*4.2. Vasorelaxant E*ff*ects of B. monnieri Active Compounds on Endothelial Intact Arteries*

Following stabilization, endothelial intact rings of mesenteric arteries were pre-contracted with 10 μM PE. After the contraction had become constant, the *B. monnieri* active compounds (0.1–100 μM), including luteolin, apigenin, bacoside A or bacopaside I were added cumulatively.

#### *4.3. Vasorelaxant E*ff*ects of B. monnieri Active Compounds on Endothelial Denuded Arteries*

Successful endothelial denudation was confirmed by the absence of relaxation upon addition of 10 μM ACh. For investigation of the role of endothelium in 0.1–100 μM *B. monnieri* active compounds (luteolin, apigenin, bacoside A or bacopaside I) induced vasorelaxation, endothelial denuded arteries were used. The data of effect of active compounds were presented as %relaxation.

#### *4.4. Study of Vasorelaxant Mechanisms of B. monnieri Active Compounds via eNOS Pathway*

The role of the endothelial relaxing factor, NO, in *B. monnieri* active compounds (luteolin, apigenin, bacoside A or bacopaside I) induced vasorelaxation were evaluated in endothelial intact ring pre-treated with NG-nitro-L-arginine methyl ester (L-NAME, 100 μM), an inhibitor of eNOS, for 30 min prior to 10 μM PE exposure.
