Antimicrobial Activity Of Alcoholic Extracts Research Articles

Antibacterial and Antibiofilm Activity of Different Species of Fabiana sp. Extract Obtained via Maceration and Ultrasound-Assisted Extraction against Staphylococcus epidermidis.

Staphylococcus epidermidis is an opportunistic pathogen that, under certain conditions, can induce aggravated infectious processes, mainly in immunosuppressed patients. Moreover, S. epidermidis is one of the leading causes of medical device- and implant-associated infections and is also recognized as a canonical biofilm producer. Fabiana punensis, F. densa and F. patagonica are three medicinal plants that grow in arid environments in Argentina (Altoandina, Puna, Prepuna and Monte regions). In this work, we studied the antimicrobial activity of alcoholic extracts of these plant species obtained via maceration (M) and ultrasound-assisted extraction (UAE) against S. epidermidis. In addition, the antibiofilm activity of the F. densa extract was also evaluated. It was found that the extracts obtained via M did not present differences with those obtained via UAE regarding the chemical profile. F. densa showed the lowest minimum inhibitory concentration (MIC) value (75 µg GAE/mL). At concentrations higher than the MIC, the extract induced the release of cellular constituents. At the concentration of 1/8× MIC, the extract inhibited biofilm formation by 78%, reducing metabolic activity by 67%. On the other hand, it presented a low percentage of preformed biofilm removal. In all assays, gallic acid (GA) has been used as a reference antimicrobial compound. Finally, it was shown via microscopy visualization that the extract reduces adhesion to hydrophobic and hydrophilic surfaces. Thus, F. densa extracts could potentially be used for the antibiotic treatment of infections produced by S. epidermidis or as an inhibitor agent of production biofilm, avoiding infections caused by medical devices.

Antimicrobial Activity of Alcoholic Extracts of Medicinal Plants against Phytopathogenic Fungi

Aims: This work aimed to evaluate the antimicrobial effects of 14 alcoholic extracts of medicinal plants on the mycelial growth of Colletotrichum gloeosporioides, Fusarium oxysporum f. sp. passiflorae, Fusarium solani and Rhizoctonia solani. Those are fungi that cause diseases in Passiflora edulis.
 Study Design: With the obtained data the mycelial growth rate index (MGRI) was calculated, afterwards the analysis of variance was performed and the means were compared by the Scott-Knott test at 5% probability.
 Place and Duration of Study: Plant Pathology Laboratory, Embrapa Eastern Amazon, Belém, Pará, Brazil, between May 2014 and April 2015.
 Methodology: The extracts were prepared with 1.0 g of powdered plant material and 10 mL of commercial ethyl alcohol 92.8º (0.1 g mL-1) under constant agitation in an orbital shaker at 200 rpm for 20 minutes. They were then kept in the refrigerator for 24 hours at rest. The extracts were centrifuged and filtered on Millipore membranes with 0.22 µm porosity. The tests with the phytopathogenic fungi were carried out in vitro with the alcoholic extracts at 1% concentration. The experimental design was completely randomized with 15 treatments and 5 replicates.
 Results: All the extracts reduced the growth of the fungi C. gloeosporioides. The extracts the Eucalyptus angulosa, Lippia alba, Zingiber officinale, Cymbopagon citratus, Azadirachta indica, Plectranthus barbathus, Hibiscus sabdariffa, Aloe vera, Pedilanthus tithymaloides, Mansoa alliacea and Chenopodium ambrosioides reduced the mycelial growth of F. oxysporum f. sp. passiflorae. Only the extract of E. angulosa presented reduction in the growth of F. solani. Meanwhile the extracts of E. angulosa, Z. officinale, L. alba, M. alliacea and P. barbathus reduced the mycelial growth of R. solani.
 Conclusion: All extracts presented antimicrobial potential, being that the extract of E. angulosa reduced the mycelial growth of all the evaluated fungi.

The antimicrobial activity of alcoholic extracts of leaves and bark from two varieties of ”Sangre de Drago” compared with the antimicrobial activity present in the latex of the same species

Background: This research was carried out in order to study the antimicrobial effectiveness of crude latex of two varieties of "Sangre de Drago": Croton lechleri Muller Arg. and Croton urucurana Baill and compare that effectiveness to the antimicrobial activity of the alcoholic extracts of its leaves and bark. Methods: The activity of the alcoholic extracts and latex were evaluated against bacterial strains of Staphylococcus epidermidis, Bacillus subtilis and Escherichia coli. The extraction of the alcoholic extracts (20% Tincture) of the leaves, bark and latex from the two Croton species was carried out by maceration using 70% alcohol as a menstruum, at room temperature, for 2 to 7 days, with shaking at least twice a day. A 20% tincture was obtained, from which the physical and chemical parameters were determined as indicated by the Ecuadorian Quality Control Standard for natural medicinal products. Results: It was found that both the alcoholic extracts of the plant material and the crude latex indicate antimicrobial activity for S. epidermidis, moderate antimicrobial activity for B. subtilis and no antimicrobial activity for E. coli. The moderate antimicrobial activity against B. subtilis, at doses of 125 p.p.m., is in line with the findings of previous studies by other authors. Conclusions: he antimicrobial activity of the latex of the two species against S. epidermidis is not registered in literature and, the negative antimicrobial activity for E. coli does not agree with what has been reported by previous studies.

To study the Photodynamic antimicrobial activity of Henna extract and preparation of topical Gel formulation

Henna, known to possess antibacterial & antifungal activities is reported to contain naphthoquinone derivatives which have potential as photodynamic agents. Current study comprises of evaluation of Photodynamic antimicrobial activity of alcoholic extract of henna, followed by preparation & evaluation of a topical gel formulation. The alcoholic extract prepared by maceration was analyzed for phytochemicals. Lawsone (2- Hydroxy-1,4 naphthoquinone) was isolated from Henna and was characterized by UV, IR & MASS to confirm its structure. The HPTLC fingerprinting of extract and quantification of lawsone in extract and fraction was carried out. The effect of light was tested on extract and fraction to assess its photosensitizing property. The antimicrobial activity of the extract was tested where one set was exposed to light and other kept in dark and zone of inhibition calculated for both sets. The yield of fraction was found to be 0.5±0.1% w/w. The quantity of lawsone in alcoholic extract & fraction was found to be 1.3 ± 0.02 % w/w and 59.57 ± 1.01 % w/w respectively. The extract is nearly 75% as active as standard Gentamicin and the activity gets 20% potentiated on exposure to light for all test samples indicating Photodynamic antimicrobial activity. The gel was evaluated for its stability with developed HPTLC method and also for physicochemical parameters. The gel containing henna extract, exhibiting good Photodynamic antifungal & antibacterial properties, was found to be stable. The current study thus has resulted in developing a potentially effective herbal topical formulation for management of skin, scalp & hair infections

ANTIMICROBIAL EFFECTS OF OCIMUM SANCTUM ON ORAL MICROBES

Objective: Ocimum sanctum (Tulsi) of the Lamiaceae family has been used since centuries for its medicinal properties. Tulsi powder has been utilized for cleaning tooth and is known to be effective in maintaining oral hygiene. Although the medical usefulness of tulsi is investigated extensively, its effectiveness in treating oral diseases is not yet established, and only a few studies are available in the literature regarding this aspect. Therefore, in the current study, the antimicrobial activity of alcoholic extract of tulsi on oral microbes was explored.Methods: Ethanolic extract was obtained from the leaves of O. sanctum (tulsi) using the Soxhlet apparatus. The concentration of 400 μg/ml was chosen to test the antimicrobial properties against common oral microbes such as Prevotella intermedia, Streptococcus mutans, Candida albicans, Lactobacillus acidophilus, Streptococcus mitis, and Peptostreptococcus using agar well diffusion and broth dilution method. Chlorhexidine was a positive control. To compare and correlate the results, Mann–Whitney U-test was applied.Results: The ethanolic extract at a concentration of 400 μg/ml showed an inhibitory effect against Streptococcus and Streptococcus with an inhibitory zone of 7.33 mm each. The extract was found to be effective against P. intermedia and Peptostreptococcus. It was also effective against candida (zone of inhibition was 10.67 mm). However, no inhibitory effect was seen on Lactobacillus.Conclusion: O. sanctum extract was found to have inhibitory effects on oral microbes, and hence, pharmaceutical formulations prepared from tulsi extracts could have a potential to be used as a part of routine dental hygiene.

Evaluation of Antimicrobial activity of stem bark of Ficus bengalensis Linn. Collected from different geographical regions

The stem bark of Ficus bengalensis is reported to have antimicrobial activity, we planned our work as to evaluate and compare antimicrobial activity of alcoholic extracts of stem bark of F. bengalensis by cup and plate method collected from three different geographical regions viz. Delhi, Gujarat and Uttaranchal. The activity of all the extracts at the dose level 1000 μg/ml, 500 μg/ml and 100 μg/ml were found to be quiet different and all the extracts showed that activity is varied as geography and environmental conditions are changed.

A Newly Observed Inhibitory Effect of Cashew Nut Extract on the Growth of Pathogenic Microorganisms

The antimicrobial activity of alcoholic extract of cashew nut ( Anacardium occidentale ) was tested on some pathogenic microorganisms collected from the laboratory. Fresh cashew nuts were macerated and extracted using absolute methanol at a dilution ratio of 1:2 (w/v) for 24 hours at room temperature (28°C). This extract was filtered using a Whatman filter paper No. 40 into a conical flask and the filtrate heated at 60°C for 30 minutes to remove the methanol. The filtrate was used to fill 5mm diameter wells on nutrient agar plates. A total of 120 organisms comprising 20 Proteus species , 20 Pseudomonas aeruginosa , 10 Candida albicans and 10 Enterococcus faecalis were used for this assay. The following organisms were susceptible to crude extract of cashew nut with mean zone diameters of 14mm for Escherichia coli , 22mm for Pseudomonas aeruginosa , 19mm for both Staphylococcus aureus and Klebsiella species, 13mm for Enterococcus faecalis , 14mm for Proteus species and 10mm for Candida albicans . This study shows that cashew nut extract has antimicrobial activity against a reasonable range of pathogenic microorganisms. Key words: cashew nut, crude extract, microbial inhibition Journal of Medical Laboratory Science Vol.13(1) 2004: 58 - 61

Studies on the Antimicrobial Activity of Heliotropium indicum Linn.

Objective: To investigate the antimicrobial activity of alcoholic extract of Heliotropium indicum . Materials and method: Antimicrobial activity was studied at concentrations of 1 μg/ml, 100μg/ml, 1 mg/ml, 50 mg/ml and 100 mg/ml of the extract dissolved in propylene glycol against four strains each of Gram positive and Gram negative bacteria, three strains of fungi and two yeast by agar cup plate diffusion method. Results: The alcoholic extract of Heliotropium indicum was found to possess dose dependent antimicrobial activity in all the test organisms. Conclusion: The study lends support for the use of the plant as folklore medicine for the treatment of infectious diseases.