Gastroprotective Effect and Chemical Constituents of Flabellaria paniculata (Malpighiaceae)

Abstract

Leaves from Flabellaria paniculata Cav (Malpighiaceae) are used in traditional medicine for wound dressing, and to treat ulcers and inflammation in Nigeria. The present study evaluates the gastroprotective activity of the ethyl acetate fraction of the methanolic leaf extract and reports on the chemical constituents from the fraction. The methanolic crude extract and solvent fractions (100 mg/kg, PO) were screened using an ethanol-induced ulcer model. The activity of the most active EtOAc fraction (25, 50, and 100 mg/kg, PO) was further evaluated in indomethacin and pylorus ligation-induced ulcer models. The EtOAc fraction was chromatographed and chemical structures of the isolated compounds were elucidated by nuclear magnetic resonance spectroscopy. The MeOH extract of F. paniculata and EtOAc fraction from this extract displayed significant gastroprotective effects. Two triterpenoids (friedelin and friedelinol), two steroids (sitosterol and sitosterol-β-d-glucoside), and a flavonoid glycoside (kaempferol-3- O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside) were identified from the EtOAc fraction. This is the first report on the isolation of these compounds from the plant. The identified compounds could be responsible in part for the observed gastroprotective effect of the EtOAc fraction.