Objective: To investigate the protective effect of tanshinone II A on porcine aortic endothelial cells (PAEC).
Methods: PAEC were stimulated with angiotensin II (Ang- II) for different acting time (1 h, 6 h and 24 h) and Tanshinone II A was added along with Ang- II stimulation (Group A) or 6 h after it (Group B). The nitric oxide (NO) level, the protein and mRNA expression of nitric oxide synthase (cNOS) in PAEC were measured by nitric acid deoxidizing assay, RT-PCR and immunohistochemical assay, respectively.
Results: With the prolongation of acting time of Ang- II, the level of NO and eNOS expression in PAEC sequentially decreased in a negative acting time dependent manner (P < 0.01), which could be inhibited by tanshinone II A treatment independent to the dosage used (P< 0.01). The inhibitory effect of tanshinone II A was better in Group A than that in Group B either at 1 h or at 6 h after treatment (P<0.05). However, 24 h later, no significant difference was found between the effect in the two groups (P >0.05).
Conclusion: Tanshinone II A could inhibit the negative effect of Ang- II on NO production and eNOS expression in PAEC.