Inhibition of adipocyte differentiation would be a key strategy to control obesity. Human adipose tissue-derived stem cells (ADSCs) are a promising tool for adipocyte differentiation research. Thymoquinone (TQ) as a potent antioxidant molecule may inhibit adipocyte differentiation. Herein, we aim to investigate the inhibitory effect of TQ on lipid differentiation in ADSCs. Quantification of cell surface markers was used by Flow-Cytometry and the effect of TQ on cell viability was assessed using the AlamarBlue test. ADSCs were subjected to induction of differentiation in the presence of non-cytotoxic concentrations of TQ (6.25, 12.5 and 25 μg/mL). Lipid accumulation was assessed using the Oil-Red O staining technique. Moreover, the expression of PPARγ (Peroxisome proliferator-activated receptor-γ) and FAS (Fatty Acid Synthetase) proteins was evaluated using Western blotting. Flow-cytometry demonstrated the expression of CD44, CD90, and CD73 as mesenchymal stem cell markers on the cell surface. At concentrations ≤100 μg/mL of TQ, no significant difference in cell viability was observed compared to the control. Lipid accumulation in ADSCs significantly decreased at 25 μg/mL (P < 0.001) and 12.5 μg/mL (P < 0.01) of TQ. The findings of the qualitative examination of Lipid Droplets also confirmed these results. Western-blot showed that TQ at 12.5 (p < 0.05) and 25 μg/mL (p < 0.01) reduced FAS/β-actin ratio compared to the positive group. TQ also decreased the expression of PPARγ at 6.25 μg/mL but not at higher concentrations. In conclusion, TQ may reduce differentiation of fat stem cells into fat cells through inhibition of the expression of PPARγ and FAS proteins and might be a potential anti-obesity compound.

抑制脂肪细胞分化将是控制肥胖的关键策略。人类脂肪组织来源的干细胞 (ADSCs) 是一种很有前途的脂肪细胞分化研究工具。百里醌 (TQ) 作为一种有效的抗氧化分子可以抑制脂肪细胞分化。在此，我们旨在研究 TQ 对 ADSCs 脂质分化的抑制作用。通过流式细胞术对细胞表面标志物进行量化，并使用 AlamarBlue 测试评估 TQ 对细胞活力的影响。在存在非细胞毒性浓度的 TQ（6.25、12.5 和 25 μg/mL）的情况下，对 ADSC 进行分化诱导。使用油红 O 染色技术评估脂质积累。而且，使用蛋白质印迹评估 PPARγ（过氧化物酶体增殖物激活受体-γ）和 FAS（脂肪酸合成酶）蛋白的表达。流式细胞术显示 CD44、CD90 和 CD73 作为间充质干细胞标志物在细胞表面的表达。在 TQ 浓度≤100 μg/mL 时，与对照相比，未观察到细胞活力的显着差异。ADSC 中的脂质积累在 25 μg/mL 时显着降低（P  < 0.001) 和 12.5 μg/mL ( P  < 0.01) 的 TQ。脂滴定性检查的结果也证实了这些结果。Western-blot 显示，与阳性组相比，12.5 ( p  < 0.05) 和 25 μg/mL ( p  < 0.01) 的 TQ 降低了 FAS/β-肌动蛋白比率。TQ 在 6.25 μg/mL 时也降低了 PPARγ 的表达，但在更高浓度时没有。总之，TQ 可能通过抑制 PPARγ 和 FAS 蛋白的表达来减少脂肪干细胞向脂肪细胞的分化，并且可能是一种潜在的抗肥胖化合物。