Brunonianines D-F, three new C19-diterpenoid alkaloids from the Delphinium brunonianum, with therapeutic effect on ovarian cancer in vitro and in vivo.

The current standard treatment for ovarian cancer consists of surgery to reduce the size of the tumor, followed by treatment with chemotherapeutic drugs, which have major side effects. Therefore, finding a new natural product drug with fewer side effects is a strategy. Delphinium brunonianum (D. brunonianum) is a traditional Tibetan medicine, mainly from southern Tibet, China, whereas the chemical constituents in this plant remain elusive. The major metabolites in the dichloromethane fraction of D. brunonianum were analyzed and purified by HPLC and various column chromatography techniques. Nine diterpenoid alkaloids (1-9) and one amide alkaloid (10) were isolated from D. brunonianum, including three novel C19-type diterpenoid alkaloids (Brunonianines D-F) (1-3). Their structures were elucidated by 1D/2D NMR, HR-ESI-MS and single-crystal X-ray diffraction analyses. All compounds were evaluated for toxicity in four tumor cell lines. Most of the compounds exhibited potent inhibitory effects on Skov-3 cell lines, with IC50 values ranging from 2.57 to 8.05 µM. The western blotting experiment was used to further analyze the expression levels of molecules in the Bax/Bcl-2/Caspase-3 signaling pathway for compound 1. Molecular docking was performed to predict the binding modes of Brunonianine D with target proteins. In vivo experiments were also performed and evaluated in real time by monitoring the size of the Skov-3 tumor. Additionally, tumor H&E staining and the TUNEL assay used to evaluate anti-tumor effects.

Structures and Tumor Cell Lines Proliferation Activities of Triterpenes Isolated from Astilbe grandis.

A total of seven compounds, including four triterpene acids and three triterpene lactones, were isolated from the ethanolic extract of the roots of Astilbe grandis Stapf ex Wils. Two of the triterpene lactones (1-2) were never reported before and compounds 3-5 were isolated for the first time from the plant. The structures of these compounds were all identified by spectroscopic analysis. Compounds 1-2 were analyzed by 2D NMR and their absolute configurations were determined using experimental CD in comparison with calculated ECD values. The structure of compound 1 was also further confirmed by single crystal X-ray diffraction analysis. The cytotoxicity of compounds 1-7 on A549, Caco-2, H460 and Skov-3 tumor cells were all evaluated using CCK-8. They all exhibited positive inhibitory effects on Caco-2 tumor cells with IC50 less than10 µM, while the inhibitory effects on H460 tumor cells were more moderate. Unfortunately, they displayed little apparent cytotoxicity to the other two types of cells.

Triterpenoid acids characterized by the oxidation of the C-27-methy from the roots of Astilbe grandis Stapf ex Wils.

Two unprecedented oleane-type triterpenes (5-6) were isolated from the roots of Astilbe grandis Stapf ex Wils, along with four known triterpenes (1-4), all of which were separated from this plant for the first time. The structures of these compounds were elucidated on the basis of spectroscopic analyses especially analysis of 2D NMR data, and the absolute configurations of 5 and 6 were determined by comparison of experimental and calculated ECD data. The structure of 5 was further confirmed by single crystal X-ray diffraction analysis. Compounds 1-6 were evaluated for their in vitro anti-tumor activities on A549, Caco-2, H460 and Skov-3 cells lines. All of the compounds exhibited obvious anti-Caco-2 activity with IC50 values ranging from 1.86 to 4.94 µM, among of them compound 6 also had the apparent effect on A549 cells. In addition, compounds 1, 4 and 5 were evaluated relatively strong inhibitory activity against H460 cells' growth with IC50 values of 5.13 µM, 5.65 µM and 8.85 µM respectively.

Dual-responsive and NIR-driven free radical nanoamplifier with glutathione depletion for enhanced tumor-specific photothermal/thermodynamic/chemodynamic synergistic Therapy.

The efficacy of free radical-based therapeutic strategies is severely hindered by nonspecific accumulation, premature release and glutathione (GSH) scavenging effects. Herein, a tumor microenvironment-responsive MPDA/AIPH@Cu-TA@HA (abbreviated as MACTH) nanoplatform was constructed by coating Cu2+ and tannic acid (TA) on the surface of azo initiator (AIPH)-loaded mesoporous polydopamine (MPDA) nanoparticles and further modifying them with hyaluronic acid (HA) to achieve tumor-specific photothermal/thermodynamic/chemodynamic synergistic therapy (PTT/TDT/CDT). Once accumulated and internalized into cancer cells through CD44 receptor-mediated active targeting and endocytosis, the HA shell of MACTH would be preliminarily degraded by hyaluronidase (HAase) to expose the Cu-TA metal-phenolic networks, which would further dissociate in response to an acidic lysosomal environment, leading to HAase/pH dual-responsive release of Cu2+ and AIPH. On the one hand, the released Cu2+ could deplete the overexpressed GSH via redox reactions and produce Cu+, which in turn catalyzes endogenous H2O2 into highly cytotoxic hydroxyl radicals (˙OH) for CDT. On the other hand, the local hyperthermia generated by MACTH under 808 nm laser irradiation could not only augment CDT efficacy through accelerating the Cu+-mediated Fenton-like reaction, but also trigger the decomposition of AIPH to produce biotoxic alkyl radicals (˙R) for TDT. The consumption of GSH and accumulation of oxygen-independent free radicals (˙OH/˙R) synergistically amplified intracellular oxidative stress, resulting in substantial apoptotic cell death and significant tumor growth inhibition. Collectively, this study provides a promising paradigm for customizing stimuli-responsive free radical-based nanoplatforms to achieve accurate and efficacious cancer treatment.

Root age-related response of fine root respiration of Chinese fir seedlings to soil warming.

The variation in fine root respiration with root age provides insight into root adaptation to climate warming, but the mechanism is poorly understood. In this study, we investigated the respiratory response of fine roots (<1 mm and 1-2 mm) of different ages (2-, 4- and 6-month old) of Chinese fir (Cunninghamia lanceolata (Lamb.)) seedlings to soil warming (4 °C above the control using cable heating). Fine roots were excised to measure the specific respiration rate at a reference temperature of 20 °C (SRR20), and root morphological and chemical traits were measured. Soil warming significantly increased SRR20 by 40% compared with the control, potentially indicating limited acclimation on a short time scale (6 months). However, soil warming increased SRR20 significantly in 2-month-old roots (by 72%) compared with 4- and 6-month-old roots, leading to a steeper decline in SRR20 with root age. This result suggests possible increased nutrient uptake efficiency in young fine roots under warmer temperatures. Soil warming significantly increased specific root length (SRL) but not root tissue nitrogen concentration (RTN). The variation in SRR20 between warming treatments, but not across root ages, was predicted by SRL and RTN individually or together. Our findings conclusively indicate that soil warming increased the respiration cost of young fine roots, which was predicted by adjusting for SRL and RTN, indicating that Chinese fir may adopt a faster fine root turnover strategy to enhance nutrient uptake and soil exploitation under warmer temperatures. Future studies should simultaneously investigate age-related root respiration and nutrient uptake in warming experiments to better understand the effects of warming on root metabolic activity.