Objective    To investigate the effect of glycyrrhizin-18α on the expression of p53 in renal tubular epithelial cells after renal ischemia-reperfusion injury (IRI).     Methods    p53(+/+) and p53(-/-) male mice aged 2 months were used to make ischemic model by clamping left renal hila for 45 min

then immediately and on each following day

the animals were treated with glycyrrhizin-18α (20 mg·kg

-1

·d

-1

) or normal sodium (control) by subcutaneous injection. On day 0

1 and 7 after reperfusion

renal tissues were processed for morphometric observation as well as NF-κB and p53 proteins analysis

using HE stain

immunohistochemistry and Western blot

respectively.     Results    In the IRI kidney

renal tubular necrosis was more severe in p53(-/-) mice and normal sodium treated mice than in p53(+/+) mice and glycyrrhizin-18α treated mice (P0.01)

respectively. The expressions of p53 and NF-κB proteins began to increase on day 0 after IRI

but the expression of NF-κB protein began to decrease on day 1 to 7

while the expression of p53 protein was still at a high level. The expression of p53 protein in p53(+/+) mice treated with glycyrrhizin-18α increased obviously compared with that in p53(+/+) mice treated with normal sodium (P0.01)

but the expression of NF-κB protein decreased obviously (P0.01). The expression of p53 protein was negatively correlated with renal tubular necrosis and the expressions of NF-κB protein (P0.01).     Conclusion    Glycyrrhizin-18α may inhibit the expression of NF-κB protein by upregulating the expression of p53 protein

resulting in relieving renal tubular necrosis.