Background: The decoction of Alisma orientale is used as a traditional medicine for the
treatment of hyperlipidemia in China with a long clinical history. The present study undertook a detailed
investigation to compare the hypolipidemic effect and chemical composition of two extracts of
Alisma orientale prepared by boiling water and organic reagent, respectively.
Methods: The hyperlipidemic mice were induced by administration of a High-Fat Diet (HFD) for one
month. The body weight of mice and the serum Cholesterol (TC), high-density lipoprotein cholesterol
(HDL-C), Superoxide Dismutase (SOD), malondialdehyde (MDA), aspartate Aminotransferase (AST)
and alanine aminotransferase (ALT) levels were determined. Meanwhile, the chemical constituents of
the extracts were characterized using liquid chromatography-quadrupole time of flight mass spectrometry
Results: The better hypolipidemic effect was observed in mice administered with the decoction compared
to that of methanol extract. In addition, the liver protective effects were confirmed by the photographs
stained with oil red lipid stain. As for the chemical constituents in the extracts, twenty major
components were identified or characterized using LC-QTOF-MS/MS. Among them, eight oligopeptides
were characterized for the first time and proved to only exist in the decoction of Alisma orientale.
Conclusions: It is reasonable to assume that the oligopeptides may partially contribute to the hypolipidemic
effect of Alisma orientale. The structural characterization procedures also provide a suitable
method to analyze oligopeptide analogues in plant samples.