[Protective effects of cordycepin on renal proximal tubular cells injury induced by lipopolysaccharide].

OBJECTIVE

To investigate the protective effect and potential mechanism of cordycepin on renal proximal tubular cells injury induced by lipopolysaccharide (LPS).

METHODS

Renal proximal tubular cells NRK-52E were incubated on a cell culture plated at a density of 1×10/mL for experiment, then divided into control group (Ctrl group), LPS group (cells were stimulated with 1 mg/L LPS), 10 μmol/L or 20 μmol/L cordycep in intervention groups (LPS+C 10 group and LPS+C 20 group). Cell viability was measured using cell counting kit-8 (CCK-8) reagent. The level of intracellular reactive oxygen species (ROS) was detected by 2',7'-dichlorofluorescin diacetate (DCFH-DA) staining. The protein expressions of inflammatory factors intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), interleukin-1β (IL-1β), and nuclear factor-κB (NF-κB) were detected by Western blotting.

RESULTS

Compared with the Ctrl group, LPS significantly inhibited NRK-52E cell viability, increased intracellular ROS, and up-regulated the expressions of ICAM-1, VCAM-1, IL-1β and NF-κB. Compared with LPS group, after treated with 10 μmol/L or 20 μmol/L cordycepin, NRK-52E cell viability was significantly increased (Ctrl group as 1: 0.717±0.017, 0.916±0.036 vs. 0.554±0.046) and intracellular ROS level was significantly decreased (Ctrl group as 1: 1.527±0.165, 1.098±0.168 vs. 2.543±0.127), meanwhile the expressions of ICAM-1, VCAM-1, IL-1β and NF-κB were significantly down-regulated [Ctrl group as 1, ICAM-1/GAPDH: 2.364±0.097, 1.561±0.074 vs. 3.101±0.121; VCAM-1/GAPDH: 2.866±0.135, 1.920±0.098 vs. 4.170±0.119; IL-1β/GAPDH: 2.358±0.107, 1.563±0.179 vs. 3.301±0.210; phosphorylation NF-κB p65 (NF-κB p-p65)/GAPDH: 2.559±0.166, 1.596±0.148 vs. 3.183±0.098], the differences were statistically significant (all P < 0.05). Compared with the LPS+C 10 group, the cell activity of LPS+C 20 group was more significant (0.916±0.036 vs. 0.717±0.017, P < 0.01), and the expressions of ICAM-1, VCAM-1, IL-1β, NF-κB were down-regulated more significantly (ICAM-1/GAPDH: 1.561±0.074 vs. 2.364±0.097, VCAM-1/GAPDH: 1.920±0.098 vs. 2.866±0.135, IL-1β/GAPDH: 1.563±0.179 vs. 2.358±0.107, NF-κB p-p65/GAPDH: 1.596±0.148 vs. 2.559±0.166, all P < 0.05).

CONCLUSIONS

Cordycepin could significantly increase the survival rate of NRK-52E cells, reduce intracellular ROS level, and inhibit inflammation, and the anti-inflammation effect can be related with NF-κB pathway.