荔枝果肉B型原花青素三聚体调节肝细胞脂代谢作用研究

Effects of B-type proanthocyanidins trimer from Litchi chinensis Sonn pulp on regulating lipid metabolism in hepatocytes

中文关键词:  荔枝  B型原花青素三聚体  肝细胞脂肪变性  分子机制

英文关键词:Litchi chinensis Sonn  B-type proanthocyanidins trimer  steatosis of hepatocytes  molecular mechanism

中文摘要:

      目的 探究荔枝果肉多酚主要活性组分B型原花青素三聚体抑制肝细胞甘油三酯(triglyceride, TG)沉积的剂量效应及其分子机制。方法 采用不同质量浓度(0.5~10.0 μg/mL) B型原花青素三聚体处理油酸(oleic acid, OA)诱导的HepG2细胞脂肪变性模型, 检测OA负荷肝细胞内TG含量及其与脂质吸收、转运、氧化和肝细胞凋亡相关基因表达。结果 0.5~10.0 μg/mL B型原花青素三聚体均能显著抑制OA负荷肝细胞内TG沉积, 但不呈现剂量依赖性; 低剂量(1.0 μg/mL) B型原花青素三聚体主要通过增强肝细胞Bcl-2和Bax表达量的比值, 抑制肝细胞凋亡进而减轻细胞TG沉积; 除上述途径外, 中、高剂量(5.0 μg/mL、10.0 μg/mL) B型原花青素三聚体还可通过下调肝细胞CD36和FATP2的表达抑制细胞脂质吸收, 同时上调肝细胞ACSL1和CPT1α的表达促进细胞脂质分解, 进而减轻肝细胞TG沉积。结论 荔枝果肉B型原花青素三聚体可以通过抑制肝细胞脂质吸收, 促进脂肪酸的β氧化以及抑制肝细胞过度凋亡, 进而改善肝脏脂质代谢紊乱。

英文摘要:

      Objective To explore the dose effects and molecular mechanism of B-type proanthocyanidins trimer, the main active component of Litchi chinensis Sonn pulp phenolics, on hepatocyte triglyceride (TG) deposition. Methods HepG2 cell steatosis model induced by oleic acid (OA) was treated with different mass concentrations (0.5–10.0 μg/mL) of B-type proanthocyanidins trimer. The content of TG and the expressions of genes related to lipid absorption, transport and oxidation, together with apoptosis of hepatocytes, were detected in oleic acid loaded hepatocytes. Results B-type proanthocyanidins trimer (0.5–10.0 μg/mL) all significantly inhibited TG accumulation in oleic acid-loaded hepatocytes, while no dose dependence was observed. Low-dose (1.0 μg/mL) B-type proanthocyanidins trimer inhibited hepatocyte apoptosis by increasing the relative expression ratio of Bcl-2 to Bax, thereby reducing TG accumulation in hepatocytes. In addition to the above-mentioned pathway, medium/high-dose (5.0 μg/mL, 10.0 μg/mL) B-type proanthocyanidins trimer also inhibited lipid absorption in hepatocytes by down-regulating CD36 and FATP2 expression, and promoted hepatocytes lipolysis by up-regulating ACSL1 and CPT1α expression, hence reducing TG accumulation in hepatocytes. Conclusion B-type proanthocyanidins trimer of Litchi chinensis Sonn pulp can inhibit lipid absorption, promote β-oxidation of fatty acids and inhibit excessive apoptosis of liver tissue cells, thereby improving lipid metabolism and preventing fatty liver.