Citrus bergamiaRisso Elevates Intracellular Ca2+in Human Vascular Endothelial Cells due to Release of Ca2+from Primary Intracellular Stores

Purum Kang,Sun Seek Min,Hyo-Keun Kim,Hea Kyung Moon,Geun Hee Seol,Jeong-Min Lee,Seung Ho Han

doi:10.1155/2013/759615

Abstract

The purpose of the present study is to examine the effects of essential oil of Citrus bergamia Risso (bergamot, BEO) on intracellular Ca2+ in human umbilical vein endothelial cells. Fura-2 fluorescence was used to examine changes in intracellular Ca2+ concentration [Ca2+]i . In the presence of extracellular Ca2+, BEO increased [Ca2+]i , which was partially inhibited by a nonselective Ca2+ channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased [Ca2+]i in a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced [Ca2+]i increase was partially inhibited by a Ca2+-induced Ca2+ release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3)-gated Ca2+ channel blocker, 2-aminoethoxydiphenyl borane (2-APB). BEO also increased [Ca2+]i in the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+ uptake. In addition, store-operated Ca2+ entry (SOC) was potentiated by BEO. These results suggest that BEO mobilizes Ca2+ from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+ release and affect promotion of Ca2+ influx, likely via an SOC mechanism.

Highlights

Bergamot essential oil (BEO) is obtained from bergamot (Citrus bergamia Risso), a roughly pear-shaped citrus fruit
We firstly demonstrate that BEO mobilized Ca2+ from extracellular and intracellular sources in endothelial cells
Our present results suggest that BEO increased intracellular Ca2+ level through both mobilization of intracellular Ca2+ stores, endoplasmic reticulum (ER) and mitochondria, and promotion of Ca2+ influx, via an SOC mechanism

Summary

Introduction

Bergamot essential oil (BEO) is obtained from bergamot (Citrus bergamia Risso), a roughly pear-shaped citrus fruit. BEO is widely used in aromatherapy to alleviate symptoms of stress-induced anxiety, mild mood disorders, and cancer pain [1] and it has anxiolytic [2] and analgesic [1, 3, 4] effects in rodents. Besides these effects of BEO, bergamottin, isolated from nonvolatile fraction of BEO, significantly decreased the typical electrocardiographic signs of coronary arterial spasm, the force of the contraction and the incidence of cardiac arrhythmias induced by vasopressin in the guinea pig [5]. Another report indirectly supports this view, demonstrating that the vasorelaxant effect of the essential oil of Ocimum gratissimum is partly dependent on the integrity of the vascular endothelium [7]

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Conclusion