Antibacterial Activity of Crude Extracts of Prinsepia utilis Royle in vitro

The purpose of this study is to isolate the active fraction from the crude extract of Prinsepia utilis Royle and to determine its antibacterial activity against the standard and drug-resistant bacteria strains in vitro. The Prinsepia utilis Royle was extracted in three portions by using petroleum ether, ethanol and water by the continuation recirculate extraction. The antibacterial activity of the extracts were evaluated by the determination of Minimum Inhibitory Concentration （MIC） and Minimum Bactericidal Concentration （MBC） values. The results showed that the ethanol extract and aqueous extract of petroleum ether showed the weakest inhibition. MIC values of the aqueous Prinsepia utilis Royle were found that they had significant effects against bacteria, while ethanol extracts against three standard bacteria （S. aureus ATCC25923, E. coli 44102, Salmonella 50041） were 25, 25, 50 mg·mL^-1 and 50, 100, 100 mg·mL^-1, MIC values of three drug-resistant bacteria （S. aureus GL17, E. coli EYAC08-56, Salmonella STQD2G.） were 50, 50, 50 mg·mL^-1 and 100, 100, 200 mg·mL^-1, respectively. MBC values of two extracts against three standard strains were 25, 50, 100mg·mL^-1 and 50, 100, 200 mg·mL^-1, MBC values of three drug-resistant bacteria were 100, 100, 100mg·mL^-1 and 200, 200, 200 mg·mL^-1, respectively.

Preliminary Isolation and Antibacterial Activity of the Ethyl Acetate Extract of <i>Prinsepia utilis</i>Royle <i>in Vitro</i>

Seven fractions were isolated from the ethyl acetate extract of Prinsepia utilis Royle by silica gel column chromatography. The antibacterial activities determined by disc diffusion method in vitro, indicated that the first and fourth fractions showed better antibacterial activity than the other fractions, while the sixth and seventh fractions did not showed any antibacterial activity. The diameters of the inhibition zone of first and fourth fractions were greater than 10 mm against three standard strains (Staphylococcus aureus ATCC25923, Escherichia coli ATCC44102 and Salmonella sp. CMCC(B)50041) at the concentration of 20 mg/ml. The first fraction was then repeatedly recrystallized in acetone to yield a white snowflake-like compound A, the inhibition zones of which were 14.03 mm, 11.54 mm and 12 mm, respectively. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were measured by broth dilution method at the concentrations ranging from 20 to 0.313 mg/mL. The MIC and MBC values of the first, fourth fractions and compound A were lower than that of oregano oil (positive control) against S. aureus ATCC25923.

In vitro antibacterial activity of Hibiscus rosa-sinensis flower extract against human pathogens

Objective:To access the in vitro antibacterial activity of Hibiscus rosa-sinensis(H.rosa-sinensis) flower extract against human pathogens.Methods:Antibacterial activity was evaluated by using disc and agar diffusion methods.The protein was run through poly acrylmide gel electrophoresis to view their protein profile.Results:The results showed that the cold extraction illustrates a maximum zone of inhibition against Bacillus suhtillis(B.suhtillis),Escherichia coli(E.coli) viz.,(17.00±2.91),(14.50±1.71)mm.followed by hot extraction against.E.coli.Salmonella sp.as(11.66 ±3.14),(10.60±3.09)mm.In methanol extraction showed a highest zone of inhibition recorded against B.suhtillis,E.coli as(18.86±0.18),(18.00±1.63) mm pursued by ethanol extraction shower) utmost zone of inhibition recorded against Salmonella sp.at(20.40±1.54) mm.The crude protein from flower showed a maximum inhibitory zone observed against Salmonella sp.,E.coli viz.,(16.55±1.16),(14.30±2.86)mm.The flower material can be taken as an alternative source of antibacterial agent against the human pathogens.Conclusions:The extracts of the H.rosasinensis art;proved to have potential antibacterial activity,further studies arc highly need for the drug development.

Evaluation of in-vitro antibacterial activity and anti-inflammatory activity for different extracts of Rauvolfia tetraphylla L.root bark

Objective:To assess the in-vitro antihacterial activity and anti-inflammatory activity of orally administered different extracts(Hydro-alcoholic,methanolic,ethyl acetate and hexane)of Rauvolfia tetraphylla(R.tetraphylla)root bark in Carrageetiaii induced acute inflammation in rats.Methods:In-vitro antibacterial activity was evaluated for extracts against four Gram positive and four Gram negative bacteria by using cylinder plate assay.Hydro-alcoholic extract(70%v/v ethanol)at 200,400 and 800 mg/kg doses and methanolic,ethyl acetate and hexane extracts at doses 100,200 and 400 mg/kg were tested for anti-inflammatory activity in Carrageenan induced rat paw oedema model and paw thickness was measured every one hour up to 6 hrs.Results:All extracts of R.tetraphylla root bark showed good zone of inhibition against tested bacterial strains.In Carrageenan induced inflammation model,hydro-alcoholic and methanolic extract of R.tetraphylla root bark at three different doses produced significant(P<0.00l)reduction when compared to vehicle treated control group and hexane,ethyl acetate extracts.Conclusions:In the present study extracts of R.tetraphylla root bark shows good in-vitro antibacterial activity and in-vivo anti-inflammatory activity in rats.

In vitro antioxidant and antimicrobial activity cycloart-23-ene-3β,25-diol(B2) isolated from Pongamia pinnata(L.Pierre)

Objective:To evaluate the in-vitro antioxidant and antimicrobial activity of cvcloart-23- ene-3β,25-diol(called as B2) isolated from stem bark of Pongamia pinnata.Methods:In vitro antioxidant activity of B2 was determined by methods for determination of Dl’PH radical scavenging,reducing power,superoxide anion radical scavenging,hydroxyl radical scavenging, hydrogen peroxide scavenging,metal chelating and nitric oxide radical scavenging at the doses of 20.40.60.80 and 100μg/mL,respectively.3 -tocopherol with same concentration was used as a standard antioxidant.In vitro antimicrobial activity of B2 was determined by cup plate method in different concentration range of 10-100μg/mL.Results:The results indicated that dose dependent%reduction against DPPH radical,reducing power,superoxide anion radical scavenging,hydroxyl radical scavenging,metal chelating,hydrogen peroxide scavenging and nitric oxide radical scavenging by B2 andβ-tocopherol.Conclusions:It is concluded that cycloart 23-ene-3β,25 diol(B2) showed dose dependent antioxidant activity.B2 showed more DPPH radical scavenging,reducing power,superoxide scavenging,hydroxyl radical scavenging, metal chelating scavenging,hydrogen peroxide radical scavenging and nitric oxide radical scavenging activity thanβ-tocopherol and in case of antimicrobial activity B2 exhibited broad-spectrum activ ity against bacteria and strong activity against yeast type of fungi.

Pectin shows antibacterial activity against <i>Helicobacter pylori</i>

Pectins are the collective name for a group of heterogeneous, high molecular weight, branched polysaccharides that are found in the cell walls of higher plants. In this study, we intend to determine the antibacterial activity of pectin against reference strains and clinical isolates of Helicobacter pylori. The results show that pectin produced antibacterial effects on all the 16 clinical isolates and 2 reference strains of H. pylori with the greatest antibacterial effect at a low pH (5.0) versus higher pHs. The lowest Minimum Inhibitory Concentration recorded was of 0.016 μg/μl. Antibiotic resistance, therapy costs, and undesirable side effects stress the need for new antimicrobials or alternative therapies. The results from our study can further our goal of future eradication of H. pylori infection using new molecules.

Preparation of titanium dioxide/silver sulfate powder and its antibacterial activity

Antibacterial powders of titanium dioxide/silver sulfate were produced by heat-treatment of the metatitanic acid, as precursor, into which the silver nitrate was added. The influences of heating temperature on the structure and composition of the product were investigated through XRD and SEM. The results show that the powder is spherical in the phase of TiO2-Ag2SO4. The granularity of the particles increases from 10.7nm to 28.7nm with the temperature of heat-treatment increasing from 300℃ to 800℃. The antibacterial activity of the powder was judged in the way of the minimum inhibitory contents （MiCs）. When the content of silver sulfate is less than 2%, the photocatalysis of titanium dioxide and silver ions cooperate to kill bacteria. And the MiCs decrease and keep around 1.0×10 -41.5×10 -4 constantly with the increase of silver content. Furthermore, the MiCs decrease with the increase of temperature of heat-treatment when the temperature is lower than 500℃. But when the temperature is beyond 600℃ the MiCs increase quickly, which shows the inferior antibacterial performance.

Antibacterial Activity of Honey from Wild Species of Stingless Bees;<i>Plebenia hylderbrandii</i>and <i>Meliponula bocandei</i>

One of the serious problems the world is facing today is the antimicrobial resistance on available antibiotics by most bacterial pathogens and the rising cost of finding effective antimicrobial agents. In recent years, efforts to find new drugs especially from natural sources have been boosted by the demand for an effective cure for infectious diseases. Only the antibacterial activity of apis mellifera honey and not stingless bee honey from western Kenya has been reported. This study was therefore carried out to determine the effect of Plebenia hylderbrandii and Meliponula bocandei honey samples on the growth of control;sensitive cases of Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923). Different honey concentrations (1.18% - 17.65% v/v) of the two samples were tested against the two micro-organisms. The samples were screened for their antibacterial potential against Escherichia coli and Staphylococcus aureus by agar well dilution method. The Partial inhibitory concentration (PIC), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined by in vitro method. The inhibitory effect of Plebenia hylderbrandii honey on E. coli and S. aureus growth was apparent at concentrations 3.53% and 1.76% (v/v) respectively. On the other hand, the inhibitory effect of Meliponula bocandei honey on S. aureus growth was at concentration 16.47% (v/v). Plebenia hylderbrandii honey had bactericidal effect on both E. coli and S. aureus at concentrations 4.71% and 2.35% (v/v) respectively. However, Meliponula bocandei honey exerted bactericidal effect on S. aureus only at 16.47% (v/v) concentration. Plebenia hylderbrandii honey had higher antibacterial potency and can be a potential source of antibacterial substances. Moreover, the honeys tested in this study showed great antibacterial potential for S. aureus.

Antibacterial and Antioxidant Activity of Rhodomyrtus Tomentosa and Cinnamomum Zeylanicum Crude Extracts

The aim of this study was to investigate the extraction method for R.to­mentosa and C.zeylanicum leaves and the evaluation of antibacterial and antioxidant activities of crude extracts.The results of the study showed that the active ingredients of crude extracts were clearly separated by Thin-layer chromatography and the presence of rhodomyrtone in R.tomentosa crude extract and cinnamaldehyde in C.zeylanicum crude ex­tract.R.tomentosa crude extract was antibacterial activity against Staph­ylococcus aureus with 13.1 mm of inhibition zone,but is not effective against Salmonella Typhimurium.C.zeylanicum leaf extract did not show antibacterial activity on both S.aureus and S.Typhimurium.At a dilution of 1/2 of the R.tomentosa crude extract can completely inhibit S.aureus growth.This study also indicated the presence of antioxidant compounds such as flavonoids,tannins,phenols and terpenoids in C.zeylanicum and R.tomentosa crude extracts.The results showed that R.tomentosa and C.zeylanicum crude extracts should be used as a biotherapy alternative to antibiotic therapy.However,further study would be needed to investigate the antibacterial activity of crude extracts in vivo.

Antimicrobial activity of green tea extract against isolates of methicillin-resistant Staphylococcus aureus and multi-drug resistant Pseudomonas aeruginosa

Objective:To evaluate antibacterial activity of the Indonesian water soluble green tea extract,Camellia sinensis,against clinical isolates of methicillin-resistantStaphylococcus aureus (S.aureus)(MRSA)and multi-drug resistant Pseudomonas aeruginosa(MDR-P.aeruginosa).Methods:Antimicrobial activity of green tea extract was determined by the disc diffusion method and the minimum inhibitory concentration(MIC)was determined by the twofold serial broth dilutions method.The tested bacteria using in this study were the standard strains and multi-drug resistant clinical isolates of S.aureus and P.aeruginosa,obtained from Laboratory of Clinical Microbiology,Faculty of Medicine,University of Indonesia.Results:The results showed that the inhibition zone diameter of green tea extracts forS.aureus ATCC 25923 and MRSA were(18.970依0.287)mm,and(19.130依0.250)mm respectively.While the inhibition zone diameter forP.aeruginosa ATCC 27853 and MDR-P.aeruginosawere(17.550依0.393)mm and(17.670依0.398)mm respectively.The MIC of green tea extracts againstS.aureus ATCC 25923 and MRSA were 400μg/mL and 400μg/mL,respectively,whereas the MIC for P.aeruginosa ATCC 27853 and MDR-P.aeruginosawere 800μg/mL,and 800μg/mL,respectively.Conclusions:Camellia sinensisleaves extract could be useful in combating emerging drug-resistance caused by MRSA andP.aeruginosa.

In Vitro Anti-Bacterial and Anti-Fungal Activities of Extracts from Different Parts of 7 Zingiberaceae Plants

This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family.The inhibitory rate,minimum inhibitory concentration(MIC),and minimum bactericidal concentration(MBC)of leaf and stem,and root and rhizome extracts from Alpinia katsumadai Hayata,Alpinia oxyphylla Miq×Alpinia henryi K.Schumann,Alpinia oblongifolia Hayata,Alpinia nigra(Gaertn.)Burtt,Amomum villosum Lour,Alpinia zerumbet(Pers.)Burtt.et Smith and Alpinia oxyphylla Miq were determined using the fungus cake method and double dilution method.The seven Zingiberaceae plants exhibited characteristic antibacterial activities against pathogenic bacteria and fungi.At a 1.5 mg mL^(−1),A.zerumbet root and rhizome extracts exhibited strong inhibitory activity against S.aureus and E.coli,with 83.23%and 79.62%,respectively.In addition,A.zerumbet leaf and stem extracts had an inhibitory rate of 90.85%against P.aeruginosa.At the same concentration,the leaf and stem,root and rhizome extracts of A.katsumadai had the best anti-bacterial effect against F.oxysporum,with inhibition rates of 84.46%and 84.73%,respectively.Moreover,A.katsumadai and A.zerumbet leaf and stem extracts had the most significant antibacterial effect against S.aureus,with a MIC of 0.063 mg mL^(−1).Thus,both A.katsumadai and A.zerumbet extracts had significant antibacterial activity.In addition,by comparing the inhibitory effect of extracts from different parts,it was found that the inhibitory rate and average inhibitory rate of extracts from leaf and stem were higher than those from root and rhizome.The chemical constituents of A.katsumadai and A.zerumbet,determined by the high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),revealed that citric acid(CA),alpinetin,and pinocembrin(PNCB)were the functional constituents yielding the antibacterial activity.Overall,A.katsumadai and A.zerumbet have the potential to be developed as new plant fungicides and bactericides.

Synthesis, Characterization and Antibacterial Activities of Polydentate Schiff Bases, Based on Salicylaldehyde

Three Schiff bases L1, L2 and L3 were synthesized by condensing salicylaldehyde with 4-aminoantipyrine, ethylendiamine and 2-aminophenol respectively and subsequently characterized by various physicochemical investigations. All the three compounds were screened for their In-vitro antibacterial activity against two gram positive bacteria, Staphylococcus aureus (S.A), Staphylococcus epidermidis (S.E) and two gram negative bacteria Klebsiella pneumoniae (K.P) and Pseudomonas aeruginosa (P.A) by agar diffusion method. On comparing the results obtained with the activity of commercially available antibiotics such as Ciprofloxacin and Chloramphenicol, the newly synthesized compounds showed comparable antibacterial activities. The solvent methanol exhibit activity against all bacterial species with IZs ranging from 8 ± 0.25 to 17 ± 0.29 mm while the standard antibiotics Ciprofloxacin and Chloramphenicol exhibited an activities with IZs varying from 21.3 ± 0.31 to 28.3 ± 0.32 and 26.3 ± 0.24 mm to 32.3 ± 0.23 mm, respectively. However, the newly synthesized Schiff bases L1, L2 and L3 showed IZs ranging from 7.4 ± 0.23 to 32.5 ± 0.14, 3 ± 0.57 to 12 ± 0.28 and 10 ± 0.20 to 32 ± 0.36 respectively. Among the Schiff bases, L3 showed the activity (32 ± 0.36) against S.E and P.A which is higher than the activity of standard antibiotics Ciprofloxacin and Chloramphenicol against the same bacterial strains. The results obtained revealed that all the synthesized Schiff bases exhibit appreciable antibacterial activity against all the bacteria species which potentially makes them, to apply as wide range antibacterial drugs, after further in-vivo cytotoxicity investigations. Their activity can also be further modified by changing the functionality of precursors for Schiff base condensation.

Comparison of Individual and Synergistic Antimicrobial Activity of Common Spices against Certain Infectious Pathogen in Bangladesh

Aims: The aim of this undertaken investigation was designed to determine the comparative antimicrobial potential of ethanol extract of six commonly consumed spices such as Garlic (Allium satilyvum), Ginger (Zingiber officinale), Turmeric (Curcuma longa), Cinnamon (Cinnamomum zeylanicum), Cumin (Cuminum cyminum) and Black cumin (Nigella sativa). Method: This study includes, the efficacy of individual and synergistic effect of these extracts that was tested against bacteria by agar well-diffusion method employing 100 μL spices-extract solution per well and was conducted in (Centre of Excellence Laboratory) Department of Microbiology, Primeasia University during November 2018 to April 2019. Minimum inhibitory concentration (MIC) was determined by the micro-broth dilution method and compared with commercial antibiotic discs such as Amoxicillin, Vancomycin, Erythromycin, Ceftriaxone, Chloramphenicol, and Ciprofloxacin. Result: According to the findings of the antibacterial assay, the ethanol extracts of the spices showed inhibitory activity against common infectious bacterial pathogens. Spice extracts have the most significant activity against B. cereus and E. coli was the least sensitive among the tested organisms. The ethanol extract had individual antibacterial activity with mean zone of inhibition 22 ± 0.5 and 20.08 ± 0.58 mm and the synergistic effect of ethanol extract had a mean zone of inhibition 30 ± 0.75 and 28.25 ± 0.9 mm against B. cereus and V. cholera, respectively, which is highly comparable to the commercial antibiotic, Ciprofloxacin (25 mm). Conclusion: The ethanol extract of indigenous spices was shown to be highly potential to be applied as an alternative of commercial drugs.

Antibacterial potential of three seagrasses against human pathogens

Objective:To evaluate the antibacterial activity of Halophila stipulacea(H.stipulacea), Cymodocea serrulata(C.serrulata) and Halodule pinifolia(H.pinifolia) against seven human bacterial pathogens.Methods:The antibacterial activities of the extracts on the various test organisms using disc diffusion method and Minimum Inhibitory Concentraction(MIC).Results: Methanol and chloroform extracts of all the three seagrasses were active against all the tested pathogens,whereas the hexane extract of seagrasses was not active against Staphylococcus aureus (S.aureus).Antibacterial activity of three seagrass screened,was in the order of H.pinifolia 】 H.stipulacea.】 C.serrulata.Conclusions:This antibacterial studies can further investigated on seagrasses for purification of bioactive substance and its possible utility in disease control.

Antimicrobial activities of the rhizome extract of Zingiber zerumbet Linn

Objective:To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet(Z.zerumbet)(L.)Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi.Methods:The fresh rhizomes of Zingiber zerumbet were extracted in cold with ethanol(4.0 L)after concentration.The crude ethanol extract was fractionated by petroleum ether and chloroform to form a suspension of ethanol extract(15.0 g),petroleum ether fraction(6.6 g)and chloroform soluble fraction(5.0 g).The crude ethanol extract and its petroleum ether and chloroform fractions were evaluated for antibacterial and antifungal activity against thirteen pathogenic bacteria and three fungi by the disc diffusion method.Commercially available kanamycin(30μg/disc)was used as standard disc and blank discs impregnated with the respective solvents were used as negative control.Results:At a concentration of 400μg/disc,all the samples showed mild to moderate antibacterial and antifungal activity and produced the zone of inhibition ranging from 6 mm to 10 mm.Among the tested samples,the crude ethanol extract showed the highest activity against Vibrio parahemolyticus(V.parahemolyticus).The minimum inhibitory concentration(MIC)of the crude ethanol extract and its fractions were within the value of 128-256μg/mL against two Gram positive and four Gram negative bacteria and all the samples showed the lowest MIC value against V.parahemolyticus(128μg/mL).Conclusions:It can be concluded that,potent antibacterial and antifungal phytochemicals are present in ethanol extract of Z.zerumbet(L.).

Antibacterial potency of methanol extracts of lower plants

Antibacterial potency of methanol extracts of three green lower plants, Pneumatopteris afra, Platycerium bifurcatum and Nephrolepsis bisserata was determined using agar dilution method on clinical strains of Escherichia coli, Staphylococcus aureus, Klebsiella spp. and Salmomelia typhi. Antibacterial activities were observed at concentrations of 12.5, 25.0, 50.0 and 100.0 μg/ml. Their minimum inhibitory concentrations ranged from 12.5~100 μg/ml. Extracts of P. afra and P. bifurcatum were most active. Antibacterial activities observed with N. bisserata were less pronounced with no detectable activity at extract con-centrations of 12.5 and 25.0 μg/ml. E. coli, together with S. aureus appeared to be the most susceptible of the test bacteria while Klebsiella spp. was least sensitive. The significance of our findings is discussed.

Natural antibacterial remedy for respiratory tract infections

Objective: To evaluate the antibacterial activity of Egyptian honey against bacteria causing respiratory tract infections.Methods: Sputum and throat swab specimens were used, from which five bacterial species were isolated, namely, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Streptococcus pneumonia were isolated,identified and grown on suitable media for further identification or confirmation. Different concentrations(100%, 75% and 25%) of honey and simulated honey solution were used for activity assay and estimation of minimum inhibitory concentration and minimum bactericidal concentration.Results: All the tested bacterial isolates were completely susceptible to the 75%concentrations of honey and to the 100% concentration of the simulated honey solution. This may be due to the high osmotic pressure exerted by the high sugar content in both honey samples. Moderate susceptibility of the isolated bacteria to honey at 100%v/v concentration, and resistance to honey at 25% concentration and the 75% and 25%concentrations of simulated honey solution, indicated the presence of other antimicrobial components responsible for the activity other than the osmotic pressure.Therefore, it was suggested that honey showed distinguished antibacterial activities against the most common bacteria causing respiratory infections with varied sensitivity.Conclusions: Honey, a non-toxic, nutritious, safe for human consumption and cheap natural antibacterial agent, should be globalized.

Influence of Modified ZnO Quantum Dots and Nanostructures as New Antibacterials

Antibacterial activities of various spherical zinc oxide nanoparticles and nano special morphological structures including quantum dots, nanorod arrays, nanoporous shapes and needle-like crystals had been investigated as new nanomedicine compounds. Also antibacterial activity based on minimal inhibitory concentration and the growth inhibitory zone (well method) was evaluated. ZnO nanostructures were fabricated by novel hydrolysis sol-gel-hydrothermal process followed with rapid quenching as new technique using glycerine, vegetable fatty esters such as coconut, sunflower and Lauric alcohol ethoxylated as organic templates soluble in eco-friendly nanofluids. The results showed that Bacillus anthracis and Pseudomonas aerogenes were extremely sensitive to treatment with unique ZnO nanostructured. Their growth inhibitory zone presented 30 mm and 25 mm inhibition zone with better inhibitory effect compared to the Gentamicin antibiotic standard. ZnO nanostructures had also been indicated to have a wide range of antibacterial activities against both Gram-positive and Gram-negative bacteria especially more effective on (gr+) species using the growth inhibitory zone. We could design and make significant formulations of fatty acids and esters-capped ZnO quantum dots nanofluids which created high promising agents for controlling Anthrax, Staphylococcus epidermidis and their influences in antimicrobial properties with low cost for future.

不同植物精油对草莓灰霉病菌的体外抑菌效果研究

为筛选出对草莓灰霉病菌具有显著抑菌作用的植物精油,采用熏蒸法,研究茶树精油、牛至精油等6种植物单方精油及其复配精油对草莓灰霉病菌的体外抑菌效果。结果表明:牛至精油的抑菌效果最佳,其次为1-辛烯-3-醇和茶树精油,其抑菌效果明显优于肉桂精油、桉叶精油和茉莉酸甲酯;茶树精油、1-辛烯-3-醇和牛至精油的最低抑菌浓度(MIC)分别为200、100、100 mg/L;茶树精油与牛至精油复配具有协同增效作用,且二者以质量比1∶4进行熏蒸时,对草莓灰霉病菌的抑制作用最强。综上,牛至精油、1-辛烯-3-醇、茶树精油及茶树精油与牛至精油复配(质量比1∶4)对草莓灰霉病菌的抑菌效果较优。该研究结果可为新型草莓保鲜剂的开发利用提供新的研究思路。

In Vitro and In Vivo Antibacterial Activity of Patchouli Alcohol from Pogostemon cablin

Objective:To investigate the antibacterial activity of patchouli alcohol(PA)against 127 bacteria strains,including the common bacteria and drug-resistant bacteria strains both in the in vitro and in vivo tests.Methods:For the in vitro trial,the antibacterial property of PA against 107 Gram-positive and 20 Gram-negative bacteria strains was screened by agar double dilution method.For the in vivo trial,specific pathogen free Kunming strain of both male and female white mice,were used to test the protective ability of PA after being injected with the median lethal dose of the tested strains.Results:PA possessed antibacterial activity against all the tested 127 strains.In the in vitro test,PA could inhibit both Gram-negative bacteria(25-768μg/m L)and Gram-positive bacteria(1.5-200μg/m L).Particularly,PA was active against some drug-resistant bacteria like methicillin-resistant Staphylococcus aureus(MRSA).PA also exhibited in vivo anti-MRSA activity in mice via intraperitoneal injection.PA could protect mice entirely infected with MRSA at 100 and 200 mg/kg,while 80% mice injected with MRSA could be protected at a low dose of 50 mg/kg.Conclusion:PA might be a potential antibacterial drug from natural sources and might be worthy to explore its mechanism and application in further study.