Prebiotic-like cyclodextrin assisted silybin on NAFLD through restoring liver and gut homeostasis.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease with no currently approved treatment. The natural compound silybin (SLN) has versatile hepatoprotective efficacy with negligible adverse effects; however, poor absorption limits its clinical applications. Gut microbiota has been proposed to play a crucial role in the pathophysiology of NAFLD and targeted for disease control. Cyclodextrins, the cyclic oligosaccharides, were documented to have various health benefits with potential prebiotic properties. This study aimed to develop a silybin-2-hydroxypropyl-ß-cyclodextrin inclusion (SHßCD) to improve the therapeutic efficacy of SLN and elucidate the mechanisms of improvement. The results showed that SLN formed a 1:1 stoichiometric inclusion complex with HP-ß-CD. The solubility of SLN was increased by generating SHßCD, resulting in improved drug permeability and bioavailability. In high-fat diet (HFD)-fed hamsters, SHßCD modulated gut health by restoring the gut microbiota and intestinal integrity. SHßCD showed superior anti-lipid accumulation, antioxidant, and anti-inflammatory effects compared with SLN alone. Transcriptome analysis in the liver tissue implied that the improved inflammation and/or energy homeostasis was the potential mechanism. Therefore, SHßCD may be a promising alternative for the treatment of NAFLD, attributing to the dual functions of HßCD on drug absorption and gut microbial homeostasis.

G226, a new epipolythiodioxopiperazine derivative, triggers DNA damage and apoptosis in human cancer cells in vitro via ROS generation.

AIM: G226 is a novel derivative of epipolythiodioxopiperazines with potent inhibitory activity against cancer cells. Here, we sought to identify potential targets involved in the anti-cancer activity of G226. METHODS: Cell proliferation assay was conducted in a panel of 12 human cancer cell lines. The activities of topoisomerase I (Topo I) and Topo II were studied using supercoiled pBR322 DNA relaxation and kDNA decatenation assays. ROS production was assessed with probes DCFH-DA and H&E. Western blot analysis and flow cytometry were used to examine DNA damage, apoptosis and cell cycle changes. RESULTS: G226 displayed potent cytotoxicity in the 12 human cancer cell lines with a mean IC50 value of 92.7 nmol/L. This compound (1-100 µmol/L) selectively inhibited the activity of Topo II, and elevated the expression of phosphorylated-H2AX in a dose-dependent manner. In Topo II-deficient HL60/MX2 cells, however, G226-induced DNA damage, apoptosis and cytotoxicity were only partially reduced, suggesting that Topo II was not essential for the anti-tumor effects of G226. Furthermore, G226 (0.125-2 µmol/L) dose-dependently elevated the intracellular levels of H2O2 and in the cancer cells, and pretreatment with GSH, NAC or DTT not only blocked G226-induced intracellular accumulation of ROS, but also abrogated G226-mediated phosphorylation of H2AX, apoptosis and cytotoxicity. CONCLUSION: G226-mediated ROS production contributes to the anti-cancer activity of this compound.

G226, a novel epipolythiodioxopiperazine derivative, induces autophagy and caspase-dependent apoptosis in human breast cancer cells in vitro.

AIM: To investigate the effects of G226, a novel epipolythiodioxopiperazine derivative, on human breast cancer cells in vitro, and to explore its anticancer mechanisms. METHODS: A panel of human breast cancer cell lines (MDA-MB-231, MDA-MB-468, MCF-7, ZR-75-30, BT474, BT549, SK-BR-3, T47D and HBL100) was examined. Cell proliferation was measured using sulforhodamine B assay, and cell apoptosis was detected with flow cytometry and caspase activity assay. Western blotting, immunofluorescence and targeted gene knockdowns were used to study autophagy in the cells. RESULTS: G226 suppressed proliferation of the 9 breast cancer cell lines with a mean IC50 value of 48.5 nmol/L (the mean IC50 value of adriamycin, a reference compound, was 170.6 nmol/L). G226 induced dose-dependent apoptosis of MDA-MB-231 and MCF-7 cells, accompanied by markedly increased activities of caspase-8 and caspase-3/7, which were abolished by caspase inhibitors zVAD or zIETD. G226 also induced mitochondrial outer membrane permeabilization, resulted in the caspase-9 activation. Moreover, G226 dose-dependently enhanced the autophagy marker LC3-II and autophagy substrate p62 accumulation in the cells, which were co-localized with caspase-8. Silencing of p62 or LC3 partially diminished caspase-8 and subsequent caspase-3 activation. LC3 silencing partially reversed G226-induced apoptosis, but p62 silencing elicited a subtle effect on G226-induced apoptosis. CONCLUSION: The novel epipolythiodioxopiperazine derivative G226 exerts potent anticancer action against human breast cancer cells in vitro, via triggering autophagy and caspase-dependent apoptosis.

Cyclohexanone derivatives with cytotoxicity from the fungus Penicillium commune.

Four new cyclohexanone derivatives (2-5) and one known analog, (-)-Palitantin (1) were isolated from the EtOAc extract of Penicillium commune, a fungal strain of low-temperature habitats. The structures of 2-5 were determined on the basis of extensive spectroscopic analysis. Furthermore, the absolute configuration of 2 was assigned by electronic circular dichroism (ECD) calculations, whereas that 3-5 were deduced via the CD data. Cytotoxicities of 2-5 against five human carcinoma cell lines (Hela, A549, MCF7, HCT116, T24) were evaluated.