Dehydroxyhispolon Methyl Ether, A Hispolon Derivative, Inhibits WNT/ß-Catenin Signaling to Elicit Human Colorectal Carcinoma Cell Apoptosis.

Colorectal cancer (CRC) is the fourth leading cause of cancer mortality worldwide. Aberrant activation of WNT/ß-catenin signaling present in the vast majority of CRC cases is indispensable for CRC initiation and progression, and thus is a promising target for CRC therapeutics. Hispolon is a fungal-derived polyphenol with a pronounced anticancer effect. Several hispolon derivatives, including dehydroxyhispolon methyl ether (DHME), have been chemically synthesized for developing lead molecules with stronger anticancer activity. Herein, a DHME-elicited anti-CRC effect with the underlying mechanism is reported for the first time. Specifically, DHME was found to be more cytotoxic than hispolon against a panel of human CRC cell lines, while exerting limited toxicity to normal human colon cell line CCD 841 CoN. Additionally, the cytotoxic effect of DHME appeared to rely on inducing apoptosis. This notion was evidenced by DHME-elicited upregulation of poly (ADP-ribose) polymerase (PARP) cleavage and a cell population positively stained by annexin V, alongside the downregulation of antiapoptotic B-cell lymphoma 2 (BCL-2), whereas the blockade of apoptosis by the pan-caspase inhibitor z-VAD-fmk attenuated DHME-induced cytotoxicity. Further mechanistic inquiry revealed the inhibitory action of DHME on ß-catenin-mediated, T-cell factor (TCF)-dependent transcription activity, suggesting that DHME thwarted the aberrantly active WNT/ß-catenin signaling in CRC cells. Notably, ectopic expression of a dominant-active ß-catenin mutant (∆N90-ß-catenin) abolished DHME-induced apoptosis while also restoring BCL-2 expression. Collectively, we identified DHME as a selective proapoptotic agent against CRC cells, exerting more potent cytotoxicity than hispolon, and provoking CRC cell apoptosis via suppression of the WNT/ß-catenin signaling axis.

Blockade of the SRC/STAT3/BCL-2 Signaling Axis Sustains the Cytotoxicity in Human Colorectal Cancer Cell Lines Induced by Dehydroxyhispolon Methyl Ether.

Colorectal cancer (CRC) is the third most prevalent human cancer globally. 5-Fluorouracil (5-FU)-based systemic chemotherapy is the primary strategy for advanced CRC treatment, yet is limited by poor response rate. Deregulated activation of signal transducer and activator of transcription 3 (STAT3) is fundamental to driving CRC malignant transformation and a poor prognostic marker for CRC, underscoring STAT3 as a promising CRC drug target. Dehydroxyhispolon methyl ether (DHME) is an analog of Hispolon, an anticancer polyphenol abundant in the medicinal mushroom Phellinus linteus. Previously, we have established DHME's cytotoxic effect on human CRC cell lines by eliciting apoptosis through the blockade of WNT/ß-catenin signaling, a preeminent CRC oncogenic pathway. Herein, we unraveled that compared with 5-FU, DHME is a more potent killer of CRC cells while being much less toxic to normal colon epithelial cells. DHME suppressed both constitutive and interleukin 6 (IL-6)-induced STAT3 activation represented by tyrosine 705 phosphorylation of STAT3 (p-STAT3 (Y705)); notably, DHME-induced CRC apoptosis and clonogenicity limitation were abrogated by ectopic expression of STAT3-C, a dominant-active STAT3 mutant. Additionally, we proved that BCL-2 downregulation caused by DHME-mediated STAT3 blockage is responsible for DHME-induced CRC cell apoptosis. Lastly, DHME inhibited SRC activation, and v-src overexpression restored p-STAT3 (Y705) levels along with lowering the levels of apoptosis in DHME-treated CRC cells. We conclude DHME provokes CRC cell apoptosis by blocking the SRC/STAT3/BCL-2 axis besides thwarting WNT/ß-catenin signaling. The notion that DHME targets two fundamental CRC signaling pathways underpins the potential of DHME as a CRC chemotherapy agent.

Methoxyhispolon Methyl Ether, a Hispolon Analog, Thwarts the SRC/STAT3/BCL-2 Axis to Provoke Human Triple-Negative Breast Cancer Cell Apoptosis In Vitro.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with few treatment options. A promising TNBC treatment approach is targeting the oncogenic signaling pathways pivotal to TNBC initiation and progression. Deregulated activation of signal transducer and activator of transcription 3 (STAT3) is fundamental to driving TNBC malignant transformation, highlighting STAT3 as a promising TNBC therapeutic target. Methoxyhispolon Methyl Ether (MHME) is an analog of Hispolon, an anti-cancer polyphenol found in the medicinal mushroom Phellinus linteus. Still, MHME's anti-cancer effects and mechanisms remain unknown. Herein, we present the first report about MHME's anti-TNBC effect and its action mechanism. We first revealed that MHME is proapoptotic and cytotoxic against human TNBC cell lines HS578T, MDA-MB-231, and MDA-MB-463 and displayed a more potent cytotoxicity than Hispolon's. Mechanistically, MHME suppressed both constitutive and interleukin 6 (IL-6)-induced activation of STAT3 represented by the extent of tyrosine 705-phosphorylated STAT3 (p-STAT3). Notably, MHME-evoked apoptosis and clonogenicity impairment were abrogated in TNBC cells overexpressing a dominant-active mutant of STAT3 (STAT3-C); supporting the blockade of STAT3 activation is an integral mechanism of MHME's cytotoxic action on TNBC cells. Moreover, MHME downregulated BCL-2 in a STAT3-dependent manner, and TNBC cells overexpressing BCL-2 were refractory to MHME-induced apoptosis, indicating that BCL-2 downregulation is responsible for MHME's proapoptotic effect on TNBC cells. Finally, MHME suppressed SRC activation, while v-src overexpression rescued p-STAT3 levels and downregulated apoptosis in MHME-treated TNBC cells. Collectively, we conclude that MHME provokes TNBC cell apoptosis through the blockade of the SRC/STAT3/BCL-2 pro-survival axis. Our findings suggest the potential of applying MHME as a TNBC chemotherapy agent.

Inhibition of AMPK-associated autophagy enhances caffeic acid phenethyl ester-induced cell death in C6 glioma cells.

An increasing number of studies show that AMP-activated protein kinase (AMPK) activation can inhibit apoptosis. To clarify the antitumor mechanism of caffeic acid phenethyl ester (CAPE) and achieve increased therapeutic efficiency, we investigated the potential roles of AMPK and autophagy in CAPE treatment against C6 glioma cells. The roles of AMPK and autophagy inhibition in CAPE's cytotoxic action were investigated. Phosphorylation of AMPK and mitogen-activated protein kinases (MAPKs) were observed in tumor cells following CAPE treatment. A combination of CAPE and the AMPK inhibitor, compound C, resulted in augmented cell death. Similar effects of compound C were observed in response to changes in the mitochondrial membrane potential ( ΔΨ(m)). Small interfering RNA-mediated AMPK downregulation increased CAPE-induced cell death. The results suggest that AMPK activation plays a role in diminishing apoptosis. CAPE treatment induced an increase in LC3 conversion as represented by the LC3-II/LC3-I ratio. Enlarged lysosomes and autophagosomes were present according to electron microscopy. The autophagy inhibitor, 3-MA, caused increased CAPE cytotoxicity, which suggests that autophagy induction protected glioma cells from CAPE. The combination of CAPE with autophagy and AMPK inhibitors markedly enhanced the cytotoxicity toward C6 glioma cells. Accordingly, CAPE-triggered activation of AMPK and the autophagic response protected tumor cells from apoptotic death. This provides new insights for combined therapy to enhance the therapeutic potential of cancer treatments.

Maternal baicalin treatment increases fetal lung surfactant phospholipids in rats.

Baicalin is a flavonoid compound purified from the medicinal plant Scutellaria baicalensis Georgi and has been reported to stimulate surfactant protein (SP)-A gene expression in human lung epithelial cell lines (H441). The aims of this study were to determine whether maternal baicalin treatment could increase lung surfactant production and induce lung maturation in fetal rats. This study was performed with timed pregnant Sprague-Dawley rats. One-day baicalin group mothers were injected intraperitoneally with baicalin (5 mg/kg/day) on Day 18 of gestation. Two-day baicalin group mothers were injected intraperitoneally with baicalin (5 mg/kg/day) on Days 17 and 18 of gestation. Control group mothers were injected with vehicle alone on Day 18 of gestation. On Day 19 of gestation, fetuses were delivered by cesarean section. Maternal treatment with 2-day baicalin significantly increased saturated phospholipid when compared with control group and total phospholipid in fetal lung tissue when compared with control and 1-day baicalin groups. Antenatal treatment with 2-day baicalin significantly increased maternal growth hormone when compared with control group. Fetal lung SP-A mRNA expression and maternal serum corticosterone levels were comparable among the three experimental groups. Maternal baicalin treatment increases pulmonary surfactant phospholipids of fetal rat lungs and the improvement was associated with increased maternal serum growth hormone. These results suggest that antenatal baicalin treatment might accelerate fetal rat lung maturation.

Capacitation suppression by mouse seminal vesicle autoantigen involves a decrease in plasma membrane Ca2+-ATPase (PMCA)-mediated intracellular calcium.

Successful fertilization is tightly regulated by capacitation and decapacitation processes. Without appropriate decapacitation regulation, sperm would undergo a spontaneous acrosome reaction which leads to loss of fertilization ability. Seminal plasma is known to negatively regulate sperm capacitation. However, the suppressive mechanisms still remain unclear. In this study, we demonstrate the decapacitation mechanism of mouse seminal vesicle autoantigen (SVA) might target membrane sphingomyelin (SPM) and regulate plasma membrane Ca(2+)-ATPase (PMCA) activity. The SVA was shown to suppress sperm capacitation induced by a broad panel of capacitation factors (bovine serum albumin (BSA), PAF, and cyclodextrin (CD)). Furthermore, SVA significantly decreased [Ca(2+)](i) and NaHCO(3)-induced [cAMP](i). Cyclic AMP agonists bypassed the SVA's suppressive ability. Importantly, the SVA may regulate PMCA activity which was evidenced by the fact that the SVA decreased the [Ca(2+)](i) and intracellular pH (pH(i)) of sperm; meanwhile, a PMCA inhibitor (carboxyeosin) could reverse SVA's suppression of [Ca(2+)](i). The potential target of the SVA on membrane SPM/lipid rafts was highlighted by the high binding affinity of SPM-SVA (with a K(d) of ~3 µM) which was close to the IC(50) of SVA's suppressive activity. Additionally, treatment of mink lung epithelial cells with the SVA enhanced plasminogen activator inhibitor (PAI)-1 expression stimulated by tumor growth factor (TGF)-ß and CD. These observations supported the membrane lipid-raft targeting of SVA. In summary, in this paper, we demonstrate that the decapacitation mechanism of the SVA might target membrane sphingolipid SPM and regulate PMCA activity to lower [Ca(2+)](i), thereby decreasing the [cAMP](i) level and preventing sperm pre-capacitation.

Identification of Dendrobium species by dot blot hybridization assay.

A method was developed for rapid identification of Dendrobium species by a dot blot hybridization assay. The dot blot system is based on species-specific amplified fragments derived from the internal transcribed spacer (ITS) region of different Dendrobium species as target DNA, which were blotted as dots on the nylon membrane. A small aliquot of the ITS amplified product from a selected species or mixed ITS DNA from several species was labeled by peroxidase and used as a probe for hybridization to the dot blot membrane. Simply visualizing the positive hybridization reaction between the probe DNA and the target DNA could identify the selected species. The D. officinal-specific and D. nobile-specific ITS-based probes could separately identify D. officinal and D. nobile. Eight Dendrobium species, including D. salaccense, D. brymerianum, D. ellipsophyllum, D. chrysanthum, D. officinale, D. thyrsiflorum, D. nobile and D. chrysotoxum could be simultaneously detected using their complex ITS amplified products as a probe, and the ITS DNA probe amount for detection by the dot blot membrane is very small, just 2.5 ng. The assay can also be used to identify the resource species of Fengdou Shihu and Huangcao Shihu from the commercial market. The identification based on the ITS sequence was superior to the conventional approaches in speed, sensitivity, and specificity. Therefore, the polymerase chain reaction (PCR)-dot blot hybridization assay can be considered a reliable method for general identification of commercial Shihu.

Taiwanese native plants inhibit matrix metalloproteinase-9 activity after ultraviolet B irradiation.

Medicinal plants have long been used as a source of therapeutic agents. They are thought to be important anti-aging ingredients in prophylactic medicines. The aim of this study was to screen extracts from Taiwanese plant materials for phenolic contents and measure the corresponding matrix metalloproteinase-9 (MMP-9) activity. We extracted biological ingredients from eight plants native to Taiwan (Alnus formosana, Diospyros discolor, Eriobotrya deflex, Machilus japonica, Pyrrosia polydactylis, Pyrus taiwanensis, Vitis adstricta, Vitis thunbergii). Total phenolic content was measured using the Folin-Ciocalteu method. MMP-9 activities were measured by gelatin zymography. The extracted yields of plants ranged from 3.7 % to 16.9 %. The total phenolic contents ranged from 25.4 to 36.8 mg GAE/g dry material. All of these extracts (except Vitis adstricta Hance) were shown to inhibit MMP-9 activity of WS-1 cell after ultraviolet B irradiation. These findings suggest that total phenolic content may influence MMP-9 activity and that some of the plants with higher phenolic content exhibited various biological activities that could serve as potent inhibitors of the ageing process in the skin. This property might be useful in the production of cosmetics.

Gene landscape and correlation between B-cell infiltration and programmed death ligand 1 expression in lung adenocarcinoma patients from The Cancer Genome Atlas data set.

Tumor-infiltrating lymphocytes are related to positive clinical prognoses in numerous cancer types. Programmed death ligand 1 (PD-L1), a mediator of the PD-1 receptor, plays an inhibitory role in cancer immune responses. PD-L1 upregulation can impede infiltrating T-cell functions in lung adenocarcinoma (LUAD), a lung cancer subtype. However, associations between the expression of PD-L1 and infiltration of B cells (a major immunoregulatory cell) remain unknown. Therefore, we investigated the role of infiltrating B cells in LUAD progression and its correlation with PD-L1 expression. The Cancer Genome Atlas (TCGA) LUAD data set was used to explore associations among B-cell infiltration, PD-L1 expression, clinical outcome, and gene landscape. Gene set enrichment analysis was used to explore putative signaling pathways and candidate genes. The drug enrichment analysis was used to identify candidate genes and the related drugs. We found that high B-cell infiltration was correlated with better prognoses; however, PD-L1 may interfere with the survival advantage in patients with high B-cell infiltration. The gene landscape was characterized comprehensively, with distinct PD-L1 levels in cell populations with high B-cell infiltration. We obtained five upregulated signaling pathways from the gene landscape: apoptosis, tumor necrosis factor (TNF)-α signaling via nuclear factor (NF)-κB, apical surface, interferon-α response, and KRAS signaling. Moreover, four candidate genes and their related target drugs were also identified, namely interleukin-2ß receptor (IL2RB), IL-2γ receptor (IL2RG), Toll-like receptor 8 (TLR8), and TNF. These findings suggest that tumor-infiltrating B cells could act as a clinical factor in anti-PD-L1 immunotherapy for LUAD.

Hispolon Suppresses LPS- or LTA-Induced iNOS/NO Production and Apoptosis in BV-2 Microglial Cells.

Hispolon (HIS) is an active polyphenol compound derived from Phellinus linteus (Berkeley & Curtis), and our previous study showed that HIS effectively inhibited inflammatory responses in macrophages [Yang, L.Y., S.C. Shen, K.T. Cheng, G.V. Subbaraju, C.C. Chien and Y.C. Chen. Hispolon inhibition of inflammatory apoptosis through reduction of iNOS/NO production via HO-1 induction in macrophages. J. Ethnopharmacol. 156: 61-72, 2014]; however, its effect on neuronal inflammation is still undefined. In this study, HIS concentration- and time-dependently inhibited lipopolysaccharide (LPS)- and lipoteichoic acid (LTA)-induced inducible nitric oxide (NO) synthase (iNOS)/NO production with increased heme oxygenase (HO)-1 proteins in BV-2 microglial cells. Accordingly, HIS protected BV-2 cells from LPS- or LTA-induced apoptosis, characterized by decreased DNA ladder formation, and caspase-3 and poly(ADP ribose) polymerase (PARP) protein cleavage in BV-2 cells. Similarly, the NOS inhibitor, N-nitro-L-arginine methyl ester (NAME), inhibited LPS- or LTA-induced apoptosis of BV-2 cells, but neither NAME nor HIS showed any inhibition of NO production or cell death induced by the NO donor, sodium nitroprusside (SNP), indicating the involvement of NO in the inflammatory apoptosis of microglial cells. Activation of c-Jun N-terminal kinase (JNK) and nuclear factor (NF)-[Formula: see text]B contributed to LPS- or LTA-induced iNOS/NO production and apoptosis of BV-2 cells, and that was suppressed by HIS. Additionally, HIS possesses activity to induce HO-1 protein expression via activation of extracellular signal-regulated kinase (ERK) in BV-2 cells, and application of the HO inhibitor, tin protoporphyrin (SnPP), or knockdown of HO-1 protein by HO-1 small interfering (si)RNA significantly reversed HIS inhibition of NO production and cell death in BV-2 cells stimulated by LPS. Results of an analysis of the effects of HIS and two structurally related chemicals, i.e. dehydroxy-HIS (D-HIS) and HIS-methyl ester (HIS-ME), showed that HIS expressed the most potent inhibitory effects on iNOS/NO production, JNK activation, and apoptosis in BV-2 microglial cells activated by LPS with increased HO-1 protein expression. Overall these results suggested that HIS possesses inhibitory activity against LPS- or LTA-induced inflammatory responses including iNOS/NO production and apoptosis in BV-2 microglial cells and that the mechanisms involve upregulation of the HO-1 protein and downregulation of JNK/NF-[Formula: see text]B activation. A critical role of hydroxyl at position C3 in the anti-inflammatory actions of HIS against activated BV-2 microglial cells was suggested.

The microRNA-302b-inhibited insulin-like growth factor-binding protein 2 signaling pathway induces glioma cell apoptosis by targeting nuclear factor IA.

MicroRNAs are small noncoding RNAs that post-transcriptionally control the expression of genes involved in glioblastoma multiforme (GBM) development. Although miR-302b functions as a tumor suppressor, its role in GBM is still unclear. Therefore, this study comprehensively explored the roles of miR-302b-mediated gene networks in GBM cell death. We found that miR-302b levels were significantly higher in primary astrocytes than in GBM cell lines. miR-302b overexpression dose dependently reduced U87-MG cell viability and induced apoptosis through caspase-3 activation and poly(ADP ribose) polymerase degradation. A transcriptome microarray revealed 150 downregulated genes and 380 upregulated genes in miR-302b-overexpressing cells. Nuclear factor IA (NFIA), higher levels of which were significantly related to poor survival, was identified as a direct target gene of miR-302b and was involved in miR-302b-induced glioma cell death. Higher NFIA levels were observed in GBM cell lines and human tumor sections compared with astrocytes and non-tumor tissues, respectively. NFIA knockdown significantly enhanced apoptosis. We found high levels of insulin-like growth factor-binding protein 2 (IGFBP2), another miR-302b-downregulated gene, in patients with poor survival. We verified that NFIA binds to the IGFBP2 promoter and transcriptionally enhances IGFBP2 expression levels. We identified that NFIA-mediated IGFBP2 signaling pathways are involved in miR-302b-induced glioma cell death. The identification of a regulatory loop whereby miR-302b inhibits NFIA, leading to a decrease in expression of IGFBP-2, may provide novel directions for developing therapies to target glioblastoma tumorigenesis.

Prevention of cellular oxidative damage by an aqueous extract of Anoectochilus formosanus.

Anoectochilus formosanus (AF) is a popular folk medicine in Taiwan whose pharmacological effects have been characterized. In this work we investigated the antioxidant properties of an aqueous extract prepared from AF. The AF extract was capable of scavenging H2O2 in a dose-dependent manner. We induced oxidative stress in HL-60 cells, either by the addition of hydrogen peroxide (H2O2) or by the xanthine/xanthine oxidase reaction. Apoptosis caused by oxidative damage was displayed by DNA fragmentation on gel electrophoresis, and the apoptotic fraction was quantified with flow cytometry. The cell damage induced by oxidative stress was prevented by the plant extract in a concentration-dependent manner. Furthermore, the proteolytic cleavage of poly(ADP-ribose) polymerase during the apoptotic process was also inhibited by AF extract. Our results provide the basis for determining an AF extract to be an antioxidant.

Kinsenoside-mediated lipolysis through an AMPK-dependent pathway in C3H10T1/2 adipocytes: Roles of AMPK and PPARα in the lipolytic effect of kinsenoside.

BACKGROUND: Currently, more than one-third of the global population is overweight or obese, which is a risk factor for major causes of death including cardiovascular disease, numerous cancers, and diabetes. Kinsenoside, a major active component of Anoectochilus formosanus exhibits antihyperglycemic, antihyperliposis, and hepatoprotective effects and can be used to prevent and manage obesity. PURPOSE: This study examined the catabolic effects of kinsenoside on lipolysis in adipocytes transformed from C3H10T1/2 cells. STUDY DESIGN/METHODS: The lipolytic effect of kinsenoside in C3H10T1/2 adipocytes was evaluated by oil-red O staining and glycerol production. The underlying mechanisms were assessed by Western blots, chromatin immunoprecipitation (IP), Co-IP, EMSA and siRNAs verification. RESULTS: We demonstrated that kinsenoside increased both adipose triglyceride lipase (ATGL)-mediated lipolysis, which was upregulated by AMP-activated protein kinase (AMPK) activation, and the hydrolysis of triglycerides to glycerol and fatty acids that require transportation into mitochondria for further ß-oxidation. We also demonstrated that kinsenoside increased the phosphorylation of peroxisome proliferator-activated receptor alpha (PPARα) and CRE-binding protein (CREB), and the protein levels of silent information regulator T1 (SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) and carnitine palmitoyltransferase I (CPT1) through an AMPK-dependent mechanism. SIRT1 deacetylated PGC-1α, facilitating AMPK-mediated PGC-1α phosphorylation and increasing the interaction of PPARα with its coactivator, PGC-1α. This interaction elevated the expression of CPT1, a shuttle for the mitochondrial transport of fatty acids, in kinsenoside-treated cells. In addition, AMPK-phosphorylation-mediated CREB activation caused kinsenoside-mediated PGC-1α upregulation. CONCLUSION: AMPK activation not only elevated ATGL expression for lipolysis but also induced CPT1 expression for further mitochondrial translocation of fatty acids. The results suggested that the mechanism underlying the catabolic effects of kinsenoside on lipolysis and increased CPT1 induction was mediated through an AMPK-dependent pathway.

Targeting of Topoisomerase I for Prognoses and Therapeutics of Camptothecin-Resistant Ovarian Cancer.

DNA topoisomerase I (TOP1) levels of several human neoplasms are higher than those of normal tissues. TOP1 inhibitors are widely used in treating conventional therapy-resistant ovarian cancers. However, patients may develop resistance to TOP1 inhibitors, hampering chemotherapy success. In this study, we examined the mechanisms associated with the development of camptothecin (CPT) resistance in ovarian cancers and identified evodiamine (EVO), a natural product with TOP1 inhibiting activity that overcomes the resistance. The correlations among TOP1 levels, cancer staging, and overall survival (OS) were analyzed. The effect of EVO on CPT-resistant ovarian cancer was evaluated in vitro and in vivo. TOP1 was associated with poor prognosis in ovarian cancers (p = 0.024). EVO induced apoptosis that was detected using flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The tumor size decreased significantly in the EVO treatment group compared with the control group (p < 0.01) in a xenograft mouse model. Effects of drugs targeting TOP1 for prognosis and therapy in CPT-resistant ovarian cancer are anticipated. EVO with TOP1 can be developed as an antiproliferative agent for overcoming CPT resistance in ovarian cancers.

Pectin hydroxamic acids exhibit antioxidant activities in vitro.

Commercial pectins with different degrees of esterification (DE) were reacted with equal volumes of 2 M alkaline hydroxylamine (pH 12.0) at room temperature for 4 h to prepare pectin hydroxamic acids (PHAs; DE94T4, DE65T4, and DE25T4) according to a previously reported method (Hou et al., J. Agric. Food Chem. 2003, 51, 6362-6366) and were used to test the antioxidant and antiradical activities in comparison with those of DE94, DE65, and DE25 pectins. The half-inhibition concentrations, IC(50), of scavenging activity against DPPH were 1.51, 5.43, and 5.63 mg/mL for DE94T4, DE65T4, and DE25T4, respectively, and were much lower than those of corresponding DE pectins under the same concentrations. The scavenging activities of PHAs for DPPH radicals were positively correlated with original DE values of pectin. The optimal pH of DE94T4 for scavenging DPPH radicals was 7.9 or 8.0. Using electron spin resonance (ESR) for scavenging hydroxyl radicals, under the same concentrations of 125 microg/mL, DE94T4, DE65T4, and DE25T4, respectively, exhibited 73.53, 69.01, and 55.17% antiradical activities. PHAs also exhibited protection against hydroxyl radical-mediated DNA damage and anti-human low-density lipoprotein peroxidation tests.

Baicalin induces differential expression of cytochrome C oxidase in human lung H441 cell.

In a previous study, we evaluated the effect of baicalin on the expression of SP-A (surfactant protein A), which was developmentally regulated in an alveolar type II cell, H441. SP-A is encoded by two similar genes, SP-A1 and SP-A2, in humans. The maximal induction of SP-A1 gene of H441 occurred at treating 150 nM of baicalin for 48 h. In the present study, cDNA subtraction analysis is performed to examine the differential expression in H441 cell upon baicalin treatment with a view to investigating the regulatory mechanism. The mRNA of H441 cell incubated with 150 nM baicalin for 48 h was compared to that of blank control. Two PCR products were obtained through subtractive cDNA amplification. A product encoding cytochrome c oxidase was demonstrated to be a differential signal by RT-PCR analysis, and the other was a false positive. The induction of cytochrome c oxidase might increase ATP level in cell, and consequently elevates cAMP, which upregulates surfactant synthesis and secretion.

Hispolon inhibition of inflammatory apoptosis through reduction of iNOS/NO production via HO-1 induction in macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: Phellinus linteus (Berkeley & Curtis), a well-known medical fungus, has long been used as a traditional medicine in Oriental countries to treat various diseases, and hispolon (HIS) is one of its bioactive components. HIS is known to possess potent antineoplastic and antiviral properties; however, its effect on inflammatory apoptosis is still undefined. MATERIALS AND METHODS: RAW264.7 macrophages were incubated with HIS for 30 min followed by LPS, LTA, or PGN stimulation for 12h. The expression of indicated proteins AP-1 and NF-κB transcriptional activities was examined by Western blotting using specific antibodies. Levels of NO and ROS were examined by Griess reaction, and DCHF-DA staining via flow cytometric analysis, respectively. AP-1 and NF-κB transcriptional activities were detected by luciferase reporter assay. Knockdown of HO-1 protein expression was performed by transfection of macrophages with HO-1 siRNA. Pharmacological inhibitors including ROS scavenger NAC, JNK inhibitor SP600125, NF-κB inhibitor BAY117082 were applied for mechanism study. RESULTS: HIS showed concentration-dependent inhibition of LPS, LTA, and PGN-induced iNOS protein expressions and NO production by RAW264.7 macrophages. Accordingly, HIS protected RAW264.7 cells from LPS-, LTA-, and PGN-induced apoptosis. Increased HO-1 by HIS was detected at both protein and mRNA levels along with an increase in intracellular peroxide, and this was inhibited by the translational inhibitor, cycloheximide (CHX), the transcriptional inhibitor, actinomycin D (Act D), and the reactive oxygen species scavenger, N-acetylcysteine (NAC). A mechanistic study indicated that inhibition of c-Jun N-terminal kinase (JNK) protein phosphorylation, and activator protein (AP)-1 and nuclear factor (NF)-κB activation were involved in the anti-inflammatory actions of HIS in macrophages. A structure-activity relationship analysis showed that HIS expressed the most potent effect of inhibiting iNOS and apoptosis elicited by LPS, LTA, and PGN with a significant increase in HO-1 protein in macrophages. CONCLUSIONS: Evidence supporting HIS prevention of inflammatory apoptosis via blocking NO production and inducing HO-1 protein expression in macrophages is provided, and the hydroxyl at position C3 is a critical substitution for the anti-inflammatory actions of HIS.

Propionibacterium acnes-induced iNOS and COX-2 protein expression via ROS-dependent NF-κB and AP-1 activation in macrophages.

BACKGROUND: Propionibacterium acnes (P. acnes), a gram-positive anaerobic bacterium, plays a critical role in the development of inflammatory lesion as a result of cytokines production by keratinocytes and macrophages activation. However, effect of P. acnes on iNOS/NO and COX-2/PGE2 production in macrophages is still uninvestigated. OBJECTIVE: This study aimed at determining the reactive oxygen species (ROS), inducible nitric oxide (NO) synthase (iNOS)/nitric oxide (NO), and cyclooxygenase (COX)-2/prostaglandin (PG)E2 produced by macrophages upon P. acnes infection, and dissecting the mechanism of P. acnes-stimulated multiplicity of infection (MOI)-dependent increases in iNOS and COX-2 protein expressions in accordance with the elevation of NO and PGE2 production by RAW264.7 macrophages. METHODS: Using an in vitro cell culture system, the effects of P. acnes on iNOS/NO, COX-2/PGE2, ROS production, ERK/JNK, and AP-1/NF-κB activation were examined via Western blotting, a flow cytometric analysis, and luciferase assay. In pharmacological studies, the ROS scavenger, N-acetyl cysteine (NAC), the NADPH oxidase inhibitor, diphenylene iodide (DPI), and mitogen-activated protein kinase (MAPK) inhibitors (U0126 and SP600125) were applied to investigate the mechanism. RESULTS: We found that P. acnes exposures increased iNOS/NO and COX-2/PGE2 expression in RAW264.7, J774A.1, and peritoneal macrophages via a MOI-dependent manner. Increased ROS production, ERK/JNK protein phosphorylation, and elevated AP-1/NF-κB luciferase activity are identified in P. acnes-induced iNOS/NO and COX-2/PGE2 production. Additionally, hispolon but not its analogs, hispolon methylether or dehydroxyhispolon, showed significant inhibition of P. acnes-induced iNOS/NO and COX-2/PGE2 production, indicating an important role of OH at C5 for hispolon's inhibition of P. acnes-induced inflammatory events in macrophages. CONCLUSION: ROS-dependent stimulation of ERK, JNK, NF-κB, and AP-1 activation contributes to P. acnes-induced iNOS/NO and COX-2/PGE2 in macrophages, and chemicals such as hispolon possessing ability to block iNOS/NO and COX-2/PGE2 production reserve potential to be further developed for treatment of the early phase of inflammation elicited by P. acnes.

Proteomics demonstration that histone H4 is a colchicine-induced retro-modulator of growth and alkaline phosphatase activity in hair follicle dermal papilla culture.

Dermal papilla cells (DPCs) control the development of hair follicles via cell-cell interactions and extracellular molecules. Colchicine affected active anagen DPCs to result in hair loss in the clinical setting. The purpose of this study was to identify the retro-modulator released by DPCs exposed to sub-toxic dose of colchicine and elucidate its effect on dermal papilla culture. The molecular-weight cutoff ultrafiltration and HPLC were used to purify the components of colchicine-treated DPC secretomes and examined their ability to down-regulate the growth and alkaline phosphatase (ALP) activity of DPCs. The active product was identified by in-gel trypsin digestion, nano-LC-ESI-MS/MS and validated by Western blot to be histone H4 (P62804), which inhibited the proliferation and diminished the ALP activity of cultured DPCs. Treating DPCs with recombinant histone H4 reproduced the growth inhibition effect whereas adding antibody to immunoneutralize histone H4 abolished this growth inhibitory consequence. DPCs with high ALP activity can induce the neogenesis of hair follicles and support the hair fiber growth in vivo. Our results indicated that sub-lethal colchicine can inactivate DPCs through releasing histone H4. Through the investigation of the retro-modulation of histone H4 on dermal papillae may give implications for understanding the mechanism of colchicine-induced hair disorder.

New constituent from Podocarpus macrophyllus var. macrophyllus shows anti-tyrosinase effect and regulates tyrosinase-related proteins and mRNA in human epidermal melanocytes.

A new biflavonoid, 2,3-dihydro-4',4'''-di-O-methylamentoflavone (5), and five known compounds, (-)-catechin (1), quercetin (2), 2,3-dihydrosciadopitysin (3), sciadopitysin (4), and isoginkgetin (6), were isolated from Podocarpus macrophyllus var. macrophyllus (Podocarpaceae). These compounds were evaluated their ability to inhibit cellular tyrosinase activity and for their melanin inhibitory activity in human epidermal melanocytes (HEMn). In the melanin synthesis assay, 2,3-dihydro-4',4'''-di-O-methylamentoflavone (5) showed a potent anti-tyrosinase effect with IC(50)=0.098 mM in HEMn. It also significantly decreased both protein and mRNA levels of the tyrosinase-related protein-2 (TRP-2) by Western blot and quantitative real-time PCR (qRT-PCR) analysis. These findings suggest that the new compound, 2,3-dihydro-4',4'''-di-O-methylamentoflavone (5), is the most active component of P. macrophyllus var. macrophyllus in inhibiting pigmentation and that this inhibition is exerted through inhibition of transcription of the genes encoding TRP2.