A mangrove is a unique ecosystem with abundant resources, in which fungi are an indispensable microbial part. Numerous mangrove fungi-derived secondary metabolites are considerable sources of novel bioactive substances, such as polyketides, terpenoids, alkaloids, peptides, etc., which arouse people’s interest in the search for potential natural anti-tumor drugs. This review includes a total of 44 research publications that described 110 secondary metabolites that were all shown to be anti-tumor from 39 mangrove fungal strains belonging to 18 genera that were acquired from the South China Sea between 2016 and 2022. To identify more potential medications for clinical tumor therapy, their sources, unique structures, and cytotoxicity qualities were compiled. This review could serve as a crucial resource for the research status of mangrove fungal-derived natural products deserving of further development.

Purpose The aim of this study was to investigate the function and regulatory mechanism of Interleukin-6 (IL-6) in pituitary-derived folliculostellate (PDFS) cells and to explore the mechanism of metformin against PDFS cells growth through IL-6. Methods Immunohistochemical staining was conducted on clinical samples from non-functioning pituitary adenomas (NFPA) patients and normal individuals to assess IL-6 and Programmed Death-Ligand 1(PD-L1) expression. PDFS cells were treated with IL-6 to evaluate their effects on cell viability, proliferation, and migration through various assays. Similar assays were performed to assess the counteractive effects of metformin, focusing on the IL-6/ERK pathway and PD-L1 expression. Western blot analysis was utilized to examine apoptosis-related proteins, and Annexin V-FITC/PI double staining was used to detect cell apoptosis. It also involves assessing the effects of metformin treatment on tumor IL-6 and PD-L1 expression, tumor size, and potential toxic side effects in PDFS xenograft mice. Results Clinical samples showed increased IL-6 and PD-L1 expression in NFPA compared to normal pituitary tissues. IL-6 treatment significantly enhanced PDFS cell viability(Increased by 46% within 48 h), proliferation(Increased by 24% within 48 h), and migration(Increased by 19% within 48 h). Metformin treatment resulted in the downregulation of IL-6 expression and mitigated IL-6-induced effects on PDFS cells. Additionally, metformin-induced apoptosis and reduced tumor size in xenograft nude mice without observable toxic side effects. Conclusion Metformin downregulates the expression of IL-6 in PDFS cells, inhibits the activation of the ERK pathway, thereby suppressing cell proliferation and PD-L1 expression, and induces cell apoptosis.