目的 探討胡黃連主要有效成分胡黃連苷I、II對3T3-L1前脂肪細胞成脂分化的影響。方法 采用MTT法檢測胡黃連苷I、II對3T3-L1細胞活力的影響，確定給藥濃度；使用誘導分化培養(yǎng)基誘導3T3-L1細胞分化為成熟脂肪細胞，通過油紅O染色法觀察胡黃連苷I、II（20、40 μmol·L^-1）對細胞脂肪蓄積的影響；實時熒光定量PCR（qRT-PCR）法檢測3T3-L1細胞脂肪合成相關的乙酰輔酶A羧化酶1（ACACA）、脂肪酸合酶（FASN）、硬脂酰輔酶A去飽和酶（SCD1）、脂肪酸結合蛋白（FABP4）和調節(jié)脂肪合成的轉錄因子過氧化物酶體增殖物激活受體γ（PPARγ）、固醇調節(jié)元件結合蛋白1（SREBP1）的mRNA表達水平；Western blotting實驗檢測CCAAT/增強子結合蛋白β（C/EBPβ）、SCD1和PPARγ的蛋白表達。結果 濃度低于50 μmol·L^-1的胡黃連苷I、II處理不會影響細胞的存活率；與對照組比較，模型組在誘導分化后細胞形態(tài)變圓，油紅O染色顯示細胞中有大量脂肪蓄積（P＜0.01）；與模型組比較，胡黃連苷I、II顯著減少了脂肪蓄積（P＜0.01）。與對照組比較，模型組ACACA、FASN、SCD1、FABP4、PPARγ和SREBP1的mRNA表達均顯著上調（P＜0.05、0.01）；與模型組比較，胡黃連苷I、II 20、40 μmol·L^-1均顯著降低了ACACA、SCD1、FASN、FABP4、SREBP1 mRNA的表達（P＜0.05、0.01），胡黃連苷I、II僅在40 μmol·L^-1時顯著抑制SREBP1 mRNA的表達（P＜0.05、0.01）。Western blotting結果顯示，與對照組比較，模型組PPARγ、C/EBPβ和SCD1的蛋白表達顯著上調（P＜0.01）；與模型組比較，胡黃連苷I、II各濃度均顯著降低了SCD1蛋白的表達（P＜0.01），胡黃連苷I 40 μmol·L^-1和胡黃連苷II 20、40 μmol·L^-1組PPARγ、C/EBPβ蛋白的表達顯著降低（P＜0.05、0.01）。結論 胡黃連苷I、II均可以顯著抑制3T3-L1細胞的脂肪分化，并減少脂肪蓄積，胡黃連苷I表現出更好的劑量相關性，其作用機制可能與抑制C/EBPβ-PPARγ通路有關。

Objective To investigate the effects of picroside I and II, the main active components of Picrorhiza scrophulariiflora, on adipogenic differentiation of 3T3-L1 preadipocytes. Methods MTT assay was used to detect the effect of picroside I and II on the viability of 3T3-L1 preadipocytes, and to determine the concentration of drug administered. 3T3-L1 preadipocytes were induced to differentiate into mature adipocytes by differentiation medium. The effects of picroside I and picroside II (20 and 40 μmol·L^-1) on lipid accumulation were observed by oil red O staining. Real-time quantitative PCR (qRT-PCR) was used to detect the expression of Acetyl-CoA carboxylase 1 (ACACA), fatty acid synthase (FASN), Stearoyl-CoA desaturase (SCD1), fatty acid binding protein (FABP4), peroxisome proliferator-activated receptor gamma (PPARγ), and sterol regulatory element binding protein 1 (SREBP1) mRNA expression levels in 3T3-L1 preadipocytes. Western blotting assay was used to detected the protein expression of CCAAT/ enhancer binding protein β (C/EBPβ), SCD1, and PPARγ. Results The treatment of picroside I and II with concentration below 50 μmol·L^-1 does not affect the cell survival rate. Compared with control group, the vast majority of 3T3-L1 preadipocytes in the model group became circular after induced differentiation, and oil red O staining showed that there was a large amount of lipid accumulation in the cells (P < 0.01). Compared with model group, lipid accumulation was significantly reduced in the picroside I and II administration groups. Compared with the control group, the mRNA expression of ACACA, FASN, SCD1, FABP4, PPARγ and SREBP1 in the model group was significantly up-regulated (P < 0.05). Compared with model group, picroside I and II 20, 40 μmol·L^-1 significantly reduced the expression of ACACA, SCD1, FASN, FABP4, and SREBP1 mRNA (P < 0.05, 0.01), while picroside I and II 40 μmol·L^-1 significantly reduced the expression of SREBP1 mRNA (P < 0.05, 0.01). Western blotting results showed that, compared with control group, the protein levels of PPARγ, C/EBPβ, and SCD1 in the model group were significantly up-regulated (P < 0.01). Compared with model group, each concentration of picroside I and II significantly reduced the expression of SCD1 protein (P < 0.01), while the expression of PPARγ and C/EBPβ protein in picroside I 40 μmol·L^-1 and picroside II 20, 40 μmol·L^-1 group was significantly reduced (P < 0.05, 0.01). Conclusion Both picroside I and II can inhibit the adipose differentiation of 3T3- L1 preadipocytes, and reduce fat accumulation. Picroside I shows a better dose dependence, and their mechanism may be related to the inhibition of C/EBPβ-PPARγ pathway.

中央高校基本科研業(yè)務費專項資金資助項目（3332022063）；國家自然科學基金資助項目（82202950）；國家自然科學基金資助項目（82104012）；中國醫(yī)學科學院醫(yī)學與健康科技創(chuàng)新工程重大協(xié)同創(chuàng)新項目資助（2021-I2M-1-042）