Experimental Biology and Medicine ( IF 3.2 ) Pub Date : 2020-10-12 , DOI: 10.1177/1535370220962708 Saimai Chatree 1 , Chantacha Sitticharoon 1 , Pailin Maikaew 1 , Kitchaya Pongwattanapakin 1 , Issarawan Keadkraichaiwat 1 , Malika Churintaraphan 1 , Chanakarn Sripong 1 , Rungnapa Sririwichitchai 1 , Sompol Tapechum 1
Obesity is one of major risk factors increasing chronic diseases including type II diabetes, cardiovascular diseases, and hypertension. The effects of epigallocatechin gallate (EGCG), the major active compound in green tea, on reduced obesity and improved metabolic profiles are still controversial. Furthermore, the effects of EGCG on human adipocyte lipolysis and browning of white adipocytes have not been elucidated. This study aimed to investigate the effects of EGCG on obesity, lipolysis, and browning of human white adipocytes. The results showed that, when compared to the baseline values, EGCG significantly decreased fasting plasma triglyceride levels (P < 0.05), systolic blood pressure (P < 0.05), diastolic blood pressure (P < 0.05), and serum kisspeptin levels (P < 0.05) after 8 weeks of supplement. On the other hand, supplement of EGCG in obese human subjects for 4 or 8 weeks did not decrease body weight, body mass index, waist and hip circumferences, nor total body fat mass or percentage when compared to their baseline values. The study in human adipocytes showed that EGCG did not increase the glycerol release when compared to vehicle, suggesting that it had no lipolytic effect. Furthermore, treatment of EGCG did not enhance uncoupling protein 1 (UCP1) mRNA expression in human white adipocytes when compared with treatment of pioglitazone, the peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, suggesting that EGCG did not augment the browning effect of PPAR-γ on white adipocytes. This study revealed that EGCG reduced 2 metabolic risk factors which are triglyceride and blood pressure in the human experiment. We also showed a novel evidence that EGCG decreased kisspeptin levels. However, EGCG had no effects on obesity reduction in humans, lipolysis, nor browning of human white adipocytes.
Impact statement
Obesity has become the worldwide problem that causes adverse health consequences in individuals. The effects of EGCG on decreased obesity and improved metabolic profiles are still inconclusive. This study revealed that EGCG decreased 2 metabolic risk factors including blood pressure and triglyceride in human obese subjects but had no effect on obesity reduction. This study also showed a novel finding that EGCG decreased kisspeptin levels in human obese subjects. The study in human adipocytes showed that EGCG had no effects on lipolysis nor browning of human white adipocytes. These findings might suggest that EGCG treatment ameliorated metabolic parameters but did not reduce obesity in obese humans. However, further studies are required to explore the relationship between the effect of EGCG on reduction of blood pressure and kisspeptin levels.
中文翻译:
表没食子儿茶素没食子酸酯降低肥胖人类受试者的血浆甘油三酯、血压和血清kisspeptin
肥胖是增加慢性病的主要危险因素之一,包括 II 型糖尿病、心血管疾病和高血压。绿茶中的主要活性化合物表没食子儿茶素没食子酸酯 (EGCG) 对减少肥胖和改善代谢状况的影响仍然存在争议。此外,尚未阐明 EGCG 对人脂肪细胞脂解和白色脂肪细胞褐变的影响。本研究旨在研究 EGCG 对人类白色脂肪细胞的肥胖、脂肪分解和褐变的影响。结果显示,与基线值相比,EGCG显着降低空腹血浆甘油三酯水平(P < 0.05)、收缩压(P < 0.05)、舒张压(P < 0.05) 和 补充 8 周后的血清 Kisspeptin 水平 ( P < 0.05)。另一方面,与基线值相比,在肥胖人类受试者中补充 EGCG 4 或 8 周不会降低体重、体重指数、腰围和臀围,也不会降低全身脂肪质量或百分比。在人类脂肪细胞中的研究表明,与载体相比,EGCG 不会增加甘油的释放,表明它没有脂肪分解作用。此外,EGCG 的处理并未增强解偶联蛋白 1(UCP1) 与过氧化物酶体增殖物激活受体 γ (PPAR-γ) 激动剂吡格列酮治疗相比,人白色脂肪细胞中的 mRNA 表达,表明 EGCG 不会增强 PPAR-γ 对白色脂肪细胞的褐变作用。这项研究表明,EGCG 在人体实验中降低了 2 个代谢危险因素,即甘油三酯和血压。我们还展示了 EGCG 降低 Kisspeptin 水平的新证据。然而,EGCG 对减少人类肥胖、脂肪分解和人类白色脂肪细胞的褐变没有影响。
影响陈述
肥胖已成为对个人造成不良健康后果的世界性问题。EGCG 对减少肥胖和改善代谢特征的影响仍然没有定论。该研究表明,EGCG 降低了人类肥胖受试者的血压和甘油三酯等 2 个代谢危险因素,但对减少肥胖没有影响。这项研究还显示了一个新发现,即 EGCG 降低了人类肥胖受试者的 Kisspeptin 水平。在人类脂肪细胞中的研究表明,EGCG 对人类白色脂肪细胞的脂肪分解和褐变没有影响。这些发现可能表明 EGCG 治疗改善了代谢参数,但没有减少肥胖人群的肥胖。然而,需要进一步的研究来探索EGCG降低血压的作用与kisspeptin水平之间的关系。