Long-term administration of an aqueous extract of dried, immature fruit of Poncirus trifoliata (L.) Raf. suppresses body weight gain in rats.
OBJECTIVE
The purpose of the present study was to examine the effects of daily administration of an aqueous extract of the dried, immature fruit of Poncirus trifoliata Raf. (Rutaceae) (PF-W) on body weight in rats.


METHODS
PF-W was used in following experiments: 10-week-long measurement of body weight and food intake, in vitro pancreatic lipase activity assay, in vivo triglyceride concentration study, and measurement of intestinal transit rate.


RESULTS
A high dose of PF-W (200 mg/2 mL/animal/day, in aqueous solution) was administered intragastrically to rats for 10 weeks. PF-W suppressed body weight gain by 6%. However, administration of PF-W at a lower dose (20 mg/animal/day) did not reduce weight gain. Administration of low- or high-dose PF-W had no effect on food intake throughout the experimental period. Additional experiments revealed that the suppressive effect of PF-W on body weight gain was not related to pancreatic lipase activity. Moreover, co-administration of PF-W with a lipid emulsion did not reduce plasma triglyceride concentration. Of interest, the high dose of PF-W significantly increased the rate of intestinal transit, whereas oral administration of the lower dose did not. Control and PF-W-treated groups did not differ in hematological and serum biochemical parameters, or in relative organ weights after 10 weeks of high-dose PF-W administration.


CONCLUSIONS
PF-W does not suppress body weight gain by interfering with fat absorption in a pancreatic lipase-dependent manner. The suppressive effect of PF-W on weight gain is likely due to the increased rate of intestinal transit, and the consequent reduction in nutrient absorption. Moreover, it appears that PF-W is relatively safe for long-term use. Taken together, the results of the present study suggest that long-term, daily administration of PF-W successfully suppressed body weight gain-apparently due to accelerated intestinal transit and not to interference with pancreatic lipase activity. Due to its apparent long-term safety, PF-W is a potential therapeutic agent for reduction of body weight in humans.
Shim
Won-Sik
WS
National Research Laboratory for Transporters Targeted Drug Design & Research Institute of Pharmaceutical Sciences, Department of Pharmaceutics, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea.
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Heejung
H
Seo
Eun-Kyoung
EK
Lee
Hyun-Tai
HT
Shim
Chang-Koo
CK
D000818:Animals; D019440:Anti-Obesity Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects*; D004041:Dietary Fats; D005638:Fruit; D005772:Gastrointestinal Transit / Q000187:drug effects*; D008049:Lipase / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000517:prevention & control*; D010179:Pancreas; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D032104:Poncirus; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014280:Triglycerides / Q000097:blood; D015430:Weight Gain / Q000187:drug effects*
D019440:Anti-Obesity Agents; D004041:Dietary Fats; D010936:Plant Extracts; D014280:Triglycerides; D008049:Lipase