Phytotoxic phenols from the needles of Cedrus deodara.

During the course of screening for anti-seed germination phytochemicals, the methanol fraction of the Cedrus deodara fresh needles showed potent activity. Bioactivity-guided fractionation led to the isolation of thirty-eight phenolic compounds. Four ones were identified as previously undescribed including (7S,8S)-3-methoxy-9'-acetoxy-3',7-epoxy-8,4'-oxyneoligna-4,9-diol (7), (7S,8R)-dihydro-3'-hydroxy-8-acetoxymethyl-7-(4-hydroxy-3-methoxy-phenyl)-1'-benzofuranpropanol (10), (8S)-4,9,9'-trihydroxy-3,3'-dimethoxy-8,4'-oxyneolignan (11) and (7S,8S)-4,7,9'-trihydroxy-3,3'-dimethoxy-9-acetoxy-8,4'-oxyneolignan (16), respectively. The potential phytotoxic effects of these compounds on the seed germination and root elongation of Arabidopsis thaliana were evaluated by the filter paper assay developed in our laboratory. Bioassay results indicated that caffeic acid (36) displayed most significant inhibitory activities against the seed germination and root elongation of A. thaliana, stronger than those of the commercial herbicides acetochlor and glyphosate at the same concentration of 200 µg/mL. Ditetrahydrofuran lignan (1), dihydrochalcone (25), and eight simple phenols (28, 29, 31, 33-35, 37 and 38) completely inhibited the seed germination of A. thaliana at the concentration of 400 µg/mL, which were as active as acetochlor. Dihydroflavone (21) and the simple phenols 32-34 displayed stronger inhibitory effects on the root elongation of A. thaliana than that of glyphosate. The inhibitory effects of these active compounds on the seed germination and root elongation of Amaranthus tricolor and Lactuca sativa were evaluated as well. The phytotoxic activity of 11, 16, 22, 25, 31, 34, 37 and 38 were detected for the first time. In addition, the structure-activity relationships of the same class of these phytochemicals were discussed.

Multifunctional Hollow MnO2 @Porphyrin@Bromelain Nanoplatform for Enhanced Photodynamic Therapy.

Photodynamic therapy (PDT) has been showing great potential in cancer treatment. However, the efficacy of PDT is always limited by the intrinsic hypoxic tumor microenvironment (TME) and the low accumulation efficiency of photosensitizers in tumors. To address the issue, a multifunctional hollow multilayer nanoplatform (H-MnO2 @TPyP@Bro) comprising manganese dioxide, porphyrin (TPyP) and bromelain (Bro), is developed for enhanced photodynamic therapy. MnO2 catalyzes the intracellular hydrogen peroxide (H2 O2 ) to produce oxygen (O2 ), reversing the hypoxic TME in vivo. The generated O2 is converted into singlet oxygen (1 O2 ) by the TPyP shell under near-infrared light, which can inhibit tumor proliferation. Meanwhile, the Bro can digest collagen in the extracellular matrix around the tumor, and can promote the accumulation of H-MnO2 @TPyP@Bro in the deeper tumor tissue, further improving the therapeutic effect of PDT. In addition, MnO2 can react with the overexpressed glutathione in TME to release Mn2+ . Consequently, Mn2+ not only induces chemo-dynamic therapy based on Fenton reaction by converting H2 O2 into hydroxyl radicals, but also activates the Mn2+ -based magnetic resonance imaging. Therefore, the developed H-MnO2 @TPyP@Bro nanoplatform can effectively modulate the unfavorable TME and overcome the limitations of conventional PDT for cancer diagnostic and therapeutic.

Specialised metabolites as chemotaxonomic markers of Coptosapelta diffusa, supporting its delimitation as sisterhood phylogenetic relationships with Rubioideae.

From the aerial extracts of Coptosapelta diffusa (Champ. ex Benth.) Steenis, twenty-one compounds were isolated and identified by means of column chromatography and NMR and MS techniques, respectively. Amongst, ten ones were determined to be undescribed compounds including six seco-iridoid glucosides (1-6), 2-(hydroxymethyl)-1,2,3,4-tetrahydroanthracene-9,10-dione (7) and three guaiane-type sesquiterpenes (15-17). Compounds 7, 8 and 9 exhibited inhibitory activities against Staphylococcus aureus ATCC25923 with MIC of 8, 4 and 8 µg/mL. The use of 1-6 (iridoids), 7-14 (anthraquinones) and 15-17 (sesquiterpenes) as chemotaxonomic markers for this species was evidenced. Structurally, 7-14 are similar to those anthraquinones isolated from other species of the family Rubiaceae, confirming their close phylogenetic relationship. Whereas, these iridoids and sesquiterpenes with unique structures provided chemotaxonomic evidence to support the genus Coptosapelta (the tribe Coptosapelteae) as a sister of the subfamily Rubioideae. These results contrast with the general producing tendency of indole alkaloids by the species of the subfamily Cinchonoideae, and merit chemotaxonomic significance for the delimitation of Coptosapelta.

Three new polyketides from vasR2 gene over-expressed mutant strain of Verrucosispora sp. NS0172.

Over-expression of the pathway specific positive regulator gene is an effective way to activate silent gene cluster. In the curret study, the SARP family regulatory gene, vasR2, was over-expressed in strain Verrucosispora sp. NS0172 and the cryptic gene cluster responsible for the biosynthesis of pentaketide ansamycin was partially activated. Two tetraketides (1 and 2) and a triketide (3) ansamycins, together with five known compounds (4-8), were isolated and elucidated from strain NS0172OEvasR2. Their NMR data were completely assigned by analysis of their HR-ESI-MS and 1H, 13C NMR, HMQC, HMBC and 1H-1H COSY spectra.

Rational design of a prodrug to inhibit self-inflammation for cancer treatment.

Photothermal therapy (PTT) has been extensively used as an effective therapeutic approach against cancer. However, PTT can trigger the proinflammatory response of dendritic cells (DCs) and macrophages to release proinflammatory cytokines, which can simulate tumor regeneration and further hinder subsequent therapy. Hence, an effective therapeutic system, comprising gold nanoparticle modified Cu2ZnSnS4 nanocrystals and aspirin (Au-CZTS/Asp), was developed to co-deliver PTT agents and inflammatory inhibitors for the synergistic treatment of cancer. Au-CZTS with high near infrared (NIR) photothermal conversion abilities can effectively induce apoptosis and tumor ablation under NIR light. Furthermore, Asp can inhibit the activation of the cGAS-STING pathway in DCs and the polarization of macrophages to intercept the PTT mediated inflammatory responses. Therefore, the as-prepared Au-CZTS/Asp can effectively realize the integration of tumor treatment and recovery. Simultaneously, the Au-CZTS/Asp with ultrasmall size can be rapidly cleared to reduce biotoxicity and side effects. In addition, the Au-CZTS/Asp showed excellent photoacoustic (PA) imaging properties around the tumor in vivo. Thus, our study provides a potential platform for a nano-prodrug that is viable for cancer diagnostic-treatment-recovery integration.

Shunt products of aminoansamycins from aas1 overexpressed mutant strain of Streptomyces sp. S35.

Constitutively expression of the pathway-specific activators is an effective method to activate silent gene clusters and improve natural product production. In this study, nine shunt products of aminoansamycins (1-9) were identified from a recombinant mutant strain S35-LAL by overexpressed the large-ATP-binding regulator of the LuxR family (LAL) gene aas1 in Streptomyces sp. S35. All the compounds showed no anti-microbial, anti-T3SS and cytotoxic activities.

Myricanol Inhibits the Type III Secretion System of Salmonella enterica Serovar Typhimurium by Interfering With the DNA-Binding Activity of HilD.

The type III secretion system (T3SS) consists of a syringe-like export machine injecting effectors from the bacterial cytosol directly into host cells to establish infection. This mechanism is widely distributed in gram-negative bacteria and can be targeted as an innovative strategy for the developing of anti-virulence drugs. In this study, we present an effective T3SS inhibitor, myricanol, inspired by the use of folk medicinal plants traditionally used against infections. Myricanol is a cyclic diarylheptanoid isolated from the medicinal plant Myrica nagi, which is found in South and East Asia. Bioassay-guided fractionation revealed that myricanol inhibited not only the secretion of type III effector proteins of Salmonella enterica serovar Typhimurium UK-1 χ8956 (S. Typhimurium) but also the invasion of S. Typhimurium into mammalian cells, but showed no toxicity to bacterial growth or the host cells. RNA-Seq data analysis showed that the transcription of the pathogenesis-related SPI-1 gene was significantly inhibited by myricanol. Further study demonstrated that myricanol binds physically to HilD and interferes with its DNA-binding activity to the promoters of the hilA and invF genes. In conclusion, we propose that myricanol is responsible for the anti-infectious properties of M. nagi and is a novel T3SS inhibitor of S. Typhimurium through a previously unappreciated mechanism of action.

The in vitro and in vivo anti-virulence activities of Cinnamomum bejolghota by inhibiting type three secretion system effector proteins of Salmonella.

The bark of Cinnamomum bejolghota (Buch.-Ham.) Sweet (C. bejolghota) is widely used as medicine to treat bacterial diarrhea in Myanmar. We previously reported that the bark extract of C. bejolghota significantly inhibited secretion effector proteins of the type three secretion system (T3SS) in Salmonella. This study is designed to investigate the anti-virulence potential of the C. bejolghota bark extract against Salmonella Typhimuriumin in in vivo and in vitro experiments. The results suggested that the polar fraction Fr.M1 inhibited the secretion of effector proteins SipA, SipB, SipC and SipD without affecting bacteria growth and the translocation of SipC into MDA-MB-231 cells. In addition, Fr.M1 alleviated inflammatory symptoms of mice in Salmonella-infected mouse model. Overall, the results provide evidence for medicinal usage of C. bejolghota bark to treat diarrhea in Myanmar.

Anti-virulence activities of biflavonoids from Mesua ferrea L. flower.

Based on the anti-virulence activity on Salmonella, the ethyl acetate extract (EAE) of Mesua ferrea flower was investigated for its chemical constituents. Ten purified compounds were identified and assayed for their inhibitory activity against Type III secretion system (T3SS) by polyacrylamide gel electrophoresis (SDS-PAGE) and Western blots experiments. We found the biflavonoids, rhusflavanone and mesuaferrone B, exhibited inhibitory effects on the secretion of Salmonella pathogenicity island 1 (SPI-1) effector proteins (SipA, B, C and D) without effecting the bacterial growth. In addition, 5, 6, 6'-trihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid (6) is a new natural product from M. ferrea flower.

Investigation on the Antibacterial and Anti-T3SS Activity of Traditional Myanmar Medicinal Plants.

Myanmar has a rich pool of, but less known, medicinal plants with traditional knowledge. In this study, we aimed to investigate the inhibitory activity of traditional Myanmar medicinal plants against the type III secretion system (T3SS) of Salmonella enterica serovar Typhimurium UK-1 χ8956 and the intestinal disease-caused by microbes including S. enterica serovar Typhimurium UK-1 χ8956, Proteusbacillus vulgaris CPCC 160013, Escherichia coli CICC 10003, and Staphylococcus aureus ATCC 25923. The EtOH extracts of 93 samples were used to screen the inhibitory activities against the secretion of T3SS effector proteins SipA/B/C/D of S. enterica and the antibacterial activity against S. enterica, P. vulgaris, E. coli, and S. aureus. Out of 71 crude drugs traditionally used, 18 were proofed to be effective either on the growth inhibition of tested bacteria and/or as inhibitors for the T3SS. The EtOH extracts of five plants, Luvunga scandens (Roxb.) Buch.-Ham. ex Wight & Arn. (My7), Myrica nagi Thunb. (My11), Terminalia citrina Roxb. ex Fleming (My21), Thymus vulgaris L. (My49), and Cinnamomum bejolghota (Buch.-Ham.) Sweet (My104), showed potent inhibitory activities against the secretion of T3SS proteins SipA/B/C/D of S. enterica serovar Typhimurium UK-1 χ 8956. Mansonia gagei J.R.Drumm (My3) and Mesua ferrea (Roxb.) L. (My10) showed strong antibacterial activities against P. vulgaris and S. aureus. This study provided the first scientific evidence of T3SS prohibiting and antibacterial properties for the traditional knowledge in Myanmar of using plants as medicines for treating infections and gastrointestinal disease. Further researches are proposed to discover the active chemical compounds and mechanism of L. scandens (Roxb.) Buch.-Ham. ex Wight & Arn, M. nagi Thunb., T. citrina Roxb. ex Fleming, T. vulgaris L., and C. bejolghota (Buch.-Ham.) Sweet as antivirulence drugs and the potential of M. gagei J.R.Drumm and M. ferrea L. as new broad spectrum plant antibiotics.

Water-Based Black Phosphorus Hybrid Nanosheets as a Moldable Platform for Wound Healing Applications.

Black phosphorus (BP) nanosheets with unique biocompatibility and superior optical performance have attracted enormous attention in material science. However, their instability and poor solution-processability severely limit their clinical applications. In this work, we demonstrate the use of silk fibroin (SF) as an exfoliating agent to produce thin-layer BP nanosheets with long-term stability and facile solution-processability. Presence of SF prevents rapid oxidation and degradation of the resultant BP nanosheets, enhancing their performance in physiological environment. The SF-modified BP nanosheets exhibit subtle solution-processability and are fabricated into various BP-based material formats. As superior photothermal agents, BP-based wound dressings effectively prevent bacterial infection and promote wound repair. Therefore, this work opens new avenues for unlocking current challenges of BP nanosheet applications for practical biomedical purposes.

A black phosphorus nanosheet-based siRNA delivery system for synergistic photothermal and gene therapy.

Gene therapy with small interfering RNA (siRNA) has been proved to be a promising technology to treat various diseases by hampering the production of target proteins. However, developing a delivery system that has high efficiency in transporting siRNA without obvious side effects remains a challenge. Herein, we designed a new survivin siRNA delivery system based on polyethyleneimine functionalized black phosphorus (BP) nanosheets which could suppress tumor growth by silencing survivin expression. Combined with the photothermal properties of the BP nanosheets, the presented delivery system shows excellent therapy efficiency for tumors. Therefore, the BP-based delivery system would be a promising tool for future clinical applications.

Galbonolides from Streptomyces sp. SR107.

Genome sequence analysis of Streptomyces sp. LZ35 has revealed a large number of secondary metabolite pathways, including a hybrid fatty acid-type PKS gene cluster-for biosynthesis of galbonolides. By sequence-guided and culture medium selection and with the aid of specific staining on TLC, galbonolides B (1) and E (2)have been identified from strain Streptomyces sp. LZ35. Further discovery and mining of galbonolides from a clean background mutant strain, Streptomyces sp LZ35Aheng (SR107), led to the isolation of galbonolides F (3) and G (4), which were elucidated by analysis of their HRESIMS and NMR spectroscopic data.

Tumor T1 Relaxation Time for Assessing Response to Bevacizumab Anti-Angiogenic Therapy in a Mouse Ovarian Cancer Model.

PURPOSE: To assess whether T1 relaxation time of tumors may be used to assess response to bevacizumab anti-angiogenic therapy. PROCEDURES: 12 female nude mice bearing subcutaneous SKOV3ip1-LC ovarian tumors were administered bevacizumab (6.25ug/g, n=6) or PBS (control, n=6) therapy twice a week for two weeks. T1 maps of tumors were generated before, two days, and 2 weeks after initiating therapy. Tumor weight was assessed by MR and at necropsy. Histology for microvessel density, proliferation, and apoptosis was performed. RESULTS: Bevacizumab treatment resulted in tumor growth inhibition (p<0.04, n=6), confirming therapeutic efficacy. Tumor T1 relaxation times increased in bevacizumab treated mice 2 days and 2 weeks after initiating therapy (p<.05, n=6). Microvessel density decreased 59% and cell proliferation (Ki67+) decreased 50% in the bevacizumab treatment group (p<.001, n=6), but not apoptosis. CONCLUSIONS: Findings suggest that increased tumor T1 relaxation time is associated with response to bevacizumab therapy in ovarian cancer model and might serve as an early indicator of response.

Siderochelins with anti-mycobacterial activity from Amycolatopsis sp. LZ149.

Three new compounds, namely siderochelins D (2), E (3), and F (4), together with one known siderochelin A (1), were isolated from Amycolatopsis sp. LZ149 and elucidated by spectroscopic analyses including1D- and 2D-NMR and X-ray single crystal diffraction. Compounds 1-3 showed antibacterial activity against Mycobacterium smegmatis.

Two new p-terphenyl derivatives from the marine fungal strain Aspergillus sp. AF119.

Two new p-terphenyl derivatives (1, 2), together with six known ones (3-8), have been isolated from the marine fungal strain Aspergillus sp. AF119. The structures for terphyl acid (1) and terphyl diacid (2) were determined on the basis of HR Q-TOF-MS, and 1D- and 2D-NMR spectroscopic data. The in vitro cytotoxic activities of compounds 1-8 were tested against human tumor cell lines HeLa, HepG-2 and MDA-MB-435; only compounds 5-8 exhibited inhibitory activity against the tested cell lines with IC50 values < 20 microM. Moreover, compound 5 showed a mechanism of inducing cell cycle arrest and apoptosis mediated by the generation of ROS and subsequent DNA double-strand break.

Identification of diverse dipeptidyl peptidase IV inhibitors via structure-based virtual screening.

Dipeptidyl peptidase IV (DPP4) is an important target for the treatment of type II diabetes mellitus. Inhibition of DPP4 will improve glycemic control in such patients by preventing the rapid breakdown and thereby prolonging the physiological actions of incretin hormones. Known DPP4 inhibitors (including marketed drugs and those drug candidates) appear to share similar structural features: the cyanopyrrolidine moieties, the xanthenes/pyrimidine parts and amino-like linkages. In this study, a multi-step virtual screening strategy including both rigid and flexible docking was employed to search for novel structures with DPP4 inhibition. From SPECS database, consisting of over 190,000 commercially available compounds, 99 virtual hits were picked up and 15 of them were eventually identified to have DPP4 inhibitory activities at 5 ~ 50 µM. Diverse structures of our compounds were out of usual structural categories. Hence a pharmacophore model was built to further explore their common binding features on the enzyme. The results provided a new pathway for the discovery of DPP4 inhibitors and would be helpful for further optimization of DPP4 inhibitors.

Intensity-modulated radiation therapy for advanced cervical cancer: a comparison of dosimetric and clinical outcomes with conventional radiotherapy.

OBJECTIVE: The aim of this study is to evaluate the dosimetry, efficacy and toxicity of reduced field intensity-modulated radiation therapy (RF-IMRT) for patients with advanced cervical cancer. METHODS: From August 2005 to August 2010, 60 patients with stage IIB-IIIB cervical cancer underwent reduced field IMRT (RF-IMRT group) and 62 patients treated with conventional radiotherapy (c-RT group) were enrolled. The RF-IMRT plans were as follows: whole pelvic IMRT plan was performed to deliver a dose of 30Gy firstly, then the irradiated volume was reduced to lymphatic drainage region as well as paracervix and parametrium for an additional 30Gy boost. Intracavitary brachytherapy and concurrent chemotherapy were performed during external irradiation. The tumor coverage and normal tissue avoidance were evaluated. Treatment response, toxicities and survival were assessed. RESULTS: The mean dose delivered to the planning target volume was significantly higher in RF-IMRT group than in c-RT group (61.5 vs. 50.8Gy, P=0.046). IMRT plans yielded better dose conformity to the target and better sparing of the rectal, bladder and small intestine. The RF-IMRT patients experienced significantly lower acute and chronic toxicities with comparable short-term effects than did those treated with conventional RT (CR: 87.7% vs. 88.3%, P=0.496; PR: 7.0% vs. 6.7%, P=0.440). No significant differences were found between treatment groups for 1year, 3year, and 5year overall survival (OS) levels, although the latter approached statistical significance in favor of IMRT, while a significantly higher progression-free survival (PFS; P=0.031) was seen for IMRT. CONCLUSIONS: RF-IMRT yields improved dose distributions, with lower toxicities, while providing comparable clinical outcomes. The increased PFS may be an advantage.

Sentinel lymph node biopsy as guidance for radical trachelectomy in young patients with early stage cervical cancer.

BACKGROUND: The purpose of this study was to assess the feasibility and accuracy of sentinel lymph nodes (SLNs) detection using 99mTc phytate in predicting pelvic lymph nodes status for radical abdominal trachelectomy (RAT) in patients with early stage cervical cancer. METHODS: Sixty-eight women with stage IA2-IB1 cervical cancer and scheduled to undergo fertility-sparing surgery enrolled in this study. 99mTc-labeled phytate was injected before surgery. Intraoperatively, SLNs were identified, excised, and submitted to fast frozen section. Systematic bilateral pelvic lymphadenectomy and/or para-aortic lymph node dissection was performed. Then RAT was performed in patients with negative SLNs. All nodes were sent for routine pathological examination and immunostained with anti-cytokeratin antibody to detect micrometastases. Outcomes of follow up and fertility were observed. RESULTS: SLNs were identified in 64 of 68 patients (94.1%). Of these, SLNs of 8 patients (11.8%) were positive on frozen sections and proved to be metastasis by final pathologic examination. The sensitivity, accuracy, and false negative rates were 100%, 100%, and 0%, respectively. All 60 patients with negative SLN underwent RAT successfully. Two relapses occurred and no one died of tumor progression during follow-up. Five of the 15 patients with procreative desire conceived 8 pregnancies (3 term delivery, 2 premature birth, 1 spontaneous abortion, and 2 were still in the duration of pregnancy) after surgery. CONCLUSIONS: The identification of SLN using 99mTc-labeled phytate is accurate and safe to assess pelvic nodes status in patients with early cervical cancer. SLNs biopsy guided RAT is feasible for patients who desire to have fertility preservation.

A novel sensitive detection platform for antitumor herbal drug aloe-emodin based on the graphene modified electrode.

This paper has presented a novel strategy to carry out direct and sensitive determination of antitumor herbal drug aloe-emodin in complex matrices based on the graphene-Nafion modified glassy carbon (GN/GC) electrode. This proposed modified electrode showed good electrochemical response towards aloe-emodin (AE). Compared with the multiwall carbon nanotubes (MWCNTs) modified electrode, the GN/GC electrode has the advantages of higher sensitivity and lower cost. Under the optimized conditions, the calibration curve for AE concentration was linear in the range from 5 nmol/L to 1 µmol/L with the detection limit of 2 nmol/L. In addition, the practical analytical performance of the GN/GC electrode was examined by evaluating the selective detection of AE in natural aloe extracts and human urine samples with satisfied recovery. Therefore, the GN/GC electrode may hold great promise for fast, simple and sensitive detection and biomedical analysis of AE in complex matrices.