Hematoxylin and eosin-stained sections of rat pancreas for Langerhans islet observation, (a) Normal control group, (b) Diabetic untreated group (negative control), (c-e) Diabetic group treated with glibenclamide (45 mg kg-1 b.wt) andrographolide (4.5 mg kg-1 b.wt) and andrographolide-enriched extract of A. paniculata (1303.8 mg kg-1 b.wt), respectively, twice daily for 8 days, Magnificationx400