Allicin relaxes isolated mesenteric arteries through activation of PKA-KATP channel in rat.

Allicin is a natural effective organosulfur compound isolated from garlic, which possesses many beneficial properties, such as antibacterial, anti-inflammatory, antimicrobial, hypotensive and hypolipidemic. In the present study, we investigated the effects and the underlying mechanisms of allicin on isolated mesenteric arteries (MAs). We examined MAs relaxation induced by allicin on rat-isolated mesenteric artery (MA) rings, the KATP channels with patch, and the expression of Kir6.1 and SUR2B with western blotting and NO production with Diaminofluorescein-FM diacetate (DAF-FMDA) in rat mesenteric artery smooth muscle cells (MASMCs). The results showed that allicin elicited the dose-dependent vasorelaxation effect with phenylephrine (PE) precontracted rat MA rings. The vasorelaxation effect was endothelium and NO independent but could be diminished by inhibition of PKA and KATP channels in the vascular smooth muscle. Allicin activated KATP channels in rat MASMCs, and the activation of KATP channels was inhibited by the inhibitors of PKA and KATP channels. But allicin had no effect on the expression of KATP subtypes Kir6.1 and SUR2B. These observations suggest that allicin exerts vasorelaxation effect through activation of PKA-KATP-signaling pathway.