Liver cells are easily damaged by oxidative stress during progression both in liver development and throughout adult life, resulting in tissue pathology that ranges from simple hepatitis to nonalcoholic fatty liver disease. In this study, we determined the attenuation of oxidative stress in liver cells with pretreatment of rosmarinic acid (RA), which is an antioxidant agent from Rosmarinus officinalis . The human liver cell line L02 was damaged by hydrogen peroxide (H ₂ O ₂ ). In the RA treatment group, the viability of L02 cells increased and the intracellular reactive oxygen species levels decreased compared with the H ₂ O ₂ -induced damage group. Analysis of flow cytometry revealed that the percentage of G2/M cell cycle arrest and cell apoptosis decreased in the RA treatment group. This alteration was associated with activation of a G2/M DNA damage and oxidative stress apoptotic signal. Furthermore, we determined the redox-sensitive protein expression of mitogen-activated protein kinases (MAPKs), quinone acceptor oxidoreductase 1 (NQO1), and nuclear factor E2-related factor 2 (Nrf2), and the expression of both MAPKs and Nrf2 was activated in the RA group. Results showed that the relevant protein expression of MAPKs and Nrf2 was activated in the RA group. Thus, RA protected L02 cells from oxidative damage through suppressing cell cycle arrest and cell apoptosis with the activation of MAPK and Nrf2 signaling pathways.

Indolizine derivatives are a class of compounds with excellent biological activity. In this study, a series of indolizine derivatives, compound 1 (C1), compound 2 (C2), compound 3 (C3), and compound 4 (C4), were synthesized. 3-(4,5-dimethylthiazole)-2,5-diphenyltetraazolium bromide (MTT) assay was used to evaluate their cytotoxicity against HepG2 (p53-wild), A549, and HeLa cell lines. HepG2 cells apoptosis induced by C3 was determined using Hoechst staining and acridine orange/ethidium bromide staining. Cells’ apoptotic ratio was measured by Annexin V–FITC/PI double staining. Changes in mitochondrial membrane potential and intracellular reactive oxygen species (ROS) in HepG2 cells after C3 treatment were determined. Immunofluorescence staining and Western blot analysis were carried out to detect p53 levels and analyze the apoptosis-associated proteins, respectively. Moreover, the cytotoxic activity of C3 was examined in two other hepatocellular carcinoma (HCC) cell lines with different p53 status including Huh-7 cells (p53-mutant) and Hep3B cells (p53-null). The results indicated that C3 showed stronger inhibition towards HepG2 cells than other cell lines. Fluorescent staining and flow cytometry analysis confirmed that C3 induced apoptosis of HepG2 cells. C3 could also increase intracellular ROS and cause a decrease in the mitochondrial membrane potential. C3 promoted p53 activation and increased p53 accumulation in nuclei. The expression of p53 and Bax was increased with the down-regulation of Bcl-2, which promoted the release of cytochrome c and caspase-3 activation. Collectively, the study demonstrated that C3 caused HepG2 cell apoptosis via the mitochondria p53 pathway. These results inspired us to further develop indolizine derivatives as potential potent inhibitors against liver cancer.

Anlotinib is a receptor tyrosine kinase inhibitor with potential anti-neoplastic and anti-angiogenic activities. It has been approved for the treatment of non-small-cell lung cancer. Lysosomes are acidic organelles and have been implicated in various mechanisms of cancer therapeutics. However, the effect of anlotinib on lysosomal function has not been investigated. In the present study, anlotinib induces apoptosis in human colon cancer cells. Through transcriptome sequencing, we found for the first time that anlotinib treatment upregulates ATP6V0E2 (ATPase H⁺Transporting V0 Subunit E2) and other lysosome-related genes expression in human colon cancer. In human colon cancer, we validated that anlotinib activates lysosomal function and enhances the fusion of autophagosomes and lysosomes. Moreover, anlotinib treatment is shown to inhibit mTOR (mammalian target of rapamycin) signaling and the activation of lysosomal function by anlotinib is mTOR dependent. Furthermore, anlotinib treatment activates TFEB, a key nuclear transcription factor that controls lysosome biogenesis and function. We found that anlotinib treatment promotes TFEB nuclear translocation and enhances its transcriptional activity. When TFEB or ATP6V0E2 are knocked down, the enhanced lysosomal function and autophagy by anlotinib are attenuated. Finally, inhibition of lysosomal function enhances anlotinib-induced cell death and tumor suppression, which may be attributed to high levels of ROS (reactive oxygen species). These findings suggest that the activation of lysosomal function protects against anlotinib-mediated cell apoptosis via regulating the cellular redox status. Taken together, our results provide novel insights into the regulatory mechanisms of anlotinib on lysosomes, and this information could facilitate the development of potential novel cancer therapeutic agents that inhibit lysosomal function.

Liver-related disease caused by alcohol is a frequent disorder of the hepatic tract. Heavy consumption of alcohol in a short period causes oxidative damage to the liver. Sea cucumber is abundant in nutrients and its various extracts have been studied for antioxidant properties. One peptide was isolated and identified from Apostichopus japonicus in our recent study. We investigated the benefits of the peptide in a model of acute ethanol-induced male C57BL/6J mice. Dietary intake of the peptide could attenuate hepatomegaly, hepatitis and the accumulation of lipid droplets, and increase antioxidant enzyme activities in mice with acute alcoholic liver injury. The results indicated that a 20 mg/kg peptide supplement could activate the Nrf2/HO-1 pathway and block the nuclear translocation of NF-κB to alleviate oxidative stress and inflammation. In addition, the preventive effects of peptide supplementation may be related to autophagy. This study suggests that dietary supplementation with a sea cucumber-derived peptide is one of the potential candidates to alleviate acute alcoholic liver injury.

Indolizine derivatives have been reported for the treatment of numerous diseases. However, few studies were carried out for non-small cell lung cancer (NSCLC). We synthesized series of indolizine compounds. The results of MTT assay showed compound 8 (C8) markedly inhibited the proliferation of A549 cells, however, C8 (15, 30 μg/mL) had little cytotoxicity in other cell lines (SH-SY5Y, HepG2, and BEAS-2B cells), Hoechst staining and JC-1 staining showed that C8 induced changes in the nucleus morphology, increased the loss in mitochondrial membrane potential in A549 cells. The results of flow cytometry manifested that cell cycle of the cells was arrested in the G2 / M phase by C8, ROS levels and the proportion of apoptosis of cells increased. We performed western blotting analysis to detect the expression levels of apoptosis and cycle-related proteins. These results validated that the apoptosis of cells was triggered by endoplasmic reticulum stress (ERS) and the PI3K/Akt-mediated mitochondrial pathway collaboratively. Besides, the utilization of PI3K/Akt inhibitors and p53 inhibitors further proves the above argument and C8-induced cycle arrest of A549 cells is majorly regulated by p53. C8 induced the accumulation of ROS contents involved in mitochondrial damage. The proliferation of A549 cells was inhibited after treatment with the compound, which induced apoptosis and cycle arrest of cells. It is suggested that C8(dithiolation indolizine) is a potential candidate compound against non-small cell lung cancer.