Inhibition of acetylcholinesterase activity by hidroalcoholic extract and their fractions of Bouvardia ternifolia (Cav.) Shcltdl (Rubiaceae)

The hydroalcoholic extract (BtHA) and its fractions of Bouvardia ternifolia were evaluated as inhibitors of the activity of the acetylcholinesterase enzyme utilizing the in vitro method (Ellman). BtHA inhibited the acetylcholinesterase enzyme competitively (IC₅₀ = 0.6 μg/ml); the ethyl acetate fraction (BtF-AcOEt) caused mixed-type inhibition (IC₅₀ = 0.96 μg/ml). A fraction insoluble on methanol (Bt-Faq-1) showed a mixed-type inhibition (CI₅₀ = 0.96 μg/ml). Finally, the methanol-soluble fraction (Bt-Faq-2), presented complex, mixed-type inhibition that corresponds to the C5 system (α = 0.740 and β = 0.842). Rutin, quercetin, kaempferol and ursolic acid were detected by HPLC and the concentration of these compounds was different in each fraction.