scholarly journals Antibacterial Activity of the Ethanolic Extracts Derived from Leaves and Pseudobulbs of Some Orchids Belonging to Coelogyne Genus Against Enterobacter Cloacae Strain

Author(s):  
Lyudmyla Buyun
Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 624
Author(s):  
Laima Česonienė ◽  
Juozas Labokas ◽  
Ina Jasutienė ◽  
Antanas Šarkinas ◽  
Vilma Kaškonienė ◽  
...  

The aim of the study was to evaluate 11 cultivars of blue honeysuckle (Lonicera caerulea L.) for bioactive compounds, antioxidant capacity, and the antibacterial activity of berries. Total phenolic contents (TPCs) and total anthocyanin contents (TACs) were established by using ethanolic extracts. For contents of organic acids and saccharides, aqueous extracts were used, and vitamin C was determined by using oxalic acid solution. DPPH• radical scavenging capacity was evaluated by using ethanolic extracts; antibacterial activity was assessed by using both ethanolic and aqueous extracts. The TPC varied from 364.02 ± 0.41 mg/100 g in ‘Vostorg’ to 784.5 ± 0.3 mg/100 g in ‘Obilnaja’, and TAC ranged from 277.8 ± 1.1 mg/100 g in ‘Čelnočnaja’ to 394.1 ± 8.4 mg/100 g in ‘Nimfa’. Anthocyanins comprised 53.8% of total phenolic contents on average. Among organic acids, citric acid was predominant, averaging 769.41 ± 5.34 mg/100 g, with malic and quinic acids amounting to 289.90 ± 2.64 and 45.00 ± 0.37 mg/100 g on average, respectively. Contents of vitamin C were 34.26 ± 0.25 mg/100 g on average. Organic acids were most effective in the inhibition of both Gram-positive and Gram-negative bacteria tested. In conclusion, berries of L. caerulea are beneficial not only for fresh consumption, but also as a raw material or ingredients of foods with high health-promoting value.


2020 ◽  
Vol 24 (2) ◽  
Author(s):  
Gina Barbosa ◽  
◽  
Cresilda Alinapon ◽  
Analyn Gultiano

Antibacterial, Etlingera elatior, Etlingera philippinensis


2006 ◽  
Vol 8 (2) ◽  
pp. 160
Author(s):  
Aswan Thamin ◽  
Chairulwan Umar ◽  
Darussadah Paransa

Grapsus albolineatus is one of marine crustaceans which have carotenoid (astaxanthin) pigment. This research was conducted to analyze carotenoids (astaxanthin) extracted from G. albolineatus, and evaluate their in vitro antibacterial activity. The research was done in March-July 2002. Samples were collected from Manado Gulf, North Sulawesi. The result indicated that the carapace contained 4 carotenoids namely ß-caroten, ecinenon, astaxanthin diester, and astaxanthin monoester. In addition, the epidermis contained free astaxanthin. In vitro antibacterial activity test indicated that astaxanthin had low bacteriostatic activity against Psedomonas aeruginosa, Enterobacter cloacae, Staphylococcus aureus, and Proteus stuartii.


2019 ◽  
Vol 2 (1) ◽  
pp. 01-06
Author(s):  
Rhazi Fouzia

Study contextual: Faced with the global problem of antimicrobial resistance, and the use of traditional medicine for the research of antibacterial biomolecules. Aim: our work focused on the valorization of a medicinal plant Dittrichia viscosa which has many therapeutic and culinary virtues worldwide. Methods: To do this, a phytochemical screening of the leafy stems of the plant is carried out according to a set of physicochemical reactions, as well as an in vitro evaluation of the antibacterial activity, of the aqueous and ethanolic extracts against multi-resistant bacterial strains, by microdilution technique on microplates. An evaluation of the synergistic interaction between extracts and weakened antibiotics against pathogenic bacteria was also highlighted in this study. Results: The tests revealed the richness of Dittrichia viscosa species by tannins, flavonoids, saponosides, sterols and triterpenes. As for the antibacterial effect, the MICs range from 0.858±0.29 to 66.66 ± 0.00 mg / ml and the MBCs from 4.300 ± 1.01 to 11.610 ± 2.31 mg / ml is an interesting antibacterial activity. Regarding the combination of extracts with antibiotics tested, it revealed a synergistic action inducing an amplification of the antibacterial power of Penicillin, Imipenem and Erythromycin with a rate that reaches 471%. Conclusion: The results of this study show that the aqueous and ethanolic extracts of Dittrichia viscosa have interesting and promising antibacterial activity in the pharmaceutical, food and cosmetic industries.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1406 ◽  
Author(s):  
Ovin Qonita Allyn ◽  
Eko Kusumawati ◽  
Rudy Agung Nugroho

The aim of this study was to determine the effects of various concentration ofTerminalia catappabrown leaves extract which can inhibit the growth ofStaphylococcus aureusATCC 25923 andPseudomonas aeruginosaATCC 27853. The crushed-brown leaves ofTerminalia catappawas extracted using 95% ethanol, filtered, and evaporated. The driedT. catappaextract was used to identify phytochemical content qualitatively. Total phenolic and flavonoid contents were also measured quantitatively from dried extract. The dried extracts were also dissolved in sterile aquadest and serial dilutions were prepared to final concentration of 30, 60 and 90%. A disc diffusion method was used to evaluate the antibacterial activity of various concentrations of ethanol extract of brown leaves ofT. catappa. Inhibition zone diameter was measured to determine antibacterial activity. Gentamycin sulfate and distilled water were used as positive and negative controls, respectively. Dried ethanolic extract of brownT. catappaleaves contained flavonoid, quinon, phenolic, triterpenoid, and tannin. A total of 208.722 mg gallic acid equivalent/g extract of total phenolic and 35.7671 mg quercetin equivalent/g extract of total flavonoid were also found in the dried extract. The inhibition zone diameters of ethanolic extracts ranged from 1.73 to 9.06 mm (S. aureus) and from 1.83 to 6.5 mm (P. aeruginosa). The higher concentration of extract, the wider the inhibition zone diameters for both bacteria.P. aeruginosawas more resistant to high concentrations of extract (90%) thanS. aureus. Ethanolic extracts of the brown leaves ofT. catappahad different antibacterial effects againstS. aureusandP. aeruginosa. The higher the concentration of extract, the wider the inhibition zone diameter for both bacteria.P. aeruginosawas more resistant to high concentrations of ethanolic extracts of the brown leaves ofT. catappa.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Bishnu P. Marasini ◽  
Pankaj Baral ◽  
Pratibha Aryal ◽  
Kashi R. Ghimire ◽  
Sanjiv Neupane ◽  
...  

The worldwide increase of multidrug resistance in both community- and health-care associated bacterial infections has impaired the current antimicrobial therapy, warranting the search for other alternatives. We aimed to find thein vitroantibacterial activity of ethanolic extracts of 16 different traditionally used medicinal plants of Nepal against 13 clinical and 2 reference bacterial species using microbroth dilution method. The evaluated plants species were found to exert a range ofin vitrogrowth inhibitory action against the tested bacterial species, andCynodon dactylonwas found to exhibit moderate inhibitory action against 13 bacterial species including methicillin-resistantStaphylococcus aureus, imipenem-resistantPseudomonas aeruginosa, multidrug-resistantSalmonella typhi, andS. typhimurium. The minimum inhibitory concentration (MIC) values of tested ethanolic extracts were found from 31 to >25,000 μg/mL. Notably, ethanolic extracts ofCinnamomum camphora, Curculigo orchioides, andCurcuma longaexhibited the highest antibacterial activity againstS. pyogeneswith a MIC of 49, 49, and 195 μg/mL, respectively; whereas chloroform fraction ofCynodon dactylonexhibited best antibacterial activity againstS. aureuswith a MIC of 31 μg/mL. Among all,C. dactylon, C. camphora, C. orchioides, andC. longaplant extracts displayed a potential antibacterial activity of MIC < 100 μg/mL.


2020 ◽  
Vol 367 (16) ◽  
Author(s):  
Tabitha Mlowoka Kayira ◽  
Hiroyuki Nakano

ABSTRACT Vibrio cholerae is an etiological cause of cholera implicated in several pandemics. Antibacterial activity of plant extracts has been established. However, these extracts exhibit activity at a concentration that may alter organoleptic attributes of water and food, hence limiting their application. In this light, there is need to device ways of reducing plant extracts' effective levels in order to widen their application. Thus, this study was conducted to improve activities of plant ethanolic extracts through combination with other generally recognized as safe antimicrobials. Combination of plant extracts with sodium acetate (NaOAc) 0.4% at pH 7.0 reduced minimum inhibitory concentrations (MICs) of clove, lemon eucalyptus, rosemary and sage from 0.2 to 0.025%. At pH 6.4, combinations were more effective reducing MICs of clove, lemon eucalyptus, rosemary and sage from 0.2 to 0.0125% with NaOAc at 0.2%. At pH 7.0, the combination resulted in additive effect. Nevertheless, at pH 6.4, synergic effect was established. No interactive effect was observed with combinations involving glycine. Combination of plant extracts with NaOAc at mildly acidic pH creates a hurdle effect that may have potential application to control the growth of V. cholerae.


Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 220 ◽  
Author(s):  
Weidong Qian ◽  
Yuting Fu ◽  
Miao Liu ◽  
Ting Wang ◽  
Jianing Zhang ◽  
...  

Vanillic acid (VA) is a flavoring agent found in edible plants and fruits. Few recent studies exhibited robust antibacterial activity of VA against several pathogen microorganisms. However, little was reported about the effect of VA on carbapenem-resistant Enterobacter cloacae (CREC). The purpose of the current study was to assess in vitro antimicrobial and antibiofilm activities of VA against CREC. Here, minimum inhibitory concentrations (MIC) of VA against CREC was determined via gradient diffusion method. Furthermore, the antibacterial mode of VA against CREC was elucidated by measuring changes in intracellular adenosine triphosphate (ATP) concentration, intracellular pH (pHin), cell membrane potential and membrane integrity. In addition, antibiofilm formation of VA was measured by crystal violet assay and visualized with field emission scanning electron microscopy (FESEM) and confocal laser scanning microscopy (CLSM). The results showed that MIC of VA against E. cloacae was 600 μg/mL. VA was capable of inhibiting the growth of CREC and destroying the cell membrane integrity of CREC, as confirmed by the decrease of intracellular ATP concentration, pHin and membrane potential as well as distinctive variation in cellular morphology. Moreover, crystal violet staining, FESEM and CLSM results indicated that VA displayed robust inhibitory effects on biofilm formation of CREC and inactivated biofilm-related CREC cells. These findings revealed that VA exhibits potent antibacterial activity against CREC, and thus has potential to be exploited as a natural preservative to control the CREC associated infections.


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