Effects of treatment with GSPE on the expression of apoptosis-associated proteins in diabetic kidneys. (A) The expression levels of cleaved caspase-3, caspase-3, Bcl-2 and Bax were determined via western blot analysis. (B) The relative intensity of cleaved caspase-3 was normalized to caspase-3. Normalization of Bax and Bcl-2 against β-actin was performed prior to determination of the Bax/Bcl-2 ratio. Treatment with GSPE significantly suppressed the expression of cleaved caspase-3 and suppressed the Bax/Bcl-2 ratio. (C) The protein and (D) mRNA expression of TXNIP was enhanced in the db/db group compared with db/m mice; however, this increase was significantly attenuated by treatment with GSPE compared with db/db group mice. (E) The protein expression of TXNIP and cyt c was analyzed by western blotting. (F) The protein expression of cyt c exhibited a similar trend to that observed with TXNIP. Values are expressed as mean ± standard deviation. **P<0.01 vs. db/m group; #P<0.05 vs. db/db group. GSPE, grape seed procyanidin; Bcl-2, B-cell lymphoma-2; Bax, Bcl-2-associated X protein; TXNIP, thioredoxin interacting protein; cyt c, cytochrome c.