Antibacterial Activity Of Methanol Extracts Research Articles

Stigmas and Petals of Crocus sativus L. (Taliouine, Morocco): Comparative Evaluation of Their Phenolic Compounds, Antioxidant, and Antibacterial Activities.

The dried stigmas of Crocus sativus L. produce saffron, a precious spice used for its culinary and medicinal properties since ancient times, while its petals are considered the main by-product of saffron production. The present study aimed to comparatively evaluate the phenolic content, antioxidant capacity, and antibacterial activity of methanolic extracts of stigmas and petals of Crocus sativus L. from Taliouine. The polyphenol content was measured using the Folin-Ciocalteu method, the antioxidant activity was determined using the DPPH free radical scavenging method, and the well-diffusion method was used to assess antibacterial activity against seven pathogenic bacterial strains (Bacillus subtilis, Escherichia coli, Listeria monocytogenes, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella enterica, and Staphylococcus aureus). Furthermore, the minimum inhibitory concentration (MIC) of the extracts was determined using the microdilution broth test. Our findings revealed that stigmas and petals contained phenolic compounds at the rate of 56.11 ± 4.70 and 64.73 ± 3.42 mg GAE/g, as well as DPPH radical scavenging capacity with IC50 of 1700 µg/ml and 430 µg/ml, respectively. Petal extract showed more effective antibacterial activity, with inhibition diameters ranging from 10.66 ± 0.57 to 22.00 ± 1.00 mm and MIC values ranging from 2.81 to 5.62 mg/ml, compared to the stigma extract, which displayed inhibition diameters from 10.00 ± 0.00 to 18.67 ± 0.76 mm and MIC from 2.81 to 11.25 mg/ml, against five of the seven bacterial strains tested, including S. aureus, E. coli, P. vulgaris, P. aeruginosa, and S. enterica. Statistical analyses were performed to determine the significance of these results. Thus, stigmas and petals of Crocus sativus L. might serve as a suitable source of natural antioxidant and antimicrobial agents for application in the food and pharmaceutical industries.

Bioassay-Guided Fractionation of Pittosporum angustifolium and Terminalia ferdinandiana with Liquid Chromatography Mass Spectroscopy and Gas Chromatography Mass Spectroscopy Exploratory Study

Bioprospecting native Australian plants offers the potential discovery of latent and novel bioactive compounds. The promising cytotoxic and antibacterial activity of methanolic extracts of Pittosporum angustifolium and Terminalia ferdinandiana led to further fractionation and isolation using our laboratory’s bioassay-guided fractionation protocol. Hence, the aim of this study was to further evaluate the bioactivity of the fractions and subfractions and characterize bioactive compounds using liquid chromatography mass spectroscopy (LC-MS/MS) and gas chromatography MS (GC-MS). Compounds tentatively identified in P. angustifolium Fraction 1 using LC-ESI-QTOF-MS/MS were chlorogenic acid and/or neochlorogenic acid, bergapten, berberine, 8′-epitanegool and rosmarinic acid. GC-MS analysis data showed the presence of around 100 compounds, mainly comprising carboxylic acids, sugars, sugar alcohols, amino acids and monoalkylglycerols. Furthermore, the fractions obtained from T. ferdinandiana flesh extracts showed no cytotoxicity, except against HT29 cell lines, and only Fraction 2 exhibited some antibacterial activity. The reduced bioactivity observed in the T. ferdinandiana fractions could be attributed to the potential loss of synergy as compounds become separated within the fractions. As a result, the further fractionation and separation of compounds in these samples was not pursued. However, additional dose-dependent studies are warranted to validate the bioactivity of T. ferdinandiana flesh fractions, particularly since this is an understudied species. Moreover, LC-MS/GC-MS studies confirm the presence of bioactive compounds in P. angustifolium Fraction 1/subfractions, which helps to explain the significant acute anticancer activity of this plant. The screening process designed in this study has the potential to pave the way for developing scientifically validated phytochemical/bioactivity information on ethnomedicinal plants, thereby facilitating further bioprospecting efforts and supporting the discovery of novel drugs in modern medicine.

Phytochemical analyses and in vitro evaluation of antioxidant, antihemolytic and antibacterial activity of methanolic extract of aerial parts of marjoram (Origanum majorana L)

ABSTRACT This work reports an in vitro study of the biological activities of the methanolic extract of the aerial parts of marjoram (Origanum majorana), including antibacterial, anti-haemolytic and antioxidant activity. The extract showed strong antibacterial activity against three bacterial strains, E. Coli, Pseudomonas aeruginosa, and Staphylococcus aureus. It also demonstrated antihaemolytic activity in human blood, inhibiting haemolysis induced by sodium chloride and temperature. The phytochemical screening revealed the presence of cathechic tannins, flavonoids, saponosids, mucilagos, and glycosids. These results suggest that the methanolic extract of marjoram could be a potential source of antimicrobial agents, and natural antioxidants.

ISOLASI DAN UJI AKTIVITAS ANTIBAKTERI SENYAWA METABOLIT SEKUNDER DARI EKSTRAK METANOL DAUN MARPUYAN (Rhodamnia cinerea Jack.)

A study on isolation and antibacterial activity of secondary metabolites from the methanol extract of Marpuyan (Rhodamnia cinerea Jack.) Leaves on Escherichia coli has been carried out. Isolation was carried out by column chromatography methods. Whereas the antibacterial activity test was carried out using agar diffusion method. The results of the isolation produced 17.9 mg of RC-F13 isolate compound in the form of light yellow crystals, with a melting point of 170-172oC and soluble in methanol. The results of identification of RC- F13 isolate compounds through testing with AlCl3 reagents, positive including the flavonoid group, were strengthened by the results of the UV spectrum and FT-IR spectrum. Based on the results of the UV spectrum, it was seen that the RC- F13 isolate compound showed λ max 353.60, 257.00 and 209.20 nm. The FT-IR spectrum shows the presence of several functional groups such as OH, C aliphatic C-H, C = O carbonyl, C = C aromatic and C-O. testing the antibacterial activity of methanol extract with a concentration of 20%; 10%; 1%; 0.1% and 0.01%, fraction 13 at 1% concentration; 0.1% and 0.01% and RC- F13 isolate compound concentration of 0.1%, against Escherichia coli bacteria did not show any antibacterial activity which was marked by the absence of clear areas around the disc.

ANTIBACTERIAL ACTIVITY OF METHANOL EXTRACT FROM INGGILI FRUIT (Xylocarpus granatum) AGAINST Propionibacterium acnes AND Escherichia coli USING WELL DIFFUSION METHOD

Inggili is a type of mangrove plant that has been traditionally used by the community for medicine. It contains many active compounds that function as antibacterials. Based on empirical data, inggili fruit is used to remove acne on the skin and diarrheal diseases. This study aims to determine the antibacterial activity of methanol extract of inggili pulp in inhibiting Propionibacterium acnes and Escherichia coli bacteria using the sumuran diffusion method. The research conducted is experimental. The object under study was the antibacterial activity of inggili fruit extract against Propionibacterium acnes and Escherichia coli bacteria. Antibacterial activity was tested using the sumuran diffusion method with extract concentrations of 10%, 15%, and 20%. The negative control used was 1% DMSO and the positive control used was 0.1% chloramphenicol

Antibacterial Activity of Metanol Extract and n-Butanol Fraction of Euphorbia milii Leaves Against Staphylococcus aureus

Euphorbia milii is a common garden plant and its leaves have antibacterial activity, due to the presence of saponins, flavonoids, and tannins. As there is an increasing antibiotic resistance to Staphylococcus aureus, there is potential for E. milii as a new antibacterial candidate. The purpose of this study was to determine secondary metabolites of saponins, flavonoids, tannins and to determine the antibacterial activity of E. milii leaves in inhibiting the growth of Staphylococcus aureus (in vitro). Simplisia was extracted by sonication method, then fractionated with a separatory funnel. Extracts and fractions were analyzed qualitatively by tube test and thin layer chromatograpy (TLC). The antibacterial activity of methanol extract (320; 160; and 80 mg/ml) and n-butanol fraction (32; 16; and 8 mg/ml) was tested by disc diffusion method. The results of qualitative test showed that the extracts and fractions were positive for saponins, flavonoids, and tannins. In antibacterial test, extract at a concentration of 320 mg/ml was able to inhibit bacterial growth with moderate activity category (6.5 mm). Extracts at 160 mg/ml and 80 mg/ml, as well as n-butanol fractions at all concentration showed weak antibacterial activity (<5 mm). Theseresult suggest that the extracts and fractions positively contain metabolites of saponins, flavonoids, and tannins. The extracts and fractions were able to inhibit the growth of staphylococcus aureus, but the activity was not greater than the positive control.

Antibacterial and phytochemical analysis of traditional medicinal plants: An alternative therapeutic Approach to conventional antibiotics

The purpose of this study was to carry out antibacterial and phytochemical analyses on six selected medicinal plants that have been traditionally used by the local people to treat and control different diseases. The antibacterial activities of methanolic extracts of these plants were assessed using the Agar well diffusion and Microtiter broth dilution methods. The root extract of Andrachne aspera showed significantly (p < 0.05) highest mean zone of inhibition at concentrations of 100 mg/ml (33 ± 0.17) and 200 mg/ml (33.5 ± 0.84) against S. epidermidis. The second highest mean zone of inhibition (24.8 ± 0.41) was recorded by Dichrostachys cinerea leaf extract against S. epidermidis at 200 mg/ml concentration. The minimum inhibitory concentrations 1.0 ± 0.0 was recorded by Andrachne aspera against E. faecalis and 2.0 ± 0.0 against S. aureus by Dichrostachys cinerea. The preliminary phytochemical analysis showed that Andrachne aspera and Dichrostachys cinerea contained strong concentration of Polyphenols and Flavonoids. Therefore, these two medicinal plant species have promising potential for further detailed investigations, including safety tests, characterization and isolation of bioactive secondary metabolites for the development of alternative drugs.

In-Vitro Antibacterial Activity of Excoecaria cochinchinensis Lour's Methanol Extract and Its Combination with Commercial Drugs

The purpose of this study was to look into the antibacterial activity of methanolic extract of Excoecaria cochinchinensis as well as the effect of its combination with antibiotics on the growth of Klebsiella pneumoniae, Enterobacter aerogenes, and Staphylococcus epidermidis. The antibacterial activity test was carried out using the well diffusion method, and the combined effect of the extract and antibiotics was observed using the paper strip diffusion method. At various concentrations (25, 50, 75, 100, 150, 200, and 250 mg/mL), the extract significantly inhibited the growth of K. pneumoniae, E. aerogenes, and S. epidermidis. The inhibitory zone's diameter increased proportionally with the extract concentration. The growth of K. pneumoniae and S. epidermidis was then classified as extremely sensitive (+++) to the addition of the extract at 200 and 250 mg/mL concentrations, meanwhile, E. aerogenes’s with 250 mg/mL of the extract. Secondary metabolites such as oleanolic acid, arjunolic acid, scopoletin, kaempferol, quercetin, diterpenoid compounds, tannins, and other phenolics have been reported from E. cochinchinensis leaves and are thought to be responsible for its antimicrobial activity. The effect of the extract’s combination with antibiotics was insignificant compared to their individual activity, thereby classifying them as indifferent.

Screening of Preliminary Phytochemicals and In vitro Antibacterial Activity of Methanolic Extracts of Stem, Leaf, Root and Leaf Callus of Corynandra felina (L.f.) Cochrane &amp; Iltis

Screening of Preliminary Phytochemicals and In vitro Antibacterial Activity of Methanolic Extracts of Stem, Leaf, Root and Leaf Callus of Corynandra felina (L.f.) Cochrane &amp; Iltis

Polyphenol Contents, Gas Chromatography-Mass Spectrometry (GC-MS) and Antibacterial Activity of Methanol Extract and Fractions of Sonneratia Caseolaris Fruits from Ben Tre Province in Vietnam.

Plants contain a large number of phytochemical components, many of which are known as bioactive compounds and responsible for the expression of various pharmacological activities. The extract of Sonneratia caseolaris fruit collected in Vietnam was investigated for its total phenolic and total flavonoid contents using methanol solvent and different fractions of S. caseolaris fruits (hexane, ethyl acetate, n-butanol, and aqueous). GC-MS analysis was conducted to identify the bioactive chemical constituents occurring in the active extract. Further, the antibacterial activity was tested in vitro on bacterial isolates, namely Escherichia coli, Staphylococcus aureus, and Bacillus subtilis, using the disc diffusion method on tryptic soya agar (TSA) medium. The methanol extract showed high total flavonoid (82.3 ± 0.41 mg QE/g extract) and phenolic (41.0 ± 0.34 mg GAE/g extract) content. GC-MS of the methanol extract and different fractions of S. caseolaris fruits detected 20 compounds, principally fatty alcohols, fatty acids, phenols, lipids, terpenes derivatives, and carboxylic acids derivatives. A 50 mg/ml concentration of methanol extract had the strongest antibacterial activity on E. coli, S. aureus, and B. subtilis. Furthermore, ethyl acetate, aqueous, and n-butanol fractions inhibited S. aureus and B. subtilis the most. The results of the present study suggested that the fruits of S. caseolaris are rich sources of phenolic compounds that can contribute to safe and cost-effective treatments.

Evaluation of therapeutic potential of Hypericum species from the Himalaya

ABSTRACT The antioxidant, antibacterial, and antidiabetic potential of Himalayan Hypericum species (H. cordifolium, H. elodeoides, H. japonicum, H. podocarpoides, and H. uralum) were examined. The antioxidant activity measured by DPPH radical scavenging assay was the highest for the methanolic extracts of H. cordifolium and the lowest for H. japonicum. The antibacterial activity of methanolic extracts of Hypericum species showed weak or no antibacterial activity against four ATCC bacterial strains compared to standard gentamicin. The inhibition for of α-amylase by plant extracts in all the species was lower than that of Acarbose. In contrast, the inhibition of α-glucosidase by the plant extracts was higher than that of Acarbose for all the species except H. podocarpoides.

Botanicals from Aframomum letestuanum Gagnep. (Zingiberaceae) can overcome the multidrug resistance of Klebsiella species overexpressing AcrAB-TolC efflux pumps

Background: Bacteria belonging to the genus Klebsiella have developed resistance mechanisms to clinically used antibiotics, leading to their loss of efficacy. In the present study, the in vitro antibacterial activity of methanol extracts from Aframomum letestuanum, as well as their modes of action against a panel of 14 bacterial species belonging to the genus Klebsiella including multidrug-resistant (MDR) phenotypes overexpressing efflux pumps were evaluated. Methods: The broth microdilution method was used to assess the antibacterial activities of plant extracts (botanicals), while standard experimental protocols were used to study modes of action. Harborne's qualitative reference methods were used to identify the major groups of secondary metabolites present in the botanicals. Results: Phytochemical screening revealed that botanicals contain alkaloids, terpenoids, phenols, flavonoids, tannins, saponins, and anthocyanins. Botanicals from A. letestuanum seed pulp and seed inhibited the growth of all the bacteria tested, with MICs ranging from 16 to 512 μg/mL (pulp) and 64 to 2048 μg/mL (seed). The pulp extract had excellent activity, with MIC values of 16 μg/mL against K2, 32 μg/mL against Kp 80, and Kp 126, and 64 μg/mL against Kp55, Kp63, and ATCC11296. The seed extract displayed a MIC of 64 μg/mL against Kp58 and Kp2. A. letestuanum seed pulp extract inhibited bacterial growth in the exponential phase and induced inhibition of ATPase-H+-dependent proton pumps in K. pneumoniae ATCC11296. Conclusion: Botanicals from A. letestuanum are potential phytomedicines that deserve further investigation to develop novel drugs to overcome the multidrug resistance of Klebsiella species. Keywords: Aframomum letestuanum; antibacterial; antibiotics; efflux pumps; multidrug resistance; Klebsiella species.

Antibacterial potential and modes of action of the methanol extracts of Elephantopus mollis Kunth (Asteraceae) against multidrug-resistant Gram-negative bacteria overexpressing efflux pumps

Background: Bacterial drug resistance still constitutes a major clinical issue. In the present study, the in vitro antibacterial potential, and modes of action of Elephantopus mollis were investigated. Methods: The antibacterial activity of methanol extracts of the various parts of E. mollis, their association with an efflux pump inhibitor, phenylalanine-arginine β-naphthylamide (PAβN) and the potentiating effect of several standard antibiotics were determined using the broth microdilution method. The effects of E. mollis leaf extract on H+ proton pump/ATPase function and bacterial growth kinetics were determined using standard methods. Phytochemical screening of the extracts was carried out using standard qualitative methods. Results: The crude extract (botanicals) from E. mollis leaf and flower had antibacterial activity with a 100% inhibition spectrum against bacterial strains and isolates with MICs ranging from 16 to 256 µg/mL and 64 to 1024 µg/mL respectively. Botanicals from the leaf extract showed excellent activity with a MIC of 16 µg/mL against K. pneumoniae KP55, a MIC of 32 µg/mL against K. pneumoniae (K2), and P. stuartti (NEA16). Botanicals from the leaf extract inhibited the exponential growth phase and H+-proton pump/ATPases of K. pneumoniae ATCC11296. In the presence of PAβN, the activity of E. mollis extracts was improved on 90% (leaves and flowers) and 63% (roots) of multidrug-resistant (MDR) bacterial strains and isolates. The various extracts of E. mollis potentiated the activities of the antibiotics: doxycycline, levofloxacin, vancomycin, imipenem, ceftriaxone, and ciprofloxacin against at least 70% of bacterial strains and isolates, with factors of increase in activity ranging from 2 to 128. Extracts from all parts of E. mollis contained alkaloids, flavonoids, tannins, and phenols. Conclusion: The results show that E. mollis is a source of antibacterial phytomedicine that can be used to treat bacterial infections caused by Gram-negative bacteria expressing MDR phenotypes. Keywords: Antibiotics; Asteraceae; bacteria; efflux pumps; Elephantopus mollis; multidrug resistance.

Activity test of Guazuma ulmifolia Lam (Jati Belanda) methanol extract against bacteria Staphylococcus aureus and Klebsiella pneumoniae

Background: Staphylococcus aureus and Klebsiella pneumoniae bacteria are a group of bacteria that can infect the respiratory tract so that they can cause complications for humans, Jati belanda leaves (Guazuma ulmifolia Lam) is a plant that has potential as an antibacterial, because it has active substances that can stop the growth of bacterial organisms, namely flavonoids, saponins, tannins, and alkaloids are its components. Purpose: This study aims to determine the antibacterial activity of methanol extract of Jati belanda leaves (Guazuma ulmifolia Lam) on the growth of Staphylococcus aureus and Klebsiella pneumoniae bacteria. Methods: Antibacterial activity test in this study was carried out using the well method, Staphylococcus aureus bacteria and Klebsiella pneumoniae bacteria as test microbes in this study, positive control (chloramphenicol), 20% DMSO negative control and five concentration groups namely 100%, 50%, 25%, 12.5% ​​and 6.25% from methanol extract of Jati belanda leaves (Guazuma ulmifolia Lam). Results: From the research results it is known that the methanol extract of Jati belanda leaves (Guazuma ulmifolia Lam) is able to inhibit Staphylococcus aureus bacteria with each inhibition zone at 100% concentration of 12.31 mm, 50% concentration of 10.48 mm, 25% concentration of 7.62 mm and the positive control (chloramphenicol) was 33.24 mm and the Klebsiella pneumonia bacteria at 100% concentration was 14.27 mm, 50% concentration was 11.14 mm and the positive control (chloramphenicol) was 40.6 mm.

Aktivitas Antibakteri Ekstrak Metanol Daun Matenasi (Garcinia Sp.) Terhadap Staphylococcus Aureus dan Eschericia Coli

Medicinal plants are very popular among the people of Indonesia as traditional medicinal ingredients. Traditional medicine is a means of supporting public health for generations, long before formal health services and modern medicines touched the layers of society. One of the medicinal plants which is efficacious as a medicine for diarrhea is matenasi leaf (Garcinia sp). Diarrhea is an infectious disease that often occurs in Indonesia due to Escherichia coli bacteria. This study aims to determine the antibacterial activity of methanol extract using the paper disc diffusion method which is dripped with 10 µl of the test solution using a micro pipette. The concentrations of the methanol extract used were 50%, 75%, and 100% compared to the positive control, namely 30 µl chloramphenicol solution. Matenasi leaves using methanol extract have strong antibacterial activity at a concentration of 100%. For Staphylococcus aureus bacteria with a concentration of 100% with a diameter of 22.67 mm (very strong category), Escherichia coli bacteria with a concentration of 100% with a diameter of 18.25 mm (strong category). The methanol extract of matenasi leaves has the potential as an antibacterial against Stapylococcus aureus and Escherichia coli bacteria.

Catheter-associated urinary tract biofilms: can achyranthes aspera extract work against them?

Catheter-associated urinary tract infection is mainly related to biofilm on the catheter surface which provides the opportunity for colonization and attachment resulting complex structured biofilm formation makes development of antibiotic resistant organism creates management of CAUTI is more critical. Therefore, there is an alarming call for drug development against multidrug resistant organisms. Hence, our study attempted the antibacterial activity of methanolic extract of Achyranthes aspera against Staphylococcus aureus one of the prevalent organisms involved in CAUTI. The A. aspera antibacterial activity was determined against S. aureus and minimum inhibitory concentration of A. aspera against S. aureus calculated was as 3.6 mg/ml which needed to inhibit the growth of tested microbe. The colony forming ability of S. aureus was studied in the presence of A. aspera methanolic extract using crystal violet staining method and the colony formation was observed after the MIC level indicates colony formation increases when decreasing the concentration of A. aspera. To ascertain the effect of A. aspera on biofilm formation after treatment with various concentrations, the biofilm formation assay performed. The A. aspera can able to reduce the biofilm formation as 80 and 88% for 1X MIC and 2X MIC against S. aureus indicating the antibiofilm forming ability. To prevent the microbial colonization on catheter surface, the coating of catheter with methanolic extract of A. aspera was investigated for its antibacterial activity against S. aureus using in vitro bladder model. The clear zone formations around the catheter piece indicating the anti-adhesive property of A. aspera against S. aureus. Collectively, methanolic extract of A. aspera can pave the way for new antibacterial agent against S. aureus.

Antibacterial activity of methanolic extract of leaves Indigofera Suffruticosa naturally grown in Iraq

Antibacterial activity of methanolic extract of leaves Indigofera Suffruticosa naturally grown in Iraq

Antifungal and antibacterial activity of marine sponges from Ratnagiri coast of India.

Marine sponges have proved to be a rich source of bioactive metabolites with multiple pharmacological properties. In this study, we have investigated the antifungal and antibacterial activities of methanol extracts of Cliona, Haliclona cratera, Hyrtios cavernosus, Spongia obscura, Sarcotragus foetidus, and Xestospongia carbonaria and fractions from X. carbonaria S. obscura and H. cratera. The antibacterial activity was determined by agar disc diffusion method against clinical gram-positive- Staphylococcus aureus, Bacillus subtilis and gram negative- Escherichia coli, Pseudomonas aeruginosa bacteria. The antifungal activity of the extracts and fractions was determined against Candida albicans and Aspergillus niger. S. obscura, X. carbonaria, H. cavernosus, and H. cratera exhibited good antibacterial activity against the tested gram-positive bacteria with larger zones of inhibition at 19±6 mm, 19.5±5.5mm, 20±0 mm and 23±0 mm. S. foetidus gave good inhibition of gram-negative bacteria at 19±0 mm. They showed moderate antifungal activities against C. albicans and A. niger. Cliona, H. cratera and H. cavernosus gave inhibition with 20±5 mm, 15.5±0.5 mm and 25.5±14.5 mm for A. niger. The MIC for Xc_PE_2, Sob_n but_1 and Hc_n but_3 was determined. H. cavernosus, S. foetidus, S. obscura and X. carbonaria showed presence of fatty acids and sterol type of compounds. The mass of molecular ions in purified fractions helped in characterization of known compounds in H. cratera, X. carbonaria and S. obscura which exhibited good antimicrobial activity.

An Investigation of the Correlation of Antibacterial Activity of Thyme (Thymus vulgaris L.) with its Nutrient Elements

The present study aimed to examine the correlation of plant nutrient elements with the antibacterial activity of methanol extract of Thymus vulgaris L. grown on soil from the experimental field without application of fertilizers or pesticides on two Gram-positive and two Gram-negative bacteria. The extract of thyme was obtained by maceration of aerial parts of the plant using methanol as the solvent. The contents of macro (P, K, Ca, and Mg) and micro (Fe, Cu, Zn, Mn, and B) nutrients were detected by ICP-OES. The results showed that the macro nutrients were compatible with herbaceous perennial plants, while Fe, Mn and B micro nutrients were high. The methanol extract was significantly effective on inhibiting P. aeruginosa, S. aureus and E. faecalis, while did not inhibit E. coli. The correlation of K and Mg was significantly positive with the growth inhibition of P. aeruginosa suggesting that higher K and Mg contents of the plant would result in higher antibacterial activity against P. aeruginosa, most probably up to a point. On the other hand, significant positive correlation of B was found with the inhibition of both Gram-positive bacteria. In addition, the positive correlation of Ca with the growth inhibition of S. aureus was highly significant. The importance of nutrient contents in medicinal aromatic plants such as thyme was shown with this study. The results therefore imply the conscious and sustainable agriculture of medicinal aromatic plants is crucial for the antibacterial activity of thyme.

Antimicrobial activity of peels and physicochemical properties of juice prepared from indigenous citrus fruits of Sylhet region, Bangladesh

Scientists are indeed fascinated by the pharmacologically important chemicals found in medicinal plants. Citrus fruits possess several curing agents for the prevention of diseases. Therefore, experiments were carried out to test the antibacterial activity of methanolic extracts of peels from various locally available citrus fruits such as citron (Citrus medica), satkora (Citrus macroptera) and adajamir (Citrus assamensis) against Bacillus spp. and E. coli using the disc diffusion method. Different physicochemical characteristics of fruit juice were also determined. Methanolic extract of satkora peel had the highest antibacterial activity of 2.2 and 2.6 cm while adajamir had the lowest antibacterial activity of 1.7 and 2.1 cm as ZOI against Bacillus spp. and E. coli, respectively. In the case of pH and total soluble solids (TSS), the three citrus varieties showed a small variation where satkora showed the highest total phenolic content (TPC), vitamin C content, and antioxidant activity than the others. Citrus fruits can be exploited as antibacterial and antioxidant ingredients in food and nutraceuticals, according to the findings of this study.