Exploration of Baicalein-Core Derivatives as Potent Antifungal Agents: SAR and Mechanism Insights.

Baicalein (BE), the major component of Scutellaria Baicalensis, exhibited potently antifungal activity against drug-resistant Candida albicans, and strong inhibition on biofilm formation. Therefore, a series of baicalein-core derivatives were designed and synthesized to find more potent compounds and investigate structure-activity relationship (SAR) and mode of action (MoA). Results demonstrate that A4 and B5 exert a more potent antifungal effect (MIC80 = 0.125 µg/mL) than BE (MIC80 = 4 µg/mL) when used in combination with fluconazole (FLC), while the MIC80 of FLC dropped from 128 µg/mL to 1 µg/mL. SAR analysis indicates that the presence of 5-OH is crucial for synergistic antifungal activities, while o-dihydroxyls and vic-trihydroxyls are an essential pharmacophore, whether they are located on the A ring or the B ring of flavonoids. The MoA demonstrated that these compounds exhibited potent antifungal effects by inhibiting hypha formation of C. albicans. However, sterol composition assay and enzymatic assay conducted in vitro indicated minimal impact of these compounds on sterol biosynthesis and Eno1. These findings were further confirmed by the results of the in-silico assay, which assessed the stability of the complexes. Moreover, the inhibition of hypha of this kind of compound could be attributed to their effect on the catalytic subunit of 1,3-ß-d-glucan synthase, 1,3-ß-d-glucan-UDP glucosyltransferase and glycosyl-phosphatidylinositol protein, rather than inhibiting ergosterol biosynthesis and Eno1 activity by Induced-Fit Docking and Molecular Dynamics Simulations. This study presents potential antifungal agents with synergistic effects that can effectively inhibit hypha formation. It also provides new insights into the MoA.

Nitidine chloride exerts anti-inflammatory action by targeting Topoisomerase I and enhancing IL-10 production.

In the effort to identify natural products that regulate immunity and inflammation, we found that nitidine chloride (NC), an alkaloid from herb Zanthoxylum nitidum, enhanced IL-10 production in lipopolysaccharide (LPS)-stimulated myeloid cells. While NC was shown to be capable of inhibiting topoisomerase I (TOP1), NC analogs that could not inhibit TOP1 failed to increase IL-10 production. Moreover, medicinal TOP1 inhibitors TPT and SN-38 also augmented IL-10 production significantly, whereas knockdown of TOP1 prevented NC, TPT, and SN-38 from enhancing IL-10 expression. Thus, NC promoted IL-10 production by inhibiting TOP1. In LPS-induced endotoxemic mice, NC and TOP1 inhibitors increased IL-10 production, suppressed inflammatory responses, and reduced mortality remarkably. The anti-inflammatory activities of TOP1 inhibition were markedly reduced by IL-10-neutralizing antibody and largely absent in IL-10-deficient mice. In LPS-stimulated RAW264.7 cells and in peritoneal macrophages from endotoxemic mice, NC and TOP1 inhibitors significantly enhanced the activation of Akt, a critical signal transducer for IL-10 production, and inhibition of Akt prevented these compounds from enhancing IL-10 production and ameliorating endotoxemia. These data indicated that NC and TOP1 inhibitors are able to exert anti-inflammatory action through enhancing Akt-mediated IL-10 production and may assist with the treatment of inflammatory diseases.

Delavatine A, an unusual isoquinoline alkaloid exerts anti-inflammation on LPS-induced proinflammatory cytokines production by suppressing NF-κB activation in BV-2 microglia.

Delavatine A, an unusual isoquinoline alkaloid isolated from I. delavayi, was first studied for anti-inflammatory effect using lipopolysaccharide (LPS)-induced BV-2 microglia. In the present study, we found that delavatine A substantially suppressed the LPS-induced pro-inflammatory mediators, nitric oxide (NO), and tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), interleukin-1ß (IL-1ß) in BV-2 microglial cells. These effects resulted from the inhibition of their regulatory genes inducible NO synthase (iNOS), cycloxygenase-2 (COX-2) and TNF-a, IL-6, IL-1ß. In addition, we examined several pathways related to inflammation. The results revealed that delavatine A significantly decreased LPS-induced the activation of nuclear factor-κB (NF-κB) by suppressing the p65 subunits, and the phosphorylation of IκBα, while not related to PI3K/Akt or MAPK pathways.

Antidepressant-like Effect of Bacopaside I in Mice Exposed to Chronic Unpredictable Mild Stress by Modulating the Hypothalamic-Pituitary-Adrenal Axis Function and Activating BDNF Signaling Pathway.

Preliminary studies conducted in our laboratory have confirmed that Bacopaside I (BS-I), a saponin compound isolated from Bacopa monnieri, displayed antidepressant-like activity in the mouse behavioral despair model. The present investigation aimed to verify the antidepressant-like action of BS-I using a mouse model of behavioral deficits induced by chronic unpredictable mild stress (CUMS) and further probe its underlying mechanism of action. Mice were exposed to CUMS for a period of 5 consecutive weeks to induce depression-like behavior. Then, oral gavage administrations with vehicle (model group), fluoxetine (12 mg/kg, positive group) or BS-I (5, 15, 45 mg/kg, treated group) once daily were started during the last two weeks of CUMS procedure. The results showed that BS-I significantly ameliorated CUMS-induced depression-like behaviors in mice, as characterized by an elevated sucrose consumption in the sucrose preference test and reduced immobility time without affecting spontaneous locomotor activity in the forced swimming test, tail suspension test and open field test. It was also found that BS-I treatment reversed the increased level of plasma corticosterone and decreased mRNA and protein expressions of glucocorticoid receptor induced by CUMS exposure, indicating that hypothalamic-pituitary-adrenal (HPA) axis hyperactivity of CUMS-exposed mice was restored by BS-I treatment. Furthermore, chronic administration of BS-I elevated expression levels of brain-derived neurotrophic factor (BDNF) (mRNA and protein) and activated the phosphorylation of extracellular signal-regulated kinase and cAMP response element-binding protein in the hippocampus and prefrontal cortex in mice subjected to CUMS procedure. Taken together, these results indicated that BS-I exhibited an obvious antidepressant-like effect in mouse model of CUMS-induced depression that was mediated, at least in part, by modulating HPA hyperactivity and activating BDNF signaling pathway.

Cytotoxic and Anti-inflammatory Sesquiterpenes from Ainsliaea henryi.

Three new sesquiterpenoids, 4α-hydroxyeudesm-11(13)-en-12-yl 3-methylbutanoate (1), diaspanolide E (2), and (13α)-germacra-1(10),4-dien-12,8α-olid-15-oic acid (3), along with eight known sesquiterpenoids (4 - 11), were isolated from the aerial parts of Ainsliaea henryi. The chemical structures of compounds 1 - 3 were elucidated by spectroscopic analysis (1D-, 2D-NMR, MS and HR/MS). All isolates were evaluated for their inhibitory activities against nitric oxide (NO) production in lipopolysaccharide-induced RAW264.7 macrophage cells. Compound 10 exhibited significantly inhibition against NO release with an IC50 value of 6.54 ± 0.16 µm. Also, all isolated compounds were tested for cytotoxicity against three human tumor cell lines A549, MGC803, and HCT116, among which compound 5 significantly inhibited the proliferation of MGC803 cell lines with an IC50 value of 2.2 ± 0.2 µm.

Inhibition of HL-60 cell growth via cell cycle arrest and apoptosis induction by a cycloartane-labdane heterodimer from Pseudolarix amabilis.

Pseudolaridimer C (), a rarely encountered cycloartane-labdane Diels-Alder adduct was isolated from the cones of Pseudolarix amabilis. The structure and absolute configuration of were established by comprehensive NMR and CD spectral analysis. The WST-8 assay indicated that time and dose dependently inhibited the proliferation of human leukemia cells HL-60 at 1-10 µM. DAPI and Annexin V-FITC/PI double staining method, and DNA ladder experiments all proved that had significant dose-dependent effects on HL-60 cell apoptosis. A further mechanism study indicated that the apoptosis was associated with the cell cycle arrest during the G2/M phase, and the activation of caspase-9, -3, -7, and poly-(ADP-ribose)-polymerase (PARP).

[Research progress in mechanism of intestinal microorganisms in human diseases].

The international cooperated research projects of the Human Microbiome Project (HMP) and Metagenomics of The Human Intestinal Tract (MetaHIT) were officially launched in 2007, which indicated the era of metagenomics research of microorganisms in human gastrointestinal tract had been coming. Each human body is a superorganism which is composed of 90% commensal microorganisms, especially the intestinal microorganisms. The intestinal microorganisms play an important role on health maintenance since they are involved in the absorption and metabolism of nutrients in the human bodies. Herein, we review the research progress in the mechanism of intestinal microorganisms in human diseases. Our purpose is to provide novel ideas on human health and therapeutic targets of diseases.

[Interaction of effective ingredients from traditional Chinese medicines with intestinal microbiota].

A large number and wide varieties of microorganisms colonize in the human gastrointestinal tract. They construct an intestinal microecological system in the intestinal environment. The intestinal symbiotic flora regulates a series of life actions, including digestion and absorption of nutrient, immune response, biological antagonism, and is closely associated with the occurrence and development of many diseases. Therefore, it is greatly essential for the host's health status to maintain the equilibrium of intestinal microecological environment. After effective compositions of traditional Chinese medicines are metabolized or biotransformed by human intestinal bacteria, their metabolites can be absorbed more easily, and can even decrease or increase toxicity and then exhibit significant different biological effects. Meanwhile, traditional Chinese medicines can also regulate the composition of the intestinal flora and protect the function of intestinal mucosal barrier to restore the homeostasis of intestinal microecology. The relevant literatures in recent 15 years about the interactive relationship between traditional Chinese medicines and gut microbiota have been collected in this review, in order to study the classification of gut microflora, the relationship between intestinal dysbacteriosis and diseases, the important roles of gut microflora in intestinal bacterial metabolism in effective ingredients of traditional Chinese medicines and bioactivities, as well as the modulation effects of Chinese medicine on intestinal dysbacteriosis. In addition, it also makes a future prospect for the research strategies to study the mechanism of action of traditional Chinese medicines based on multi-omics techniques.

Total sesquiterpene lactones isolated from Inula helenium L. attenuates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in mice.

BACKGROUND: Inula helenium L. is an herb whose anti-inflammatory properties are attributed to its active components, the sesquiterpene lactones (SLs). Our previous study demonstrated that the total sesquiterpene lactones isolated from Inula helenium L. (TSL-IHL), consisting mainly of alantolactone (AL) and isoalantolactone (IAL), may have potential in the prevention and treatment of rheumatoid arthritis (RA). However, the effect of TSL-IHL on atopic dermatitis (AD) has not been studied yet. AIM OF THE STUDY: The present study evaluates the potential of TSL-IHL as a treatment for AD. METHODS/STUDY DESIGNS: The effects of TSL-IHL on the expression of inflammatory genes and the activation of NF-κB signaling pathway in HaCat cells were examined by quantitative real-time PCR and western blotting, respectively, and compared with those of AL and IAL. The protective effect of TSL-IHL against AD was tested in a mouse model induced by 2,4-dinitrochlorobenzene (DNCB), in which AD-like skin lesions were induced in ICR mice by sensitizing once with 100 µl of 7% DNCB painted on their shaved back skin and then challenging with 20 µl of 0.2% DNCB five times on their right ears at 3 day intervals starting on day 5 post-sensitization. RESULTS: TSL-IHL, as well as AL and IAL, could all inhibit TNF-α-induced activation of NF-κB and the expression of TNF-α, IL-1, and IL-4 in HaCat cells in a dose-dependent manner in the range of 0.6-2.4 µg/ml. The topical application of TSL-IHL (1% W/W in emollient cream) attenuated DNCB-induced dermatitis severity and right ear swelling. The serum levels of IgE, TNF-α and IFN-γ in TSL-IHL-treated mice were reduced by 81.39%, 89.69%, and 87.85%, respectively, while the mRNA levels of IL-4, IL-5 and IL-13, in the back-skin lesions of TSL-IHL-treated mice were reduced by 39.21%, 40.62% and 48.12%, respectively, compared with the untreated controls. Histopathological examination showed that TSL-IHL treatment reduced epidermis/dermis thickening and dermal inflammatory infiltration in both ear and back skins. CONCLUSIONS: We suggest that TSL-IHL inhibited the development of AD-like skin symptoms by regulating cytokine expression and may be an effective alternative therapy for AD.

Metabolism and pharmacokinetics of alantolactone and isoalantolactone in rats: Thiol conjugation as a potential metabolic pathway.

Alantolactone (AL) and isoalantolactone (IAL), two major active sesquiterpene lactones isolated from Radix Inulae extract, have a wide range of pharmacological activities. The predominant metabolic pathway of AL and IAL observed was glutathione (GSH) conjugation in vitro, which could occur in the absence of metabolic enzymes. Non-enzymatic conjugation with cysteine (Cys) couldalso be observed. Four metabolites (AL-GSH, AL-Cys, IAL-GSH, IAL-Cys) were subsequently isolated and confirmed by nuclear magnetic resonance (NMR). The results indicated that the thiol of GSH or Cys can be reacted with the exomethylene carbon atoms of α, ß-unsaturated carbonyl of AL and IAL. After intravenous administration in rats, AL and IAL were extensively metabolized, and the exposure, as measured by area under the concentration-time curve (AUC), for AL-GSH, AL-Cys, IAL-GSH, and IAL-Cys was approximately 1.54-, 0.96-, 1.50-, and 0.91-fold that of the parent drug, respectively. The AUC ratio of metabolites to parent compounds of oral administration was 3.66-, 9.19-, 12.97-, and 9.92-fold that of the parent drug for the above metabolites, respectively. The bioavailability of AL-total (AL, AL-GSH, AL-Cys) and IAL-total (IAL, IAL-GSH, IAL-Cys) was, respectively, 8.39% and 13.07%, which was 3.62- and 6.95- fold that of AL (2.32%) and IAL (1.88%), respectively. The oral exposure will be underestimated if the parent drugs are tested alone. These findings provide useful information for preclinical safety evaluation, and for predicting AL and IAL metabolism in humans.

Simultaneous quantification of 11 active constituents in Shexiang Baoxin Pill by ultraperformance convergence chromatography combined with tandem mass spectrometry.

On account of the complexity of chemical constituents of Shexiang Baoxin Pill (SBP), a famous traditional Chinese medicine (TCM) formula, a novel and effective UPC2-MS/MS method was developed to simultaneously determine the content of 11 active compounds of SBP with outstanding separation ability. Eleven components in SBP, including 2 ginsenosides, 2 bile acids, 3 bufadienolides and 4 volatiles were detected by electrospray ionization tandem mass spectrometry in positive and negative ion modes with multiple reaction monitor (MRM). The analysis was performed at 30°C using an Acquity UPC2 Diol (3.0×50mm, 1.7µm) column with linear gradient elution (eluent A, CO2; eluent B, methanol containing 20mM ammonium acetate), back pressure of 2000 psi, flow rate of 1.2mL/min and the injection volume of 1.0µL. The method was extensively validated regarding the linearity (r≥0.9974), precision (≤3.11%), recovery (93.34-104.50%), repeatability (≤2.00%) and stability (≤4.20%). Using this method, 11 active compounds of SBP with different polarity were simultaneously quantified in one chromatography analysis within 8min. Statistical analysis of the effects of 11 compounds on the quality of SBP revealed that the content of cinnamaldehyde varied widely in different batches. This work presents an exemplary study for quality control of complex samples, especially for TCMs.

Discovery of Potent Small-Molecule Inhibitors of Ubiquitin-Conjugating Enzyme UbcH5c from α-Santonin Derivatives.

As a therapeutic target for antitumor necrosis factor (TNF)-α interventions, UbcH5c is one of the key ubiquitin-conjugating enzymes catalyzing ubiquitination during TNF-α-triggered nuclear factor kappa B (NF-κB) activation. In the present study, three series of analogues were designed and synthesized from α-santonin, and their UbcH5c inhibitory activities were screened by Western blotting and NF-κB luciferase assay. Further BIAcore, in-gel fluorescence imaging, and immunoprecipitation assays demonstrated that compound 6d exhibited robust and specific inhibition of UbcH5c, exceeding that of the positive compound 1 (IJ-5). Mechanistic investigations revealed that compound 6d preferentially bound to and inactivated UbcH5c by forming a covalent adduct with its active site Cys85. Furthermore, compound 6d exhibited potent anti-inflammatory activity against complete Freund's adjuvant-induced adjuvant arthritis in vivo. These findings suggest that the novel α-santonin-derived UbcH5c inhibitor 6d is a promising lead compound for the development of new antirheumatoid arthritis (RA) agent.

Bruceine D inhibits hepatocellular carcinoma growth by targeting ß-catenin/jagged1 pathways.

Hepatocellular carcinoma (HCC) is known for high mortality and limited available treatments. Aberrant activation of the Wnt and Notch signaling pathways is critical to liver carcinogenesis and progression. Here, we identified a small molecule, bruceine D (BD), as a Notch inhibitor, using an RBP-Jκ-dependent luciferase-reporter system. BD significantly inhibited liver tumor growth and enhanced the therapeutic effects of sorafenib in various murine HCC models. Mechanistically, BD promotes proteasomal degradation of ß-catenin and the depletion of its nuclear accumulation, which in turn disrupts the Wnt/ß-catenin-dependent transcription of the Notch ligand Jagged1 in HCC. Our findings provide important information about a novel Wnt/Notch crosstalk inhibitor that is synergistic with sorafenib for treatment of HCC, and therefore have high clinical impact.