBV in a preventive experiment than at 500mg/kg in a therapeutic experiment. Furthermore, body weight gain was significantly suppressed by over 4 weeks treatment of ESTBV compared with control. Interestingly, the expression of p38 mitogen-activated protein kinase (MAPK) was significantly downregulated in 3T3-L1 cells by ESTBV and the expression of uncoupled protein 3 (UCP-3) was activated in fats and liver tissues of ESTBV treated group compared with high fat diet control.


CONCLUSIONS
ESTBV has anti-obesity potential via inhibition of lipid metabolism through p38 MAPK and UCP-3 pathways.
Yoon
Sung-Soo
SS
College of Oriental Medicine, Kyunghee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, Republic of Korea.
Rhee
Yun-Hee
YH
Lee
Hyo-Jung
HJ
Lee
Eun-Ok
EO
Lee
Min-Ho
MH
Ahn
Kyoo-Seok
KS
Lim
Hak-Tae
HT
Kim
Sung-Hoon
SH
D041721:3T3-L1 Cells; D050153:Abdominal Fat / Q000187:drug effects; D000818:Animals; D019440:Anti-Obesity Agents / Q000494:pharmacology*; D002784:Cholesterol / Q000097:blood; D007473:Ion Channels / Q000235:genetics / Q000502:physiology*; D020738:Leptin; D050356:Lipid Metabolism / Q000187:drug effects; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D051379:Mice; D024101:Mitochondrial Proteins / Q000235:genetics / Q000502:physiology*; D008517:Phytotherapy; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011198:Solanum tuberosum; D014280:Triglycerides / Q000097:blood; D000071247:Uncoupling Protein 3; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000502:physiology*
D019440:Anti-Obesity Agents; D007473:Ion Channels; D020738:Leptin; D024101:Mitochondrial Proteins; D010936:Plant Extracts; D014280:Triglycerides; C000604393:Ucp3 protein, mouse; C000604394:Ucp3 protein, rat; D000071247:Uncoupling Protein 3; D002784:Cholesterol; D048051:p38 Mitogen-Activated Protein Kinases