[Antiobesity actions of Zingiber officinale Roscoe]

Zingiber officinale Roscoe has been used as a folk medicine in China. An aqueous extract of Z. officinale Roscoe inhibited the hydrolysis of triolein emulsified with phosphatidylcholine by pancreatic lipase in vitro and it reduced the elevation of rat plasma triacylglycerol levels 1 and 2 h after oral administration of a lipid emulsion containing corn oil. These results suggest that the aqueous extract of Z. officinale Roscoe might inhibit the intestinal absorption of dietary fat by inhibiting its hydrolysis. Therefore we investigated the antiobesity effects of the aqueous extract of Z. officinale Roscoe by feeding a high-fat diet to mice for 8 weeks. Body weights at 2-8 weeks and final parametrial adipose tissue weights were significantly lower in mice fed the high-fat diet containing 3% aqueous extract of Z. officinale Roscoe than in the controls fed the high-fat diet. Feeding a high-fat diet containing 1% aqueous extract of Z. officinale Roscoe also significantly reduced final parametrial adipose tissue weights that were elevated in mice fed the high-fat diet alone. Our data suggest that the antiobesity effect of aqueous extract of Z. officinale Roscoe in mice fed a high-fat diet may be due in part to the inhibition of intestinal absorption of dietary fat by the active compounds of Z. officinale Roscoe.