Although adequate intake of manganese (Mn) is essential to humans, Mn in excess is neurotoxic. Exposure to extremely high doses of Mn results in "manganism", a condition that exhibits Parkinson-like symptoms. However, the mechanisms underlying its neurotoxic effects in Mn-induced parkinsonism pathogenesis are unclear. In this study, 8-week-old male C57BL/6 J mice were injected intraperitoneally with saline and 50 mg/kg MnCl₂ respectively once daily for 14 days to produce an acute Mn neurotoxicity model. Accumulation of Mn in the midbrain, motor dysfunction and loss of dopaminergic neurons in the substantia nigra evidenced Mn neurotoxicity. Untargeted lipidomic analysis demonstrated that Mn overexposure altered lipidome profiles. A significant modulation of 12 lipid subclasses belonging to 5 different categories were found in the midbrain and among the most abundant lipids were sphingolipids, glycerophospholipids, and glycerides. The levels of sphingomyelin (SM) were significantly decreased after Mn treatment. The expression of SM biosynthesis genes was decreased dramatically while sphingomyelinase was up-regulated. In addition, we observed oxidative stress in both the midbrain of mice and MN9D cells, indicated by the increase of MDA level, the decrease of reduced GSH level and the inhibition of SOD and GPx enzyme activities. There was a correlation between these changes and motor dysfunctions. Overall, our study is the first to use lipidomics techniques to explore the pathogenesis of Mn-induced parkinsonism in C57BL/6 J mice. Mn induced molecular events in the midbrain, such as lipid metabolism disorders, oxidative stress and dopaminergic neurons injury, may mechanistically play important roles in the pathogenesis of Parkinson-like symptoms. Moreover, these findings emphasize the necessity for reducing the health risk of environmental neurotoxic pollutants in relation to parkinsonism.

Worldwide, 19.3 million new cancer cases and almost 10.0 million cancer deaths occur each year. Recently, much attention has been paid to the ocean, the largest biosphere of the earth that harbors a great many different organisms and natural products, to identify novel drugs and drug candidates to fight against malignant neoplasms. The marine compounds show potent anticancer activity in vitro and in vivo, and relatively few drugs have been approved by the U.S. Food and Drug Administration for the treatment of metastatic malignant lymphoma, breast cancer, or Hodgkin′s disease. This review provides a summary of the anticancer effects and mechanisms of action of selected marine compounds, including cytarabine, eribulin, marizomib, plitidepsin, trabectedin, zalypsis, adcetris, and OKI-179. The future development of anticancer marine drugs requires innovative biochemical biology approaches and introduction of novel therapeutic targets, as well as efficient isolation and synthesis of marine-derived natural compounds and derivatives.

Liver cancer is one of the most lethal malignancies with an annual death of over 830,000 cases. Although targeted therapeutic drugs have achieved certain clinical efficacy, only sorafenib and lenvatinib are currently marketed as first-line targeted drugs to treat patients with advanced liver cancer. Therefore, developing more drugs are urgently needed. Ferroptosis is an iron-dependent programmed cell death (PCD) distinct from known PCDs including apoptosis, necrosis, and autophagy. Targeting ferroptosis is recognized as a promising potential therapeutic modality for liver cancer. Activating transcription factor 3 (ATF3) is an important ferroptosis inducer and targeting ATF3 offers a potential means to cancer therapy. In the present study, we reported for the first time a sophoridine derivative 6j with promising anti-liver cancer effects in vitro and in vivo. Compound 6j could induce liver cancer cells ferroptosis by promoting the accumulation of intracellular Fe²⁺, reactive oxygen species (ROS), and MDA. Inhibition of ferroptosis by ferrostatin-1 alleviated 6j induced accumulation of Fe²⁺, ROS, and MDA and restored cell viability. Further study revealed that compound 6j upregulated the expression of ATF3 via ER stress and knockdown of ATF3 by RNA interference attenuated 6j induced ferroptosis and cell proliferation inhibition. This study would provide new insights for the design of ferroptosis inducers and the development of anti-liver cancer drugs.