Abstract: Slight modifications of microplate-based screening model were carried out with single factor and orthogonal experiments.The inhibitory effect of n-butanol fraction of Alisma orientailis (AOB) on mice intestinal α-glucosidase was assayed by this model.The results showed that AOB significantly inhibited mice intestinal α-glucosidase activity with a dose dependent manner with IC₅₀ value of 126 μg/mL in vitro and suppressed intestinal α-glucosidase activities in normal mice compared with control group after orally administered for 10 days.AOB has the potential to inhibit activities of mice α-glucosidase.

Key words: Alisma orientailis, n-butanol fraction, &alpha, -glucosidase, inhibition, screening model