| Abstract: | 為改善人類肥胖與代謝相關疾病的發生、提高畜產動物之飼料效率與降低飼養成本。本研究嘗試以功能性的物質探討其對脂肪細胞功能之影響。試驗以3T3-L1脂肪細胞作為試驗材料，探討聖約翰草萃取物（Saint John’s wort extracts, SJWE）對脂肪細胞脂質蓄積功能與約日節律的影響。細胞經SJWE處理，由oil-Red O脂質染色與三酸甘油酯含量分析，顯示SJWE似乎可降低脂肪細胞的油脂堆積。根據相對定量聚合酶連鎖反應分析結果，顯示SJWE會降低脂質代謝與脂肪細胞分泌激素相關基因，如peroxisome proliferator-activated receptor（PPAR）、Perilipin、hormone-sensitive lipase（HSL），及脂肪細胞分泌激素Adiponectin與Leptin mRNA之表現，而此抑制作用在缺乏胰島素的培養條件下更形顯著。此外，SJWE可使同步化標幟基因–Per2於處理後1小時提升，並於第8小時降至低點，使細胞生理時鐘同步化；並可使Per2、Bmal1、Rev-erbα、PPARγ、HSL、Perilipin mRNA表現節律性變化較為鮮明。然而脂肪細胞分泌激素基因（Adiponectin、Leptin）mRNA表現，雖於SJWE處理初期增加，但卻未影響其節律性變化。最後，細胞Leptin分泌量分析顯示，SJWE可顯著降低Leptin分泌量，而此抑制能力會隨時間而有週期性變化。綜合上述結果，SJWE可抑制3T3-L1脂肪細胞脂質蓄積及代謝與細胞激素相關基因之表現，並調節約日節律及脂質代謝相關基因的節律性變化與Leptin分泌量。至於SJWE抑制脂肪細胞脂質蓄積之作用機制，與約日節律間之關聯性仍有待進一步探討。
In order to improve obesity and metabolic disorders in human and feed conversion in domestic animals, this study attempted to explore the effects of functional materials on the functions of adipocytes. The experiments were performed to investigate the effects of Saint John’s wort extracts (SJWE) on fat accumulation, adipokine secretion, and biological clock of adipocytes using 3T3-L1 adipocyte model. Fat accumulation of adipocytes was decreased by SJWE treatments as evidenced by morphological observation, oil-Red O staining and triglycerides assays. The mRNA levels, measured by RT-PCR analysis, of lipid metabolism-related genes, including peroxisome proliferator-activated receptorg (PPARg), Perilipin, hormone- sensitive lipase (HSL), Adiponectin and Leptin, were lower in the SJWE-treated cells than those in the control cells. The inhibitory effect of SJWE on the Leptin mRNA level was enhanced in the absence of insulin. In addition, SJWE, mimicking the effect of 50% FBS, synchronized the biological clocks of adipocytes and their metabolic performances, as evidenced by the mRNA analysis of circadian- and metabolism- related genes. Finally, Leptin secretion was inhibited in the cells treated with SJWE, and this effect of SJWE was related to the biological clocks of cells. Taken together, SJWE has effects on regulating lipid metabolism, adipokine secretion, and biological clocks of adipocytes, and may be used for the improvement of metabolic disorders in human and feeding efficiency in domestic animals. |
