scholarly journals Antibacterial activity of crude extracts and pure compounds isolated from Vernonia galamensis leaves

2018 ◽  
Vol 12 (11) ◽  
pp. 136-141
Author(s):  
Tafesse Geremew ◽  
Mekonnen Yalemtsehay ◽  
Makonnen Eyasu ◽  
R. T. Majinda Runner ◽  
Bojase-Moleta Gomotsang ◽  
...  
Planta Medica ◽  
2014 ◽  
Vol 80 (16) ◽  
Author(s):  
D Jæger Knudsen ◽  
B Lindberg Møller ◽  
P Weinstein ◽  
S Semple

Author(s):  
Gouse Basha Sheik ◽  
Muazzam Sheriff Maqbul ◽  
Gokul Shankar S. ◽  
Ranjith M S

Objective: To isolate and characterize novel actinomycetes and to evaluate their antibacterial activity against drug-resistant pathogenic bacteriaMethods: In the present study, 19 soil samples were collected from different localities of Ad-Dawadmi, Saudi Arabia. Actinomycetes were isolated from these samples using serial dilution and plating method on Actinomycetes isolation agar supplemented with nalidixic acid and actidione to inhibit bacteria and fungi. Crude extracts of potential actinomycetes were produced by submerged fermentation. The antimicrobial activity of crude extracts of actinomycetes was tested against different bacteria using the agar well diffusion method. Characterization of the isolates was done by morphological, physiological and biochemical methods.Results: A total of 9 (47%) isolates of actinomycetes were isolated from 19 different soil samples tested. Among them, 4 (44%) isolates confirmed as Streptomyces sp. showed potential antimicrobial activity against one or more test organisms. Crude extracts were made from these 4 actinomycetes isolates(DOM1, DOM3, DP3, DP4)and tested for their antibacterial activities against 4 different clinical bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus). Crude extract from DP3 isolate showed highest antibacterial activity against all the four test organisms (28 mm, 21 mm, 20 mm and 18 mm) respectively and DP4 showed lowest antibacterial activity against all the four test organisms (14 mm, 12 mm, 0 mm, 6 mm) respectively. The highest zone of inhibition was shown by DP3 against Staphylococcus aureus (28 mm) and Escherichia coli was resistant for DP4. Most of the Inhibition zones produced by crude extracts showed significant differences when compared with control, tested against test organisms (P<0.05). Inhibition zones produced by DP3 and DOM1 against Staphylococcus aureus were 28 mm and 23 mm, respectively which were strong active when compared with control Ciprofloxacin (18 mm).Conclusion: Further studies for purification of bioactive metabolites and molecular characterization analysis of isolated Streptomyces sp. are in progress which would be helpful in discovering novel compounds of commercial value.


Author(s):  
Triveni A G ◽  
Suresh Kumar Mendem ◽  
Channapa T Shivannavar ◽  
Subhaschandra M Gaddad

 Objective:The continuous rise in the prevalence of multi drug resistance pathogens globally is threatening the treatment and management of infectious diseases. Ethno medicine plays a key role in the exploration for novel bioactive compounds. The present study evaluates the antibacterial and antibiofilm activities of the crude extracts of Lawsonia inermis against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA).Materials and methods: Shade dried and finely powdered leaves of the plant were extracted by maceration method using six solvents methanol, acetone, ethyl acetate, chloroform, petroleum ether and n-hexane. Antibacterial and antibiofilm activities of the extracts against MDR MRSA by agar cup diffusion and tube method respectively.Results: Methanol extract showed the highest antibacterial activity of 18mm compared to other extracts. Similarly, petroleum ether extract showed highest biofilm inhibition of 84.7%. Other solvent extracts also exhibited significant biofilm inhibition [n-Hexane-83.6%, Ethyl acetate -79.5%, Chloroform-79.2%, Acetone -77% and Methanol-77%].Conclusion: The leaf extracts of L. inermis have shown promising biofilm inhibitory activity and good antibacterial activity, which can be explored for the development of new drugs for the MDR pathogens. Keywords: Antibioticacivity, Antibiofilm activity, L.inermis, MRSA


2019 ◽  
Vol 21 ◽  
pp. 101328 ◽  
Author(s):  
S. Dhanasekaran ◽  
A. Rajesh ◽  
Thangavel Mathimani ◽  
S. Melvin Samuel ◽  
Rajasree Shanmuganathan ◽  
...  

2014 ◽  
Author(s):  
Muhammad Muzammal

Comparative study of plant extracts crude and aqueous, methanolic and ethanolic with antibiotics, provide evidence that calotropis procera extracts has the similar antibacterial activity as these antibiotics against test pathogens i.e. Salmonella typhi and E.coli. The analysis of antimicrobial activity of aqueous, methanolic and ethanolic extract of leaves and flower of Calotropis procera was carried out in disc method and also determined MIC value at 600nm through optical density using spectrophotometer. The zone of inhibition produced by extracts was examined and compares it with zone produced by antibiotics. The effect exhibited by ethanolic extract of leaves and flower was significantly greater than the aqueous and methanolic extract of leaves and flower. Crude extracts i.e. latex, leaves, fruit and flower crude extracts. Among them, flower crude extracts shows similar zone of inhibition to test anitibiotics.while in MIC value, we made different concentration of extracts and antibiotics.i.e for crude we made 25%, 50%.75% and 100% concentration of crude juice and for the aqueous, methanolic and ethanolic we made 0.5mg/mL,1mg/mL,2mg/mL,3mg/mL,4mg/mL, 5mg/mL and 6mg/mL in Dimethyl salfoxide, and same antibiotics concentration. Aqueous leaves extracts show MIC at 0.5mg/ml against E.coli while against Salmonella it shows MIC at 1mg/ml... We also determine phytochemical analysis for presences of different compounds in crude extracts. The obtained results provide a support for the use of Calotropis procera, in traditional medicine and suggest its further advance investigation.


2001 ◽  
Vol 39 (5) ◽  
pp. 399-401 ◽  
Author(s):  
Shahla Mansouri ◽  
Alireza Foroumadi ◽  
Teimour Ghaneie ◽  
Ahmad Gholamhosseinian Najar

Author(s):  
Dan Zhou ◽  
Ze-Hua Liu ◽  
Dong-Mei Wang ◽  
Deng-Wu Li ◽  
Li-Na Yang ◽  
...  

Abstract Background Plant secondary metabolites and phytochemicals that exhibit strong bioactivities have potential to be developed as safe and efficient natural antimicrobials against food contamination and addressing antimicrobial resistance caused by the overuse of chemical synthetic preservative. In this study, the chemical composition, antibacterial activities and related mechanism of the extracts of the valonia and the shell of Quercus variabilis Blume were studied to determine its potential as a safe and efficient natural antimicrobial. Methods The phenolic compositions of valonia and shell extracts were determined by folin-ciocalteau colourimetric method, sodium borohydride/chloranil-based assay and the aluminium chloride method and then further identified by the reverse-phase HPLC analysis. The antibacterial activities of valonia and shell extracts were evaluated by the agar disk diffusion method and agar dilution method. The related antibacterial mechanism was explored successively by the membrane of pathogens effect, phosphorous metabolism, whole-cell proteins and the microbial morphology under scanning electron microscopy. Results The n-butanol fraction and water fraction of valonia along with n-butanol fraction of the shell contains enrich phenolics including ellagic acid, theophylline, caffeic acid and tannin acid. The n-butanol fraction and ethanol crude extracts of valonia exhibited strong antibacterial activities against Salmonella paratyphi A (S. paratyphi A) and Staphylococcus aureus (S. aureus) with the DIZ values ranged from 10.89 ± 0.12 to 15.92 ± 0.44, which were greater than that of the Punica granatum (DIZ: 10.22 ± 0.18 and 10.30 ± 0.21). The MIC values of the n-butanol fraction and ethanol crude extracts of valonia against S. paratyphi A and S. aureus were 1.25 mg/ml and 0.625 mg/ml. The related antibacterial mechanism of n-butanol fraction and ethanol crude extracts of valonia may be attributed to their strong impact on membrane permeability and cellular metabolism. Those extracts exhibited strong antibacterial activity according to inhibit the synthesis of bacterial proteins and seriously change morphological structure of bacterial cells. Conclusions The n-butanol fraction and ethanol crude extracts of valonia had reasonably good antibacterial activities against S. paratyphi A and S. aureus. This study suggests possible application of valonia and shell as natural antimicrobials or preservatives for food and medical application.


2018 ◽  
Vol 10 (03) ◽  
pp. 320-325 ◽  
Author(s):  
Hamzah Abdulrahman Salman ◽  
Sankarasetty Venkatesh ◽  
Ramasamy Senthilkumar ◽  
B. S. Gnanesh Kumar ◽  
Aamer Mousa Ali

ABSTRACT BACKGROUND: Ruta graveolens is one of the most used phytomedicines. To date, there is no report of determining the bioactivity of R. graveolens against cariogenic causing bacteria (Streptococcus mutans and Streptococcus sobrinus). OBJECTIVE: The objective of the present study was to determine the antibacterial activity and metabolite profile of R. graveolens against S. mutans and S. sobrinus. MATERIAL AND METHODS: R. graveolens plant material was collected and processed in the month of February. The plant material was extracted by Soxhlet apparatus using methanol solvent. Two strains of S. mutans and two strains of S. sobrinus were isolated from dental caries-active participants and cultured on mitis salivarius-bacitracin agar. The antibacterial susceptibility testing of methanolic extract of R. graveolens was performed by disc diffusion method. The metabolite profile of the plant extract was determined using electrospray ionization-tandem mass spectrometry. RESULTS: The methanolic extract of R. graveolens showed a promising antibacterial activity against S. mutans and S. sobrinus. Two compounds named γ-fagarine and kokusaginine were identified from the methanolic extract of R. graveolens. CONCLUSIONS: The study concluded that R. graveolens contains significant antibacterial activity. However, further investigations are suggested to understand the anticaries properties of these pure compounds.


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