Cellular and Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Iran Biomed J. 2024 Jan 1;28(1):31-7. doi: 10.61186/ibj.4005. Epub 2023 Oct 28.
Liver fibrosis, associated with hepatic stellate cells (HSCs), occurs when a healthy liver sustains damage, thereby impairing its function. NADPH oxidases (NOXs), specifically isoforms 1, 2, and 4, play a role in reactive oxygen species (ROS) production during hepatic injuries, resulting in fibrosis. Curcumin has shown strong potential in mitigating liver fibrosis. Our research aimed to investigate the effects of curcumin on lowering NOX and ROS levels. This compound was also studied for its effects on NOXs, ROS concentrations through the inhibition of Smad3 phosphorylation in transforming growth factor beta (TGF-β)-activated human HSCs.
MTT assay investigated the cytotoxic effects of curcumin on HSCs. The cells were activated by exposure to TGF-β (2 ng/mL) for 24 hours. After activating, the cells were treated with curcumin at 25-150 μM concentrations. After administering curcumin to the cells, we employed RT-PCR and Western blot techniques to evaluate the related gene and protein expression levels. This evaluation was primarily focused on the mRNA expression levels of NOX1, NOX2, NOX4 and phosphorylated Smad3C.
The mRNA expression level of aforesaid NOXs as well as α-smooth muscle actin (α-SMA), collagen1-α, and ROS levels were significantly reduced following 100 μM curcumin treatment. Furthermore, curcumin significantly decreased the p-Smad3C protein level in TGF-β-activated cells, with fold changes of 3 and 2 observed at 75 and 100 μM, respectively.
Curcumin decreased the levels of ROS and NOX, as well as the expression of α-SMA and collagen1-α. The primary mechanism for this reduction could be linked to the level of p-Smad3C. Hence, curcumin could serve as an effective therapeutic agent for liver fibrosis.
当健康的肝脏受到损伤时，肝星状细胞（HSCs）会发生肝纤维化，从而损害其功能。NADPH 氧化酶（NOXs），特别是 1、2 和 4 同工型，在肝损伤时产生活性氧（ROS）的过程中发挥作用，导致纤维化。姜黄素在减轻肝纤维化方面显示出很强的潜力。我们的研究旨在探讨姜黄素降低 NOX 和 ROS 水平的作用。还研究了该化合物通过抑制转化生长因子β（TGF-β）激活的人 HSCs 中 Smad3 磷酸化对 NOXs 和 ROS 浓度的影响。
MTT 测定法研究了姜黄素对 HSCs 的细胞毒性作用。将细胞暴露于 TGF-β（2ng/ml）中 24 小时以激活细胞。激活后，用 25-150μM 浓度的姜黄素处理细胞。用姜黄素处理细胞后，采用 RT-PCR 和 Western blot 技术评估相关基因和蛋白表达水平。主要评估 NOX1、NOX2、NOX4 和磷酸化 Smad3C 的 mRNA 表达水平。
用 100μM 姜黄素处理后，上述 NOXs 的 mRNA 表达水平以及α-平滑肌肌动蛋白（α-SMA）、胶原 1-α和 ROS 水平均显著降低。此外，姜黄素显著降低了 TGF-β 激活细胞中的 p-Smad3C 蛋白水平，在 75 和 100μM 时分别观察到 3 和 2 的折叠变化。
姜黄素降低了 ROS 和 NOX 的水平，以及α-SMA 和胶原 1-α的表达。这种减少的主要机制可能与 p-Smad3C 的水平有关。因此，姜黄素可以作为治疗肝纤维化的有效治疗剂。
