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The enhanced inhibitory effect of paclitaxel (PTX) combined with hypericin (HY) on B16-F10 cells may be realized through the ROS-related cytochrome c release pathway. The apoptotic characteristics of the B16-F10 cells, such as DNA fragmentation, chromatin condensation, and apoptotic body formation, were all enhanced in the combined treatment group. Further investigation showed that the combination of paclitaxel and HY could increase the level of mitochondrial damage and the concentration of cytochrome c, causing the expression of caspase-3 and the cleavage of PARP.1. Compared with paclitaxel or HY alone, the level of reactive oxygen species (ROS) increased significantly, while glutathione reductase (GR) activity and intracellular glutathione (GSH) levels decreased significantly in the combination group.

Objectives The combination of gemcitabine (Gem) and hypericin (HY) enhances the apoptosis of Capan-2 cells, providing a promising option for the treatment of pancreatic cancer. Our study further explored the cytotoxic mechanism of HY combined with chemotherapy drugs on pancreatic cancer. Methods The proliferation rate of the cells assayed with the MTT method. The ROS (reactive oxygen species) levels of each treatment were evaluated by DCFH-DA oxidisation methods. The activity of glutathione reductase and the levels of reduced glutathione (GSH) and oxidised glutathione (GSSG) were assessed using assay kits. The expression levels of apoptosis-related proteins were analysed by western blotting. Key findings The activity of glucose-6-phosphate dehydrogenase (G6PDH), a key enzyme of the pentose phosphate pathway, significantly decreased in Gem + HY groups, however, the ROS level enhanced accompanying with GSH depleting, mitochondrial membrane depolarisation and cytochrome C release. Gem + HY inhibits the expression of Bcl-2 but stimulates Bax level, triggering caspase activation and PARP cleavage and thus promoted apoptosis of Capan-2 cells. Conclusions We demonstrated that Gem combined HY-PDT could inhibit the proliferation of Capan-2 cells and induce cell apoptosis. HY-PDT combined with Gem had a great potential on pancreatic cancer treatment clinically.

As part of our program to discover new bioactive agents from endophytic fungi, three new indole alkaloids (1–2, 4) along with twelve known compounds were isolated from an inset derived endophytic strain Aspergillus lentulus. Their structures were determined by comprehensive spectroscopic analyses of 1D/2D NMR and HR-ESI-MS data. The absolute configurations were confirmed by ECD calculation using Time-dependent Density functional theory (TD-DFT) at the B3LYP/6–31 + g (d, p) level and Rh2(OCOCF3)4-induced ECD experiments. Compounds 2, 4, 5, 13 and 15 exhibited moderate cytotoxic effects on A549 cell line with IC50 in the range of 17.92–48.29 μM. Compounds 1, 2 and 13–15 displayed the anti-bacterial activity against Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola with MIC values ranging from 25 to 100 μg/mL.

Emodin is a widely distributed anthraquinone derivative with a variety of biological activities, one that can be efficiently produced by marine-derived fungus Aspergillus favipes HN4-13. However, its relatively low fermentation yield limits further development and pharmaceutical research work. In this study, Plaekett–Burman design and central composite design were adopted to optimize the fermentation conditions of A. favipes HN4-13. Optimal fermentation conditions in a 250-mL Erlenmeyer flask with 50 mL of medium were 59.3 g/L soluble starch, 10 g/L yeast extract paste, 30 g/L seawater salt, 1.04 g/L KH2PO4, 0.05 g/L MgSO4·7H2O, 0.01 g/L FeSO4·7H2O, seed culture 24 h, pH 5, inoculum size 18%, culture temperature 32 °C, and shaking at 160 rpm/min for 7 days. The production of emodin could achieve 132.40 ± 3.09 mg/L, with no significant difference from the predicted value (132.47 mg/L). Furthermore, KH2PO4 supplementation strategy was employed to regulate the mycelial morphology, upregulate the transcriptional level of biosynthesis gene cluster, and enhance emodin production (185.56 ± 4.39 mg/L).

Ginseng saponins 20( S )-ginsenoside Rg 2 extracted from cultured Panax notoginseng cells in a fermenter show a protection effect on human umbilical cord vein endothelial cells (VEC-304) from H 2 O 2 -induced cell apoptosis. When 50 μg/ml 20( S )-ginsenoside Rg 2 was present in the culture medium for 8 h, the H 2 O 2 -damaged VEC-304 cells acquired about 11-fold ( p p 2 has a strong ability in scavenging intracellular ROS induced by H 2 O 2 .

Reactive oxygen species are believed to play a role in the development of several diseases including vascular diseases and the aging process. It is reported that increased reactive oxygen species were implicated as an important mechanism that contributes to endothelial dysfunction. So, human umbilical cord vein endothelial cells were used to study the antioxidative effect of L-ascorbic acid and its derivative. The study indicated that L-ascorbic acid as a traditional antioxidant was instable and could protect the cells against hydrogen peroxide induced cytotoxicity as its concentration below 50 microg/ml, but hardly could protect the cells against tert-butyl hydroperoxide induced cytotoxicity. Ascorbic acid-2-o-phosphate-6-o-palmitate could effectively protect the cells against hydrogen peroxide and tert-butyl hydroperoxide induced cytotoxicity, and exhibited no cytotoxicity within the tested concentration range. The study indicated that ascorbic acid-2-o-phosphate-6-o-palmitate could not only significantly reduce the intracellular reactive oxygen species level in 3 h culture, but also increase the cell viability in 15 h culture. In addition, ascorbic acid-2-o-phosphate-6-o-palmitate could keep stable in RPMI-1640 medium and water for 4 days, permeate the cell membrane, which in turn may scavenge the intracellular reactive oxygen species, increase the cell viability and the plasminogen activators'activity. All the above results suggested that addition of some hydrophobic groups to the traditional antioxidants could form novel compounds with better properties.