The Effect of Naringin on the Lysophosphatidylcholine-induced Proliferation of Vascular Smooth Muscle Cells

Abstract

Background and Objectives:Lysophosphatidylcholine (lysoPC), an atherogenic lysophospholipid, is known to induce the proliferation of vascular smooth muscle cells (VSMCs). Naringin is a flavonoid in grapes and grapefruits and has anti-inflammatory as well as antioxidative effects. We investigated whether naringin could protect VSMCs from the effect of lysoPC. Additionally, we investigated the changes of nuclear translocation of nuclear factor-kappa B (NF-κB). Materials and Methods:VSMCs were prepared from the aorta of Sprague-Dawley rats. Near-confluent VSMCs were preincubated in media containing 0, 10, 100 μM naringin, and incubated with 0, 10, 20, 100 μM lysoPC. The degree of proliferation of VSMCs was evaluated with [H3]-thymidine incorporation and MTT assay. The changes of nuclear translocation of NF-κB in VSMCs were investigated with EMSA. Results:LysoPC promoted the growth of VSMCs, whereas naringin inhibited the proliferative effect of lysoPC on VSMCs. MTT assay showed a 63±24% and 89±17% increase of cellular growth in the 10 and 20 μM lysoPC groups, respectively, as compared with the control group with media only (p<0.01). [H3]-thymidine incorporation assay also showed 61±25% and 92±25% increase in the 10 and 20 μM lysoPC groups, respectively (p<0.01). However, the growth of VSMCs was suppressed in the 100 μM lysoPC group (p<0.01). Naringin inhibited the proliferative effects of lysoPC on VSMCs by 34±5% (MTT assay) and 35±5% ([H3]-thymidine incorporation assay) in the 100 μM naringin group (p=0.01). The nuclear translocation of NF-κB was stimulated by lysoPC and suppressed by naringin. Conclusion:LysoPC promoted the growth of VSMCs, whereas naringin inhibited the proliferative effect of lysoPC on VSMCs. These 논문접수일:2001년 7월 4일 심사완료일:2001년 11월 14일 교신저자:채인호, 110-744 서울 종로구 연건동 28번지 서울대학교 의과대학 내과학교실 전화:(02) 760-2684·전송:(02) 766-8904·E-mail:ihchae@snu.ac.kr