RESUMEN
ObjectiveTo investigate the induction of ferroptosis by polyphyllin Ⅱ （PPⅡ） in hepatocellular carcinoma HepG2 cells and its underlying mechanism. MethodThe effect of PPⅡ （0， 1.5， 3.0， 4.5， 6.0， 9.0， 18.0 mg·L-1） on the in vitro proliferation of HepG2 cells was assessed using the methyl thiazolyl tetrazolium （MTT） assay. Colony formation ability of HepG2 cells was evaluated through a colony formation assay. Cell migration ability was assessed via a scratch assay. Lactate dehydrogenase （LDH） content in HepG2 cells was measured using a kit. Reactive oxygen species （ROS） levels in HepG2 cells were observed using a fluorescence inverted microscope. Malondialdehyde （MDA）， glutathione （GSH）， and free Fe2+ content in HepG2 cells were detected using respective kits. The mitochondrial ultrastructure in HepG2 cells was observed by transmission electron microscopy. The expression of ferroptosis-related proteins p53， solute carrier family 7 member 11 （SLC7A11）， glutathione peroxidase 4 （GPX4）， long-chain acyl-CoA synthetase 4 （ACSL4）， and transferrin receptor 1 （TFR1） in HepG2 cells was detected using Western blot. ResultCompared with the control group， the PPⅡ treatment groups showed significantly decreased survival rate of HepG2 cells in a dose-dependent manner （P<0.01）， significantly reduced number of cell colonies （P<0.01）， significantly shortened scratch healing distance， inverse correlation of the migration distance with drug concentration （P<0.01）， significantly increased LDH leakage in cells （P<0.01）， significantly enhanced relative fluorescence intensity of intracellular ROS， and significantly increased accumulation of lipid peroxide MDA （P<0.01）， decreased intracellular GSH content with increasing drug concentration （P<0.01）， and significantly enhanced fluorescence intensity of FeRhoNox-1 in cells （P<0.01）. Moreover， cells exhibited vacuolation， and mitochondria showed significant shrinkage with reduced or even disappeared cristae. Compared with the results in the control group， the expression of p53， ACSL4， and TFR1 proteins significantly increased， while the expression of SLC7A11 and GPX4 proteins significantly decreased in the PPⅡ treatment groups （P<0.05）. ConclusionIn summary， PPⅡ induces ferroptosis in HepG2 cells by regulating the p53/SLC7A11/GPX4 signaling axis， promoting ACSL4 expression and Fe3+ uptake， leading to an imbalance in the antioxidant system.
RESUMEN
Ferroptosis， a new form of programmed cell death different from apoptosis， necrosis， and autophagy， is closely associated with a variety of physiological and pathological processes. Iron-mediated accumulation of reactive oxygen species is the main inducement of ferroptosis， the mechanism of which is related to intracellular lipid metabolism， iron metabolism， and antioxidant defense pathways. Multiple signaling axes and regulators jointly regulate the occurrence and disruption of ferroptosis. Studies have demonstrated that ferroptosis regulates the growth and proliferation of tumor cells. Inducing ferroptosis in tumor cells can control the growth， metastasis， and multi-drug resistance of tumors. Therefore， the effect and mechanism of ferroptosis on tumor cells have become a hot topic in anti-cancer research. As the research advances， a variety of ferroptosis inducers has been used in the clinical chemotherapy for cancers and demonstrate significant efficacy. Accordingly， the development of ferroptosis-inducing anticancer drugs has become a new research direction for tumor treatment. Some active ingredients such as lycorine， oleanolic acid， dihydroartemisinin， pseudolaric acid B， and ophiopogonin B of Chinese medicines can induce ferroptosis in tumor cells via lipid metabolism， iron metabolism， system Xc-， and GPX4/GSH to regulate the development of tumors， demonstrating a promising prospect in clinical treatment. Based on the theory of the mechanism of ferroptosis， this paper reviews the research progress in ferroptosis induced by active ingredients of Chinese medicines in tumor cells and describes the metabolic regulatory network of ferroptosis from signaling pathways and regulatory factors， providing new strategies for applying active ingredients of Chinese medicines in the treatment of tumors.
RESUMEN
Paridis Rhizoma possesses the functions of clearing heat and detoxifying， alleviating swelling and relieving pain， cooling the liver and calming the convulsion. Saponins are the main active components of Paridis Rhizoma. Studies have shown that total saponins in Paridis Rhizoma have obvious inhibitory effect on solid tumors such as breast cancer， lung cancer， gastric cancer， and liver cancer and non-solid tumors such as leukemia. The saponins may exert the anti-tumor effects by inhibiting the proliferation， migration， and invasion of tumor cells， regulating cell cycle， inducing apoptotic and non-apoptotic death pathways， and regulating metabolism and tumor microenvironment. Furthermore， total saponins in Paridis Rhizoma showed anti-inflammatory， antioxidant， antimicrobial， hemostatic， and uterus-contracting activities. At the same time， they may induce apoptosis of normal cells， inflammation and oxidative stress， and metabolic disorders. In recent years， the reports of liver injury， reproductive injury， gastrointestinal injury， hemolysis， and other adverse reactions caused by total saponins in Paridis Rhizoma have been increasing. Pharmacokinetic studies have shown that there are significant differences in the metabolism of total saponins in Paridis Rhizoma administrated in different ways. Injection has a fast clearance rate， while oral administration may have hepatoenteric circulation. Meanwhile， due to the low solubility and activation of P-glycoprotein （P-gp） molecular pump， the prototype absorption， intestinal permeability， and recovery rate of total saponins in Paridis Rhizoma are poor， which affects the bioavailability. The bioavailability can be improved to some extent by preparing new dosage forms or new drug delivery systems with advanced technology. This paper reviews the pharmacological effect， pharmacokinetics， and adverse reactions of Rhizoma Paridis total saponins by searching the China National Knowledge Infrastructure （CNKI）， VIP， and Web of Science with ''Rhizoma Paridis total saponins'' as the keywords， hoping to provide references for the research， development， and clinical application of such components.