Inhibition of intestinal
alpha glucosidase plays a major role in preventing rise in postprandial
glucose level in diabetics. Cymbopogon martinii (CM) (family Poaceae) is used in traditional Indian medicine in treatment of
diabetes mellitus. The
alpha glucosidase inhibitory action of the plant is studied. The active component was separated using hot water extraction of the whole plant
powder, differential
solvent extraction, and
silica gel column chromatography. The 30 : 70
toluene :
ethyl acetate fraction showed optimum activity. The
silica gel chromatography fraction demonstrated 98, 98, and 68% inhibition for
starch,
maltose, and
sucrose, respectively, at 5 mg/kg
body weight of rats. Intestinal absorption studies using noneverted intestinal sacs, as well as in vivo studies in
streptozotocin-induced diabetic rats using oral
glucose tolerance with
maltose and
sucrose load, revealed better inhibition of
alpha glucosidase as compared to
acarbose. Kinetic studies using Lineweaver Burk plot showed mixed to noncompetitive type of inhibition by CM. In vivo studies with
maltose load of 2 mg and 3 mg/gm
body weight showed a noncompetitive pattern of inhibition at 5 mg/kg
body weight of CM as against 60 mg/kg
body weight of
acarbose. Thus CM is more effective
alpha glucosidase inhibitor and at lower concentration than
acarbose.