Department of Pharmacology, Norman Bethune Medical College, Jilin University, Changchun 130021, China.
Metabolism. 2013 Aug;62(8):1159-67. doi: 10.1016/j.metabol.2013.02.007. Epub 2013 Mar 26.
Insulin resistance plays an important role in the pathogenesis of diabetic cardiomyopathy. Berberine (BBR) is a plant alkaloid which promotes hypoglycemia via increasing insulin sensitivity in peripheral tissues. Little is known of BBR's role in regulating glucose metabolism in heart.
MATERIALS/METHODS: We examined the effect and mechanism of BBR on glucose consumption and glucose uptake in insulin sensitive or insulin resistant rat H9c2 cardiomyocyte cells. H9c2 myoblast cells were differentiated into cardiomyocytes and incubated with insulin for 24h to induce insulin resistance.
BBR-treatment of H9c2 cells increased glucose consumption and glucose uptake compared to controls. In addition, BBR-treatment attenuated the reduction in glucose consumption and glucose uptake in insulin resistant H9c2 cells. Compound C, an inhibitor of AMP-activated protein kinase (AMPK), abolished the enhancement of glucose consumption and glucose uptake mediated by BBR in both insulin sensitive and insulin resistant H9c2 cells compared to controls.
BBR significantly increased AMPK activity, but had little effect on the activity of protein kinase B (AKT) in insulin resistant H9c2 cells, suggesting that berberine improves insulin resistance in H9c2 cardiomyocytes at least in part via stimulation of AMPK activity.
胰岛素抵抗在糖尿病心肌病的发病机制中起着重要作用。小檗碱（BBR）是一种植物生物碱，通过增加外周组织的胰岛素敏感性来促进降血糖。目前尚不清楚 BBR 在调节心脏葡萄糖代谢中的作用。
材料/方法：我们研究了 BBR 对胰岛素敏感或胰岛素抵抗的大鼠 H9c2 心肌细胞葡萄糖消耗和摄取的影响及其作用机制。H9c2 成肌细胞分化为心肌细胞，并孵育胰岛素 24 小时以诱导胰岛素抵抗。
与对照组相比，BBR 处理的 H9c2 细胞增加了葡萄糖消耗和摄取。此外，BBR 处理可减轻胰岛素抵抗的 H9c2 细胞中葡萄糖消耗和摄取的减少。与对照组相比，AMP 激活的蛋白激酶（AMPK）抑制剂 Compound C 消除了 BBR 在胰岛素敏感和胰岛素抵抗的 H9c2 细胞中对葡萄糖消耗和摄取的增强作用。
BBR 显著增加了 AMPK 活性，但对胰岛素抵抗的 H9c2 细胞中蛋白激酶 B（AKT）的活性影响不大，这表明小檗碱至少部分通过刺激 AMPK 活性改善 H9c2 心肌细胞的胰岛素抵抗。
