Five new terpenoids from Viburnum odoratissimum var. sessiliflorum / 中国天然药物

Five new terpenoids, including two vibsane-type diterpenoids (1, 2) and three iridoid allosides (3-5), together with eight known ones, were isolated from the leaves and twigs of Viburnum odoratissimum var.sessiliflorum. Their planar structures and relative configurations were determined by spectroscopic methods, especially 2D NMR techniques. The sugar moieties of the iridoids were confirmed as β-D-allose by GC analysis after acid hydrolysis and acetylation. The absolute configurations of neovibsanin Q (1) and dehydrovibsanol B (2) were determined by quantum chemical calculation of their theoretical electronic circular dichroism (ECD) spectra and Rh2(OCOCF3)4-induced ECD analysis. The anti-inflammatory activities of compounds 1, 3, 4, and 5 were evaluated using an LPS-induced RAW264.7 cell model. Compounds 3suppressed the release of NO in a dose-dependent manner, with an IC50 value of 55.64 μmol·L-1. The cytotoxicities of compounds 1-5 on HCT-116 cells were assessed and the results showed that compounds 2 and 3 exhibited moderate inhibitory activities with IC50 values of 13.8 and 12.3 μmol·L-1, respectively.

Aristolochic acids exposure was not the main cause of liver tumorigenesis in adulthood

Aristolochic acids (AAs) have long been considered as a potent carcinogen due to its nephrotoxicity. Aristolochic acid I (AAI) reacts with DNA to form covalent aristolactam (AL)-DNA adducts, leading to subsequent A to T transversion mutation, commonly referred as AA mutational signature. Previous research inferred that AAs were widely implicated in liver cancer throughout Asia. In this study, we explored whether AAs exposure was the main cause of liver cancer in the context of HBV infection in mainland China. Totally 1256 liver cancer samples were randomly retrieved from 3 medical centers and a refined bioanalytical method was used to detect AAI-DNA adducts. 5.10% of these samples could be identified as AAI positive exposure. Whole genome sequencing suggested 8.41% of 107 liver cancer patients exhibited the dominant AA mutational signature, indicating a relatively low overall AAI exposure rate. In animal models, long-term administration of AAI barely increased liver tumorigenesis in adult mice, opposite from its tumor-inducing role when subjected to infant mice. Furthermore, AAI induced dose-dependent accumulation of AA-DNA adduct in target organs in adult mice, with the most detected in kidney instead of liver. Taken together, our data indicate that AA exposure was not the major threat of liver cancer in adulthood.