In vitro activity of xanthorrhizol against Streptococcus mutans biofilms

AIMS: We determined the effect of xanthorrhizol (XTZ) purified from the rhizome of Curcuma xanthorrhiza Roxb. on the Streptococcus mutans biofilms in vitro. METHODS AND RESULTS: The biofilms of S. mutans at different phases of growth were exposed to XTZ at different concentrations (5, 10 and 50 micromol l(-1)) and for different time exposures (1, 10, 30 and 60 min). The results demonstrated that the activity of XTZ in removing S. mutans biofilm was dependent on the concentration, exposure time and the phase growth of biofilm. A concentration of 5 micromol l(-1) of XTZ completely inhibited biofilm formation by S. mutans at adherent phases of growth, whereas 50 micromol l(-1) of XTZ removed 76% of biofilm at plateau accumulated phase when exposed to S. mutans biofilm for 60 min. CONCLUSIONS: Xanthorrhizol isolated from an edible plant (C. xanthorrhiza Roxb.) shows promise as an antibacterial agent for inhibiting and removing S. mutans biofilms in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY: XTZ could be used as a potential antibacterial agent against biofilm formation by S. mutans.     

Synergistic anticandidal activity of xanthorrhizol in combination with ketoconazole or amphotericin B

Candida species are responsible for the fourth most common nosocominal bloodstream infection. Xanthorrhizol, a sesquiterpene compound isolated from Curcuma xanthorrhiza Roxb. has been reported to have anticandidal activity. The aim of this study is to investigate the synergistic anticandidal effect of xanthorrhizol in combination with ketoconazole or amphotericin B against Candida albicans, Candida glabrata, Candida guilliermondii, Candida krusei, Candida parapsilosis , and Candida tropicalis . Mostly, xanthorrhizol in combination with ketoconazole or amphotericin B exhibited the synergistic anticandidal effects against all species of Candida tested. In combination with xanthorrhizol, the concentration of ketoconazole or amphotericin B for inhibiting the growth of the tested Candida species could be reduced by ≥50%. Time–kill curves showed that 1/2 minimum inhibitory concentration (MIC) dose of xanthorrhizol, amphotericin B, or ketoconazole alone against each of the six Candida species did not inhibit the growth of all Candida species tested. However, 1/2 MIC dose of xanthorrhizol in combination with 1/2 MIC dose of ketoconazole or 1/2 MIC dose of amphotericin B exhibited growth inhibition of all Candida species tested and reduced viable cells by several logs within 4 h. These results support the potential use of xanthorrhizol as an anticandidal agent, and it can be used complementarily with other conventional antifungal agents.     

Quantitative determination of curcuminoids in Curcuma rhizomes and rapid differentiation of Curcuma domestica Val. and Curcuma xanthorrhiza Roxb. by capillary electrophoresis

The three major curcuminoids, curcumin, demethoxycurcumin and bis-demethoxycurcumin, from Curcuma domestica Val. (Curcuma longa L.) and Curcuma xanthorrhiza Roxb. (Zingiberaceae) were fully separated and quantified in less than 5 min using a capillary zone electrophoresis method with standard fused-silica capillaries and photodiode array detection. An electrolyte solution of 20 mM phosphate, 50 mM sodium hydroxide and 14 mM beta-cyclodextrin was found to be appropriate. Quantification was performed with 3,4-dimethoxy-trans-cinnamic acid as internal standard, and the limit of detection was 0.01 mg/mL. Extraction, stabilisation during sample storage and quantification procedures were optimised and carried out with drugs and commercial curry powder from different provenances. The results were compared with the photometric method of the monograph Curcumae xanthorrhizae rhizoma of the European Pharmacopoeia.     

Isolation, characterization and molecular cloning of a lipolytic enzyme secreted from Malassezia pachydermatis

Lipophilic Malassezia species may induce catheter-associated sepsis in premature neonates and immunocompromised patients receiving parenteral lipid emulsions. To assess the participation of lipolytic enzymes in the pathogenesis of this yeast, we cloned a gene encoding the enzyme. A lipolytic enzyme in the culture supernatant of Malassezia pachydermatis was purified 210-fold to homogeneity. The enzyme showed high esterase activity toward p-nitrophenyl octanoate. The cDNA encoding the enzyme was cloned using a degenerate oligonucleotide primer constructed from the N-terminal amino acid sequence. The cDNA consisted of 1582 bp, including an open reading frame encoding 470 amino acids. The first 19 amino acids and the following 13 amino-acid sequence were predicted to be the signal peptides for secretion and prosequence, respectively. The predicted molecular mass of the 438-amino acid mature protein was 48 kDa. Analysis of the deduced amino acid sequence revealed that it contains the consensus motif (Gly-X-Ser-X-Gly), which is conserved among lipolytic enzymes. Homology investigations showed that the enzyme has similarities principally with 11 lipases produced by Candida albicans (29-34% identity) and some other yeast lipases.     

In vitro susceptibility to 9 antifungal agents of 14 strains of Zygomycetes isolated from clinical specimens

Fourteen clinical isolates of Zygomycetes were tested for their in vitro susceptibility to nine antifungal agents. Susceptibility assessment was performed using a microtiter broth dilution method. Synthetic broth with YNB and glucose was used for 5-fluorocytosine and BHI broth for all the other antimycotics. Amphotericin B exhibited the strongest activity against all isolates tested. MIC values of other two polyenes — nystatin and pimaricin — ranged within the susceptibility limits, with a little pronounced higher activity of pimaricin. The isolates of the genusAbsidia andSyncephalastrum were well sensitive to all antimycotics with the exception of 5-fluorocytosine and naftifine. A very weak or zero growth inhibitory effect against all members of the generaMucor andRhizopus was found in azoles, 5-fluorocytosine and naftifine.     

Antimicrobial activity of Curcuma xanthorrhiza nanoemulsions on Streptococcus mutans biofilms

Abstract

In this study, an optimal nanoemulsion formulation for Curcuma xanthorrhiza oil (Xan) was investigated using different sonication times. The antimicrobial effects of the nanoemulsion, the original emulsion, distilled water (DW), and Listerine, on Streptococcus mutans biofilms were compared. The optimum ultrasonic time, determined in terms of droplet size and stability, was found to be 10?min. Cell viability was the lowest on exposure to the nanoemulsion, and significantly different compared with exposure to DW or Listerine. The emulsion’s effect was similar to that of the nanoemulsion, but was non-uniform with a high interquartile range. Confocal microscope analysis revealed that the live/dead cell ratio in the nanoemulsion was 50% and 40% less than those in DW and Listerine, respectively. Biofilm treated with the nanoemulsion was thinner than biofilms exposed to the other treatments. Xan nanoemulsions exhibited stable and strong antimicrobial effects due to nano-sized particles, highlighting their potential use in oral health treatment.     

In Vitro Clonal Propagation of Curcuma caesia Roxb and Curcuma zedoaria Rosc from Rhizome Bud Explants

Two species of Curcuma (C. caesia and C. zedoaria) have been propagated through tissue culture using rhizome bud explant. The best response for shoot multiplication was obtained on MS basal medium supplemented with 4 mg l^?1 BAP and 1.5 mg l^?1 NAA for C. caesia (3.5 ± 0.79 shoots per explant) and 1 mg l^?1 BAP + 0.5 mg l^?1 NAA for C. zedoaria (4.5 ± 0.15 shoots per explant). A maximum of 9.2 ± 0.15 and 8.9 ± 0.09 roots per explant were obtained for C. caesia and C. zedoaria, respectively when MS was supplemented with 0.5 mg l^?1 IAA. The rooted plants could be established in soil.     

体内和体外评价法分析内生真菌粗提取物的抗氧化活性

对几株经初筛具较高抗氧化活性的疏花水柏枝的内生真菌展开研究,在体内和体外两种方法下分析了其抗氧化能力。本研究选择1,1-二苯基-2-三硝基苯肼(DPPH)法、总抗氧化能力(T-AOC)试剂盒和铁氰化钾还原力测定法来评价内生真菌的体外抗氧化活性,并对不同方法进行了比较分析;建立并优化了大肠杆菌的氧化损伤模型,并将内生真菌对其保护作用与对人神经母瘤细胞SH-SY5Y的氧化损伤保护作用进行比较,分析了不同内生真菌在体内的抗氧化活性。结果表明体内和体外的抗氧化分析方法存在一定偏差,体外分析中活性最高的菌株是SJ-12和QY-1,体内分析中对大肠杆菌抗氧化保护效果最好的菌株也是QY-1和SJ-12,但对神经细胞保护效果最好的菌株是QY-1和MG-9。综合几种方法,本实验证明了内生真菌QY-1及其发酵产物具较强的抗氧化活性,可以作为潜在的新型抗氧化剂开发利用。     

In vitro translation of the genome of a small RNA virus from Trichoplusia ni

The genomic RNA of a member of the “Nudaurelia β virus” group functioned as a mRNA in vitro. The translation products included a protein, which comigrated with the single virus capsid protein, and a stable 100 × 10³ MW protein, which was synthesized by cleavage of a precursor protein. No precursor proteins were involved in synthesis of the putative capsid protein. Attempts to inhibit proteolytic cleavage did not result in the appearance of a product corresponding to the entire coding capacity of the genome.     

In vitro acclimatization of Curcuma longa under controlled iso-osmotic conditions

In vitro acclimatization has been validated as the successful key to harden the plantlets before transplanting to ex vitro conditions. In the present study, we investigated the potential of different sugar types (glucose, fructose, galactose, sucrose) in regulating morphological, physiological and biochemical strategies, survival percentage and growth performance, and rhizome traits of turmeric under iso-osmotic potential. Leaf greenness (SPAD value) in acclimatized plantlets (4% glucose; −1.355 MPa osmotic potential) of ‘ST018’ was retained and greater than in ‘PB009’ by 1.69-fold, leading to maintain high F_v/F_m (maximum quantum yield of PSII), Φ_PSII (photon yield of PSII) and P_n (net photosynthetic rate) levels, and retained shoot height, leaf length, leaf width, shoot fresh weight and shoot dry weight after one month upon transplanting to ex vitro conditions. In addition, P_n, C_i (intracellular CO₂), g_s (stomatal conductance) and E (transpiration rate) in acclimatized plantlets (6% sucrose; −1.355 MPa osmotic potential) of ‘PB009’ were stabilized as physiological adapted strategies, regulating the shoot and root growth and fresh and dry weights of mini-rhizome. Interestingly, the accumulation of total curcuminoids in mini-rhizome derived from 6% sucrose acclimatized plantlets of ‘ST018’ was greater than in ‘PB009’ by 3.76-fold. The study concludes that in vitro acclimation of turmeric ‘PB009’ and ‘ST018’ using 6% sucrose and 4% glucose, respectively, promoted percent survival, physiological adaptations, and overall growth performances under greenhouse conditions.     

布洛芬对曲霉的体外抗真菌活性评价

目的观察布洛芬对曲霉临床分离株的体外抗真菌活性。方法分别用微量液基稀释法和纸片扩散法,测定布洛芬对10株烟曲霉、黄曲霉和土曲霉的抗菌活性。结果微量液基稀释法显示布洛芬对曲霉的最低抑菌浓度（MIC）范围为1000～2000μg/mL,最低杀菌浓度（MFC）范围为2000～8000μg/mL;纸片扩散法也显示布洛芬有体外抗曲霉活性：48h时,1000μg布洛芬对曲霉产生的抑菌圈直径为（20.1±3.89）mm。结论布洛芬有体外抗曲霉活性。     

米卡芬净对分离自中国的念珠菌和曲霉临床株体外抑菌活性的研究

目的了解新型抗真菌药物米卡芬净(micafungin,MFG)对分离自中国的念珠菌和曲霉临床株的体外抑菌活性。方法参照CLSI(Clinical and Laboratory Standards Institute,以前为NCCLS)制定的M27-A2和M38-A方案测定86株念珠菌和35株曲霉的最低抑菌浓度(MIC)或最低有效浓度(MEC)。结果MFG对大多数念珠菌属和曲霉属均有较好的抑菌作用。对念珠菌属的MIC90从高到低依次为:氟康唑(FLC)敏感的白念珠菌、热带念珠菌、光滑念珠菌为0.125μg/ml,FLC耐药和剂量依赖敏感株为0.25μg/ml,克柔念珠菌为0.5μg/ml,近平滑念珠菌8μg/ml,季也蒙念珠菌>16μg/ml。MFG对烟曲霉的MEC90为≤0.03μg/ml,对非烟曲霉的曲霉属MEC90为0.06μg/ml。MFG与唑类药物、两性霉素B(AMB)不存在交叉耐药,对FLC耐药的念珠菌、伊曲康唑耐药的曲霉、AMB不敏感的曲霉均有好的抑菌活性。结论MFG对多数念珠菌属和曲霉属(包括对唑类耐药和AMB不敏感的菌株)有较好的体外抑菌作用。     

猕猴桃属(Actinidia)植物的离体种质保存

本文研究了猕猴桃属植物离体种质资源保存的方法。在一年中于盛夏时采取的植物材料在离体培养时能得到最好的效果;改进的剥离茎尖的方法使污染率大大降低,在MS附加BA 0.5,Z 0.1,GA 0.1～0.5 mg/L,蔗糖3％,琼脂0.55％的培养基中茎尖生长良好并且不产生不定芽。通过茎尖培养方法已保存了10多个种,40多个猕猴桃的离体种质。     

工程抗体的体外成熟

工程抗体在诊断或治疗方面有其优点,但制备的各种工程抗体的亲和力通常较原亲本抗体的低,为方便在体外迅速地改善工程抗体的生物特性,目前已发展了一系列针对抗体库构建,筛选和阳性克隆鉴定等与抗体外成熟密切相关的方法和技术。     

In vitro organogenesis from diploid tissues of Cycas revoluta Thunb.

Leaf base and mesocotyl explants derived from in vitro-grown seedlings of Echinochloa colona were cultured on Murashige and Skoog's (MS) medium containing various concentrations of benzyladenine (BA), -naphthaleneacetic acid (NAA) and kinetin. Leaf base and mesocotyl segments exhibited optimal morphogenetic response by using 6.66 M BA with 2.68 M NAA. Induction of rooting from regenerated shoots was readily achieved in half strength MS medium without organics and growth regulators. Histological studies revealed the sequence of shoot bud regeneration in the monocot system. The in vitro-raised plants were established in chromite minewaste.Abbreviations BA benzyladenine - NAA -naphthaleneacetic acid - MS medium Murashige & Skoog's (1962) medium