Oral (p.o.) administration of a single dose of kalmegh leaf extract (KE; 0.5 g/kg and 1.0 g/kg) or andrographolide (A; 5 mg/kg and 10 mg/kg) to adult male albino rats (100-120 g) produced a dose-related and time-dependent characteristic activation of brush-border membrane-bound hydrolases, viz. lactase, maltase and sucrase in three regions of small intestine (viz. duodenum, jejunum and ileum). The maximum stimulation of these disaccharidases was obtained at 6 hr of either KE or A administration. Further, it was also noted that the extent of activation of the disaccharidases with KE or A, both at higher and lower doses, followed the order: (a) Maltase greater than sucrase greater than lactase in duodenum and (b) Maltase greater than lactase greater than sucrase in jejunum and ileum. Long term administration (for 7, 15 and 30 consecutive days) of either KE (500 p.o.) or A (5 mg/kg/day; p.o.) stimulated lactase, maltase and sucrase in all parts of the small intestine. Maximum stimulation of lactase and maltase was noted after 30 consecutive days of treatment while sucrase exhibited maximum activation after 15 consecutive of treatment with either KE or A. These results suggest that both KE and A accelerate intestinal digestion and absorption of carbohydrate by activating these intestinal disaccharidases.