Dihydroartemisinin elicits immunogenic death through ferroptosis-triggered ER stress and DNA damage for lung cancer immunotherapy.

BACKGROUND: The immunosuppressive microenvironment of lung cancer serves as an important endogenous contributor to treatment failure. The present study aimed to demonstrate the promotive effect of DHA on immunogenic cell death (ICD) in lung cancer as well as the mechanism. METHODS: The lewis lung cancer cells (LLC), A549 cells and LLC-bearing mice were applied as the lung cancer model. The apoptosis, ferroptosis assay, western blotting, immunofluorescent staining, qPCR, comet assay, flow cytometry, confocal microscopy, transmission electron microscopy and immunohistochemistry were conducted to analyze the functions and the underlying mechanism. RESULTS: An increased apoptosis rate and immunogenicity were detected in DHA-treated LLC and tumor grafts. Further findings showed DHA caused lipid peroxide (LPO) accumulation, thereby initiating ferroptosis. DHA stimulated cellular endoplasmic reticulum (ER) stress and DNA damage simultaneously. However, the ER stress and DNA damage induced by DHA could be abolished by ferroptosis inhibitors, whose immunogenicity enhancement was synchronously attenuated. In contrast, the addition of exogenous iron ions further improved the immunogenicity induced by DHA accompanied by enhanced ER stress and DNA damage. The enhanced immunogenicity could be abated by ER stress and DNA damage inhibitors as well. Finally, DHA activated immunocytes and exhibited excellent anti-cancer efficacy in LLC-bearing mice. CONCLUSIONS: In summary, the current study demonstrates that DHA triggers ferroptosis, facilitating the ICD of lung cancer thereupon. This work reveals for the first time the effect and underlying mechanism by which DHA induces ICD of cancer cells, providing novel insights into the regulation of the immune microenvironment for cancer immunotherapy by Chinese medicine phytopharmaceuticals.

A new modified pterocarpan glycoside from Sophora flavescens.

Sophora flavescens is a widely used traditional Chinese herbal medicine. In this work, a new pterocarpan glycoside, kurarinol C (1) together with six known compounds, sophoracarpan A (2), trifohrhizin-6'-monoacetate (3), trifohrhizin (4), maackiain (5), (6S,6aS,11aR）-6α-methoxy-pterocarpin (6), L-maackiain (7) were isolated from the roots of S. flavescens. Among them, compounds 2 and 6 were discovered from S. flavescens for the first time. Their chemical structures were elucidated on the basis of extensive NMR and MS analyses. Furthermore, the antioxidant activities of these compounds were evaluated by the ABTS and DPPH free radical scavenging assay. Three compounds (5, 6, 7) exhibited stronger antioxidant capacity against the ABTS enzyme at 20 µg/mL (scavenging rates > 55%).

Systematic elucidation of the bioactive alkaloids and potential mechanism from Sophora flavescens for the treatment of eczema via network pharmacology.

ETHNOPHARMACOLOGY RELEVANCE: Sophora flavescens is a frequently used traditional Chinese medicine (TCM) for the treatment of skin disorders, diarrhea, vaginal itching and inflammatory diseases. In particular, the root of S. flavescens combination with other herbs mainly treat eczema ailment in the clinical applications. However, a holistic network pharmacology approach to understanding the mechanism by which alkaloids in S. flavescens treat eczema has not been pursued. AIM OF THE STUDY: To examine the network pharmacological potential effect of S. flavescens on eczema, we studied the alkaloids, performed protein targets prediction and investigated interacting signal pathways. Furthermore, animal experiment was carried out to evaluate its efficacy and real-time quantitative polymerase chain reactions (RT-qPCR) analysis was explored the mechanism of action. MATERIALS AND METHODS: The detail information on alkaloids from S. flavescens were obtained from a handful of public databases on the basis of oral bioavailability (OB ≥ 30%) and drug-likeness (DL ≥ 0.18). Then, correlations between compounds and protein targets were linked using the STRING database, and targets associated with eczema were gathered by the GeneCards database. Human genes were identified and subjected to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Ontology (GO) functional enrichment analysis. Particularly, matrine, the crucial alkaloid from S. flavescens, was estimated using a 2,4-dinitrochlorobenzene (DNCB)-induced eczema Kunming (KM) mice model, administered (50 mg/kg and 10 mg/kg) to mice for 22 days. On the last day, the activities of serum tumor necrosis factor α (TNF-α), interleukin-4 (IL-4) and histopathologic examinations were determined. For further to elucidate the mechanisms, the mRNA levels of TNF-α, STAT3, TP53, AKT1, IL-6, JUN and EGFR in dorsal skin tissues were also tested. RESULTS: Network analysis collected and identified 35 alkaloids from S. flavescens. Among them, in total 10 dominating alkaloids, including matrine, oxymatrine, sophoridine, sophocarpine, oxysophocarpine, allomatrine, sophoramine, anagyrine, cytisine and N-methylcytisine. And 71 related targets were provided of alkaloids for the treatment of eczema from S. flavescens. Furthermore, matrine dose-dependently (50 or 10 mg/kg, 22 days, apply to dorsal skin) remarkable decreased the serum levels of TNF-α and IL-4, and significantly alleviated the skin lesions. The effects of 50 mg/kg of matrine were almost identical to those of 200 mg/kg of the positive drug dexamethasone (DXM). The further RT-qPCR analyses could reveal that matrine down-regulate TNF-α, STAT3 and TP53 at transcriptional level in dorsal skin tissues. CONCLUSION: Pharmacological network analysis can utilize to illuminate the pharmacodynamic substances and the potential molecular mechanism of S. flavescens for treating eczema. Matrine, as the crucial alkaloid from S. flavescens, could be a promising drug candidate for the treatment of eczema ailment.

Dihydroartemisinin remodels macrophage into an M1 phenotype via ferroptosis-mediated DNA damage.

Lung cancer recruits tumor-associated macrophages (TAMs) massively, whose predominantly pro-tumor M2 phenotype leads to immunosuppression. Dihydroartemisinin (DHA) has been proven to remodel TAM into an anti-tumor M1 phenotype at certain concentrations in the present study, which was hypothesized to facilitate anti-lung cancer immunotherapy. However, how DHA remodels the TAM phenotype has not yet been uncovered. Our previous work revealed that DHA could trigger ferroptosis in lung cancer cells, which may also be observed in TAM thereupon. Sequentially, in the current study, DHA was found to remodel TAM into the M1 phenotype in vitro and in vivo. Simultaneously, DHA was observed to trigger ferroptosis in TAM and cause the DNA damage response and NF-κB activation. Conversely, the DHA-induced DNA damage response and NF-κB activation in TAM were attenuated after the inhibition of ferroptosis in TAM using an inhibitor of ferroptosis. Importantly, a ferroptosis inhibitor could also abolish the DHA-induced phenotypic remodeling of TAM toward the M1 phenotype. In a nutshell, this work demonstrates that DHA-triggered ferroptosis of TAM results in DNA damage, which could activate downstream NF-κB to remodel TAM into an M1 phenotype, providing a novel strategy for anti-lung cancer immunotherapy. This study offers a novel strategy and theoretical basis for the use of traditional Chinese medicine monomers to regulate the anti-tumor immune response, as well as a new therapeutic target for TAM phenotype remodeling.

A nanoreactor boosts chemodynamic therapy and ferroptosis for synergistic cancer therapy using molecular amplifier dihydroartemisinin.

BACKGROUND: Chemodynamic therapy (CDT) relying on intracellular iron ions and H2O2 is a promising therapeutic strategy due to its tumor selectivity, which is limited by the not enough metal ions or H2O2 supply of tumor microenvironment. Herein, we presented an efficient CDT strategy based on Chinese herbal monomer-dihydroartemisinin (DHA) as a substitute for the H2O2 and recruiter of iron ions to amplify greatly the reactive oxygen species (ROS) generation for synergetic CDT-ferroptosis therapy. RESULTS: The DHA@MIL-101 nanoreactor was prepared and characterized firstly. This nanoreactor degraded under the acid tumor microenvironment, thereby releasing DHA and iron ions. Subsequent experiments demonstrated DHA@MIL-101 significantly increased intracellular iron ions through collapsed nanoreactor and recruitment effect of DHA, further generating ROS thereupon. Meanwhile, ROS production introduced ferroptosis by depleting glutathione (GSH), inactivating glutathione peroxidase 4 (GPX4), leading to lipid peroxide (LPO) accumulation. Furthermore, DHA also acted as an efficient ferroptosis molecular amplifier by direct inhibiting GPX4. The resulting ROS and LPO caused DNA and mitochondria damage to induce apoptosis of malignant cells. Finally, in vivo outcomes evidenced that DHA@MIL-101 nanoreactor exhibited prominent anti-cancer efficacy with minimal systemic toxicity. CONCLUSION: In summary, DHA@MIL-101 nanoreactor boosts CDT and ferroptosis for synergistic cancer therapy by molecular amplifier DHA. This work provides a novel and effective approach for synergistic CDT-ferroptosis with Chinese herbal monomer-DHA and Nanomedicine.

Spectrum-Efficacy Relationships between GC-MS Fingerprints of Essential Oil from Valerianae Jatamansi Rhizoma et Radix and the Efficacy of Inhibiting Microglial Activation.

The bioactive ingredients of essential oil from Valerianae Jatamansi Rhizoma et Radix (the Rhizome et Radix from Valerianae Jatamansi Jones) (EOVJRR) on the efficacy of inhibiting microglial activation were investigated with the approach of spectrum-efficacy relationship. Fourteen batches of Valerianae Jatamansi Rhizoma et Radix were extracted and analyzed by gas chromatography-mass spectrometry (GC-MS), and their activities in the efficacy of inhibiting microglial activation were assayed by measuring the inflammatory responses induced by lipopolysaccharide (LPS) in microglia cells from mice. The spectrum-efficacy relationships between fingerprints and the efficacy of inhibiting microglial activation of EOVJRR were established by grey relational analysis (GRA). Twenty common peaks were obtained from the GC-MS fingerprints of EOVJRR. P12 (vetivenol), P1 (bornyl acetate), P5 (seychellene), and P3 (ß-elemene) indicated inhibition on microglia activation together, according to the spectrum-efficacy relationships. The current results established a general model for the spectrum-efficacy relationships of EOVJRR by GC-MS and the efficacy of inhibiting microglial activation, which could be applied to identify the bioactive ingredient and control the quality of herbs.

Protective Effect of Simplicillium sp. Ethyl Acetate Extract against High Glucose-Induced Oxidative Stress in HUVECs.

This study aimed at investigating the cytoprotective effect of an ethyl acetate extract of insect fungi against high glucose- (HG-) induced oxidative damage in human umbilical vein endothelial cells (HUVECs). An insect fungus strain termed CH180672 (CH) was found for protecting HUVECs from HG-induced damage. In this study, CH was identified as Simplicillium sp. based on a phylogenetic analysis of ITS-rDNA sequences. Ethyl acetate extract (EtOAc) of this strain (CH) was subjected to the following experiments. Cell viability was examined with the MTT method. To evaluate the protection of CH, intracellular reactive oxygen species (ROS), malondialdehyde (MDA) levels, and the activities of antioxidant enzymes were measured and the expression of oxidation-associated proteins was assessed. In the current study, it has been found that CH can increase the survival rate of HUVECs induced by HG. Additionally, we found that HG-induced nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) signal decreased and increased the intracellular ROS and MDA generation in HUVECs. However, CH treatment strongly promoted the translocation of Nrf2 and its transregulation on HO-1 and ultimately inhibited the high level of ROS and MDA induced by HG. The regulatory ability of CH was similar to Nrf2 agonist bardoxolone, while the effect was abolished by ML385, suggesting that Nrf2 mediated the inhibition of CH on HG-induced oxidative stress in HUVECs. Taken together, CH can improve HG-induced oxidative damage of HUVECs, and its mechanism may be related to the regulation of the Nrf2/HO-1 pathway.

Two new N-acetyldopamine tetrapolymers from periostracum Cicadae.

Two new N-acetyldopamine tetrapolymers, cicadamide A (1) and cicadamide B (2), were isolated from periostracum Cicadae, and their structures were elucidated as 3-acetylamino-7-(3″-acetylamino-7″-(N-acetyl-2‴-aminoethyl)-1″,4″-benzodioxan-2″-yl)-2-(2'-(3″″,4″″-dihydroxyphenyl)-3'-acetylamino-1',4'-benzodioxan-7'-yl)-1,4-benzodioxane (1) and 3-acetylamino-7-(3″-acetylamino-6″-(N-acetyl-2‴-aminoethyl)-1″,4″-benzodioxan-2″-yl)-2-(2'-(3″″,4″″-dihydroxyphenyl)-3'-acetylamino-1',4'-benzodioxan-7'-yl)-1,4-benzodioxane (2), by the combined analysis of 1D NMR and 2D NMR, and mass spectrometry. Pharmacological investigation on two compounds obtained in this study showed that part of them had anti-inflammatory activities.