Fig. 2

Expression of insulin receptor substrate 2 (IRS2), pancreas duodenum homeobox-1 (PDX-1), and glucokinase mRNAs in islets isolated from rats. Isolated islets were administered with vehicle (DMSO), 50 μg/ml extracts of Galla rhois, R. radix, M. bark, Ginseng radix, P. or S. radix, or 2.5 nM exendin-4 in high glucose DMEM medium for 8 h. Total RNA extracted from islets was reverse transcribed to make cDNA, and mRNA levels of IRS2, PDX-1, glucokinase and cyclophilin were measured by realtime PCR using primer sets for the full length of IRS2, PDX-1, glucokinase and cyclophilin genes. The results are presented as the ratio of mRNA levels of the gene of interest (IRS2, PDX-1 and glucokinase) to those of a housekeeping gene (cyclophilin). Asterisks indicate significant differences from the control (DMSO-treated) group in two-sample t-test at P < 0.05