Glabridin Relaxes Vascular Smooth Muscles by Activating BK_Ca Channels and Inhibiting Phosphodiesterase in Human Saphenous Vein

Abstract

The aim of the current study was to investigate the pharmacological activity of glabridin on the isolated human saphenous vein (SV) and explore the underlying mechanisms. Samples of patients’ SVs were removed during bypass surgery, and 4-mm lengths of the vessels were placed in Krebs solution at +4°C and hung in an isolated organ bath to assess their contraction/relaxation responses. The contraction/relaxation responses were recorded to observe if the cyclic guanosine monophosphate (cGMP)/protein kinase G (PKG) pathway mediates the relaxant effect of glabridin after treatment with blockers like ODQ (a guanylate cyclase inhibitor), KT5823 (a PKG inhibitor), isobutylmethylxanthine [IBMX, a phosphodiesterase (PDE) inhibitor], and cantharidin [Cant, a myosin light-chain phosphatase (MLCP) inhibitor]. Moreover, nitric oxide (NO), cGMP, and PKG levels in SV tissues were determined by ELISA after incubation with glabridin, N(ω)-nitro-L-arginine methyl ester (L-Name, a NO synthetase inhibitor), phenylephrine (PE), ODQ, IBMX, and KT5823. The results showed that glabridin relaxed the vascular smooth muscle of human SV pretreated with PE in a dose-dependent manner, which was independent of the endothelium. The vasorelaxant effect of glabridin was only inhibited by iberiotoxin (IbTX), Cant, and KT5823. Glabridin increased cGMP and PKG levels in SV homogenates, whereas it did not alter the NO level. The enhancing effects of cGMP and PKG levels by glabridin were abolished by ODQ and KT5823. In conclusion, glabridin has a vasorelaxant effect, which is associated with the activation of BK_Ca channels and inhibition of PDE.

Keywords

glabridin / BKCa channels / human saphenous vein (SV) grafts / cyclic guanosine monophosphate (cGMP) / protein kinase G (PKG)

References

[1] HussainH, GreenIR, ShamraizU, et al.. Therapeutic potential of glycyrrhetinic acids: a patent review (2010–2017). Expert Opin Ther Pat, 2018, 28(5): 383-398

[2] SinghP, SinghD, GoelRK. Protective effect on phenytoin-induced cognition deficit in pentylenetetrazol kindled mice: A repertoire of Glycyrrhiza glabra flavonoid antioxidants. Pharm Biol, 2016, 54(7): 1209-1218

[3] AlwanAM, NesrullahZ, FarajE. Study the Effect of Ethanolic Extract of Glycyrrhiza glabra on Pathogenic Bacteria. Int J Curr Microbiol Applide Sci, 2015, 4(5): 473-484

[4] YangR, YuanBC, MaYS, et al.. The anti-inflammatory activity of licorice, a widely used Chinese herb. Pharm Biol, 2017, 55(1): 5-18

[5] KangJS, YoonYD, ChoIJ, et al.. Glabridin, an Isoflavan from Licorice Root, Inhibits Inducible Nitric-Oxide Synthase Expression and Improves Survival of Mice in Experimental Model of Septic Shock. J Pharmacol Exp Ther, 2004, 312(3): 1187-1194

[6] YokotaT, NishioH, KubotaY, et al.. The inhibitory effect of glabridin from licorice extracts on melanogenesis and inflammation. Pigment cell Res, 1998, 11(6): 355-361

[7] ParlarA, ArslanSO, ÇamSA. Glabridin alleviates inflammation and nociception in rodents by activating BK_Ca channels and reducing NO levels. Biol Pharm Bull, 2020, 43(5): 884-897

[8] KangMR, ParkKH, OhSJ, et al.. Cardiovascular protective effect of glabridin: Implications in LDL oxidation and inflammation. Int Immunopharmacol, 2015, 29: 914-918

[9] TsantoulasC. Emerging potassium channel targets for the treatment of pain. Curr Opin Support Palliat Care, 2015, 9: 147-154

[10] ChenSR, CaiYQ, PanHL. Plasticity and emerging role of BK_Ca channels in nociceptive control in neuropathic pain. J Neurochem, 2009, 110(1): 352-362

[11] LuR, LukowskiR, SausbierM, et al.. BK_Ca channels expressed in sensory neurons modulate inflammatory pain in mice. Pain, 2014, 155(3): 556-565

[12] ChandaD, Prieto-LloretJ, SinghA, et al.. Glabridin-induced vasorelaxation: Evidence for a role of BK_Ca channels and cyclic GMP. Life Sci, 2016, 165: 26-34

[13] LeeMS, ParkSJ, KandzariDE, et al.. Saphenous vein graft intervention. JACC Cardiovasc Interv, 2011, 4: 831-843

[14] MotwaniJG, TopolEJ. Aortocoronary saphenous vein graft disease: Pathogenesis, predisposition, and prevention. Circulation, 1998, 97: 916-931

[15] PalR, ChaudharyMJ, TiwariPC, et al.. Pharmacological and biochemical studies on protective effects of mangiferin and its interaction with nitric oxide (NO) modulators in adjuvant-induced changes in arthritic parameters, inflammatory, and oxidative biomarkers in rats. Inflammopharmacology, 2019, 27(2): 291-299

[16] GuptaVK, FatimaA, FaridiU, et al.. Antimicrobial potential of Glycyrrhiza glabra roots. J Ethnopharmacol, 2008, 116(2): 377-380

[17] El-AshmawyNE, KhedrNF, El-BahrawyHA, et al.. Downregulation of iNOS and elevation of cAMP mediate the anti-inflammatory effect of glabridin in rats with ulcerative colitis. Inflammopharmacology, 2018, 26(2): 551-559

[18] PereiraASP, Banegas-LunaAJ, Peña-GarcíaJ, et al.. Evaluation of the Anti-Diabetic Activity of Some Common Herbs and Spices: Providing New Insights with Inverse Virtual Screening. Molecules, 2019, 24(2): 4030

[19] FuhrmanB, BuchS, VayaJ, et al.. Licorice extract and its major polyphenol glabridin protect low-density lipoprotein against lipid peroxidation: in vitro and ex vivo studies in humans and in atherosclerotic apolipoprotein E-deficient mice. Am J Clin Nutr, 1997, 66(2): 267-275

[20] BoltonTB, LangRJ, TakewakiT. Mechanisms of action of noradrenaline and carbachol on smooth muscle of guinea-pig anterior mesenteric artery. J Physiol, 1984, 351(1): 549-572

[21] KnockGA, SmirnovSV, AaronsonPI. Voltage-gated K+ currents in freshly isolated myocytes of the pregnant human myometrium. J Physiol, 1999, 518(3): 769-781

[22] LiuJ, LiuH, LiY, et al.. Cross regulation between cGMP-dependent protein kinase and Akt in vasodilatation of porcine pulmonary artery. J Cardiovasc Pharmacol, 2014, 64(5): 452-459

[23] WhiteRE, KrymanJP, El-MowafyAM, et al.. cAMP-dependent vasodilators cross-activate the cGMP-dependent protein kinase to stimulate BK(Ca) channel activity in coronary artery smooth muscle cells. Circ Res, 2000, 86(8): 897-905

[24] CarrierGO, FuchsLC, WinecoffAP, et al.. Nitrovasodilators relax mesenteric microvessels by cGMP-induced stimulation of Ca-activated K channels. Am J Physiol — Hear Circ Physiol, 1997, 273(1): 76-84 Pt2

[25] KyleBD, HurstS, SwayzeRD, et al.. Specific phosphorylation sites underlie the stimulation of a large conductance, Ca²⁺-activated K⁺ channel by cGMP-dependent protein kinase. FASEB J, 2013, 27(5): 2027-2038

[26] BaeH, LimI. Effects of nitric oxide on large-conductance Ca2+-activated K+ currents in human cardiac fibroblasts through PKA and PKG-related pathways. Clin Exp Pharmacol Physiol, 2017, 44(11): 1116-1124

[27] DantasBPV, RibeiroTP, AssisVL, et al.. Vasorelaxation induced by a new naphthoquinone-oxime is mediated by NO-sGC-cGMP pathway. Molecules, 2014, 19(7): 9773-9785

[28] LiH, ShinSE, SeoMS, et al.. The anti-diabetic drug dapagliflozin induces vasodilation via activation of PKG and Kv channels. Life Sci, 2018, 197: 46-55

[29] WangP, WuP, MyersJG, et al.. Characterization of human, dog and rabbit corpus cavernosum type 5 phosphodiesterases. Life Sci, 2001, 68(17): 1977-1987