Hepatoprotective amide constituents from the fruit of Piper chaba: Structural requirements, mode of action, and new amides.
The 80% aqueous acetone extract from the fruit of Piper chaba (Piperaceae) was found to have hepatoprotective effects on D-galactosamine (D-GalN)/lipopolysaccharide-induced liver injury in mice. From the ethyl acetate-soluble fraction, three new amides, piperchabamides E, G, and H, 33 amides, and four aromatic constituents were isolated. Among the isolates, several amide constituents inhibited D-GalN/tumor necrosis factor-alpha (TNF-alpha)-induced death of hepatocytes, and the following structural requirements were suggested: (i) the amide moiety is essential for potent activity; and (ii) the 1,9-decadiene structure between the benzene ring and the amide moiety tended to enhance the activity. Moreover, a principal constituent, piperine, exhibited strong in vivo hepatoprotective effects at doses of 5 and 10 mg/kg, po and its mode of action was suggested to depend on the reduced sensitivity of hepatocytes to TNF-alpha.
Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan.
Hisashi
H
Matsuda
Kiyofumi
K
Ninomiya
Toshio
T
Morikawa
Daisuke
D
Yasuda
Itadaki
I
Yamaguchi
Masayuki
M
Yoshikawa
D000577:Amides / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D008070:Lipopolysaccharides / Q000633:toxicity; D008099:Liver / Q000187:drug effects* / Q000293:injuries; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D031701:Piper / Q000737:chemistry*
D000577:Amides; D008070:Lipopolysaccharides