Sedum middendorffianum Maxim Induces Apoptosis and Inhibits the Invasion of Human Ovarian Cancer Cells via Oxidative Stress Regulation.

Sedum middendorffianum Maxim (SMM) is a Korean endemic plant belonging to the Crassulaceae family. This study aimed to investigate the antitumor effects of the SMM extract on human ovarian cancer cells. Among five endemic plants grown in Korea, the SMM extract showed the most potent cytotoxicity in ovarian cancer cells and had little effect on normal ovarian surface epithelial cells. Furthermore, we revealed that the SMM extract dose-dependently induced apoptosis in human ovarian cancer A2780 and SKOV3 cells. The SMM extract markedly stimulated the activation of caspase-3/8, while the broad-spectrum caspase inhibitor and caspase-8 selective inhibitor significantly reversed SMM extract-induced apoptosis. In addition, the SMM extract significantly inhibited cell invasion and the expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 in ovarian cancer cells. Notably, the SMM extract increased the generation of intracellular ROS, and pretreatment with antioxidant N-acetyl-L-cysteine (NAC) significantly suppressed SMM-induced cytotoxicity and anti-invasive activity. Moreover, NAC treatment reversed the SMM-induced inhibition of MMP-2/9 expression. Taken together, these data suggest that the SMM extract induces caspase-dependent apoptotic cell death and inhibits MMP-dependent invasion via ROS regulation.

Gomisin L1, a Lignan Isolated from Schisandra Berries, Induces Apoptosis by Regulating NADPH Oxidase in Human Ovarian Cancer Cells.

The fruits of Schisandra chinensis (Schisandra berries) are used as health food supplements and popular food ingredients in East Asia. Lignans, major and characteristic polyphenol compounds of Schisandra berries, possess various biological activities, including hepatoprotective and anticancer effects. However, the biological activities of gomisin L1, a lignan isolated from Schisandra berries, are less to be investigated. In this study, the antitumor activity of gomisin L1 and its underlying molecular mechanism in human ovarian cancer cells were investigated. Gomisin L1 exhibited potent cytotoxic activity against A2780 and SKOV3 ovarian cancer cells. Flow cytometry analysis revealed that the growth inhibitory effects of gomisin L1 were mediated by the induction of apoptosis. Furthermore, gomisin L1 induced an increase in intracellular reactive oxygen species (ROS) levels, and the antioxidant N-acetyl cysteine significantly negated gomisin L1-induced cell death. Moreover, inhibition of NADPH oxidase (NOX) using an inhibitor and siRNA attenuated gomisin L1-induced death of, and ROS production in, human ovarian cancer cells. Taken together, these data indicate that the lignan gomisin L1 from Schisandra berries induces apoptotic cell death by regulating intracellular ROS production via NOX.

CC Chemokine Ligand 7 Derived from Cancer-Stimulated Macrophages Promotes Ovarian Cancer Cell Invasion.

In the tumor microenvironment, macrophages have been suggested to be stimulated by tumor cells, becoming tumor-associated macrophages that promote cancer development and progression. We examined the effect of these macrophages on human ovarian cancer cell invasion and found that conditioned medium of macrophages stimulated by ovarian cancer cells (OC-MQs) significantly increased cell invasion. CC chemokine ligand 7 (CCL7) expression and production were significantly higher in OC-MQs than in the control macrophages. Peritoneal macrophages from patients with ovarian cancer showed higher CCL7 expression levels than those from healthy controls. Inhibition of CCL7 using siRNA and neutralizing antibodies reduced the OC-MQ-CM-induced ovarian cancer cell invasion. CC chemokine receptor 3 (CCR3) was highly expressed in human ovarian cancer cells, and a specific inhibitor of this receptor reduced the OC-MQ-CM-induced invasion. Specific signaling and transcription factors were associated with enhanced CCL7 expression in OC-MQs. CCL7-induced invasion required the expression of matrix metalloproteinase 9 via activation of extracellular signal-related kinase signaling in human ovarian cancer cells. These data suggest that tumor-associated macrophages can affect human ovarian cancer metastasis via the CCL7/CCR3 axis.

Reduced Levels of Intestinal Neuropeptides and Neurotrophins in Neurotoxin-Induced Parkinson Disease Mouse Models.

Intestinal neuropeptides and neurotrophins as endocrine messengers play a key role in the bidirectional gut-brain interaction both in health and disease status. Their alterations in several neurological disorders have been reported, but whether a remarkable change occurs in Parkinson disease (PD) remains unexplored. In this study, we aimed to investigate the levels of 13 neuropeptides and 4 neurotrophins in the intestine of neurotoxin-induced PD mice. The PD mice were obtained by chronic injection of 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) or MPTP/probenecid (MPTP/p). The levels of mRNA and protein expression in mouse intestines were measured by using real-time reverse transcription polymerase chain reaction and Western blotting, respectively. We found that the mRNA expression of 2 neuropeptides (cholecystokinin [CCK] and dynorphin A [Dyn A]) and 2 neurotrophins (brain-derived neurotrophic factor [BDNF] and neurotrophin-5) was significantly decreased in the colon of MPTP group compared to the vehicle-treated group. The protein levels of CCK, Dyn A, and BDNF were reduced in the colon of MPTP- or MPTP/p-treated mice compared to those of the vehicle-treated group. These data suggest that the intestinal expression of CCK, Dyn A, and BDNF was significantly reduced in PD animal models, and may play a role in the gut-brain axis in PD.

Chemical Constituents of the Leaves of Butterbur (Petasites japonicus) and Their Anti-Inflammatory Effects.

Two new aryltetralin lactone lignans, petasitesins A and B were isolated from the hot water extract of the leaves of butterbur (Petasites japonicus) along with six known compounds. The chemical structures of lignans 1 and 2 were elucidated on the basis of 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data, electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) spectra. Petasitesin A and cimicifugic acid D showed significant inhibitory effects on the production of both prostaglandin E2 (PGE2) and NO in RAW264.7 macrophages. The expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were inhibited by compound 1 in RAW264.7 cells. Furthermore, compounds 1 and 3 exhibited strong affinities with both iNOS and COX-2 enzymes in molecular docking studies.

Transfer of a mobile Staphylococcus saprophyticus plasmid isolated from fermented seafood that confers tetracycline resistance.

The complete nucleotide sequence of a tetracycline-resistance gene (tetK)-carrying plasmid from a Staphylococcus saprophyticus isolate from jeotgal, a Korean high-salt-fermented seafood, was determined. The plasmid, designated pSSTET1, was 4439 bp in length and encoded typical elements found in plasmids that replicate via a rolling-circle mechanism, including the replication protein gene (rep), a double-stranded origin of replication, a single-stranded origin of replication, and a counter-transcribed RNA sequence. Additionally, the plasmid recombination enzyme gene (pre), which may be involved in inter-plasmid recombination and conjugation, was found. Each gene exhibited >94% sequence identity with those harbored in other Staphylococcus species. pSSTET1 was conditionally transferred to Staphylococcus species in a host-dependent manner and transferred to an Enterococcus faecalis strain in vitro. Antibiotic susceptibility of the transconjugants was host-dependent and transconjugants maintained a tetracycline-resistant phenotype in the absence of selective pressure over 100 generations.

(-)-Asarinin from the Roots of Asarum sieboldii Induces Apoptotic Cell Death via Caspase Activation in Human Ovarian Cancer Cells.

Two tetrahydrofurofurano lignans (1 and 2), four phenylpropanoids (3⁻6), and two alkamides (7 and 8) were isolated from the EtOAc-soluble fraction of the roots of Asarum sieboldii. The chemical structures of the isolates were identified by analysis of spectroscopic data measurements, and by a comparison of their data with published values. The isolates (1, 2, 4⁻8) were evaluated for their cytotoxicity against human ovarian cancer cells (A2780 and SKOV3) and immortalized ovarian surface epithelial cells (IOSE80PC) using a MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay. Of the isolates, (-)-asarinin (1) exhibited the most potent cytotoxicity to both A2780 and SKOV3 cells. A propidium iodide/annexin V-fluorescein isothiocyanate (V-FITC) double staining assay showed that (-)-asarinin (1) induces apoptotic cell death in ovarian cancer cells. In addition, (-)-asarinin (1) increased the activation of caspase-3, caspase-8, and caspase-9 in ovarian cancer cells. Pretreatment with caspase inhibitors attenuated the cell death induced by (-)-asarinin (1). In conclusion, our findings show that (-)-asarinin (1) from the roots of A. sieboldii may induce caspase-dependent apoptotic cell death in human cancer cells.

Chemical Constituents of Apios americana Tubers and Their Inhibitory Activities on Nitric Oxide Production in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages.

Apios americana is an important food crop producing edible tubers with high nutritional and medicinal values and is widely cultivated in many countries. Despite its usefulness, research on its secondary metabolites and biological activities has been limited. In the present study, a new coumaronochromone, (2 R,3 S)-3,7,4'-trihydroxy-5-methoxycoumaronochromone (1), and two new isoflavone glucosides, 7,2',4'-trihydroxy-5-methoxyisoflavone-4'- O-ß-d-glucopyranoside (3) and 5,7,4'-trihydroxyisoflavone-7- O-ß-d-gentiotrioside (5), were isolated from the tubers of A. americana via chromatographic separation. Seventeen known compounds (2, 4, and 6-20) were also obtained from this plant part. The chemical structures of 1, 3, and 5 were determined by the interpretation of spectroscopic data. The absolute structure of the new compound 1 was established from experimental and calculated electronic circular dichroism spectra. This is the first study to determine the absolute configuration of a 3-hydroxycoumaronochromone derivative. The potential anti-inflammatory activity of the 20 isolates obtained was evaluated by measuring their inhibitory effects on nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages. Among the isolates, seven compounds (1, 3, 6-8, 15, and 20) showed substantial inhibition of nitric oxide production in RAW 264.7 cells, with the most active being compound 1 (IC50 value of 0.38 ± 0.04 µM).

9-Hydroxycanthin-6-one isolated from stem bark of Ailanthus altissima induces ovarian cancer cell apoptosis and inhibits the activation of tumor-associated macrophages.

The stem bark of Ailanthus altissima is used in traditional medicine in Asia to treat a variety of diseases, including cancer. The aim of this study was to identify compounds with tumoricidal activity from A. altissima stem bark and to investigate their mechanisms of action. Among the 13 compounds isolated from the ethyl acetate fraction of A. altissima stem bark, the ß-carboline alkaloid 9-hydroxycanthin-6-one had potent cytotoxicity in all three ovarian cancer cell types examined. 9-Hydroxycanthin-6-one induced apoptosis through the activation of caspases-3, -8, and -9. 9-Hydroxycanthin-6-one increased the intracellular levels of reactive oxygen species (ROS), and pre-treatment with the antioxidant N-acetyl-l-cysteine (NAC) attenuated the pro-apoptotic activity of 9-hydroxycanthin-6-one. Additionally, 9-hydroxycanthin-6-one was found to decrease the expressions of MCP-1 and RANTES, major determinants of macrophage recruitment at tumor sites, in ovarian cancer cells. Treatment with 9-hydroxycanthin-6-one inhibited the levels of M2 phenotype markers and some cancer-promoting factors, such as MMP-2, MMP-9, and VEGF, in macrophages educated in ovarian cancer conditioned medium. Taken together, these data suggest that 9-hydroxycanthin-6-one isolated from A. altissima stem bark induces apoptosis in human ovarian cancer cells through the caspase- and ROS-dependent pathways and inhibits the activation of tumor-associated macrophages.

Anti-inflammatory Effects of Canthin-6-one Alkaloids from Ailanthus altissima.

Canthin-6-one (CO) alkaloids possess various biological activities, including antibacterial, antitumor, antifungal, and antiviral activities. However, their anti-inflammatory effects and underlying molecular mechanisms are poorly characterized. This study aimed to investigate the anti-inflammatory effects of CO and its derivative 5-(1-hydroxyethyl)-canthin-6-one (5-HCO), isolated from the stem barks of Ailanthus altissima in lipopolysaccharide (LPS)-stimulated macrophages. CO (1 and 5 µM) and 5-HCO (7.5 and 15 µM) significantly inhibited the LPS-induced expression of inducible nitric oxide synthase. In addition, CO (1 and 5 µM) and 5-HCO (15 µM) markedly suppressed the production of prostaglandin E2 (PGE2) and expression of cyclooxygenase-2, a key enzyme in PGE2 synthesis, in LPS-stimulated macrophages. Moreover, CO treatment significantly reduced monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) expression, whereas 5-HCO inhibited MCP-1, but not TNF-α expression. Both CO and 5-HCO inhibited the phosphorylation of inhibitor kappa B and transcriptional activation of nuclear factor kappa B (NF-κB) in LPS-stimulated macrophages. In addition, CO, but not 5-HCO, markedly reduced Akt phosphorylation. Taken together, these data suggest that CO, but not 5-HCO with a hydroxyethyl moiety on the D ring, has potent anti-inflammatory activity in LPS-stimulated macrophages through the downregulation of both the NF-κB and the Akt pathway.

Kudsuphilactone B, a nortriterpenoid isolated from Schisandra chinensis fruit, induces caspase-dependent apoptosis in human ovarian cancer A2780 cells.

A phytochemical study on the fruits of Schisandra chinensis led to the isolation and characterization of nineteen compounds. The structures of the isolates were determined to be schizandrin, deoxyschizandrin, angeloylgomisin H, gomisin A, gomisin J, (-)-gomisin L1, (-)-gomisin L2, wuweizisu C, gomisin N, meso-dihydroguaiaretic acid, kadsuphilactone B, α-ylangenol, α-ylangenyl acetate, ß-chamigrenal, ß-chamigrenic acid, 4-hydroxybenzoic acid, protocatechuic acid, p-methylcarvacrol, and indole-3-acetic acid. Of these, some lignans and a nortriterpene showed cytotoxic activity in human ovarian and endometrial cancer cells. In particular, a nortriterpenoid kadsuphilactone B exhibited significant cytotoxic activity with IC50 values below 25 µM in both A2780 and Ishikawa cells. Kadsuphilactone B induced apoptotic cell death and stimulated the activation of caspase-3, -8, and -9 and the cleavages of poly (ADP-ribose) polymerase. Caspase inhibitors attenuated the pro-apoptotic activity of kudsuphilactone B. In addition, kadsuphilactone B altered the expression levels of B cell lymphoma 2 (Bcl-2) family proteins. Moreover, activation of MAPKs was modulated by kadsuphilactone B in a dose-dependent manner. Taken together, these results show that kadsuphilactone B induces caspase-dependent apoptosis in human cancer cells via the regulation of Bcl-2 family protein and MAPK signaling.

Isocyperol, isolated from the rhizomes of Cyperus rotundus, inhibits LPS-induced inflammatory responses via suppression of the NF-κB and STAT3 pathways and ROS stress in LPS-stimulated RAW 264.7 cells.

The rhizomes of Cyperus rotundus (cyperaceae) have been used in Korean traditional medicines for treating diverse inflammatory diseases. However, little is known about the biological activities of isocyperol, a sesquiterpene isolated from C. rotundus, and their associated molecular mechanisms. In this study, we found that isocyperol significantly inhibited lipopolysaccharide (LPS)-induced production of nitrite oxide (NO) and prostaglandin E2 (PGE2) and suppressed LPS-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the mRNA and protein levels in RAW 264.7 macrophages. In addition, isocyperol downregulated the LPS-induced expression of several proinflammatory cytokines, such as interleukin-1beta (IL-1ß), IL-6, and monocyte chemotactic protein-1 (MCP-1). Isocyperol treatment suppressed the LPS-induced nuclear translocation and transcriptional activation of nuclear factor-kappaB (NF-κB) in macrophages. Moreover, the activation of STAT3, another proinflammatory signal, was suppressed by isocyperol in LPS-stimulated RAW 264.7 cells. Isocyperol pretreatment also induced heme oxygenase-1 (HO-1) expression and reduced LPS-stimulated reactive oxygen species (ROS) accumulation in macrophages. Furthermore, isocyperol significantly increased the survival rate and attenuated serum levels of NO, PGE2, and IL-6 in LPS-induced septic shock mouse model. Taken together, these data indicate that isocyperol suppress septic shock through negative regulation of pro-inflammatory factors through inhibition of the NF-κB and STAT3 pathways and ROS. To our knowledge, this is the first report on the biological activity of isocyperol and its molecular mechanism of action.

A New Canthinone-Type Alkaloid Isolated from Ailanthus altissima Swingle.

The present investigation of the chemical constituents of the stem barks of Ailanthus altissima has resulted in the isolation of six canthinone-type alkaloids, including a new compound, (R)-5-(1-hydroxyethyl)-canthine-6-one (1), and five known compounds (2-6). Moreover, four phenyl propanoids (7-10), two lignans (11 and 12), two triterpenoids (13 and 14) and a fatty acid (15) having previously known chemical structures were isolated during the same course of this study. The structure of the new compound was elucidated by physical (m.p., [α]D) and spectroscopic data (¹H-NMR, (13)C-NMR, 2D NMR, and HR-DART-MS) interpretation and its absolute configuration was determined by electronic circular dichroism (ECD) data and quantum chemical calculations. The inflammatory activities of the isolates were screened on lipopolysaccharide (LPS)-induced nitric oxide (NO), a proinflammatory mediator, in RAW 264.7 cells. Among these isolated compounds, six compounds exhibited significant inhibition of NO production, with IC50 values in the range of 5.92 ± 0.9 to 15.09 ± 1.8 µM.

PCR-DGGE analysis of population dynamics of lactic acid bacteria in kimchi by addition of bacteriocins.

The effects of two crude bacteriocins (DF01 and K10) on lactic acid bacteria (LAB) communities and pH during kimchi fermentation were analyzed by polymerase chain reactiondenaturing gradient gel electrophoresis (PCR-DGGE). Crude LAB bacteriocins, prepared by ammonium sulfate precipitation, were added at 5 AU/mL, and kimchi was incubated at 20°C for 7 days. The pH and titratable acidity of the kimchies were determined daily, and the amplified 16S rRNA products were analyzed by PCR-DGGE. The common and main LAB were Weissella spp., Leuconostoc spp., and Lactobacillus spp. from both control and bacteriocin-treated samples. Among them, W. koreensis, W. confusa, and Lb. sakei were the predominant microorganisms throughout the fermentation period. Some obligate and facultatively heterofermentative LAB were detected from the bacteriocin-treated samples. The pH of the kimchi samples treated with each bacteriocin was higher (ca. 0.8 unit) than that of the control at day 4 and 5.

Synergistic effect of fucoidan with antibiotics against oral pathogenic bacteria.

BACKGROUND: Fucoidan is a sulphated polysaccharide that is primarily extracted from brown seaweeds; it has been broadly studied in recent years due to its numerous biological properties, including anticoagulant, antithrombotic, antitumour and antiviral activities. OBJECTIVE AND DESIGN: In this study, fucoidan was evaluated against oral bacteria, either alone or with antibiotics, via the broth dilution method and chequerboard and time-kill assay. RESULTS: Minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) values for the fucoidan against all the tested bacteria ranged between 0.125 and 0.50/0.25 and 1.00mgml(-1), for ampicillin 0.125 and 64/0.5 and 64µgml(-1) and for gentamicin 2 and 256/4 and 512µgml(-1), respectively. Furthermore, the MIC and MBC were reduced to one half-eighth as a result of the combination of the fucoidan with antibiotics. One to 3h of treatment with MIC50 of fucoidan with MIC50 of antibiotics resulted from an increase of the rate of killing in colony forming units (CFUs) ml(-1) to a greater degree than was observed with alone. CONCLUSION: These results suggest that fucoidan is important in the antibacterial actions of the agents.

Heterogeneous nuclear ribonucleoprotein C1/C2 controls the metastatic potential of glioblastoma by regulating PDCD4.

MicroRNAs (miRNAs) have been implicated in the pathogenesis and progression of brain tumors. miR-21 is one of the most highly overexpressed miRNAs in glioblastoma multiforme (GBM), and its level of expression correlates with the tumor grade. Programmed cell death 4 (PDCD4) is a well-known miR-21 target and is frequently downregulated in glioblastomas in accordance with increased miR-21 expression. Downregulation of miR-21 or overexpression of PDCD4 can inhibit metastasis. Here, we investigate the role of heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNPC) in the metastatic potential of the glioblastoma cell line T98G. hnRNPC bound directly to primary miR-21 (pri-miR-21) and promoted miR-21 expression in T98G cells. Silencing of hnRNPC lowered miR-21 levels, in turn increasing the expression of PDCD4, suppressing Akt and p70S6K activation, and inhibiting migratory and invasive activities. Silencing of hnRNPC reduced cell proliferation and enhanced etoposide-induced apoptosis. In support of a role for hnRNPC in the invasiveness of GBM, highly aggressive U87MG cells showed higher hnRNPC expression levels and hnRNPC abundance in tissue arrays and also showed elevated levels as a function of brain tumor grade. Taken together, our data indicate that hnRNPC controls the aggressiveness of GBM cells through the regulation of PDCD4, underscoring the potential usefulness of hnRNPC as a prognostic and therapeutic marker of GBM.

MAPK activation is necessary to the apoptotic death of KB cells induced by the essential oil isolated from Artemisia iwayomogi.

AIM OF THE STUDY: Artemisia iwayomogi is a perennial small herbal plant that has long been used as a chemopreventive agent in traditional Korean medicine. Previously, the purified essential oil was isolated from Artemisia iwayomogi, herein named AIEO, and found to contain the active components responsible for the chemopreventive potential of the herb. MATERIALS AND METHODS: This study examined whether or not AIEO has potential chemopreventative effects against cancer using the human oral epidermoid carcinoma cell line, KB cells. The possible mechanism of AIEO-induced apoptosis was also examined. RESULTS: The results showed that AIEO induces the apoptotic death of KB cells, which is mediated by mitogen-activated protein kinases (MAPKs). In addition, AIEO not only induced an imbalance between the mitochondrial Bcl-2 and Bax levels with the concomitant release of Cytochrome c into the cytosol but also induced the activation of caspases and the cleavage of PARP. This induction was significantly suppressed by MAPK inhibitors. Moreover, pretreating the cells with each of the caspase or MAPK-specific inhibitors apparently inhibited AIEO-induced cytotoxicity of KB cells. CONCLUSIONS: These results strongly suggest that AIEO might have cancer chemopreventive and therapeutic potential, which is closely related to its ability to activate the MAPK-mediated signaling pathways with the subsequent induction of a mitochondria- and caspase-dependent mechanism.

Essential Oil Prepared from Cymbopogon citrates Exerted an Antimicrobial Activity Against Plant Pathogenic and Medical Microorganisms.

Essential oils are mixtures of volatile, lipophilic compounds originating from plants. Some essential oils have useful biological activities including antimicrobial, spasmolytic, antiplasmodial, and insect-repelling activities. In this study, we tested the antimicrobial activity of essential oil prepared from the aromatic plant, Cymbopogon citrates, against three important plant pathogenic and medical microorganisms, Pectobacterium carotovorum, Colletotrichum gloeosporioides, and Aspergillus niger. It effectively inhibited the growth of the bacterium, Pectobacterium carotovorum, in a dose-dependent fashion, and 0.5% of the oil inhibited the growth of bacteria completely. Similarly, the essential oil inhibited the growth of plant pathogenic fungus, Colletotrichum gloeosporioides, and the addition of 1% of essential oil completely inhibited the growth of fungus even after 5 days of culture. Finally, it effectively inhibited the growth of the medically and industrially important fungal species, Aspergillus spp. These results suggest that the essential oil from Cymbopogon citrates may be an environmentally safe alternative to inhibit antimicrobial agents for various uses.

Antibacterial activity of sophoraflavanone G isolated from the roots of Sophora flavescens.

This study investigated the antibacterial activities of sophoraflavanone G from Sophora flavescens in combination with two antimicrobial agents against oral bacteria. The combined effect of sophoraflavanone G and the antimicrobial agents was evaluated using the checkerboard method to obtain a fractional inhibitory concentration (FIC) index. The sophoraflavanone G+ampicillin (AM) combination was found to have a synergistic effect against S. mutans, S. sanguinis, S. sobrinus, S. gordonii, A. actinomycetemcomitans, F. nucleatum, P. intermedia, and P. gingivalis, whereas the sophoraflavanone G+gentamicin (GM) combination had a synergistic effect against S. sanguinis, S. criceti, S. anginosus, A. actinomycetemcomitans, F. nucleatum, P. intermedia, and P. gingivalis. Neither combination exhibited any antagonistic interactions (FIC index >4). In particular, the MICs/MBCs for all the bacteria were reduced to one-half - one-sixteenth as a result of the drug combinations. A synergistic interaction was also confirmed by time-kill studies for nine bacteria where the checkerboard suggested synergy. Thus, a strong bactericidal effect was exerted through the drug combinations, plus in vitro data suggested that sophoraflavanone G combined with other antibiotics may be microbiologically beneficial rather than antagonistic.

Chemical composition and antimicrobial activity of the essential oil of Cryptomeria japonica.

The composition and the antibacterial activity of the essential oil obtained from Cryptomeria japonica D. Don on oral bacteria were studied. The chemical composition of the essential oil was analysed by GC and GC-MS. Sixty-eight compounds accounting for 95.82% of the oil were identified. The main compounds in the oil were alpha-pinene (6.07%), sabinene (8.86%), terpinen-4-ol (9.77%), alpha-terpineol (6.13%), elemol (11.17%) and 10(15)-cadinen-4-ol (7.16%). The essential oil and some of its major compounds were tested for antimicrobial activity against 15 different genera of oral bacteria. The essential oil of C. japonica exhibited considerable inhibitory effects against all bacteria tested (MICs, 0.025-0.05 mg/mL; MBCs, 0.025-0.1 mg/mL), while its major compounds demonstrated various degrees of growth inhibition.