Effect of coating the wells of a polystyrene microtiter plate with xanthorrhizol on the biofilm formation of Streptococcus mutans

Enhanced antimicrobial activity against oral bacteria Actinomyces viscous by cinnamaldehyde emulsion microencapsulated with cyclodextrin glycosyltransferase-catalyzed products

Actinomyces viscous (A. viscous) is well documented as a major cariogenic bacterium in the oral cavity and needs to be inhibited and removed timely. Essential oils (EOs) are recognized as secure antibacterial agents for treating oral diseases, but their volatility and insolubility limit their application. In this study, cinnamaldehyde was screened as the optimum EO for inhibiting the A. viscous growth by a micro-agar dilution method and microencapsulated by cyclodextrin glycosyltransferase (CGTase)-catalyzed products. The antibacterial effects against A. viscous were investigated and compared with the free cinnamaldehyde. Antibacterial diameter, antibacterial efficiency and stability, and time-kill curve results revealed that the cinnamaldehyde emulsion had better antibacterial properties. 1 MIC of the cinnamaldehyde emulsion had an inhibitory zone of 9.92 nm, a 100 % inhibition rate when acting for 2 min or 5 min, and still maintained the same inhibitory effect for 2 years. The extracellular environment showed more pH decrease, conductivity increase, and protein leakage, suggesting damage to the cell membrane. Microstructure and flow cytometric analysis further revealed that the CGTase-catalyzed products induced more changes in the A. viscous membrane integrity. Based on the results, CGTase-catalyzed products can be used as a potential substance for encapsulating EOs for treating oral bacteria.

Identification of terpenoids as dihydropteroate synthase and dihydrofolate reductase inhibitors through structure-based virtual screening and molecular dynamic simulations

Bacterial infections are rising, and antimicrobial resistance (AMR) in bacteria has worsened the scenario, requiring extensive research to find alternative therapeutic agents. Terpenoids play an essential role in protecting plants from herbivores and pathogens. The present study was designed to focus on in silico evaluation of terpenoids for their affinity towards two necessary enzymes, i.e. DHFR and DHPS, which are involved in forming 5, 6, 7, 8-tetrahydrofolate, a key component in bacterial DNA synthesis proteins. Additionally, to account for activity against resistant bacteria, their affinity towards the L28R mutant of DHFR was also assessed in the study. The structure-based drug design approach was used to screen the compound library of terpenes for their interaction with active sites of DHFR and DHPS. Further, compounds were screened based on their dock score, pharmacokinetic properties, and binding affinities. A total of five compounds for each target protein were screened, having dock scores better than their respective standard drug molecules. CNP0169378 (-8.4 kcal/mol) and CNP0309455 (-6.5 kcal/mol) have been identified as molecules with a higher affinity toward the targets of DHFR and DHPS, respectively. At the same time, one molecule CNP0298407 (-5.8 kcal/mol for DHPS, -7.6 kcal/mol for DHFR, -6.1 kcal/mol for the L28R variant), has affinity for both proteins (6XG5 and 6XG4). All the molecules have good pharmacokinetic properties. We further validated the docking study by binding free energy calculations using the MM/GBSA approach and molecular dynamics simulations.Communicated by Ramaswamy H. Sarma.

Antibacterial and Antimicrobial Effects of Xanthorrhizol in the Prevention of Dental Caries: A Systematic Review

Background

Xanthorrhizol is one of the numerous phytochemicals whose pharmacological benefits have been explored for its antibacterial and antimicrobial effects. In light of the role bacteria play for initiating tooth decay, this present systematic review assessed xanthorrhizol’s effect against dental caries.

Methods

The electronic databases including Pubmed, Scopus and Embase were searched up to September 2020, Studies examining the antibacterial and antimicrobial effects of xanthorrhizol in the prevention and treatment of dental caries.

Results

Eleven studies met the criteria for final inclusion. Findings from these studies showed that xanthorrhizol showed significant inhibition of notable caries causing bacteria including Streptococcus mutans, Streptococcus sanguinis, Enterococcus faecalis and Bacillus cereus. Furthermore, there was no reported toxicity. However, it could not selectively target the growth of cariogenic bacteria.

Conclusion

So far, studies exploring the use of xanthorrhizol as a potential drug for the prevention and treatment of dental caries have shown promising outcomes. However, more work needs to be done especially in areas such as optimal dose or concentration, in addition, in vitro, in vivo and clinical studies and selective targeting of cariogenic bacteria has been performed.

Antimicrobial activity of Curcuma xanthorrhiza nanoemulsions on Streptococcus mutans biofilms

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.

Terpene Derivatives as a Potential Agent against Antimicrobial Resistance (AMR) Pathogens

The evolution of antimicrobial resistance (AMR) in pathogens has prompted extensive research to find alternative therapeutics. Plants rich with natural secondary metabolites are one of the go-to reservoirs for discovery of potential resources to alleviate this problem. Terpenes and their derivatives comprising of hydrocarbons, are usually found in essential oils (EOs). They have been reported to have potent antimicrobial activity, exhibiting bacteriostatic and bactericidal effects against tested pathogens. This brief review discusses the activity of terpenes and derivatives against pathogenic bacteria, describing the potential of the activity against AMR followed by the possible mechanism exerted by each terpene class. Finally, ongoing research and possible improvisation to the usage of terpenes and terpenoids in therapeutic practice against AMR are discussed.

Hybrid combinations containing natural products and antimicrobial drugs that interfere with bacterial and fungal biofilms

BACKGROUND

Biofilms contribute to the pathogenesis of many chronic and difficult-to eradicate infections whose treatment is complicated due to the intrinsic resistance to conventional antibiotics. As a consequence, there is an urgent need for strategies that can be used for the prevention and treatment of biofilm-associated infections. The combination therapy comprising an antimicrobial drug with a low molecular weight (MW) natural product and an antimicrobial drug (antifungal or antibacterial) appeared as a good alternative to eradicate biofilms.

PURPOSE

The aims of this review were to perform a literature search on the different natural products that have showed the ability of potentiating the antibiofilm capacity of antimicrobial drugs, to analyze which are the antimicrobial drugs most used in combination, and to have a look on the microbial species most used to prepare biofilms.

RESULTS

Seventeen papers, nine on combinations against antifungal biofilms and eight against antibacterial biofilms were collected. Within the text, the following topics have been developed: breaf history of the discovery of biofilms; stages in the development of a biofilm; the most used methodologies to assess antibiofilm-activity; the natural products with capacity of eradicating biofilms when acting alone; the combinations of low MW natural products with antibiotics or antifungal drugs as a strategy for eradicating microbial biofilms and a list of the low MW natural products that potentiate the inhibition capacity of antifungal and antibacterial drugs against biofilms.

CONCLUSIONS AND PERSPECTIVES

Regarding combinations against antifungal biofilms, eight over the nine collected works were carried out with in vitro studies while only one was performed with in vivo assays by using Caenorhabditis elegans nematode. All studies use biofilms of the Candida genus. A 67% of the potentiators were monoterpenes and sesquiterpenes and six over the nine works used FCZ as the antifungal drug. The activity of AmpB and Caspo was enhanced in one and two works respectively. Regarding combinations against bacterial biofilms, in vitro studies were performed in all works by using several different methods of higher variety than the used against fungal biofilms. Biofilms of both the gram (+) and gram (-) bacteria were prepared, although biofilm of Staphylococcus spp. were the most used in the collected works. Among the discovered potentiators of antibacterial drugs, 75% were terpenes, including mono, di- and triterpenes, and, among the atibacterial drugs, several structurally diverse types were used in the combinations: aminoglycosides, β-lactams, glucopeptides and fluoroquinolones. The potentiating capacity of natural products, mainly terpenes, on the antibiofilm effect of antimicrobial drugs opens a wide range of possibilities for the combination antimicrobial therapy. More in vivo studies on combinations of natural products with antimicrobial drugs acting against biofilms are highly required to cope the difficult to treat biofilm-associated infections.

Antibacterial activities of medicinal plants used in Mexican traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species.

MATERIALS AND METHODS

We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro.

CONCLUSIONS

Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.

Plant Natural Products Targeting Bacterial Virulence Factors

Decreased antimicrobial efficiency has become a global public health issue. The paucity of new antibacterial drugs is evident, and the arsenal against infectious diseases needs to be improved urgently. The selection of plants as a source of prototype compounds is appropriate, since plant species naturally produce a wide range of secondary metabolites that act as a chemical line of defense against microorganisms in the environment. Although traditional approaches to combat microbial infections remain effective, targeting microbial virulence rather than survival seems to be an exciting strategy, since the modulation of virulence factors might lead to a milder evolutionary pressure for the development of resistance. Additionally, anti-infective chemotherapies may be successfully achieved by combining antivirulence and conventional antimicrobials, extending the lifespan of these drugs. This review presents an updated discussion of natural compounds isolated from plants with chemically characterized structures and activity against the major bacterial virulence factors: quorum sensing, bacterial biofilms, bacterial motility, bacterial toxins, bacterial pigments, bacterial enzymes, and bacterial surfactants. Moreover, a critical analysis of the most promising virulence factors is presented, highlighting their potential as targets to attenuate bacterial virulence. The ongoing progress in the field of antivirulence therapy may therefore help to translate this promising concept into real intervention strategies in clinical areas.

Natural Antimicrobials and Oral Microorganisms: A Systematic Review on Herbal Interventions for the Eradication of Multispecies Oral Biofilms

Oral diseases such as caries and periodontitis are mainly caused by microbial biofilms. Antibiotic therapy has reached its limits with regard to antimicrobial resistance, and new therapeutic measures utilizing natural phytochemicals are currently a focus of research. Hence, this systematic review provides a critical presentation of the antimicrobial effects of various medicinal herbs against in vitro, ex vivo, and in situ formed multispecies oral biofilms. Searches were performed in three English databases (PubMed, EMBASE, CAMbase) and the electronic archives of five German journals from the times of their establishment until October 10th, 2014, with the search terms “(plant extracts OR herbal extracts OR plant OR herb) AND (oral biofilm OR dental biofilm OR dental plaque OR oral disease OR dental disease).” The pooled data were assessed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). Initially, 1848 articles were identified, out of which 585 full-text articles were screened, 149 articles were reevaluated for eligibility and finally, 14 articles met all inclusion criteria. The data of 14 reports disclosed enhanced antiadhesive and antibiofilm activity by the plant extracts obtained from Vitis vinifera, Pinus spp., Coffea canephora, Camellia sinensis, Vaccinium macrocarpon, Galla chinensis, Caesalpinia ferrea Martius, Psidium cattleianum, representative Brazilian plants and manuka honey. Overall, a positive correlation was revealed between herb-based therapies and elimination rates of all types of multispecies oral biofilms. In that context, integrating or even replacing conventional dental therapy protocols with herbal-inspired treatments can allow effective antimicrobial control of oral biofilms and thus, dental diseases.

Xanthorrhizol: a review of its pharmacological activities and anticancer properties

Xanthorrhizol (XNT) is a bisabolane-type sesquiterpenoid compound extracted from Curcuma xanthorrhiza Roxb. It has been well established to possess a variety of biological activities such as anticancer, antimicrobial, anti-inflammatory, antioxidant, antihyperglycemic, antihypertensive, antiplatelet, nephroprotective, hepatoprotective, estrogenic and anti-estrogenic effects. Since many synthetic drugs possess toxic side effects and are unable to support the increasing prevalence of disease, there is significant interest in developing natural product as new therapeutics. XNT is a very potent natural bioactive compound that could fulfil the current need for new drug discovery. Despite its importance, a comprehensive review of XNT's pharmacological activities has not been published in the scientific literature to date. Here, the present review aims to summarize the available information in this area, focus on its anticancer properties and indicate the current status of the research. This helps to facilitate the understanding of XNT's pharmacological role in drug discovery, thus suggesting areas where further research is required.

In vitro activity of xanthorrhizol isolated from the rhizome of Javanese turmeric (Curcuma xanthorrhiza Roxb.) against Candida albicans biofilms

The purpose of this study was to investigate the activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. on Candida albicans biofilms at adherent, intermediate, and mature phase of growth. C. albicans biofilms were formed in flat-bottom 96-well microtiter plates. The biofilms of C. albicans at different phases of development were exposed to xanthorrhizol at different concentrations (0.5 µg/mL-256 µg/mL) for 24 h. The metabolic activity of cells within the biofilms was quantified using the XTT reduction assay. Sessile minimum inhibitory concentrations (SMICs) were determined at 50% and 80% reduction in the biofilm OD₄₉₀ compared to the control wells. The SMIC₅₀ and SMIC₈₀ of xanthorrhizol against 18 C. albicans biofilms were 4--16 µg/mL and 8--32 µg/mL, respectively. The results demonstrated that the activity of xanthorrhizol in reducing C. albicans biofilms OD₄₉₀ was dependent on the concentration and the phase of growth of biofilm. Xanthorrhizol at concentration of 8 µg/mL completely reduced in biofilm referring to XTT-colorimetric readings at adherent phase, whereas 32 µg/mL of xanthorrhizol reduced 87.95% and 67.48 % of biofilm referring to XTT-colorimetric readings at intermediate and mature phases, respectively. Xanthorrhizol displayed potent activity against C. albicans biofilms in vitro and therefore might have potential therapeutic implication for biofilm-associated candidal infections.

In vitro activity of xanthorrhizol against Candida glabrata, C. guilliermondii, and C. parapsilosis biofilms

The formation of Candida biofilms has important clinical ramifications, because these biofilms exhibit increased resistance to conventional antifungal therapies. The aim of this study was to investigate the activity of xanthorrhizol on biofilms produced by non-C. albicans Candida (NCAC) species, including C. glabrata, C. guilliermondii, and C. parapsilosis. NCAC biofilms were generated in flat-bottom 96-well microtiter plates and quantified using the XTT (2, 3 - bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenyl amino) carbonyl]-2H-tetrazolium hydroxide) reduction assay. The NCAC biofilms at adherent, intermediate, and mature growth phases were treated with 0.5-512 μg/ml of xanthorrhizol for 24 h. The ranges of sessile minimum inhibitory concentrations (SMICs) of xanthorrhizol against C. glabrata, C. guilliermondii, and C. parapsilosis biofilms were 8-32 μg/ml, 8-16 μg/ml, and 8-64 μg/ml, respectively. Xanthorrhizol affected cell density that had an indirect effect on the biofilm OD(490). The compound eradicated the viable cells of the C. glabrata and C. parapsilosis biofilms at the adherent growth phase at 16 μg/ml and that of C. guilliermondii at 8 μg/ml. Treatment with 128 μg/ml of xanthorrhizol reduced the OD(490) of C. glabrata, C. guilliermondii, and C. parapsilosis biofilms at the mature growth phase by 77.8%, 88.5%, and 64.5%, respectively. These results indicate that xanthorrhizol exhibits potent activity against NCAC biofilms in vitro. Therefore, xanthorrhizol has potential therapeutic value in treating biofilm-associated NCAC infections and should be further evaluated in vivo.

Activity of panduratin A isolated from Kaempferia pandurata Roxb. against multi-species oral biofilms in vitro

The formation of dental biofilm caused by oral bacteria on tooth surfaces is the primary step leading to oral diseases. This study was performed to investigate the preventive and reducing effects of panduratin A, isolated from Kaempferia pandurata Roxb., against multi-species oral biofilms consisting of Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus. Minimum inhibitory concentration (MIC) of panduratin A was determined by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution assay. Prevention of biofilm formation was performed on 96-well microtiter plates by coating panduratin A in mucin at 0.5-40 microg/ml, followed by biofilm formation at 37 degrees C for 24 h. The reducing effect on the preformed biofilm was tested by forming the biofilm at 37 degrees C for 24 h, followed by treatment with panduratin A at 0.2-10 microg/ml for up to 60 min. Panduratin A showed a MIC of 1 microg/ml for multi-species strains. Panduratin A at 2 x MIC for 8 h exhibited bactericidal activity against multi-species planktonic cells for 8 h. At 8 x MIC, panduratin A was able to prevent biofilm formation by > 50%. Biofilm mass was reduced by > 50% after exposure to panduratin A at 10 microg/ml for 15 min. Panduratin A showed a dose-dependent effect in preventing and reducing the biofilm. These results suggest that panduratin A is applicable as a natural anti-biofilm agent to eliminate oral bacterial colonization during early dental plaque formation.

Combined xanthorrhizol-curcumin exhibits synergistic growth inhibitory activity via apoptosis induction in human breast cancer cells MDA-MB-231

Background

It has been suggested that combined effect of natural products may improve the treatment effectiveness in combating proliferation of cancer cells. The present study was undertaken to evaluate the possibility that the combination of xanthorrhizol and curcumin might show synergistic growth inhibitory effect towards MDA-MB-231 human breast cancer cells via apoptosis induction. The effective dose that produced 50% growth inhibition (GI₅₀) was calculated from the log dose-response curve of fixed-combinations of xanthorrhizol and curcumin generated from the sulforhodamine B (SRB) assay. The experimental GI₅₀ value was used to determine the synergistic activity of the combination treatment by isobolographic analysis and combination-index method. Further investigation of mode of cell death induced by the combination treatment was conducted in the present study.

Results

Isobole analysis revealed that substances interaction was synergistic when xanthorrhizol and curcumin were added concurrently to the cultures but merely additive when they were added sequentially. The synergistic combination treatment was then applied to the cultures to investigate the mode of cell death induced by the treatment. Immunofluorescence staining using antibody MitoCapture™ revealed the possibility of altered mitochondrial transmembrane potential, which is one of the hallmark of apoptosis. Hoechst 33258 nuclear staining assay showed the rate of apoptosis of MDA-MB-231 cells to increase in response to the treatment. Apoptotic cell death was further confirmed by DNA fragmentation assay, where internucleosomal excision of DNA was induced upon treatment with xanthorrhizol-curcumin.

Conclusion

This is the first time the combined cytotoxic effect of xanthorrhizol and curcumin on MDA-MB-231 cells has been documented and our findings provide experimental support to the hypothesis that combined xanthorrhizol-curcumin showed synergistic growth inhibitory activity on MDA-MB-231 cells via apoptosis induction.

Antibacterial activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. against foodborne pathogens

Xanthorrhizol, isolated from the ethanol extract of Curcuma xanthorrhiza Roxb., is a sesquiterpene compound with a molecular weight of 218. The aim of this study was to investigate the antibacterial activity of xanthorrhizol against foodborne pathogens. The antibacterial activity of xanthorrhizol was measured in terms of the MIC and the MBC. MICs and MBCs of xanthorrhizol against Bacillus cereus, Clostridium perfringens, Listeria monocytogenes, Staphylococcus aureus, Salmonella Typhimurium, and Vibrio parahaemolyticus were 8, 16, 8, 8, 16, 8 microg/ml and 16, 32, 16, 16, 16, 16 microg/ml, respectively. The bactericidal study, as determined by the viable cell count method, revealed that xanthorrhizol treatment at 4 x MIC reduced viable cells by at least 6 to 8 log for all six foodborne pathogens in 4 h. Xanthorrhizol maintained its antibacterial activity after thermal treatments (121 degrees C, 15 min) under various pH ranges (pH 3.0, 7.0, and 11.0). These results strongly suggest that xanthorrhizol, conferring strong antibacterial activity with thermal and pH stability, can be effectively used as a natural preservative to prevent the growth of foodborne pathogens.

In Vitro antimycotic activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. against opportunistic filamentous fungi

Xanthorrhizol was isolated from the rhizome of Curcuma xanthorrhiza (Zingiberaceae) and its in vitro activity against opportunistic filamentous fungi was evaluated using the NCCLS (M38-A) standard method. Xanthorrhizol was found to be active against all the species tested, namely Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Fusarium oxysporum, Rhizopus oryzae and Trichophyton mentagrophytes: the MICs being 2.0, 2.0, 2.0, 4.0, 1.0 and 1.0 microg/mL, while the MFCs were 4.0, 4.0, 4.0, 8.0, 2.0 and 2.0 microg/mL, respectively. The susceptibility of six species of filamentous fungi to xanthorrhizol was comparable to that of the commercial antifungal, amphotericin B. Xanthorrhizol also has activity to inhibit the conidial germination of all tested species. The results strongly suggest that xanthorrhizol can be developed as a natural antifungal agent.

In vitro anti-Malassezia activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb

AIMS

This study aimed at investigating the anti-Malassezia activity of xanthorrhizol (XTZ) isolated from Curcuma xanthorrhiza Roxb. against Malassezia furfur ATCC 14521 and Malassezia pachydermatis ATCC 14522.

METHODS AND RESULTS

The in vitro susceptibility tests for XTZ were carried out in terms of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), using broth microdilution method with endpoint after 48 h. Time-kill curves were determined at concentrations ranging from 0 to 25 microg ml(-1). The MIC values of XTZ against M. furfur and M. pachydermatis were 1.25 and 0.25 mug ml(-1), respectively. The MFC of XTZ was 5 microg ml(-1) for M. furfur and 2.5 microg ml(-1) for M. pachydermatis. Time-kill curves demonstrated that treatment with 25 microg ml(-1) of XTZ for 5 h was able to kill 100% of M. furfur, while 20 microg ml(-1) of XTZ for 15 min killed M. pachydermatis completely.

CONCLUSION

XTZ shows potential as an anti-Malassezia agent for inhibiting the growth of M. furfur ATCC 14521 and M. pachydermatis ATCC 14522 in vitro.

SIGNIFICANCE AND IMPACT OF THE STUDY

XTZ may be a useful alternative for treating Malassezia-associated diseases.