Antimicrobial Activity Of Plant Extracts Research Articles

IN-VITRO ANTIMICROBIAL ACTIVITY OF ETHYL ACETATE EXTRACT OF CENTAUREA BEHEN LINN

This work aims to evaluate the antimicrobial potential of ethyl acetate extracts of Centaurea Behen Linn (C. Behen) on some microorganisms. Agar well diffusion method has been used to determine the antimicrobial activities of plant extracts against Gram-positive bacteria, Gram-negative bacteria (Streptococcus mutans, Staphylococcus aureus, Salmonella bongori and Escherichia coli), and two fungus (Candida albicans and Aspergillus niger). The extracts exhibited both antibacterial and antifungal activities against tested microorganisms using standard ofloxacin, ciprofloxacin and fluconazole (10-30μg/ml). The antimicrobial activity was determined by measuring the diameter of the zone of inhibition in term of millimeter (mm). To analyze the antimicrobial activity, ethyl acetate extract of C. Behen was tested by well diffusion method against six selected strain and which shows significant inhibitory action against all the tested strain. The antimicrobial activity of ethyl acetate extract of root against all microorganisms was concentration dependent but less than standard drug. It is concluded that the antimicrobial activity showed by the plant is due to the presence of phytochemicals. For future studies, phytochemcials responsible for these activities can be isolated and modified for pharmacological purpose.

Green synthesis, characterization, photocatalytic activity, and biological applications of gelatin-sodium alginate zinc oxide nanocomposite

The present study stated a green approach for synthesizing zinc oxide nanoparticles using Oldenlandia umbellata (Rubiaceae) plant extract, which was used as the biological reducing agent for synthesizing zinc oxide nanoparticles from zinc nitrate hexahydrate. The synthesized ZnO nanoparticles were loaded with Gelatin-Sodium alginate biopolymers to convert them into Gelatin-Sodium alginate-Zinc oxide (GSZnO) nanocomposite hydrogels. The UV–Visible spectroscopy showed maximum absorbance at 376 nm for ZnO Nanoparticles and 360 nm for GSZnO nanocomposite. Different functional groups in ZnO Nps and GSZnO nanocomposites are identified using FT-IR spectroscopy. The SEM analysis of ZnO Nps and GSZnO nanocomposites demonstrates the size in the range of 67–80 nm. DLS Particle size analysis shows 71 nm for ZnO.A NPs and 74 nm for GSZnO nanocomposites. XRD analysis proved the crystalline nature and sharp highest peak at 101) plane confirm the hexagonal shape. While the EDAX analysis confirmed the formation of zinc oxide in the nanoparticles. Antioxidant studies were carried out for ZnO.A Nps showed better antioxidant properties compared to plant extract. The antimicrobial activity of plant extract and ZnO.A Nanoparticles were done against Staphylococcus aureus, Proteus vulgaris, Aspergillus flavus, and Candida albicans. ZnO.A nanoparticles showed good photocatalytic activity of methylene red dye in the presence of visible light irradiation. GSZnO nanocomposite was studied for In-vitro cytotoxicity on Vero cells, The IC50 value for the GSZnO nanocomposite was 101.5 µg/ml.

Comparative In-vitro Antioxidant and Antimicrobial Activity of Hydroalcoholic Extract of Miliusa tomentosa

Green medicine, the drugs derived from plants attained a wide spread interest, as believed to be safe and dependable, compared with costly synthetic drugs that have adverse effects. The present study aimed to analyze a comparative in vitro free radical scavenging and antimicrobial potentials of leaf hydroalcoholic extract fractions of Miliusatomentosa (Roxb.) J. Sinclair (M. tomentosa, Annonaceae) commonly known as hoom, kari.It is a large deciduous tree, growing up to 20 m tall and are given to children to cure the weakness in summer. The hydroalcoholicextract of leaves of M. tomentosa was studied for antioxidant activity on different in vitro models namely 1,1-diphenyl, 2-picryl hydrazyl (DPPH) assay, Hydrogen peroxide (H2O2) and Nitric oxide (NO) radical scavenging method. Agar well diffusion method has been used to determine the antimicrobial activities of plant extracts against Gram-positive bacteria, Gram-negative bacteria (Enterococcus faecalis, Salmonella Bongori,Propionibacterium acnes), and fungus (Aspergillusflavus). In the investigated models, the extract showed dose-dependent free radical scavenging properties. For the DPPH technique, M. tomentosa leaves extract had an IC50 value of 335.92g/ml, which was close to that of ascorbic acid (IC50=17.68g/ml). The IC50 value for hydrogen peroxide was determined to be 96.42g/ml, which compares favourably to ascorbic acid (IC50=36.61g/ml). The IC50 value for nitric oxide was 105.87g/ml, which was close to that of ascorbic acid (IC50=24.63g/ml). The extracts exhibited both antibacterial and antifungal activities against tested microorganisms using standardampicilin, ciprofloxacin, clindamycin and fluconazole (10-30μg/ml). The antimicrobial activity was determined by measuring the diameter of the zone of inhibition in term of millimeter (mm). The antimicrobial activity of hydroalcoholic extract of leaves against all microorganisms was concentration dependent but less than standard drug. On the basis of results obtained, it is suggested that both M. tomentosa leaves extracts may be a potential source of natural antioxidants and antimicrobial compounds to be used in the treatment of various oxidative disorders, infectious diseases caused by resistant microorganisms.

Evaluation of the antimicrobial activity of plant extracts on Escherichia coli and Candida albicans

This study aimed to investigate the antimicrobial activity of watermelon extracts of Teucrium polium and Citrullus colocynthis on Escherichia coli and Candida albicans isolated from women's Urinary tract infections. T. polium and C. colocynthis were collected from the Sistan region of Iran. Extraction was performed with ethyl acetate, methanol, acetone, and ethanol solvents using a rotary apparatus. E. coli strains were isolated from urinary infections. The minimum inhibitory concentration and the Minimum Bactericidal Concentration were prepared by dilution method in the well. The lowest inhibitory concentration of C. colocynthis ethyl acetate extract was equal to 3.1 ppm, in which 2 strains were inhibited. In comparison, the highest inhibitory concentration was 100 ppm, in which one strain was inhibited in this concentration. The lowest inhibitory concentration of T. polium ethyl acetate extract of E. coli was 3.1 ppm, with 2 strains inhibited. In comparison, the highest inhibitory concentration was 50 ppm, with one strain at this concentration. This study showed that the lower inhibitory concentration of C. colocynthis ethyl acetate extract against C. albicans was 25 ppm. The lowest inhibitory concentration of T.polium methanol extract against C. albicans was 12.5 ppm, which was unilaterally inhibited in this concentration. According to the obtained results and the increasing resistance of bacteria to chemical antibiotics, it is suggested that with further studies on this plant, the antibacterial compounds of this plant can be used in the treatment of bacteria.
 

Antimicrobial and Antioxidant Secondary Metabolites from Trifolium baccarinii Chiov. (Fabaceae) and Their Mechanisms of Antibacterial Action.

The treatment of infectious diseases with antimicrobial agents continues to present problems in modern-day medicine with many studies showing significant increase in the incidence of bacterial resistance to several antibiotics. The screening of antimicrobial activity of plant extracts and natural products has shown that medicinal plants are made up of a potential source of new anti-infective agents. The aim of this study was to evaluate the antimicrobial and antioxidant activities of extracts and compounds from the whole plant Trifolium baccarinii Chiov. and to determine their modes of antibacterial action. The plant extracts were prepared by maceration in organic solvents. The antimicrobial activities were evaluated using the broth microdilution method. The antioxidant activity was evaluated using the 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) assays. The mechanisms of antibacterial action were determined by lysis, salt tolerance assays, and antioxidant enzyme activities. The cytotoxic effect on the erythrocytes was determined by a spectrophotometric method. Biochanin A, formononetin, luteolin, luteolin-4′-O-β-D-glucopyranoside, 4,7,2′-trihydroxy-4′-methoxyisoflavanol, sissotrin, 1-methyl-β-D-glucopyranoside, ononin, D-mannitol, and 3-O-β-D-glucuronopyranosylsoyasapogenol B were isolated from Trifolium baccarinii. The MeOH, EtOAc, and n-BuOH extracts as well as biochanin A, formononetin, luteolin, luteolin-4′-O-β-D-glucopyranoside, 4,7,2′-trihydroxy-4′-methoxyisoflavanol, and sissotrin from Trifolium baccarinii displayed the highest antimicrobial and antioxidant activities. The MeOH extract and 4,7,2′-trihydroxy-4′-methoxyisoflavanol exhibited antibacterial activity through the bacteriolytic effect and reduction of the antioxidant defenses in the bacterial cells. The present study portrays Trifolium baccarinii as a potential natural source of antibacterial, antifungal, and antioxidant agents.

The THE ROLE OF AERVA JAVANICA (BURM.F.) JUSS. GROWING IN JAZAN, SAUDI ARABIA AS ANTIMICROBIAL AND COAGULATING FACTOR

In deserted conditions, plants suffer from shortage of water and minerals. Though, they try to adapt with harsh conditions by building an internal defense system via making different chemical compounds, especially secondary metabolites. These secondary metabolites have several medicinal effect. Saudi Arabia is considered as semi-arid region. Therefore, it has many plants with high adaptation level to survive in the exotic environment.  South west of Saudi Arabia is the richest in plant biodiversity. One of the common plants that grows nearly everywhere in the country is Aerva javanica (Burm.f.) Juss. It is a widely distributed herbal plant and is called desert cotton (in Arabic Tarf). It has different human usage. Flowers sometimes are used as cotton filling for pillows. Moreover, it has different medicinal practices among indigenous people. One of its uses among local people is using flowers to stop the bleeding if wounds persists. Therefore, this research investigate the medicinal implication of A. javanica as antibacterial agent and as a blood-coagulating factor. Dichloromethane, methanol, ethanol and water extractions from different parts of the plant (stem, leaf and flower) were investigated. The antimicrobial activity of plant extracts were evaluated with microorganism by disc diffusion method on three different strains of bacteria (Escherichia coli, Staphylococcus aureus and Bacillus subtilis). Moreover, coagulating rate by manual method on blood samples from female rat was restrained. Escherichia coli growth was inhibited only by the dichloromethane extraction from the three parts of the plant. Staphylococcus aures growth was inhibited by the aqueous extraction of the three parts of the plant and the methanol extraction of the leaves. All the other extractions has no effect on the growth of Bacillus subtilis or the other bacteria. For the blood coagulating, all extracts were very effective on exceeding blood clotting time. The clotting time was less than the time of the control. The finding and results are discussed in detail.

Towards Advances in Medicinal Plant Antimicrobial Activity: A Review Study on Challenges and Future Perspectives.

The increasing incidence of drug- resistant pathogens raises an urgent need to identify and isolate new bioactive compounds from medicinal plants using standardized modern analytical procedures. Medicinal plant-derived compounds could provide novel straightforward approaches against pathogenic bacteria. This review explores the antimicrobial activity of plant-derived components, their possible mechanisms of action, as well as their chemical potential. The focus is put on the current challenges and future perspectives surrounding medicinal plants antimicrobial activity. There are some inherent challenges regarding medicinal plant extracts and their antimicrobial efficacy. Appropriate and optimized extraction methodology plant species dependent leads to upgraded and selective extracted compounds. Antimicrobial susceptibility tests for the determination of the antimicrobial activity of plant extracts may show variations in obtained results. Moreover, there are several difficulties and problems that need to be overcome for the development of new antimicrobials from plant extracts, while efforts have been made to enhance the antimicrobial activity of chemical compounds. Research on the mechanisms of action, interplay with other substances, and the pharmacokinetic and/or pharmacodynamic profile of the medicinal plant extracts should be given high priority to characterize them as potential antimicrobial agents.

Phytochemical Screening and in vitro Antimicrobial Activity of Cyperus rotundus Leaf Extracts

Cyperus rotundus, a member of family Cyperaceae is a perennial, stoloniferous herb. The study investigated the secondary metabolites present in the leaf of Cyperus rotundus and antimicrobial activities of the hexane, ethyl acetate and methanol extracts. Phytochemical analysis revealed the presence of saponins, alkaloids, phenolic compounds, tannins, steroids, flavonoids, cardiac glycosides and terpenoids. The qualitative test of the extracts show the presence of steroid only in the hexane extract; flavonoid, cardiac glycoside in both the ethyl acetate and methanol extracts; saponin and tannin and phenolics in just the methanol extract. While alkaloid was present in all the extracts, terpenoid was absent in all. Antimicrobial activity of plant extracts were monitored using the agar disk-diffusion method against strains gram-positive bacterial: Staphylococcus aureus, Pseudomonas aeruginosa; and gram-negative bacteria: Escherichia coli, Salmonela typhi, and strains of fungi: Candida albicans and Aspergillus niger. The antimicrobial activity of the extracts was monitored at different concentrations of 50, 25, 12.5 and 6.25 mg/mL prepared from the stock concentration (100mg/mL) by serial dilution; with standard drugs: ciprofloxacin and fluconazole. The inhibition of the test organisms were concentration dependent. The methanol extract showed significantly higher Inhibition Zone (IZ) and Activity Index (AI) against the microbes at all concentrations compared to the ethyl acetate and hexane extracts due to the much phytochemicals (saponins, tanins, phenols, flavonoids, cardiac glycocides and alkaloids) found present in its extract. The overall study results signify the potential of Cyperus rotundus as a source of therapeutic agents. The methanol extract showed the best activity against both bacterial and fungal pathogens at the highest concentration of 100 mg/mL, especially the most susceptible bacteria: Staphylococcus aureus (IZ of 25.0±1.5; AI of 0.96) and Candida albicans (IZ of 25.5±0.5; AI of 0.91). At MIC, MBC and MFC of 6.25 mg/mL and 12.5 mg/mL, the plant extracts showed effective bactericidal and fungicidal effect against the test microbes.

Chemical compositions, antibacterial, antifungal and cytotoxic effects of Alhagi mannifera five extracts.

Plants were used as medicines thousands of years ago. Conventional medicine use is increasing and many of the currently used drugs are extracted from herbal sources. In Palestinian traditional medicine, the Alhagi mannifera plant is used for the treatment of cancer. Our study aimed to extract this plant using five solvent fractions, identifying their chemical compositions, and evaluating their antimicrobial and cytotoxic effects. The successive technique was used to extract five solvent fractions of A.mannifera. While the spectral analysis was used to characterize quantitatively and qualitatively the chemical components of these extracts. The antimicrobial activity of plant extracts was evaluated against seven microbial strains using a broth micro-dilution assay. The cytotoxic activity was assessed using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay against cervical cancer cell line (HeLa). A total of 165 compounds were identified in A.mannifera different extracts. In the petroleum etherextract were found a total of 55 compounds. The major compounds were 2,5-cyclooctadien-1-ol (9.42%), 3-chloropropionic acid, heptyl ester (9.42%), carbonic acid, ethyl nonyl ester (9.42%) and chloroacetic acid. In methylene chloride extract a total of 11 compounds were found, and the major compounds were m-ainobenzenesulfonyl fluoride (14.35%), dodecane,2,6,10-trimethyl- (14.35%) and propanoic acid,2,2-dimethyl-,2-ethylexyl ester (14.35%). In chloroform extract, a total of 23 compounds were found. The major compounds were 5-ethyl-1-nonene (21.28%), and decanedioic acid, bis(2-ethylhexyl) ester (21.28%). In acetone extract were found a total of 47 compounds and the major compound was phenol,2,4-bis(1,1-dimethylethyl)- (5.22%). In methanol extract a total of 29 compounds were found and the major compounds were 3-o-methyl-d-glucose (10.79%), myo-inositol, 2-c-methyl- (10.79%), myo-inositol, 4-c-methyl- (10.79%), and scyllo-inositol,1C-methyl- (10.79%). All extracts showed antimicrobial activity. However, the petroleum ether extract showed the most potent antimicrobial effect against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, MRSA, and Candida albicans with minimal inhibitory concentration (MIC) values of 1.25, 1.25, 6.25, 0.325, 6.25, and 1.56μg/mL, respectively. De facto, chloroform extract followed by ether extract displayed potential cytotoxic activity with IC50 values of 0.2 and 1.2mg/mL, respectively. A.mannifera was found to contain a variety of phytochemicals and its chloroform extract showed a potent cytotoxic effect on HeLa cancer cells. In addition, petroleum ether showed potent antimicrobial agents and these extracts look promising as drug candidates. Further in vivo investigations should be conducted to provide the basis for developing new cancer and microbial infections treatments.

Antimicrobial Evaluation of Extracts and Fractions of Daniella oliveri Leaf on Selected Clinical Enteropathogens

Background: Diarrhoea is one of the major health threats to the populace in the tropics, and also one of the killer diseases in children under 5 years of age. Antimicrobial resistance and its spread pose serious public health threats, hence the need for development of safer and more effective antibacterial agents. Daniella oliveri Hutch and Dalz is used in ethnomedicine for the treatment of diarrhoea and other gastrointestinal disturbances.
 Objective: To investigate the antimicrobial activity of Daniella oliveri leaves on diarrhoeal pathogens.
 Methods: Successive plant extraction was carried out with hexane, ethylacetate and methanol using soxhlet apparatus. Methanol extract was fractionated using vacuum liquid chromatography (VLC). Phytochemical screening was done using standard chemical assays. Antibiogram of test isolates was carried out using disc diffusion assay. Antimicrobial activity of plant extract and fractions against strains of diarrhoeagenic Escherichia coli, Salmonella cholerae-suis, Shigella dysenteriae, Proteus mirabilis and Acinetobacter baumannii was determined by agar well diffusion and MIC by agar dilution methods. Kill-kinetics study was carried out using viable count technique.
 Results: Terpenoids, steroids and anthraquinones were detected in fractions of D. oliveri. Antibiogram assay showed that 66% of isolates were MDR. Extract and fractions produced appreciable zones of inhibition on all challenge organisms except Acinetobacter baumannii. MICs ranged between 6.25-25 mg/ml. Kill kinetics studies showed total kill on susceptible pathogens after 24 hours.
 Conclusion: This research has shown D. oliveri is a promising drug candidate for the management and treatment of diarrhoea.

Evaluation of Antimicrobial Activity of Plants Extract Against Bacterial Pathogens Isolated from Urinary Tract Infection among Males Patients

Background: Urinary tract infection (UTI) is a considerable problem affecting the health of peopleeach year. It is caused by various Gram-positive (G+ve) and Gram-negative (G-ve) pathogens. Itis an important illness in the world affecting all age groups across their life span.Objectives: To identify the most common aerobic bacteria that cause UTIs and their antibioticsusceptibility and antimicrobial activity of plant extracts of the males’ patients.Materials and methods: The study involved 35 midstream urine samples from the male students(University of Baghdad, Baghdad, Iraq) with suspicious symptoms of UTI, during the period fromJanuary-March 2018. Each urine sample was cultured first on Mannitol Salt Agar and MacConkeyagar plates to differentiate between G+ve and -ve bacteria. The isolated bacteria were subjectedto certain antibiotics and 100% plant extract oils.Results: Out of 35 urine samples, there were 62 isolates. There were 34 (54.8%) G-ve and28 (45.2%) G+ve pathogens. Staph. epidermidis (n=17, 27.4%) was the most common isolatedpathogen, while P. aeruginosa (n=5, 8.1%) was the least isolated organism. Vancomycin wasthe most sensitive antibiotic for the Staph. epidermidis (52.9%) and Staph. epidermidis (45.5%).While oregano oil was more sensitive to Staph. epidermidis and Staph. aureus in 64.7% and 63.6%respectively. Imipenem was the most effective antibiotic for the three common G-ve isolates E. coli,K. Pneumoniae, and Enterobacter spp in 83.3%, 90%, and 85.7% respectively. Oregano oil was themost susceptible plant extract for E. coli (91.7%).Conclusion: Plants oils are potentially a good source of antimicrobial agents. Besides, the plantextract oils are cheaper than antibiotics. Therefore, they could be used in UTI medicine.

Synergistic Effect of Plant Extracts on Endodontic Pathogens Isolated from Teeth with Root Canal Treatment Failure: An In Vitro Study.

Background and objectives: This study aimed to evaluate the synergistic antimicrobial activity of extracts obtained from Salvadora persica (Miswak), Commiphora molmol (myrrh) and Azadirachta indica (neem) in combination with commercially available antimicrobial agents: penicillin, tetracycline, ofloxacin and fluconazole on endodontic pathogens such as Enterococcus faecalis, Streptococcus mitis, Actinomyces naeslundii and Candida albicans. Materials and Methods: Microbiological samples from the root canals of the teeth undergoing retreatment were taken using sterile paper points kept at full length in the canal for 30 s. The disc diffusion method was used to check the susceptibility of microbes to the plant extracts and antimicrobials by measuring the diameter of the inhibition zones. Against the microbes, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of the plant extracts were assessed. The fractional inhibitory concentration index (FICI) was used to estimate the synergistic effect of plant extracts combined with antimicrobials against the resistant endodontic microbes. Results: The findings clearly indicate the effectiveness of all the three plant extracts, Commiphora molmol, Azadirachta indica, Salvadora persica, against all the experimental pathogenic microorganisms except for the ineffectiveness of Azadirachta indica, Salvadora persica against Candida albicans. Maximum antimicrobial activity was displayed by Azadirachta indica against Enterococcus faecalis (MIC = 0.09 ± 1.2 mg/mL, MBC = 0.78 ± 1.25 mg/mL) and the minimum antimicrobial activity was displayed by Commiphora molmol against Actinomyces naeslundii (MIC = 12.5 ± 3.25 mg/mL, MBC = 100 ± 3.75 mg/mL). The best synergy was displayed by Commiphora molmol with fluconazole against Candida albicans (FICI = 0.45). Conclusions: The current study delineates the variable antimicrobial activity of plant extracts against the experimental endodontic pathogenic microorganisms. Plant extracts in conjunction with various antimicrobials can be valuable aids in combating relatively resistant endodontic microorganisms that have been the cause of worry in recent years, leading to failure even in treatment procedures following all required protocols.

Evaluation of 2,2-diphenyl-1-picrylhydrazyl, secondary metabolite contents and antimicrobial efficacy of Blastonia garcinii(Burm.f.) Cogn.

This study emphasizes screening of DPPH, secondary metabolites and antimicrobial activity of Blastonia garcinii an annual wine with a slender stem, climbing using tendrils, leaves are ovate and flowers are unisexual. The leaves were collected, shade dried and powdered. The powdered sample was extracted by using soxhlet apparatus with petroleum ether and ethanol. The antioxidant activity of the plant extracts was measured using spectrophotometry by their ability to scavenge free radicals such as DPPH (2,2-diphenyl-1-picrylhydrazyl), hydrogen peroxide and also quantification of total flavonoids, total phenol content and antimicrobial activity of plant extracts. The significant result observed in when compared Petroleum ether and Ethanol extract, the DPPH and H 2 O 2 activities and the total phenol and total flavonoid content and Antibacterial and antifungal activity were shown significant activity in ethanolic extract of B. garcinii.

Pharmacological properties of edible Asparagus acutifolius and Asparagus officinalis collected from North Iraq and Turkey (Hatay)

AbstractIn this study, antioxidant, oxidant, antimicrobial, and antiproliferative activities of Asparagus acutifolius L. and Asparagus officinalis L., known for their nutritional properties, were determined. In this context, methanol (MeOH) and dichloromethane (DCM) extracts of plants were obtained. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were determined using Rel Assay kits. Antimicrobial activities of plant extracts were determined against the test microorganisms using the agar dilution method. Antiproliferative activity was tested on the lung cancer cell line A549. As a result of the studies, it has been determined that the plant species have high antioxidant potential. In addition, it was observed that the antifungal potentials of plant extracts are high. Antiproliferative activity was determined to be at high level in both plant species. As a result, it has been determined that A. acutifolius and A. officinalis have medical potential and can be used as natural agents in pharmacological designs.

Antibacterial potential of indigenous plant extracts against multidrug-resistant bacterial strains isolated from New Delhi region

The extensive use of antibiotics to treat bacterial infections has led to the widespread emergence of multidrug-resistant (MDR) pathogens, becoming increasingly difficult to treat with currently available antibacterial agents. The present study is based on prospecting the ethnomedicinal potential of Indian plant varieties for the treatment of MDR bacteria. Plants produce an array of diverse pharmacological compounds in defence against microbial pathogens which may be employed as a novel intervention strategy to combat MDR human pathogens. In the present study, the antimicrobial activity of extracts of four common Indian plants: Azadirachta indica (Neem), Murraya koenigii (Kadipatta), Phyllanthus emblica (Amla), and Ocimum sanctum (Tulsi) prepared in four solvents, water, methanol, ethanol, and chloroform was tested against nine MDR bacterial isolates. Kirby-Bauer well diffusion assays were adopted to assess the antimicrobial activity of plant extracts against the MDR strains. The potency of plant extracts was examined by determining the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). All MDR isolates including Staphylococcus haemolyticus, Bacillus subtilis, B. thuringiensis, B. cereus, Enterobacter xiangfangensis, Klebsiella pneumoniae, and Pseudomonas aeruginosa were significantly inhibited by the plant extracts. Test extracts showed promising antibacterial potential against MDR P. aeruginosa and Bacillus sp. with low MIC values ranging between 0.02-1.56 mg/ml, while most plant extracts exhibited either moderate MBC values or bacteriostatic effects. To the best of our knowledge, this is the first study that demonstrates the potential use of endemic A. indica, M. koenigii, P. emblica, and O. sanctum as therapeutic agents against circulating MDR human pathogens in the national capital.

Phytochemical Activities of Artemissia absinthium and Butea monosperma Plant Extracts

With the developing time, there is a tremendous need to deliver highly potential antimicrobial drugs and treatment from different herbaceous plants because plants are now days commonly used to provide resistance against disease-causing pathogens. This study has been done by using agar well diffusion method. The bacterial along with fungal strains were collected and were cultured on agar plates. Afterwards, these plates were put in incubate for 24 hours at 370C temperature. Within this duration, the zones were developing all around the plates, wherever plant extracts were poured. The activities of microorganisms were measured by using inhibition diameter zones. The inhibition zones were shown clearly on petri plates. Antimicrobial activities of plant extracts of Artemissia absinthium and Butea monosperma tested against bacterial and fungal strains viz. Pseudomonas aeruginosa, Bacillus subtilis and Escherichia coli as well as fungal strains were also used viz. Aspergillus niger and Fusarium oxysporum.

Antimicrobial Air Filter Coating with Plant Extracts Against Airborne Microbes

Antimicrobial air filters are required to protect humans from the risk of secondary bioaerosol pollution as well as airborne particles. Three plant extracts (tea-tree oil, rosemary, and garlic) were selected to replace antimicrobial chemicals in air filters. The antimicrobial activity of plant extracts was investigated using Micrococcus luteus and Escherichia coli. Phytochemicals present in the three plant extracts were identified using a gas chromatograph coupled with a mass spectrometer. The extracts were spray-coated on polyethylene terephthalate filter surfaces using silicate polymeric coating and evaluated via X-ray photoelectron spectroscopy and a scanning electron microscope with energy dispersive spectroscopy. After coating, an increase of 9.1% in the pressure drop was observed. The strain Micrococcus luteus was used to evaluate the antimicrobial activity of the air filter. After bioaerosol exposure, the tea-tree oil-coated filters immediately induced M. luteus cell inactivation (40–55%), whereas the rosemary and garlic coated filters did not. However, 48 h after exposure, a significant M. luteus inactivation of 99.99%, 99.0%, and 99.9% was recorded for concentrations of 2.89, 6.73, and 11.51 mg/cm2 for the tea-tree, rosemary, and garlic extracts, respectively. The coated filters exhibited high antimicrobial activity, thereby indicating significant potential for application as self-cleaning air filters.

Antimicrobial activity of plant extracts against carbapenem-producing Klebsiella pneumoniae and in vivo toxicological assessment

ABSTRACT The global spread of multidrug-resistant strains has prompted the scientific community to explore novel sources of chemicals with antimicrobial activity. The aim of the study was to examine the antimicrobial activity in vitro of 28 extracts against carbapenem-producing Klebsiella pneumoniae, individually and in combination with antibiotics and in vivo toxicological assessment of the most active product. The multi-resistant K. pneumoniae strain was submitted for phenotypic and molecular characterization. The antibacterial activity of 28 plant extracts was evaluated alone and in combination with antibiotics against this strain through the agar disk diffusion. Of these, 16 extracts showed synergism against carbapenem-producing K. pneumoniae, being that B. crassifolia extract exhibited synergism with three antibiotics. Based on this assessment, B. crassifolia-extract-induced toxicity on Swiss male mice was evaluated by administering this extract and subsequently determining apoptosis and splenic phagocytosis using the comet and micronucleus assays. The results of this study showed that B. crassifolia extract had synergistic activity promising and groups treated with B. crassifolia exhibited no genotoxic or mutagenic activity, indicating that B. crassifolia extract exerted beneficial effects and appeared safe to use at the studied concentrations.

Interaction of Folk Medicinal Plants with Levofloxacin against Escherichia Coli

The present study was conducted to assess the in vitro activities of folk medicinal plants in combination with levofloxacin against TG1 and mutant KAM3-1(∆acrB-∆tolC) Escherichia coli strains. Plants were chosen based on their traditional use in combination with antibiotics among laymen. Standard protocols were followed to examine the antimicrobial activity of plant extracts and levofloxacin against E. coli in term of their minimum inhibitory concentrations (MICs) and to evaluate the plant extracts-levofloxacin interaction using checkerboard method. Among the twelve plants investigated, Thymus vulgaris, Zingiber officinale, Teucrium polium, Matricaria chamomilla and Curcuma longa had the best antimicrobial activities against E. coli strains with MIC values at 250 μg/ml. It is noteworthy to mention that other folk plants extracts reveled no effects against E coli strains. Furthermore, additive interactions were observed between levofloxacin and T. polium or T. vulgaris against E. coli wild-type TG1 strain. There was no antagonism being observed in this study. The detection of additive interaction between the extracts and levofloxacin demonstrates the prospective of these folk medicinal plants as a source of compounds to modulate antibiotic resistance.

Nazam Khan, Amir Khan, Umar Farooq

Abstract-Medicinal Plants are always of immense vital component for pharmaceutical word. Azadirachta indica, commonly known as neem, has attracted worldwide prominence in recent years owing to its wide range of medicinal properties. Neem is a medicinal plant which is always at top from ancient world to modern world. The importance of the neem tree has been recognized by the US National Academy of Sciences, which published a report in 1992 entitled 'Neem- a tree for solving global problems'. Various parts of neem are sources for mankind to treat many severe diseases. More than 140 compounds have been isolated from different parts of neem. All parts of the neem tree- leaves, flowers, seeds, fruits, roots and bark have been used traditionally for the treatment of inflammation, infections, fever, skin diseases and dental disorders. Neem leafanditsconstituentshavebeendemonstrated to exhibit immunomodulatory, anti-inflammatory,antihyperglycaemic,antiulcer,antimalarial,antifungal,antibacterial,antiviral,antioxidant,antimutagenicandanticarcinogenicproperties. Keeping these points in view the present study is aimed to study antimicrobial activity of plant extracts prepared from leaves of neem plant against Klebsiella pneumoniae,Pseudomonasaeruginosa,Bacillus subtilis, Staphylococcus aureus and Escherichia coli. There is a significant antimicrobial activity observed by neem leave extract against these microbial strains.