Yanling Lin

Chelerythrine (CHE) is a majorly harmful isoquinoline alkaloid ingredient in Chelidonium majus that could trigger potential hepatotoxicity, but the pivotal molecular mechanisms remain largely unknown. In the present study, CHE-induced cytotoxicity and the underlying toxic mechanisms were investigated using human HepG2 cells in vitro. Data showed that CHE treatment (at 1.25–10 μM)-induced cytotoxicity in HepG2 cells is dose-dependent. CHE treatment increased the production of ROS and induced oxidative stress in HepG2 cells. Additionally, CHE treatment triggered the loss of mitochondrial membrane potential, decreased the expression of mitochondrial complexes, upregulated the expression of Bax, CytC, and cleaved-PARP1 proteins and the activities of caspase-9 and caspase-3, and downregulated the expression of Bcl-XL, and HO-1 proteins, finally resulting in cell apoptosis. N-acetylcysteine supplementation significantly inhibited CHE-induced ROS production and apoptosis. Furthermore, CHE treatment significantly downregulated the expression of phosphorylation (p)-Akt (Ser473), p-mTOR (Ser2448), and p-AMPK (Thr172) proteins in HepG2 cells. Pharmacology inhibition of Akt promoted CHE-induced the downregulation of HO-1 protein, caspase activation, and apoptosis. In conclusion, CHE-induced cytotoxicity may involve the inhibition of Akt pathway and the activation of oxidative stress-mediated mitochondrial apoptotic pathway in HepG2 cells. This study sheds new insights into understanding the toxic mechanisms and health risks of CHE.

Ivermectin (IVM) could cause potential neurotoxicity; however, the precise molecular mechanisms remain unclear. This study explores the cytotoxicity of IVM in human neuroblastoma (SH-SY5Y) cells and the underlying molecular mechanisms. The results show that IVM treatment (2.5–15 μM) for 24 h could induce dose-dependent cell death in SH-SY5Y cells. Compared to the control, IVM treatment significantly promoted the production of ROS, mitochondrial dysfunction, and cell apoptosis. IVM treatment also promoted mitophagy and autophagy, which were charactered by the decreased expression of phosphorylation (p)-Akt and p-mTOR proteins, increased expression of LC3II, Beclin1, ATG5, PINK, and Pakin1 proteins and autophagosome formation. N-acetylcysteine treatment significantly inhibited the IVM-induced production of ROS and cell death in SH-SY5Y cells. Autophagy inhibitor (e.g., 3-methyladenine) treatment significantly inhibited IVM-induced autophagy, oxidative stress, and cell apoptosis. Taken together, our results reveal that IVM could induce autophagy and apoptotic cell death in SH-SY5Y cells, which involved the production of ROS, activation of mitochondrial pathway, and inhibition of Akt/mTOR pathway. Autophagy inhibition improved IVM-induced oxidative stress and apoptotic cell death in SH-SY5Y cells. This current study provides new insights into understanding the molecular mechanism of IVM-induced neurotoxicity and facilitates the discovery of potential neuroprotective agents.