Ginsenoside Rb1 protects human vascular smooth muscle cells against resistin-induced oxidative stress and dysfunction

Figure 1. Resistin-induced human coronary artery smooth muscle cells (HCASMC) proliferation was ameliorated by Rb1. HCASMC proliferation, evaluated by MTS assay, was significantly increased by resistin and acetyl-LDL, which could be restored by Rb1. Note that Rb1 alone had no effect on proliferation of HCASMC. Cell Viability = (ODs−ODb)/(ODc−ODb) × 100%. ODs, the OD value of the samples; ODb, the OD value of the background; ODc, the OD value of the negative control. Values were means and SD (n = 5). *P < 0.05.

Figure 2. Rb1 inhibited resistin-induced HCASMC migration. (A) Transwell migration chamber assay and wound healing assay showed resistin-induced HCASMC migration was inhibited by Rb1. (B) Cell migration was calculated as the fold change of wound closure relative to controls (T = 0). Resistin (40 ng/ml) treatment time dependently increased HCASMC migration, which could be significantly attenuated by Rb1 (20 µM) at 18 h and 24 h (B). Values were means and SD (n = 5). * P < 0.05.

Figure 3. Rb1 pretreatment reduced resistin-induced ROS production in HCASMC. HCASMC ROS production was detected by DCF-DA fluorescence assay. After treated with resistin (40 ng/ml) or acetyl-LDL (20 µg/ml) for 2 h, the intracellular ROS were significantly increased to a similar level. Rb1 pretreatment (24 h) significantly reduced HCASMC ROS generation induced by resistin and acetyl-LDL, while Rb1 co-treatment (2 h) had no such effect. Values were means and SD (n = 5). *P < 0.05.

Figure 4. Rb1 pretreatment dose dependently inhibited resistin-induced HCASMC ROS generation. Resistin dose dependently increased ROS generation in HCASMC, which could be significantly inhibited by Rb1 (>20 µM) in a dose-dependent manner. Values were means and SD (n = 5). *P < 0.05, #P < 0.01.

Figure 5. Rb1 attenuated resistin-induced suppression of HCASMC SOD activity. (A) The SOD activity of the samples was calculated from the linear regression of the standard curve. One unit of SOD is defined as the amount of enzyme needed to exhibit 50% dismutation of superoxide radical. (B) The mitochondrial SOD activity was significantly reduced by resistin. In contrast, Rb1 significantly increased both cytosolic and mitochondrial SOD activity in HCASMC, which attenuated resistin-induced reduction of mitochondrial SOD activity. Values were means and SD (n = 5). *P < 0.05, #P < 0.01.