Antibacterial activity of some medicinal plants of Sri Lanka (original) (raw)
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International Journal of Microbiology, 2019
Introduction. Antibiotic resistance is one of the greatest threats of the 21 st century. Scientists search for potential antimicrobial sources that can cope with antibiotic resistance. Plants used in traditional medicine can be identified as potential candidates for the synthesis of novel drug compounds to act against antibiotic-resistant bacteria. Objective. To determine the potential antimicrobial effects of ethanol, aqueous, and hexane extracts of five Sri Lankan medicinal plants against four human pathogens. Methods. Asparagus falcatus (tubers), Asteracantha longifolia (whole plant), Vetiveria zizanioides (roots), Epaltes divaricata (whole plant), and Coriandrum sativum (seeds) were used in the study. Plant extracts were screened against four clinically important Grampositive and Gram-negative bacterial strains, Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 700603). Antibacterial activity of plant extracts were monitored using the agar disc diffusion method. Eight concentrations of each positive plant extract were used to determine the minimum inhibitory concentration (MIC) by 5-fold dilution of plant extracts yielding a serial dilution of the original extract. Results. Ethanol, aqueous, and hexane extracts of E. divaricata gave the maximum zones of inhibition of 16.3 mm, 7.4 mm, and 13.7 mm and MIC values of 0.48 mg/ml, 1.2 mg/ml, and 1.6 mg/ml, respectively, against S. aureus. Ethanol and hexane extracts of V. zizanioides gave the maximum zones of inhibition of 12.1 mm and 11.4 mm and MIC values 2.4 mg/ml and 0.003 mg/ml, respectively, against S. aureus. None of the other plants were effective against any microorganism used for the study. Conclusions. It can be concluded that E. divaricata and V. zizanioides crude ethanol, aqueous, and hexane extracts exhibited significant in vitro antibacterial activity against S. aureus, and the active compounds isolated from them can be potential sources for the synthesis of antibacterial drugs.
Antibacterial activity of some Indian medicinal plants
Aqueous extracts of ten medicinal plants were examined for their antibacterial potential against some reference strains of human pathogenic bacteria. Anethum graveolens, Elettaria cardamomum, Foeniculum vulgare, Trachyspermum ammi and Viola odorata were found to be better/equally effective compared to standard antibiotics. V. odorata was the most effective antibacterial with minimum inhibitory concentration values ranging from 1 to 2%. The results provide a scientific basis for the centuries-old usage of aqueous extracts of these medicinal plants.
International Journal of Advanced Research (IJAR), 2019
Ethanolic and aqueous extracts of 10 Indian medicinal plants traditionally used in medicine at Vidisha district were studied for their antimicrobial activity against human pathogenic bacteria of clinical origin. Of these, 09 ethanolic extracts and 08 aqueous extracts of medicinal plant showed varied levels of antibacterial activity against one or more tested human pathogenic bacterial strains. Overall, broad-spectrum antibacterial activity was observed in 05 Indian medicinal plants (both ethanolic and aqueous extracts) against all test microorganisms (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhi and Streptococcus pneumoniae).
The Pharma Innovation Journal, 2019
Evaluation of phytochemical analysis and antibacterial activity of few medicinal plants collected from nearby area of Junagadh, Gujarat, India was carried out. Presence of phytochemicals in different types of extracts (chloroform, alcoholic and aqueous) was evaluated as per standard chemical methods. All extracts were evaluated for having antibacterial action using disc diffusion assay with selected bacterial cultures. Out of 16 medicinal plants methanolic extract of Adansonia digitata L. leaves showed a zone of inhibition against Klebsiella pneumoniae (20.02±0.08 mm) and Salmonella typhi (20.69±0.08 mm). Methanol and water extracts of Ficus racemosa L. bark showed a zone of inhibition of 18.48±0.02 mm and 19.68±0.03 mm, respectively against Escherichia coli. Whereas chloroform and methanol extracts of Pueraria tuberosa (Willd.) DC tuber has showed a zone of inhibition of 20.68±0.03 mm and 19.73±0.3 mm, respectively against Klebsiella pneumoniae and Streptococcus agalactiae. Phytoch...
Asian Pacific Journal of Tropical Disease, 2012
Objective: The present study was to evaluate the antibacterial properties of 21 crude extracts from leaf and flower of Aristolochia indica (A. indica), Cassia angustifolia (C.angustifolia), leaf of Catharanthus roseus (C. roseus), Diospyros melanoxylon (D.melanoxylon), Dolichos biflorus (D. biflorus), Gymnema sylvestre (G. sylvestre) and Justicia procumbens (J. procumbens). Methods: The ethyl acetate, acetone and methanol extract of medicinal plants were evaluated against Gram-positive Bacillus cereus (B. cereus) and Gram-negative bacteria Aeromonas hydrophila (A. hydrophila), Enterobacter aerogenes (E. aerogenes), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) by using well diffusion assay and minimum inhibitory concentration (MIC). Results: The crude plant extracts demonstrated broad spectrum activity against all bacteria. The highest inhibitory zone was observed in leaf methanol extract of A. indica against E. aerogenes (25 mm), and E. coli (20 mm), flower methanol extract of C. angustifolia against B. cereus (22 mm) and leaf acetone extract of G. sylvestre against B. cereus (22mm). The MIC values of leaf methanol extract of A. indica against K. pneumonia (22.6 毺 g/ ml), and flower extract showed against E. coli (MIC: 24.2 毺 g/ml), leaf ethyl acetate extract of C. angustifolia against K. pneumoniae (MIC: 28.4 毺 g/ml). Acetone ethyl acetate and methanol extracts of D. melanoxylon and D. biflorus showed the lowest MIC activity value of >30 毺 g/ml against all tested pathogens. Conclusion: The antibacterial activity could be confirmed in most species used in traditional medicine in South India. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents.
Antibacterial Activities of Some Folk Medicinal Plants of Eastern Ghats
Antibacterial activity in the crude extracts of the selected parts (roots/ leaves/ fruits/ seeds/ bark) of different traditional folk medicinal plants of North Coastal Andhra Pradesh was examined. Of the 14 plants studied only 10 plants showed various levels of antibacterial activity against Gram positive (Bacillus subtilis, Staphylococcus aureus) and Gram negative (Escherichia coli, Klesbsiella pneumonia & Proteus vulgaris) bacteria with the diameters of growth inhibition zone in the range of 10–25mm. However, Abelmoschus moschatus (Fabaceae), Thespesia populnea (Malvaceae), Abutilon indicum (Malvaceae) and Amaranthus spinosis (Amaranthaceae) have not shown any antimicrobial activity in the extracts with solvents such as methanol, 95% ethyl alcohol and methanol: chloroform: water (MCW – 12:5:3) mixture. Eclipta prostrata (Compositae), which is used as folk medicine, showed antibacterial activity only in the ethyl alcohol extract of its leaves. Present studies indicate that the ten plants, which showed antibacterial activity, may be used as good sources for the isolation of the active principle(s) for therapeutic applications.
Screening of 34 Indian medicinal plants for antibacterial properties
Journal of Ethnopharmacology, 1998
A total of 34 plant species belonging to 18 different families, selected on the basis of folklore medicinal reports practised by the tribal people of Western Ghats, India, were assayed for antibacterial activity against Escherichia coli, Klebsiella aerogenes, Proteus 6ulgaris, and Pseudomonas aerogenes (Gram-negative bacteria) at 1000-5000 ppm using the disc diffusion method. Of these 16 plants showed activity; among them Cassia fistula, Terminalia arjuna and Vitex negundo showed significant antibacterial activity against the tested bacteria. Our findings confirm the traditional therapeutic claims for these herbs.
Antibacterial and phytochemical studies on twelve species of Indian medicinal plants
The aqueous and methanol extracts of 12 plants each belonging to different families were evaluated for antibacterial activity against medically important bacteria viz. B. cereus ATCC11778 , S. epidermidids ATCC12228 , E. aerogenes ATCC13048, P. vulgaris NCTC 8313, S. typhimurium ATCC 23564. The in vitro antibacterial activity was performed by agar disc diffusion and agar well diffusion method. The aqueous extracts were inactive but methanol extracts showed some degree of antibacterial activity against the tested bacterial strains. S. typhimurium was the most resistant bacteria while B. cereus was the most susceptible bacteria. Amongst the plant species screened, methanol extract of Bauhinia variegata bark showed best antibacterial activity. (Afr. J. Biomed. Res. 10: 175 -181)
Evaluation of the antimicrobial activity of three medicinal plants of South India
Malaysian Journal of Microbiology, 2011
The present study was carried out to evaluate the antimicrobial activity of the crude methanolic extracts of Memecylon malabaricum Clarke. (leaves), Cochlospermum religiosum Linn. (leaves and flowers) and Andrographis serpyllifolia Vahl. (leaves) using the standard disc diffusion assay against eight strains of bacterial species, viz., Staphylococcus aureus, Salmonella typhi, Enterobacter aerogenes, Pseudomonas aeruginosa, Xanthomonas oryzae pv. oryzae, Xanthomonas axonopodis pv. malvacearum, Bacillus cereus and Micrococcus sp. The extracts of the plants at a concentration of 1.25 mg/disc showed minimum to moderate activity against both Gram positive and Gram negative bacteria indicating a broad spectrum activity. A preliminary phytochemical screening was conducted on the selected plant extracts using standard qualitative procedures that revealed the presence of several secondary metabolites. The extracts failed to show antioxidant activity by reducing power assay. The result indicates the potential usefulness of these plants especially Memecylon malabaricum and Cochlospermum religiosum, in treating microbial infections in humans and plants and justifies the need for further investigations and characterization of the bioactive compounds present in the methanolic extracts of the plants.
Antimicrobial activity of some Indian medicinal plants
African journal of traditional, complementary, and alternative medicines : AJTCAM / African Networks on Ethnomedicines, 2007
The antimicrobial potential of seventy-seven extracts from twenty-four plants was screened against eight bacteria and four pathogenic fungi, using microbroth dilution assay. Lowest concentration of the extract, which inhibits any visual microbial growth after treatment with p-iodonitrotetrazolium violet, was considered to be minimum inhibitory concentration (MIC). Water extracts of Acacia nilotica, Justicia zelanica, Lantana camara and Saraca asoca exhibited good activity against all the bacteria tested and the MIC was recorded in range of 9.375-37.5 microg/ml and 75.0-300.0 microg/ml against the bacterial and fungal pathogens, respectively. The other extracts of Phyllanthus urinaria, Thevetia nerifolia, Jatropha gossypifolia Saraca asoca, Tamarindus indica, Aegle marmelos, Acacia nilotica, Chlorophytum borivilianum, Mangifera indica, Woodfordia fruticosa and Phyllanthus emblica showed antimicrobial activity in a range of 75-1200 microg/ml.