Costus afer Possesses Carbohydrate Hydrolyzing Enzymes Inhibitory Activity and Antioxidant Capacity In Vitro

Table 4

Kinetic parameters of effective extracts of Costus afer on alpha-amylase and alpha-glucosidase activities in vitro.

Plant parts	Extracts	Alpha-amylase		Alpha-glucosidase
		(mg/mL/s)	(mg/mL)	(mg/mL/s)	(mg/mL)
	Control	0.23	0.81	0.39	17.39
Leaf	EA	0.14	1.06	nd	nd
	MeOH	0.23	4.43	0.02	2.01
Stem	MeOH	Nd	nd	0.39	30.4
	H2O	0.24	1.51	nd	nd
Rhizome	EA	0.23	3.76	nd	nd
	MeOH	Nd	nd	0.39	43.2

nd: not determined.