A new semisynthetic 1- O -acetyl-6- O -lauroylbritannilactone induces apoptosis of human laryngocarcinoma cells through p53-dependent pathway

Chronic bisphenol A induced neurotoxicity: Exposure risk, molecular fate within carp and its potential phytoremediation

Bisphenol A (BPA) is an endocrine-disrupting toxicant commonly used in the plastics industry, as a result, it is present in large quantities in the environment. Therefore, current study was designed to assess BPA induced neurotoxicity and molecular fate within common carp (Cyprinus carpio), largely used edible fish. Following 6 weeks exposure to BPA 1/5th of 96 h LC50 (1.31 mg/L), brain exhibited oxidative damage, which was evidenced by compromised antioxidant system (CAT, SOD, GSH) and increased level of biomacromolecule peroxidation (MDA and 8-OHDG). Functional damage to the brain observed in the form of blood-brain barrier disruption (decreased tight junction gene expression) and nerve conduction impairment (reduced acetylcholinesterase activity). Mechanistically, apoptotic cell death indicated by characteristic alteration in key biomarkers (bcl-2, caspase, and p53-related gene family). Whereas, coadministration of powdered PP (pomegranate peel) (8 %) with BPA effectively mitigated the BPA toxicity, as evidenced by the restoration of the above-mentioned bioindicators. Thereby, BPA-induced neurotoxicity could be potentially detoxified by applying PP dietary enrichment.

Research progress on antitumor mechanisms and molecular targets of Inula sesquiterpene lactones

The pharmacological effects of natural product therapy have received sigificant attention, among which terpenoids such as sesquiterpene lactones stand out due to their biological activity and pharmacological potential as anti-tumor drugs. Inula sesquiterpene lactones are a kind of sesquiterpene lactones extracted from Inula species. They have many pharmacological activities such as anti-inflammation, anti-asthma, anti-tumor, neuroprotective and anti-allergic. In recent years, more and more studies have proved that they are important candidate drugs for the treatment of a variety of cancers because of its good anti-tumor activity. In this paper, the structure, structure-activity relationship, antitumor activities, mechanisms and targets of Inula sesquiterpene lactones reported in recent years were reviewed in order to provide clues for the development of novel anticancer drugs.

Involvement of a AS3MT/c-Fos/p53 signaling axis in arsenic-induced tumor in human lung cells

Arsenite methyltransferase (AS3MT) is an enzyme that catalyzes the dimethylation of arsenite (+3 oxidation state). At present, the studies on arsenic carcinogenicity mainly focus on studying the polymorphisms of AS3MT and measuring their catalytic activities. We recently showed that AS3MT was overexpressed in lung cancer patients who had not been exposed to arsenic. However, little is known about the molecular mechanisms of AS3MT in arsenite-induced tumorigenesis. In this study, we showed that AS3MT protein expression was higher in the arsenic-exposed population compared to the unexposed population. AS3MT was also overexpressed in human lung adenocarcinoma (A549) and human bronchial epithelial (16HBE) cells exposed to arsenic (A549: 20-60 μmol/L; 16HBE: 2-6 μmol/L) for 48 h. Furthermore, we investigated the effects of AS3MT on cell proliferation and apoptosis using siRNA. The downregulation of AS3MT inhibited the proliferation and promoted the apoptosis of cells. Mechanistically, AS3MT was found to specifically bind to c-Fos, thereby inhibiting the binding of c-Fos to c-Jun. Additionally, the siRNA-mediated knockdown of AS3MT enhanced the phosphorylation of Ser392 in p53 by upregulating p38 MAPK expression. This led to the activation of p53 signaling and the upregulated expression of downstream targets, such as p21, Fas, PUMA, and Bax. Together, these studies revealed that the inorganic arsenic-mediated upregulation of AS3MT expression directly affected the proliferation and apoptosis of cells, leading to arsenic-induced toxicity or carcinogenicity.

Endogenous reactive oxygen species burst induced and spatiotemporally controlled multiple drug release by traceable nanoparticles for enhancing antitumor efficacy

Reactive oxygen species (ROS) are not only used as a therapeutic reagent in chemodynamic therapy (CDT), to stimulate the release of antineoplastic drugs, they can also be used to achieve a combined effect of CDT and chemotherapy to enhance anticancer effects. Herein, we synthesized a pH-responsive prodrug (PEG2k-NH-N-DOX), ROS-responsive prodrug (PEG2k-S-S-CPT-ROS), organic CDT agents (TPP-PEG2k-LND, TPP-PEG2k-TOS), and T1-enhanced magnetic resonance imaging contrast agents (Gd-DTPA-N16-16), and used them to encapsulate combrestatinA4 (CA4) to prepare traceable pH/ROS dual-responsive multifunctional nanoparticles (TLDCAG NPs) with endogenous ROS burst and spatiotemporally controlled multiple drug release ability. Firstly, TLDCAG NPs were accumulated in the tumor cell microenvironment via an enhanced permeability and retention (EPR) effect. Secondly, CA4 was released and specifically destroyed angiogenesis to facilitate the interaction between the tumor and the remaining TLDCG NPs. After accumulating in tumor cells, the TLDCG NPs could be destroyed under acidic conditions to quickly release doxorubicin (DOX), TPP-PEG2k-LND, and TPP-PEG2k-TOS. Thirdly, TPP-PEG2k-LND and TPP-PEG2k-TOS quickly targeted mitochondria, induced endogenous ROS bursts, reduced the mitochondrial membrane potential, and induced tumor cell apoptosis. Endogenous ROS can not only be used as a therapeutic reagent for CDT, but also can cut off the thioketal bond in PEG2k-S-S-CPT-ROS and release camptothecin (CPT). Finally, TLDCAG NPs were traced by magnetic resonance imaging (MRI). Furthermore, in vitro and vivo results indicate that the TLDCAG NPs have vigorous antitumor activity and negligible systemic toxicity. Therefore, the TLDCAG NPs provide an efficient strategy for enhancing antitumor efficacy.

Arsenite induce neurotoxicity of common carp: Involvement of blood brain barrier, apoptosis and autophagy, and subsequently relieved by zinc (Ⅱ) supplementation

Arsenic pollution is a common threat to aquatic ecosystems. The effects of chronic exposure to arsenite on the brains of aquatic organisms are unknown. This study was designed to evaluate arsenic-induced brain damage in common carp (Cyprinus carpio) and the ameliorating effects of divalent zinc ion (Zn2+) supplementation from the aspects of oxidative stress (OxS), tight junction (TJ), apoptosis and autophagy. After arsenite exposure (2.83 mg/L) for 30 days, oxidative damage to the brain was determined, as indicated by inhibited antioxidants system (catalase-superoxide dismutase system, and glutathione system) and elevated levels of biomacromolecule peroxidation (malondialdehyde and 8-hydroxydeoxyguanosine). Moreover, we also found functional damage to the brain as suggested by injuries to the blood-brain barrier (decreases in tight junction) and nerve conduction (depletion of AChE). Mechanisticly, apoptotic and autophagic cell death were indicated by typical morphologies including karyopyknosis and autophagosome, accompanying by key bio-indicators (Bcl-2, caspase and autophagy related gene family proteins). In contrast, the coadministration of Zn2+ (1 mg/L) with arsenite effectively alleviated this damage as suggested by the recovery of the aforementioned bioindicators. This study provides new insight into the brain toxicity caused by arsenite and suggests the application of zinc preparations in the aquatic pollution of arsenic.

1, 6-O, O-Diacetylbritannilactone from Inula britannica Induces Anti-Tumor Effect on Oral Squamous Cell Carcinoma via miR-1247-3p/LXRα/ABCA1 Signaling

Introduction

Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy affecting the oral cavity and is associated with severe morbidity and high mortality. 1, 6-O, O-Diacetylbritannilactone (OODBL) isolated from the medicinal herb of Inula britannica has various biological activities such as anti-inflammation and anti-cancer. However, the effect of OODBL on OSCC progression remains unclear. Here, we were interested in the function of OODBL in the development of OSCC.

Methods

The effect of OODBL on OSCC progression was analyzed by MTT assays, colony formation assays, transwell assays, apoptosis analysis, cell cycle analysis, and in vivo tumorigenicity analysis. The mechanism investigation was performed by qPCR assays, Western blot analysis, and luciferase reporter gene assays.

Results

We found that OODBL inhibits the proliferation of OSCC cells in vitro. Moreover, the migration and invasion were attenuated by OODBL treatment in the OSCC cells. OODBL arrested cells at the G0/G1 phase and induced cell apoptosis. OODBL was able to up-regulate the expression of LXRα, ABCA1, and ABCG1 in the system. In addition, OODBL activated LXRα/ABCA1 signaling by targeting miR-1247-3p. Furthermore, the expression levels of cytochrome c in the cytoplasm, cleaved caspase-9, and cleaved caspase-3 were dose-dependently reduced by OODBL. Besides, OODBL increased the expression ratio of Bax to Bcl-2. Moreover, OODBL repressed tumor growth of OSCC cells in vivo.

Discussion

Thus, we conclude that OODBL inhibits OSCC progression by modulating miR-1247-3p/LXRα/ABCA1 signaling. Our finding provides new insights into the mechanism by which OODBL exerts potent anti-tumor activity against OSCC. OODBL may be a potential anti-tumor candidate, providing a novel clinical treatment strategy of OSCC.

Microbial Transformations of Two Beyerane-Type Diterpenes by Cunninghamella echinulata

Microbial transformations of two tetracyclic beyerane-type diterpenes, ent-16β-oxobeyeran-19-oic acid (1) and its chemical reduction product, ent-16β-hydroxybeyeran-19-oic acid (2), by the filamentous fungus Cunninghamella echinulata ATCC 8688a yielded eight metabolites (3-10). Incubation of the substrate 2 with C. echinulata afforded three new hydroxylated ones (3-5) along with two known ones (6-7), while incubation of 1 gave three known ones (8-10). The new compounds were characterized by 1D and 2D NMR as well as HRESIMS analysis, and the stereostructures of 3 and 4 were confirmed by X-ray crystallography. The bioreactions were involved not only in stereoselective incorporation of hydroxyl groups at inert positions C-7, -9, -12, and -14 of the two beyerane diterpenes but also in glucosidation at C-19 of 2. This is the first report on the biotransformation of the diterpenes by using C. echinulata. All compounds were assayed for their α-glucosidase inhibitory, neurotrophic, anti-inflammatory, and phytotoxic activity, and only in neurotrophic assay compounds, 2 and 9 were found to display nerve growth factor-mediated neurite-outgrowth promoting effects in PC12 cells; the others were inactive.

Buforin IIb induces androgen-independent prostate cancer cells apoptosis though p53 pathway in vitro

Prostate cancer (PCa) is one of the most common male cancer types, androgen-independent prostate cancer possesses poor prognosis. Buforin IIb, an attractive antibacterial peptide derived from histone H2A, showed selective cytotoxicity against most cancer cell lines. However, the molecular mechanism of buforin IIb on prostate cancer cell has still not been determined. In this study, we found buforin IIb significantly inhibited the prostate cancer cells proliferation, Furthermore, buforin IIb-induced cell apoptosis through downregulation of pro-caspase 3/8/9, poly (ADP-ribose) polymerase PARP and anti-apoptotic Bcl-2 and upregulation of pro-apoptotic Bax. In addition, buforin IIb increased the expression of tumor suppressor p53 and its target genes - p21, fas, noxa and puma. The cytotoxicity of buforin IIb on PC-3 and Du-145 cells is decreased by p53 knockdown. In conclusion, our results indicated that buforin IIb induced PC-3 and Du-145 cell apoptosis and could be considered as a potential drug for prostate cancer.

Diversity Modification and Structure-Activity Relationships of Two Natural Products 1β-hydroxy Alantolactone and Ivangustin as Potent Cytotoxic Agents

Sesquiterpene lactones (STLs) are a class of plant secondary metabolites widely found in nature with potent antitumor activities. In this work, two isolated STLs 1β-hydroxy alantolactone (1) and ivangustin (2) were derivatized through diversity-oriented strategy, and in vitro cytotoxic activity assessments were conducted against six cell lines including HeLa, PC-3, HEp-2, HepG2, CHO and HUVEC. The cytotoxic structure-activity relationship showed that the double bond between C5 and C6 was beneficial to improve activity; C1-OH oxidized derivatives showed a slight stronger activity, comparable to the positive drug etoposide (VP-16). Yet, C1-OH esterified derivatives decreased the potency which were different from those of 1-O-acetylbritannilactone (ABL) reported previously by us, and C13-methylene reductive and spiro derivatives resulted in almost complete ablation of cytotoxic activity. Mechanistic basis of cytotoxicity of the representative compound 1i was assayed to relate with apoptosis and cell cycle arrest. Furthermore, 1i inhibited TNF-α-induced canonical NF-κB signaling in PC-3 cells. Molecular modeling studies exhibited additional hydrogen bond interaction between 1i and the residue Lys37 of p65, indicating that 1i could form covalent protein adducts with Cys38 on p65.