Antibacterial Activity Of Methanol Extracts Research Articles

Anti-proteolytic activity of Ganoderma lucidum methanol extract against Pseudomonas aeruginosa.

Protease enzyme is considered one of the most serious virulence factors produced by extended-spectrum β-lactamase-producing and multidrug-resistant Pseudomonas aeruginosa (ESβLMDRPA) clinical isolates. The antibacterial activity of methanol extract of Ganoderma lucidum fruiting bodies was tested against a protease-producing ESβLMDRPA clinical isolate, showing its mode of action. The extract showed high antibacterial activity. Its effect on purified protease indicated a reversible non-competitive protease inhibition (kis= 0.45 mg/mL). The G. lucidum extract could be a promising anti-proteolytic active against ESβLMDRPA. It may form a primary platform for further phytochemical studies and development of new drugs for therapy of skin burn infections.

Antibacterial activity of Hibiscus sabdariffa L. calyces against hospital isolates of multidrug resistant Acinetobacter baumannii

ObjectiveTo evaluate the antibacterial activity of methanol extract of Hibiscus sabdariffa (H. sabdariffa) calyces employed in Sudanese folk medicine against five hospital isolates of multidrug resistant Acinetobacter baumannii (MDR A. baumannii). MethodsThe antibacterial activity of 80% methanol extract (v/v) of H. sabdariffa calyces was evaluated by agar disc diffusion, minimum inhibitory concentration and minimum bactericidal concentration methods. Antibiotic susceptibility of selected A. baumannii strains was tested. ResultsIn the present investigation, the methanol extract from the calyces of H. sabdariffa exhibited significant antibacterial properties against the non-MDR A. baumannii as well as the MDR A. baumannii strains with a zone of inhibition ranging from (11.3 ± 0.3) to (13.6 ± 0.3) mm. The relative percentage inhibition of H. sabdariffa extract (10 mg/disc) with respect to gentamicin (10 μg/disc) had potent antibacterial properties and was much more effective than gentamicin. Values of minimum inhibitory concentration and minimum bactericidal concentration ranged from 25 to 50 and 50 to 100 mg/mL, respectively, revealing the potential bactericidal properties of the extract. ConclusionsAccording to the present study, the calyces of H. sabdariffa can be used as a substitute source of the current ineffective synthetic antibiotics used against MDR A. baumannii.

In vitro antibacterial and antifungal activities of twelve sponges collected from the Anambas Islands, Indonesia

ObjectiveTo evaluate antimicrobial activities in methanolic extracts of twelve sponges collected from the Anambas Islands, Indonesia. MethodsThe antibacterial activity of methanolic extracts was tested against two Gram-positive bacteria, viz. Bacillus subtilis (ATCC 6633) and Staphylococcus aureus (ATCC 25923), and two Gram-negative bacteria, viz. Eschericia coli (ATCC 25922) and Vibrio anguillarum (ATCC 19264) using the disk diffusion assay. The antifungal activity was similarly tested against Candida albicans (ATCC 10231) and Aspergillus niger (ATCC 16404). The minimum inhibitory concentrations of promising sponges extracts were determined by the microdilution technique. ResultsAll the sponge species in this study showed antimicrobial activities against at least one of the test strains. Antibacterial activities were observed in 66.7% of the sponges extracts, while 30.0% of the extracts exhibited antifungal activities. Among them, the extracts of the sponges Stylissa massa and Axinyssa sp. were the most active against four tested bacteria and the yeast Candida albicans. The sponge Theonella swinhoei and two species of Xestospongia also displayed significant activities against two fungal pathogens Candida albicans and Aspergillus niger. ConclusionsAntimicrobial activities were demonstrated in extracts from various marine sponges collected from the Anambas Islands, Indonesia. The most promising sponges among them were Stylissa massa and Axinyssa sp. This is the first report of antimicrobial activity in extracts of marine sponges from the Indonesian Anambas Islands.

The Antibacterial Activity of Coriolus versicolor Methanol Extract and Its Effect on Ultrastructural Changes of Staphylococcus aureus and Salmonella Enteritidis.

The antibacterial activity of methanol extract obtained from fruiting body of industrially grown basidiomycete Coriolus versicolor was examined. The Minimum Inhibitory Concentration (MIC) values against various bacteria ranged from 0.625 to 20 mg mL-1. C. versicolor expressed bactericidal activity against both Gram-positive and Gram-negative bacteria. The growth curves of Staphylococcus aureus and Salmonella enterica serovar Enteritidis, measured at 630 nm, and confirmed with macrodilution method showed that the obtained extract could inhibit the growth of tested bacteria. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and the loss of 260-nm-absorbing material were used to examine the ultrastructural changes in bacteria induced by the extract. When S. aureus was exposed to the MIC of C. versicolor, elongated and malformed cells were observed by SEM, while S. Enteritidis treated cells appeared shorter and aggregated with ruptured cell walls. TEM revealed the formation of non-membrane-enclosed bodies and depleted inner content of S. aureus. Larger and irregular periplasmic space and deformed and scattered components of the cell envelope were observed in treated S. Enteritidis. The loss of 260-nm-absorbing material indicated that the disruptive action of the extract on cytoplasmic membrane was more pronounced in S. aureus than in S. Enteritidis treated cells. The UV and FTIR spectrophotometric analyses revealed diverse composition of C. versicolor extract and high content of total phenolics. Altogether, mushroom extracts could be used to develop nutraceuticals or drugs effective against pathogenic microorganisms.

Inhibitory effect of different fennel (Foeniculum vulgare) samples and their phenolic compounds on formation of advanced glycation products and comparison of antimicrobial and antioxidant activities

In this study, antioxidant, antibacterial and antiglycation properties of methanolic extracts of 23 fennel samples were evaluated and their major compounds were determined using HPLC analysis. The anti-glycative activity of extracts was evaluated in the bovine serum albumin (BSA)/glucose system. The level of glycation, conformational alterations and protein binding to RAGE receptors were assessed by Congo red binding assay and a brown staining method. Among samples, Kh1 from Iran possessed the highest TFC (14.8mgQUEg−1), TPC (262mg/g DW) and antioxidant activity (IC50=76μg/ml). The HPLC results revealed high variation in 23 fennel samples according to their major flavonoid (quercetin, apigenin and rutin) and phenolic (chlorogenic, caffeic and 1,5-dicaffeoylquinic acid) compounds. The antibacterial activity of methanolic extracts against four food-borne pathogens was also assessed. The seed extracts of Kh1 and En samples showed moderate to good inhibitory activities (MICs=62.5–125μg/ml) against three bacteria, as well as high anti-glycative activity.

In vitro Antioxidant and Antibacterial Activities of Methanol Extract of Kyllinga nemoralis.

The present study was designed to evaluate the antioxidant and antibacterial activity of methanol extract of Kyllinga nemoralis. Six different in vitro antioxidant assays including 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide anion radical, hydrogen peroxide radical, ferric reducing antioxidant power assay and reducing power were carried out to ensure the scavenging effect of the plant on free radicals. In addition, total antioxidant capacity assay, total phenolic contents, tannins, flavonoids and flavonol contents of the plant were also analysed by the standard protocols. Kyllinga nemoralis exhibited high antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl assay (IC50= 90 μg/ml), superoxide radical scavenging assay (IC50= 180 μg/ml) and hydrogen peroxide radical scavenging assay (IC50= 200 μg/ml), compared with standards. These observations provide comprehensible supporting evidence for the antioxidant potential of the plant extract. Reducing power (IC50= 213.16 μg/ml) and hydroxyl radical scavenging activity (IC50= 223 μg/ml) of the plant extract was remarkable. The methanol extract of K. nemoralis exhibited significant antimicrobial activity against Gram-positive human pathogenic bacteria. Standard in vitro antioxidant assays assessed the electron donating ability of the plant extract in scavenging free radicals. The inhibitory effect of the plant extract against bacterial pathogens may be due to the presence of phytochemicals. Thus, the results suggest that Kyllinga nemoralis is a potential source of antioxidants and could serve as the base for drug development.

Antibacterial activities of methanol extracts from Alchornea cordifolia and four other Cameroonian plants against MDR phenotypes

Multidrug-resistant (MDR) bacterial infections, especially those caused by Gram-negative phenotypes, have emerged as one of the major health concerns worldwide. In the present study, we investigated the antibacterial activity of methanol extracts from five Cameroonian medicinal plants (Alchornea cordifolia, Eremomastax speciosa, Laportea aestuans, Pennisetum purpureum and Spathodea campanulata) against 15 Gram-negative bacteria that included MDR phenotypes. The broth microdilution method was used to determine the minimal inhibitory concentrations (MIC) and the minimal bactericidal concentrations (MBC) of all of the samples. Standard phytochemical methods were used for a preliminary phytochemical screening of the plant extracts. Phytochemical analysis showed the presence of polyphenols, tannins, triterpenes and sterols in all of the studied extracts. Other chemical classes of secondary metabolites were selectively identified. The best antibacterial activities (MICs ranges of 64–1024 μg/mL) obtained against the 15 tested bacteria were found in extracts of leaves (93.3%), bark (86.7%) and roots (80%) of A. cordifolia as well as extracts of L. aestuans (86.7%) and P. purpureum (66.7%). The lowest MIC value of 64 μg/mL was recorded for the A. cordifolia bark extract against Pseudomonas aeruginosa PA01. The findings of this study provide deep insights into the possible use of the studied plants, especially A. cordifolia and L. aestuans, for the control of Gram-negative bacterial infections, especially against MDR species.

Evaluation of Antioxidant and Antimicrobial Properties of Potato (Solanum tuberosum) Peels

Peels of vegetables are generally considered as waste products and are normally thrown away by us. But different studies conducted on peels revealed the presence of important constituents. A number of components are isolated from potato peels which have different properties like antioxidant, antimicrobial, anti-inflammatory, antiproliferative etc. The present study was designated to evaluate the antioxidant and antimicrobial properties of potato peels. The methanolic extract of dried potato peel showed an appreciable DPPH radical scavenging activity and ferric reducing ability. Total phenolic content was also higher in potato peel extract. Secondary metabolite screening of the methanolic extract of potato peels showed the higher levels of flavonoids. The antibacterial activity of methanolic extract of potato peel was determined by agar well diffusion method and it showed significant effect on growth inhibition of gram positive (Bacillus amyloiquefaciens and Staphylooccus aureus) and gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa).

Spectral Analysis and Antibacterial Activity of Methanol Extract of Roots of Echinops echinatus and its Fractions

Objective: The root of Ecinops echiantus L. (Asteraceae) is reported to have great medicinal value. The aim of the present study was to determine the chemical profile of methanol extract of Echinops echiantus by two different spectral analyses which will be useful for its proper identification when therapeutically used. Isolated compounds and crude methanol extract were screened for antibacterial activity. Methods: Spectral analysis was done by different analytical methods such as Infrared spectroscopy (FTIR) and Ultraviolet spectroscopy. The in vitro antibacterial activity of E. echinatus root extracts was studied by the hole plate diffusion method against several human pathogenic gram positive and gram negative bacteria. Results: Five compounds were isolated from crude methanol extract using column chromatography and characterized by techniques like Infrared spectroscopy (FTIR) and Ultraviolet spectroscopy. Compounds showed different Rf values ranging from 67 to 9.4. All the five isolated compound and crude methanol extract showed significant antibacterial activity against all strains. However, maximum activity shown by compound Ee-4, Ee-1, Ee-3 against Staphylococcus aureus (17.0 mm), (15.3 mm), (12.3 mm) respectively. While Ee-5 give maximum activity against E. coli (13.5 mm). Conclusion: The result of this study suggested that methanol extract of Echinops echiantus root and its isolated compounds exhibited marked antibacterial activity. Therefore, the results of this study may act as biochemical markers for this medicinally important plant in the pharma industry and plant systematic studies.

Phytochemical screening, antimicrobial activity and cytotoxicity of Nepalese medicinal plants Swertia chirayita and Dendrobium amoenum

Research on medicinal plants are important to Nepal because most of its rural population relies on it as mode of medicine. Medicinal plants namely Swertia chirayita and Dendrobium amoenum were collected from mid hills of Nepal. The present study was undertaken to find the antimicrobial activity, phytochemical presence and their cytotoxicity in different extraction medium. The percentage yield from the plants were highest in warm methanol extraction with 12.6%, followed by ethyl acetate and lowest was for cold methanol. Plant extract showed the presence of antioxidants like alkaloid, terpenoids, flavonoids, tannin, glycosides. The Brine Shrimp Bioassay of methanol and ethyl acetate extract showed cytotoxicity. Chiraito extract showed LC50 of 199 ppm for Dhunche sample, 128.82 ppm for Daman sample and 131.82 ppm of Illam sample. The antibacterial activity of methanol extract of Chiraito and Dendrobium amoenum showed significant bioactivity by inhibiting growth of microbial species selected for the test. The zone of inhibition shown by the extracts was comparable to the standard antibiotics. Similarly, methanol extract of Chiraito also showed significant antifungal activity with the zone of inhibition comparable to amphotericin.Nepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 48-54

BIOAKTIVITAS EKSTRAK METANOL DAUN NAMNAM SERTA KOMBINASINYA DENGAN MADU TRIGONA

Namnam (Cynometra cauliflora L ) and trigona honey are two natural ingredients that are potential to be developed in Indonesia. However, scientific evidence of its active compounds and bioactivity is still rarely found, particularly the combination of these two materials. Therefore , this research is to explore their active ingredients of combination of these two materials such as total phenolic, flavonoids, vitamin C and β-carotene and bioactive capabilities such as antioxidant activity and antibacterial activity. The analysis showed that antibacterial activity of methanol extract of Nam n am leaves (EMDN) and trigona honey either in their sole form or combined form has antioxidant and antibacterial activity. The EMDN was more sensitive to Staphylococcus aureus (23.7±3.3 mm) than to Escherichia coli, while the Trigona honey (MT) more sensitive to Escherichia coli (32.6 ± 4.4 mm) than Staphylococcus aureus (16.6±4.1 mm). Similarly, the combination of EMDN and MT was more sensitive to Escherichia coli (23±1.9 mm) than Staphylococcus aureus (17.6±2.6 mm). Analysis of the antioxidant activity also showed that EMDN provided the highest activity (IC 50 0.0048±0.000 mg/mL), a combination EMDN and MT (IC 50 0.0085±0.000 mg/mL) and MT (IC 50 3.736±0.112 mg/mL). Moreover, this analysis also showed thatsole samples of MT and EMDN have total phenolic content, flavonoids, and vitamin C that were higher than the combination of MT and EMDN. However, the content of β-carotene in the combined form of MT and EMDN was higher. Thus trigona honey , methanol extract of leaves Nam n am (Cynometra cauliflora L ) in a single form or in a combination are potential to be utilized and developed as a source of antioxidants and antibacterial in the form of functional food.

Chemical Composition of Essential Oils and in vitro Antibacterial Activity of Methanolic Extract of Sonchus arvensis and Eremurus spectabilis against Food-borne Pathogenic Bacteria

In this experimental study, chemical composition of essential oils of aerial parts of Sonchus arvensis and roots of Eremurus spectabilis were determined by GC-MS technique. Also antibacterial activity of methanolic extracts of these plants was evaluated on some gram-positive and gram-negative bacteria by disk-diffusion and micro-dilution method to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bacterial strains included: Bacillus cereus PTCC1015, Staphylococcus aureus PTCC1431, Salmonella enterica PTCC1709 and Escherichia coli PTCC1399. The serial dilutions of the oil were between 3.125 to 400 mg ml-1 prepared in 96 wells microplates using Mueller-Hinton broth for micro-dilution. Results showed thirty-five compounds in the hydro-distilled essential oil from aerial parts of S.arvensis, representing 99.82 % of the total oil. N-Octane (29.82 %) and n-Decane (11.09 %) were the main components. The MIC and MBC varied respectively between 12.5-100 and 100 to >400 mg ml-1 for all gram-positive and gram-negative bacteria. The lowest MIC and MBC observed against S.aureus (12.5 and 100 mg ml-1, respectively). The methanolic extracts of S.arvensis and E.spectabilis also could inhibit the growth of gram-positive and gram-negative bacteria. However, the inhibitory effect was more on gram-positive rather than gram-negative bacteria.

Evaluation of Antibacterial Activity and Phytochemical Screening of Azadirachta indica Leaves Extracts Against Staphylococcus aureus

Azadirachta indica is an Indian tree well known for its several pharmacological activities, including antimicrobial activity. A. indica leaves extract was used to screen antibacterial activity against S. aureus. The methanol extract of leaves of A. indica was prepared and its phytochemical screening was performed. The phytochemical analysis exhibited the presence alkaloids, polyphenol, tannins, flavonoids and glycoside in extract. The methanol extract of A. indica leaves tested against S. aureus using disc diffusion method. Gentamicin was used as standard and compared the effect of antibacterial activity of methanol extract. The methanol extract of A. indica leaves demonstrated potent antibacterial activity against tested bacteria.

Rapid Identification of Antibacterial Compounds from Turkey Berry by HPLC-Based Metabolomics

The aim of this study was to identify antibacterial compounds from Solanum torvum fruit extract by HPLC-based metabolomics method. The antibacterial activity of methanolic extracts, hexane, chloroform, ethyl actetate, and water fractions was assessed by well-diffusion agar method. Only methanol extracts and chloroform fraction showed medium inhibition activity against Staphylococcus aureus. The HPLC chemical profiles of the fractions were then correlated to their antibacterial activity profile by means of Orthogonal Projection to Latent Sructure (OPLS) analysis. Based on Y-related coefficient value, peak of HPLC chromatogram found to be significantly corelated to the antibacterial activity was collected by semi-preparative HPLC and its chemical profile was analyzed by LC-MS. Torvoside A, torvoside G, and torvoside H were found to be dominant in this concentrated fractions; thus, these are the possible compounds responsible for antibacterial activity of the fraction. To confirm this, chemical validation by isolating the compounds and testing its antibacterial activity is required. In this study, the active principals in plant crude extract can be identified rapidly; thus, isolation of the active compounds can be performed in more efficient way.

In vitro antimicrobial activity of common species of seaweeds native to Trinidadian coasts

Marine macrophytes have been recently recognized as promising sources of bioactive molecules and as such many drugs leads have arisen from them. We investigated the antibacterial activity of methanol extracts of seaweeds against several human pathogens. Among the seaweeds screened, three species showed inhibitory effects against at least one pathogen, with Ulva fasciata and Amphiroa rigida exhibiting bacteriostatic activity and Chaetomorpha crassa showing bactericidal action against pathogenic Gram-positive cocci. Further testing revealed that the extracts of Chaetomorpha crassa displayed the ability to inhibit biofilm formation and virulence gene expression in Methicillin resistant Staphylococcus aureus (MRSA). Isolation and identification of the bioactive molecules of Chaetomorpha crassa revealed the two free fatty acids stearic acid and linolenic acid. This research shows that several species of marine plants found in Trinidad comprise bioactive compounds and may be good candidates for further investigations aimed at isolating and evaluating these compounds for potential medical applications.

Antibacterial activity of methanolic extracts from Cotoneaster nummularioides, Cynodon dactylon and Cardaria draba on typical food-borne pathogens

The present study aimed at evaluating the in vitro antibacterial activity of methanolic extract of Cotoneaster nummularioides, Cynodon dactylon and Cardaria draba against different pathogenic microorganisms. The agar disk diffusion method was used to study the antibacterial activity of C. nummularioides, C. dactylon and C. draba methanolic extracts against 2 gram-positive and 2 gram-negative bacteria at concentration 300 and 400 mg/ml. The results revealed that the methanol extract of C. nummularioides presented the highest zone of inhibition against tested pathogens (7-12 mm inhibition zones). Other plants did not show significant zone inhibition. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were quantified by micro-dilution method. The leaf extract of C. nummularioides against Bacillus cereus (PTTC 1015) and Staphylococcus aureus (PTTC 1431) strains showed the best activities, with the lowest minimal inhibitory concentration (MIC) of 3.125 mg ml-1 and MBC was 102.08 and 108.33 mg ml-1 respectively for Staphylococcus aureus (PTTC 1431) and Bacillus cereus (PTTC 1015). The results showed that the methanol extract of the herb has antibacterial activity and therefore it could be used as a natural preservative ingredient in food and/or pharmaceutical industries.

Chemical composition and antibacterial activity of methanolic extract and essential oil of Iranian Teucrium polium against some of phytobacteria

The antibacterial activity of essential oil and methanolic extract of Teucrium polium was determined against Pseudomonas aeruginosa, Pantoea agglomerans, Brenneria nigrifluens, Rhizobium radiobacter, Rhizobium vitis, Streptomyces scabies, Ralstonia solanacearum, Xanthomonas campestris and Pectobacterium cartovorum by disc diffusion method. Minimum inhibitory concentration and minimum bactericidal concentration were determined by using the serial dilution method. Chemical composition of essential oil and methanolic extract was determined by GC-MS and HPLC. α-Pinene (25.769%) and myrcene (12.507) were of the highest percentage in T. polium essential oil, and sinapic acid (15.553 mg/g) and eugenol (6.805 mg/g) were the major compounds in the methanolic extract. Our results indicate that both methanolic extract and essential oil did not show antibacterial activity against P. aeruginosa. Also the essential oil did not show antibacterial activity against P. cartovorum. In general, both methanolic extract and essential oil showed the same antibacterial activity against R. solanacearum, P. agglomerans, B. nigrifluens and S. scabies.

Antioxidant and Antibacterial Activities of Methanolic Extract of BAU Kul (Ziziphus mauritiana), an Improved Variety of Fruit from Bangladesh

BAU Kul (Ziziphus mauritiana) is a new and improved variety of plum fruit from Bangladesh. This study aims to investigate the antioxidant potency and antibacterial activity of methanolic extracts of BAU Kul using Soxhlet extraction followed by complete evaporation of residual methanol. BAU Kul is a very good source of phenolics, flavonoids, ascorbic acid and tannins. The reducing sugar and protein content of BAU Kul were 1.68 and 0.81% by weight, respectively. BAU Kul was very active in 1,1-diphenyl-2- picrylhydrazyl radical (DPPH) scavenging and ferric reducing antioxidant power assay (527.28 ± 9.2 [μM Fe (II)]/100 g), thus confirming its high antioxidant potential. Antibacterial activities were measured using the agar well-diffusion method. BAU Kul was most toxic to Pseudomonas aeruginosa, followed (in order) by Staphylococcus aureus, Salmonella paratyphi, Escherichia coli and Chromobacterium violaceum. In conclusion, BAU Kul is a nutritious fruit that provides good antioxidant and antibacterial activities (in particular toward P. aeruginosa) and a cheap source of vitamins. Practical Applications BAU Kul is a new and sweet seasonal fruit which is very popular to the consumers of Bangladesh. This fruit can be a good source of nutrients as well as the antioxidants applicable in different types of diseases caused by oxidative stresses. BAU Kul can also be used as traditional medicine for different types for infectious diseases.

Phenolic composition and antibacterial activity of crude methanolic Calendula officinalis flower extract against plant pathogenic bacteria

Plant-derived compounds comprise diverse biological activities with different mechanisms of actions. Aim of this study was to comparatively evaluate antibacterial activities of methanol and aqueous flower and leaf extracts of Calendula officinalis (pot marigold) on plant-borne pathogens, with total phenolic contents and analysis of phenolics. Flower methanol and aqueous extracts had activity against 4 and 5 strains, respectively out of 11 phytopathogens tested. Highest activity was obtained with methanol extract of flower against E. amylovara and C. michiganensis in all strains tested with 256 and 512 µg/mL minimum inhibitory concentrations, respectively. Total phenolic content of flower extracts were higher than leaf extracts, and the methanol extract of the flower had the highest total phenols among four extracts obtained. Two flower extracts with antibacterial activity were tested for phenolic content. Chlorogenic acid, caffeic acid, rutin, and salicylic acid were common in both methanol and aqueous flower extracts. Gallic acid was only present in methanol extract, whereas vanillic acid was present in the aqueous extract. Higher antibacterial activity of the methanol extract may be correlated to the considerably higher relative rutin amount. Considering eco-safety and effectiveness, antibacterial activities of plant extracts would be important in phytopathogen control.

Antibacterial activity of clove, gall nut methanolic and ethanolic extracts on Streptococcus mutans PTCC 1683 and Streptococcus salivarius PTCC 1448

IntroductionAntimicrobial compounds from herbal sources have good therapeutic potential. In this study, the antibacterial effects of clove and gall nut, methanolic and ethanolic extractions, were evaluated for their effect on Streptococcus mutans PTCC 1683 and Streptococcus salivarius PTCC 1448, as both the two cause oral diseases. MethodThe clove and gall nut methanolic and ethanolic extracts were prepared and antibacterial activity was evaluated for S. mutans and S. salivarius in the base of inhibition zone diameter using agar diffusion method. In this part minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were assessed. ResultsThese extracts showed effective antibacterial activity on bacteria. Antibacterial activity of Methanolic extract of clove was more than that of ethanolic extract, and ethanolic extracts of gall nut had antibacterial activity more than that of methanolic extracts. MIC and MBC results for clove methanolic extract were 1.5 mg/ml and 3 mg/ml for S. mutans and 6.25 mg/ml and 12.5 mg/ml for S. salivarius, respectively. These results for clove ethanolic extracts were 12.5 mg/ml and 25 mg/ml for S. mutans and 25 mg/ml and 50 mg/ml for S. salivarius, respectively. MIC and MBC results for gall nut methanolic extract were 25 mg/ml and 50 mg/ml for S. mutans and 12.5 mg/ml and 25 mg/ml for S. salivarius, respectively. These results for gall nut ethanolic extracts were 3.1 mg/ml and 6.2 mg/ml for S. mutans and 25 mg/ml and 50 mg/ml for S. salivarius, respectively. DiscussionThe results showed effective antibacterial activity using clove and gall nut methanolic extracts. If other properties such as tolerance of tissue can also be studied, these extracts can be used as a mouthwash.