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

Figure 4

Effects of SB on ROS levels and the viability of renal tubular epithelial cells injured with H₂O₂. (a) HK-2 cells were incubated with SB (50 μM) or vehicle for 1 h and then incubated with 250 mM H₂O₂ or vehicle for 3 h. Fluorescence intensity was measured at an excitation wavelength of 485 nm and an emission wavelength of 535 nm. (b) HK-2 cells were incubated with SB (50 μM) or vehicle for 1 h and then incubated with 250 mM H₂O₂ or vehicle for 24 h and then incubated with the CCK-8 solution for 3 h at 37°C. The maximum absorption of the strong orange CCK-8 formazan was 450 nm. The viability of HK-2 cells was quantified by optical density (OD) measurements using a spectrophotometer. Treatment with H₂O₂ markedly increased cellar ROS levels and decreased cell viability, while treatment with SB decreased cellar ROS levels and improved cell viability. In contrast, the supportive effect of SB was blunted in cells transfected with siNrf2. (c, d) Representative immunoblots and statistical data of (c) phosphorylated and total Akt (56 KDa) and (d) nuclear-Nrf2 (68 KDa) at 24 h after treatment with H₂O₂ or vehicle. SB could activate Nrf2 by inducing the phosphorylation of Akt, which was inhibited by wortmannin. SFN could activate Nrf2. siNrf2 suppressed the expression of nuclear-Nrf2. Note that SB protected the kidneys from oxidative stress through the PI3K/Akt/Nrf2 pathway. versus the H₂O₂ group; versus the SB + H₂O₂ group; and versus the siCTRL + SB + H₂O₂ group; . The values shown are the mean ± SD.

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