Effect on beta cells of rat pancreas: In addition to rat pancreatic islets morphology, we also observed the influence on the morphology of pancreatic beta cells using Victoria blue staining. In the staining, beta cell is represented as a cell with blue-stained cytoplasm. The comparison between pancreatic beta cells in normal rats and in neonatal STZ-induced diabetics rats were showed in Fig. 4a and b. In diabetics rats, histological changes of beta cells have occurred such as extensive degenerative of beta cells and decreased cellular density. In line with previous experiment, shrunken pancreatic islets and beta cells changes were also observed in diabetic rats. Treatment of either andrographolide (4.5 mg kg-1 b.wt) or glibenclamide for 8 days could improve the rat pancreatic beta cells (Fig. 4d). Treatment with andrographolide-enriched extract of A. paniculata improved the beta cell of rat pancreas moderately (Fig. 4c and e). Andrographolide 4.5 mg kg-1 b.wt, glibenclamide and AEEAP 1303.8 mg kg-1 b.wt increased the beta cells density by 60, 33 and 64%, respectively (Fig. 5).