Salvianolic Acid B Prevents Iodinated Contrast Media-Induced Acute Renal Injury in Rats via the PI3K/Akt/Nrf2 Pathway

Figure 3

SB decreased the levels of oxidative stress induced by iohexol through the Akt/GSK-3β/Nrf2 pathway. (a, c) Representative photomicrographs of immunohistochemical staining for the redox product oxidized derivative, 8-OHdG, in renal sections and quantitative analysis of 8-OHdG-positive cells. The 8-OHdG-positive staining was localized in nuclei. (b, e) Representative photomicrographs of immunostaining for Nrf2 in the renal sections and quantitative analysis of the Nrf2-positive cells. The extent of staining for Nrf2 in the nuclear fraction represents their activity. (d) MDA concentrations in the renal tissues. SB resulted in a marked reduction in the number of 8-OHdG-positive cells and the MDA concentrations and a marked increase in the number of Nrf2-positive cells in renal tissues 24 h after iohexol injection. These effects were inhibited by treatment with wortmannin, and SFN could mimic the effects of SB. (f, g) Representative immunoblots and statistical data of (f) phosphorylated and total Akt (56 KDa), (g) nuclear-Nrf2 (68 KDa), and (h) HO-1 (32K Da) in the renal lysates from rats 3 h after the injection of iohexol. SB could activate Nrf2/HO-1 by inducing the phosphorylation of Akt, which was inhibited by wortmannin. SFN could activate Nrf2/HO-1. Note that SB protected the kidneys from oxidative stress through the PI3K/Akt/Nrf2 pathway. Original magnification (a, b): ×200. versus the CM group and versus the SB + CM group; . The values shown are the mean ± SD.

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