Minimum Inhibitory Concentration Of Extract Research Articles

Antibacterial and Anti-biofilm Effect of Lactuca serriola Extract Against Clinically Isolated Porphyromonas gingivalis and Prevotella intermedia: An in vitro study

Objective: To investigate the antibacterial and anti-biofilm effect of Lactuca serriola (LS) extract against clinically isolated Porphyromonas gingivalis (P. gingivalis) and Prevotella intermedia (P. intermedia). 
 Methods: LS extract was prepared by solvent extraction method. Gas chromatography mass spectrometry (GC-MS) was used to analyze phytochemical components. Plaque samples were obtained from periodontitis patients with probing pocket depth ≥6mm to isolate P. intermedia. Microbiological tests and conventional polymerase chain reaction (PCR) were used to confirm P. intermedia. Antibacterial activities of LS against the confirmed clinical strains (P. intermedia and revised P. gingivalis) were determined by agar well diffusion method. Broth macro dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The anti-biofilm assay of the LS was performed by using tube adhesion method. 
 Results: Antibacterial activity of LS against clinical isolates revealed that the inhibition zones ranged from 11.75 ±0.95mm to 24.25 ±1.7mm for P. gingivalis and 12.75 ±0.95mm to 25.5 ±1.29mm for P. intermedia. The MICs of LS extract were 212.5mg/mL and 106.2 mg/mL, while the MBCs were 425mg/mL and 212.5mg/mL against P. gingivalis and P. intermedia, respectively. The anti-biofilm of LS extract exhibited strong anti-biofilm activity. 
 Conclusions: LS extract exhibited bactericidal and anti-biofilm activity against clinically isolated P. gingivalis and P. intermedia in an in vitro study.

MIC and MBC of red fruit extract (Pandanus conoideus Lam) against periodontal pathogens bacteria

There are only few studies on the antibacterial activity of red fruit extract (Pandanus conoideus Lam) against oral pathogenic bacteria. Thus, this study aims to determine the effectiveness of red fruit extracts by looking at the Minimum inhibitory Concentrations (MIC) and Minimal Bactericidal Concentrations (MBC) against periodontal pathogenic bacteria. The subjects of this study were Streptococcus mutans (ATCC 25175), Fusobacterium nucleatum (ATCC 25586), and Porphyromonas gingivalis (ATCC 33277). The antibacterial effectiveness of red fruit extract was tested by the liquid dilution method (microdilution). The data were analyzed using the one-way ANOVA test followed by a double comparison test with the Post Hoc Least Significance Different (LSD) test method. The red fruit extract effectively inhibited and eliminated test bacteria (p <0.05). Our study showed that the red fruit extracts at a concentration of 20% could inhibit the growth of Streptococcus mutans and Porphyromonas gingivalis, which was determined as the MIC strength of 80% as MBC of both bacteria tested. Furthermore, red fruit extract at the concentration of 10% showed an inhibitory effect on the growth of Fusobacterium nucleatum, which was determined as MIC of Fusobacterium nucleatum and the strength of 40% as MBC of Fusobacterium nucleatum. The red fruit extracts were significantly effective against the growth of Streptococcus mutans, Fusobacterium nucleatum, and Porphyromonas gingivalis provide essential information for further in vivo clinical studies to determine the exact dosage and clinical effectiveness of periodontal disease.

Compound Identification from Bromelia karatas Fruit Juice Using Gas Chromatography–Mass Spectrometry and Evaluation of the Bactericidal Activity of the Extract

Fruits of species of the genus Bromelia contain compounds with health benefits and potential biotechnological applications. For example, Bromelia karatas fruits contain antioxidants and proteins with bactericidal activity, but studies regarding the activity of these metabolites and potential benefits are required. We evaluated the bactericidal activity of the methanolic extract (treated and not treated with activated charcoal) and its fractions (hexane, ethyl acetate, and methanol) from ripe B. karatas fruit (8 °Brix) against Escherichia coli, Enterococcus faecalis, Salmonella enteritidis, and Shigella flexneri. The methanolic extract (ME) minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at eight concentrations. The methanolic extract MIC was 5 mg/mL for E. faecalis and 10 mg/mL for the other bacteria; the MBC was 20 mg/mL for E. coli and E. faecalis, and 40 mg/mL for S. enteritidis and S. flexneri. Through gas chromatography–mass spectrometry, 131 compounds were identified, some of which had previously been reported to have biological activities, such as bactericidal, fungicide, anticancer, anti-inflammatory, enzyme inhibiting, and anti-allergic properties. The most abundant compounds found in the ME of B. karatas fruits were maleic anhydride, 5-hydroxymethylfurfural, and itaconic anhydride. This study shows that B. karatas fruits contain metabolites that are potentially beneficial for health.

Antibacterial mechanism of beetroot (Beta vulgaris) extract against Listeria monocytogenes through apoptosis-like death and its application in cooked pork

Due to riching in polyphenolic compounds, betalains, and ascorbic acid, beetroot (Beta vulgaris) extract exhibits an antibacterial activity. However, its effect on Listeria monocytogenes is unclear. In this study, the antibacterial activity of beetroot extract against L. monocytogenes was assessed by measuring its minimum inhibitory concentration (MIC) and the time-kill curve. Results revealed that the MIC of beetroot extract against L. monocytogenes was 20 mg/mL and bacterial survival decreased as beetroot extract concentration increased. The antibacterial mechanism of beetroot extract involved the reduction of intracellular 5ʹ-adenosine triphosphate levels of L. monocytogenes after treatment. L. monocytogenes exhibiting membrane depolarization, caspase-like protein activation, phosphatidylserine externalization, and DNA fragmentation, demonstrated that L. monocytogenes underwent apoptosis-like death (ALD) following beetroot extract treatment. Furthermore, the reason of ALD in L. monocytogenes is reactive oxygen species depletion. Beetroot extract decreased the number of L. monocytogenes cells, pH values, and lipid oxidation in cooked pork. Meanwhile, cooked pork become darker and redder than the control samples. It suggested that beetroot extract could be used as a natural preservative in cooked meat production to inhibit the growth of L. monocytogenes.

Evaluation of Thymus pseudopulegioides plant extracts for total phenolic contents, antioxidant and antimicrobial properties

In this study, the ethanolic extracts of leaf and flower of Thymus pseudopulegioides Klokov & Des. Shost collected from Sultan Murat Plateau of Trabzon, Turkey was assessed for total phenolic contents and antioxidant activities. In addition, antibacterial activity of extracts against nine different bacterial strains (Staphylococcus aureus, Escherichia coli, Pseudomanas aeruginosa, Bacillus cereus, B. pumilus, B. subtilis, B. licheniformis, Listeria innocua and L. monocytogenes) were determined using the agar-dilution method. The extraction yields from leaf and flower were obtained as 10.95% and 0.94% (w/w), respectively. The total phenolic contents of leaf and flower extracts were determined as 7.84 and 0.39 mg GAE/g, respectively. Antioxidant activities of the ethanolic extracts from leaf and flower were evaluated by using DPPH radical scavenging, and leaf extract showed better antioxidant activity than flower extract. Although, minimum inhibitory concentration (MIC) of leaf extracts was determined as 1.028 mg/mL for all bacteria except B. subtilis (0.256 mg/mL), MIC of flower extracts for B. subtilis and B. pumilis was found as 0.256 mg/mL and for others was 0.512 mg/mL. The extracts of the tested parts of Thymus pseudopulegioides, especially the leaves might be valuable for functional food and therapeutic applications.

ANTIBACTERIAL EFFECTIVENESS OF BEETROOT AGAINST STREPTOCOCCUS MUTANS

Introduction: Antibacterial effectiveness is the level of an antibacterial agent’s ability in controlling bacteria through growth-inhibiting or killing activities. A natural antibacterial agent that has the potential to be used as an alternative is beetroot (Beta vulgaris L.) because it contains phenolic compounds, flavonoids, saponins, tannins, and betalains. Antibacterial agents have been widely used as preventive for dental caries in children with the main causative bacteria being Streptococcus mutans. This study aims to evaluate the antibacterial effectiveness of beetroot extract against Streptococcus mutans. Methods: This study was in vitro experimental laboratory study with a post-test-only control group design. The maceration method used to obtain beetroot extract which will diluted into various concentrations, 12,500 μg/ml, 25,000 μg/ml, 50,000 μg/ml, and 100,000 μg/ml. Antibacterial effectiveness was tested by measuring the inhibition zone using disc diffusion, determining the Minimum Inhibitory Concentration (MIC) using broth dilution, and the Minimum Bactericidal Concentration (MBC) using agar dilution with 0,2% chlorhexidine gluconate as the positive control. Analysis of inhibition zone data was performed statistically using one-way ANOVA and Tukey Post Hoc. MIC and MBC tests were analyzed descriptively. Results: The results show all concentrations of beetroot extract were able to form an inhibition zone with the largest mean was 0.40 ± 0.05 mm, but still lower than the positive control. MIC and MBC of extract were 25,000 μg/ml and 50,000 μg/ml respectively. Conclusion: It can be concluded that beetroot extract has antibacterial effectiveness against Streptococcus mutans, therefore it can be used as a natural alternative for dental caries prevention.

In silico profiling of analgesic and antihyperglycemic effects of ethanolic leaves extract of Amischotolype mollissima: Evidence from in vivo studies

The aim of this study is to assess the antioxidative profile and related pharmacological potentialities of the ethanolic extract of Amischotolype mollissima leaves, traditionally used in treating pain, injury, malarial fever, epilepsy and hyperacidity, followed by a computational approach for the analysis of bioactive compounds identified by GC–MS. In GC–MS analysis, the extract yielded ten compounds, with 4,6-di-t-butyl-2-alpha-methyl benzyl phenol having the highest amount. In vitro investigation of the antioxidative properties of the plant was conducted with 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical and hydrogen peroxide scavenging assays. The amounts of secondary metabolites phenolics, flavonoids, and tannins were measured at 142 mg GAE/g, 534 mg QE/g, and 110 mg GAE/g, respectively. An acute toxicity study was carried out on mice, which revealed no toxicity up to the dosage of 4000 mg/kg bw. For the dosages of extract at 250 and 500 mg/kg bw, the writhing response test induced by acetic acid exhibited a statistically significant (p < 0.05) analgesic effect in mice. The oral glucose tolerance test (OGTT) and alpha-glucosidase enzyme inhibitory activity assay were used to examine the antihyperglycemic potential, in which the extract reduced the blood glucose level to 6.22 mmol/l and 3.82 mmol/l, at dosages of 250 and 500 mg/kg bw, respectively at 60 min in OGTT even though no activity was observed in the α-glucosidase enzyme inhibitory assay. In an antibacterial assay, the extract's minimum inhibitory concentration (MIC) against E. coli, P. aeruginosa, and S. aureus was determined to be 8, 16, and 8 µg/ml, respectively. This study shows that the usage of A. mollissima leaves in folklore medication is justified.

Loquat leaf extract and alginate based green composite edible coating for preserving the postharvest quality of Nanfeng tangerines

The present study was designed to investigate the preventive effect of loquat leaf (LL) based green extract combined with alginate-based composite against fungal infection in Nanfeng tangerine fruit. The sensory quality, physiological, and biochemical characteristics of postharvest citrus were estimated after the treatment. Results showed that LL extract's minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) to Penicillium digitatum were 0.625 mg/mL and 1.25 mg/mL, respectively. The scanning electron microscopy showed that LL extract could break, bend, and inhibit the average expected growth of P. digitatum hyphae. Concurrently, a composite coating of LL extract effectively reduces postharvest decay rate and weight loss, postpones fruit respiration, and delays the nutrient degradation of Nanfeng tangerines during cold storage. Also, a significant delay in MDA accumulation and an improved antioxidant defense system are shown by higher non-enzymatic antioxidants (ascorbic acid, phenols, and flavonoids) and higher ROS-scavenging enzymes (SOD, CAT, POD, and APX) were recorded. The green composite treatment could effectively delay the senescence and prolong the storage time of citrus. These results suggested that the green composite coating containing plant extract had great potential for citrus preservation.

Evaluation of Antibacterial Effect on Propionibacterium acnes and Antioxidant Activity of Various Mushrooms, Chinese Herbs, and Plant Essential Oils

Aims: The inhibitory effects of 30 kinds of mushrooms, Chinese Herbs, and plant essential oils on Propionibacterium acnes (P. acnes) were compared to screen high activity antibacterial materials. Furthermore, their minimum inhibitory concentration (MIC), antioxidant activity, total flavonoids, and total phenol content were determined.&#x0D; Methodology: The optimal antibacterial samples were screened using the paper diffusion method. The MIC was determined using the microdilution method. The antioxidant activity was evaluated by the 1,1-Diphenyl-2-Trinitrophenylhydrazine (DPPH), Ferric Ion Reducing Antioxidant Power (FRAP), and 2, 2'-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS) methods, and the total flavonoids and total phenol contents were determined using Rutin Method and Folin-Ciocalteu Method.&#x0D; Results: The MIC of mushroom Tricholoma quercicola and Boletus edulis's extracts were 0.391mg/mL and 3.125mg/mL, showing better antibacterial effects on P. acnes. The Chinese herbs Pericarpium granati and Folium artemisia argyi's extracts (MIC 3.13mg/mL), plant essential oils of Eugenia caryophyllus flower, and Lavandula angustifolia (MIC 61.76mg/mL and 112.7mg/mL) exhibited satisfactory antibacterial effects on P. acnes. Antioxidant evaluation of the above six samples with high antibacterial activity revealed that Folium artemisiae argyi and Pericarpium granati's extract had good antioxidant activity. In addition, the determination results of total flavonoids and total phenols were consistent with the antioxidant activity.&#x0D; Conclusion: The above results showed that Boletus edulis, Tricholoma quercicola, Pericarpium granati, and Folium artemisiae argyi could be used as candidate materials for the antibacterial, antioxidant materials, providing a feasible idea for the development of subsequent skincare products for the treatment of P. acnes.

Characterization and Antidermatophyte Activity of Henna Extracts: A Promising Therapy for Humans and Animals Dermatophytoses.

Dermatophytoses representing a major global health problem and dermatophyte species with reduced susceptibility to antifungals are increasingly reported. Therefore, we investigated for the first time the antidermatophyte activity and phytochemical properties of the sequential extracts of the Egyptian privet Henna (Lawsonia inermis) leaves. Total phenolic content (TPC), total flavonoids(TF), and antioxidant activity of chloroform, diethyl ether, acetone, ethanol 80%, and aqueous extracts were evaluated. The antifungal activity of henna leaves extracts (HLE) toward 30 clinical dermatophytes isolates, including Trichophyton mentagrophytes, Microsporum canis, and T. rubrum, was determined. Morphological changes in hyphae were investigated using scanning electron microscopy (SEM) analysis. Following the polarity of ethanol and acetone, they exhibited distinct efficiency for the solubility and extraction of polyphenolic polar antioxidants from henna leaves. Fraxetin, lawsone, and luteolin-3-O-glucoside were the major phenolic compounds of henna leaves, as assessed using high-performance liquid chromatography analysis. A high and significant positive correlation was found between TPC, TF, the antioxidants, and the antidermatophyte activities of HLE. Acetone and ethanol extracts exhibited the highest antifungal activity toward the tested dermatophyte species with minimum inhibitory concentration (MIC) ranges 12.5-37.5 and 25-62.5µg/mL, respectively. Structural changes including collapsing, distortion, inflating, crushing of hyphae with corrugation of walls, and depressions on hyphal surfaces were observed in SEM analysis for dermatophyte species treated with MICs of griseofulvin, acetone, and ethanol extracts. In conclusion, acetone and ethanolic extracts of henna leaves with their major constituent fraxetin exhibited effective antifungal activity toward dermatophyte species and may be developed as an alternative for dermatophytosis treatment. These findings impart a useful insight into the development of an effective and safe antifungal agent for the treatment of superficial fungal infections caused by dermatophytes.

In vitro comparison between antimicrobial and antibiofilm effects of Green Propolis and Baccharis dracunculifolia against Staphylococcus pseudintermedius isolate.

Staphylococcus pseudintermedius is the leading cause of canine pyoderma. Honeybee products are common to treat this and other types of infections. High average annual population loss of bees has been observed. This study evaluated antibacterial and antibiofilm profile of Green Propolis and Baccharis dracunculifolia against S. pseudintermedius and the chemical similarities among both. Ethanolic extracts were produced and chemically characterized. The isolates were subjected to treatment with the extracts in both planktonic and sessile forms. Green propolis minimum inhibitory concentration (MIC) was 0.156 mg / mL, and minimum bactericidal concentration (MBC) was 0.312mg / mL. Baccharis dracunculifolia extract MIC and MBC was 0.312mg / mL and 2.5 mg / mL, respectivelly. Both extracts reduced SD55 formation of biofilm at minimum inhibitory concentration and at 1/8 minimum inhibitory concentration. The results observed in relation to ED99, were similar for both extracts. Besides that, similar chemical indicators between both extracts, including the presence of Artepellin C, suggest that the Baccharis dracunculifolia extract could be an alternative to the Green Propolis extract in the treatment of staph infections.

ANALYSIS OF ANTIOXIDANT AND ANTIBACTERIAL ACTIVITY OF LEAVES OF FIG (Ficus carica L.) FROM CIWIDEY DISTRIC, WEST JAVA, INDONESIA

Leaves of Fig (Ficus carica L., Moraceae) contain flavonoids, tannins, phenolic compounds, saponins, alkaloids, steroids, and terpenoids. These compounds create an opportunity to utilize Fig leaves as herbal medicine. This study aimed to analyze the antioxidant and antibacterial activity of Staphylococcus epidermidis and Propionibacterium acnes of Fig leaves. Antioxidant activity was conducted by the DPPH method, while antibacterial activity was conducted by the agar diffusion method, followed by the microdilution method to determine Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The results showed the IC50 values of extract, the fraction of ethyl acetate, n-hexane, and distilled water were 78.79, 22.29, 1052.00, and 133.90 µg/mL, respectively. The diameter of the inhibition zone of the extract was higher in S. epidermidis compared to P. acnes. The antibacterial activity was proportional to the extract concentration. The extract MICs for S. epidermidis and P. acnes were in the range of 6.25 and 12.5% w/v, while the MBCs value was in the range of 12.5 and 25% w/v. It concluded that the ethyl acetate fraction had the best antioxidant activity compared to the extract, distilled water, and n-hexane fraction. The antibacterial activity of the extract was better on S. epidermidis than on P. acnes.

In-vitro anti-bacterial effectiveness test of 2% chlorhexidine digluconate and ethanol extract of green meniran leaves (Phyllanthus niruri Linn) on the growth of Enterococcus faecalis bacterial colony

Background: Necrotic teeth with periapical lesions often experience root canal treatment failure. Enterococcus faecalis bacteria cause 85-90% of root canal infections. 2% Chlorhexidine digluconate (CHX) can eliminate Enterococcus faecalis bacteria but cannot dissolve necrotic tissue, while green meniran phytochemical compounds (Phyllantus niruri Linn) have anti-bacterial properties. This study aims to determine the effectiveness, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) between green meniran leaf extract with 2% chlorhexidine digluconate and meniran extract only against the growth of Enterococcus faecalis.Method: This is an in vitro experimental study with a broth microdilution method consisting of two treatment groups. The negative control contained BHIB media and 0.05 ml of bacteria; the positive control had 0.05 ml of bacteria with 2% chlorhexidine digluconate, the group one consisted of BHIB media, bacteria and various concentrations of meniran extract. In contrast, group two consisted of BHIB media, bacteria, various concentrations of green meniran with 2% chlorhexidine digluconate. Data were analyzed using the One Way Anova test with LSD test.Results: Compared with negative control, in group one, we found the MIC of meniran extract was 3.125% with 94% anti-bacterial power, and the MBC was 6.25% with no bacterial growth. In group 2, we found the MIC of meniran extract and the 2% chlorhexidine digluconate was 0.78% with 9.3% anti-bacterial power, while the MBC was 1.56%.Conclusion: The increasing concentration of meniran extract also increases the anti-bacterial effect. A combination of meniran extract and 2% chlorhexidine digluconate give better anti-bacterial effects than meniran extract only.

Identification of Antibiotic-Resistant Genes and Effect of Garlic Ethanolic Extract on Mycobacterium tuberculosis Isolated from Patients in Zabol, Iran

Background: Mycobacterium is a genus of Actinobacteriaceae and the Mycobacterium family, including important pathogens, such as Mycobacterium tuberculosis (i.e., the cause of tuberculosis) and Mycobacterium leprae (i.e., the cause of leprosy). Tuberculosis is still a major cause of death in human societies. Objectives: The current study aimed to evaluate the effect of ethanolic extract of garlic on Mycobacterium tuberculosis isolated from patients in Zabol, Iran, and investigate the presence of antibiotic-resistant genes in Mycobacterium tuberculosis. Methods: Garlic (Allium sativum) was collected from Zabol, and the ethanolic extract of garlic leaf was obtained. In this study, 50 strains of Mycobacterium tuberculosis were obtained from the patients in Zabol. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. Some antibiotics, such as isoniazid, pyrazinamide, ethambutol, amikacin, streptomycin, and rifampicin, were used for positive control. Genomic deoxyribonucleic acid was extracted by the sodium dodecyl sulfate method. Furthermore, the presence of antibiotic-resistant genes, namely KatG, PncA, embC, embA1, embA2, embB1, embB2, rrs, rpsL, and ropB, in Mycobacterium tuberculosis was investigated using polymerase chain reaction. Results: The lowest MIC and MBC of garlic ethanolic extract against Mycobacterium tuberculosis were 3.25 and 7.5 ppm, respectively. The highest MIC and MBC were 60 and 120 ppm, respectively. Following the investigation of the presence of antibiotic-resistant genes in Mycobacterium tuberculosis, it was determined that it contains KatG, PncA, embC, embA1, embA2, ropB, rpsL, rrs, embB2, and embB1 genes. The highest resistance of Mycobacterium tuberculosis was against rifampin (81%) and then amikacin (76.6%) belonging to ropB and rrs genes, respectively. Conclusions: The results of the present study showed that the ethanolic extract of garlic was very effective in Mycobacterium tuberculosis and the most effective genes in mycobacteria were ropB and rrs. Although garlic is very effective in Mycobacterium tuberculosis, it is not recommended to directly use the results of this study. Therefore, it is required to perform clinical trials to confirm the results.

Preliminary phytochemical screening andin vitroantibacterial activity ofPlumbago indica(Laal chitrak) root extracts against drug-resistantEscherichia coliandKlebsiella pneumoniae

AbstractDrug resistance is one of the problems affecting the world where drug-resistantEscherichia coliandKlebsiella pneumoniaehave been shown to be ubiquitous, frequently isolated from foods and commonly associated with surgical site infection in hospitals worldwide. The aims of this work were to analyze the antibacterial activity of root extracts of the plant obtained by serial extraction (using petroleum ether, chloroform, methanol, and water) and byin vitrotechniques and preliminary screen phytochemicals present in the extract by qualitative means. Fresh roots ofPlumbago indicawere collected, oven-dried, and extracted using Soxhlet apparatus; antibacterial activity, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs) of the active extract were evaluated by standard methods against clinically isolated drug-resistantE. coliandK. pneumoniae;preliminary phytochemical screening was taken to detect the presence of alkaloids, saponins, flavonoids, steroids, tannins, reducing sugars, phenolics, protein, and oil and fat; and bioactive compounds were detected by GCMS analysis of the active extracts. Determination of antibacterial activity showed that the test organisms were susceptible to methanol and aqueous extracts only. MIC of methanolic extract was found to be 20 µg/mL on bothE. coliandK. pneumoniae,while aqueous extract had MIC of 10 and 20 µg/mL onE. coliandK. pneumoniae,respectively. Preliminary phytochemical screening showed the presence of all the above-mentioned phytochemicals except oil and fat. The significance of this work is to find a lasting solution to the current problem of emerging drug-resistant bacteria (E. coliandK. pneumoniae) through the use of extracts obtained fromP. indicawhich have long history of use as traditional medicine. The methanolic and aqueous extract can be recommended as an alternative and candidates for drug development against drug-resistantE. coliandK. pneumoniae.

THE ANTIBIOFILM ACTIVITY OF HIBISCUS SABDRIFFA L. AGAINST METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS

The current study was aimed to investigate the antibacterial and antibiofilm activity of ethanolic extract of Hibiscus sabdariffa L. calyx against locally isolated methicillin-resistant Staphylococcus aureus (MRSA) at different concentrations were started from 0.078 to 40 mg/ml. The extract was prepared by soaked calyces powder of Hibiscus sabdariffa L. with 80% ethanol in the Soxhlet extraction unit, and then it was aseptically filtered. The antibacterial activity was tested by agar diffusion method and broth microdilution method, this method was used to determine the minimum inhibitory concentration of extract, while the antibiofilm activity was determined by using 96-well polystyrene microtiter plates. The results revealed that the ethanolic extract has antibacterial activity in a concentration-dependent manner, the average diameter zone of inhibition observed against MRSA isolates ranged from 14±0.5 mm to 20±0.5 mm Moreover, at sub-inhibitory concentration, this extract developed an isolate-specific antibiofilm effect and presented highly significant (P&lt; 0.05) variability in biofilm formation before and after addition of ethanolic extract, Mr1, and Mr7 isolates were gave the lowest and highest antibiofilm activity, respectively. In conclusion, the ethanolic extract of H. sabdariffa L. calyx is a promising alternative medication that can be used to treat the infection caused by MRS.

Antifungal Effect of Different Plant Extracts against Phytopathogenic Fungi Alternaria alternata and Fusarium oxysporum Isolated from Tomato Plant

The antifungal activity of 10 plant extracts was tested against the phytopathogenic fungi, Alternaria alternata and Fusarium oxysporum, the pathogens of early blight and wilt diseases of tomato. Plants tested related to different families. Three doses (10, 50 and 100 mg/ml) of plant extracts were assayed on A. alternata and F. oxysporum by measuring the inhibition zone of mycelial growth of fungi by disc-diffusion method on the Potato dextrose agar (PDA). The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of plant extracts were determined. The inhibitory effect of plant extracts ranged from 10-29 and 12-31 mm against A. alternata and F. oxysporum, respectively. The extracts of Pulicaria crispa and Olea chrysophylla were the most effective antifungal followed by Citrullus colocynthis, Psiadia arabica and Otostegia fruticosa. These plant extracts contain biologically active major compounds such as alkaloids, flavonoids, saponins, tannins and terpenoids. The remaining plant extracts did not emerge any inhibitive effect on tested fungi. The MIC and MFC of plant extracts ranged 6–38, 7-34 and 28-56, 22-50 mg/ml for A. alternata and F. oxysporum, respectively. Therefore, these plant extracts have biologically active compounds and have a potential to control fungal phytopathogens in agricultural crops.

A Proposal Towards a Rational Classification of the Antimicrobial Activity of Acetone Tree Leaf Extracts in a Search for New Antimicrobials.

Many scientists investigate the potential of finding new antibiotics from plants, leading to more than a thousand publications per year. Many different minimum inhibitory concentrations of extracts have been proposed to decide if an extract has interesting activity that could lead to the discovery of a new antibiotic. To date, no rational explanation has been given for the selection criteria different authors have used. The cumulative percentage of plant extracts with different activities from a large experiment determining the activity of 714acetone tree leaf extracts of 537 different South African tree species against 4 nosocomial pathogenic bacteria and 2yeasts was calculated using a widely accepted serial dilution microplate method with p-iodonitrotetrazolium violet as indicator of growth. All the extracts were active at a concentration of 2.5 mg/mL. The formula, % of active extracts = 439 × minimum inhibitory concentration in mg/mL1.5385, describes the results for minimum inhibitory concentrations below 0.16 mg/mL, with a correlation coefficient of 0.9998. A rational approach could be to determine the minimum inhibitory concentrations of the most active 1, 3, 9, 25, 50, and > 50% of a large number of plant extracts investigated against these six important microbial pathogens. Starting with an extract concentration of 10 mg/mL, I propose the following classification based on minimum inhibitory concentrations: OUTSTANDING ACTIVITY: < 0.02 mg/mL, EXCELLENT ACTIVITY: 0.021 - 0.04 mg/mL, VERY GOOD ACTIVITY: 041 - 0.08 mg/mL, GOOD ACTIVITY: 0.081 - 0.16 mg/mL, AVERAGE ACTIVITY: 0.161 - 0.32 mg/mL, and WEAK ACTIVITY: > 0.32 mg/mL. Higher minimum inhibitory concentrations may still be effective in ethnopharmacological studies.

Phytochemical Screening and in-vitro Evaluation of Antibacterial Activities of Echinops amplexicaulis, Ruta chalepensis and Salix subserrata Against Selected Pathogenic Bacterial Strains in West Shewa Zone, Ethiopia.

BackgroundAlthough traditional healers in Ethiopia have a long history of using medicinal plants to treat diseases in animals and humans, studies on the antibacterial activities and potential bioactive ingredients of most medicinal plants have been insufficient. Therefore, this study aimed to evaluate the in-vitro antibacterial activities and to screen phytochemical constituents of selected medicinal plants against reference bacterial strains.MethodsThe fresh and healthy roots of Echinops amplexicaulis, fruits of Ruta chalepensis, and leaves of Salix subserrata were collected from West Shewa Zone, Ethiopia. Agar well diffusion and agar dilution methods were used to evaluate antibacterial activities and minimum inhibitory concentrations (MIC). All the crude plant extracts were tested against Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli and Pseudomonas aeruginosa at concentrations of 100, 50, and 25 mg/mL in each triplet (3x). MIC of crude extracts ranging from 1.5625 to 12.50 mg/mL was applied to all bacterial strains. The positive control was ciprofloxacin disk (5 μg) and the negative control was 5% dimethyl sulfoxide. The presence of secondary metabolites of each crude extract was screened. The group means comparisons were done using one-way ANOVA and results were presented as mean ± standard deviation.ResultsAlthough all selected plant extracts had shown antibacterial activities, methanol extracts had a greater zone of inhibition against all reference bacterial strains when compared to petroleum ether extracts. The growth of P. aeruginosa was inhibited at a minimum concentration of both methanol and petroleum extracts (1.5625 mg/mL) when compared to the remaining bacterial strains. Phytochemical screening showed that saponins and alkaloids were found in all crude plant extracts, while phytosterol was meager.ConclusionThis study revealed that all tested plants had significant secondary metabolites and antibacterial activities against reference bacterial strains.

Ointment Formulation and Characterization of Arum Manis Mango (Mangifera indica L.) Leaves’ Methanol Extract as an Antibacterial Agent Against Propionibacterium acnes

Background: Acne is caused by several factors, including the active secretion of sebaceous sweat glands, hyperkeratosis in the hair infundibulum and the effects of bacteria. One plant which has the potential as an antibacterial agent is the extract of Arum Manis mango leaves. Methods: The Minimum Inhibitory Concentration (MIC) of methanol extract of mango leaves was determined, which can inhibit Propionibacterium acnes activity. The antibacterial activity tests were performed using agar diffusion. The ointment formulation, the characteristics of ointment preparations, and the ointment activity against P. Acnes are discussed. Results: MIC of methanol extract of mango leaves value is 5 ppm with an inhibition zone of 1 mm. The ointment obtained is white, has a distinctive smell, semisolid form, possesses a pH of 4.92 - 5.87, dispersive power of 5.05 - 6.30 cm, and adhesive power of 1 - 3.67 seconds, homogeneous and protective. Ointment preparations of methanol extract of mango leaves have activity on P. acnes on the 0 and 15th day of storage. The activities of ointment preparation on day 0 with concentrations of 0, 5, 10 and 15 ppm are 0.00 mm; 10.20 mm; 19.97 mm and 23.60 mm respectively, while the inhibition zones produced by the preparation of ointment on day 15 with concentrations of 0, 5, 10 and 15 ppm are 0.00 mm; 5.71 mm; 9.58 mm and 21.88 mm respectively. Conclusion: Methanol extract of mango leaves (Mangifera indica L.) and ointment preparation can inhibit the growth of Propionibacterium acnes.