Ethnobotanical survey, phytoconstituents and antibacterial investigation of Rapanea melanophloeos (L.) Mez. bark, fruit and leaf extracts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Thabile Lukhele ◽  
Denise Olivier ◽  
Marthe C. D. Fotsing ◽  
Charlotte M. Tata ◽  
Monisola I. Ikhile ◽  
...  

Abstract Rapanea melanophloeos is traditionally used in South Africa in the treatment of ailments of the skin, pulmonary and gastro intestinal tract. This study was aimed at giving an overview of these traditional uses and comparing the phytochemicals and antibacterial activities of various crude extracts of the leaves, fruits and bark in order to validate these uses. The three plant parts were extracted using petroleum ether (PE), ethyl acetate (EtOAc), methanol (MeOH) and water. Various phytochemicals were compared using TLC, while alcohol precipitable solids (APS), non-polar terpenes and amino acids were analysed by GC-MS. Antibacterial activity was determined against three Gram-positive and three Gram-negative strains by microdilution assays. Caryophyllene oxides, α-cadinol and (−)-spathulenol were identified in the PE extracts. All nine essential amino acids were present in fruit extracts in significantly higher levels than in the leaves and bark; 255.1, 23.4 and 21.3 mg/g respectively. Most of the extracts showed good antibacterial activity, especially against the Gram-positive pathogens (MIC of ≤1 mg/mL), the EtOAc extracts exhibited the best activity with the fruit having an MIC values of 0.1 ± 0.2 mg/mL against Staphylococcus epidermidis and Enterococcus faecalis, 0.05 mg/mL against Bacillus cereus. Results from this study validate the ethnomedicinal uses of R. melanophloeos extracts for ailments of bacterial etiology. The plant had a rich supply of secondary metabolites, APS and amino acids and TLC and antibacterial activities of the extracts showed slight variations in chemical composition due to geographic distribution.

2018 ◽  
Vol 29 ◽  
pp. 70-77 ◽  
Author(s):  
Anjana Devkota ◽  
Ritu Kumari Das

Antibacterial activities of Xanthium strumarium L. (Asteraceae) was carried out in laboratory. Distilled water and methanol extracts of the leaves of plant was prepared. The antibacterial activity was studied against six pathogenic bacteria, three gram negative: Klebsiella pneumoniae (ATCC 15380), Proteus mirabilis (ATCC 49132), Escherichia coli (ATCC 25922) and three gram positive: Bacillus subtilis (ATCC 6633), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25932) at different concentrations (50 mg/ml, 100 mg/ml, 150 mg/ml, 200 mg/ ml, 250 mg/ml) of leaf extracts of X. strumurium. The phytochemical screening depicted the presence of terpenoids, saponins, flavonoids, tannins and alkaloids. The antibacterial activity of extracts was determined by disc diffusion method and zone of inhibition (ZOI) was measured. Gram negative bacteria was found more resistant than gram positive bacteria. The most susceptible bacterium was S. aureus while the most resistant bacterium was E. coli. Methanolic extract was found more effective than distilled water. These findings suggest that extracts obtained from leaves of X. strumurium possess biobactericidal potential, which can suitably be exploited for making antibacterial drugs.J. Nat. Hist. Mus. Vol. 29, 2015, Page: 70-77


2020 ◽  
Vol 11 (3) ◽  
pp. 4857-4865
Author(s):  
Tekleweyni Tadege ◽  
Kidu Hintsa ◽  
Tesfay Weletnsae ◽  
Gopalakrishnan V K ◽  
Muthulingam M ◽  
...  

Acacia etbaica Schweinf belongs to the family Fabaceae widely distributed in Africa and various parts of this plant such as bark, leaves, flowers and roots are widely used as a folk medicine for curing of various ailments.This study was aimed to screen the phytoconstituents and evaluate the antibacterial activity of leaf extract of A. etbaica against selected multidrug resistant Enterobacteriaceae family. Leaves of A. etbaica were extracted with petroleum ether, chloroform, acetone, and ethanol by sequential soxhlet extraction. Phytochemical screening of organic leaf extract of A.etbaica was carried out for the detection of phytoconstituents accountable for antibacterial activity. In vitro antibacterial activities of A.etbaica leaf extracts against selected Enterobacteriaceae family gram‑positive bacteria such as (B.subtilis, E.faecalis,S.aureus)and gram-negative (E. coli, K. pneumonia, V. cholera) were evaluated by agar well diffusion. The antibacterial potential of acetone and ethanol leaf extracts of A.etbaica were determined by 96 well plate broth dilution assay. Among the tested organic leaf extracts, both acetone and ethanolic leaf extract of A.etbaica showed a potentially broad spectrum of in vitro antibacterial activity against tested multiple drug resistant Enterobacteriaceae family gram-positive pathogens such as B.subtilis, E. faecalis , and S.aureus and gram-negative bacterial strains E. coli, K. Pneumonia and V. Cholera with significant MIC values. The significant antibacterial activity of both acetone and ethanolic leaf extracts of A.etbaica was due to the subsistence of secondary metabolites phytoconstituents such as flavonoids and phenolic compounds.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Séverine Boisard ◽  
Anne-Marie Le Ray ◽  
Anne Landreau ◽  
Marie Kempf ◽  
Viviane Cassisa ◽  
...  

During this study, thein vitroantifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains:Candida albicans, C. glabrata, andAspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains includingStaphylococcus aureus. Organic extracts showed a significant antifungal activity againstC. albicansandC. glabrata(MIC80between 16 and 31 µg/mL) but only a weak activity towardsA. fumigatus(MIC80= 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially againstS. aureus(SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC10030–97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.


1986 ◽  
Vol 5 (1) ◽  
pp. 40-45 ◽  
Author(s):  
S. Botha ◽  
L. M. Van der Vijver

A chemical and biological screen was performed on Gomphrena celosioides (Amaranthaceae) known as prostrate globe amaranth. Chemical tests showed the presence of saponins, steroids, phenolic substances, flavonoids, amino acids, sugars and betacyanins in the plant. The roots exhibited a weak antibacterial activity against three Gram positive bacteria. An action on the autonomic nervous system of rats was shown by all the plant parts, when tested by the method of Malone and Robichaud. Sympathetic and parasympathetic symptoms were observed.


2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Yohannes Kelifa Emiru ◽  
Ebrahim Abdela Siraj ◽  
Tekleab Teka Teklehaimanot ◽  
Gedefaw Getnet Amare

Objective. To evaluate the antibacterial effects of the leaf latex of Aloe weloensis against infectious bacterial strains. Methods. The leaf latex of A. weloensis at different concentrations (400, 500, and 600 mg/ml) was evaluated for antibacterial activities using the disc diffusion method against some Gram-negative species such as Escherichia coli (ATCC 14700) and Pseudomonas aeruginosa (ATCC 35619) and Gram-positive such as Staphylococcus aureus (ATCC 50080) and Enterococcus fecalis (ATCC 4623). Results. The tested concentrations of the latex ranging between 400 and 600 mg·mL−1 showed significant antibacterial activity against bacterial strain. The highest dose (600 mg/ml) of A. weloensis leaf latex revealed the maximum activity (25.93 ± 0.066 inhibition zone) followed by the dose 500 mg/ml against S. aureus. The lowest antibacterial activity was observed by the concentration 400 mg/ml (5.03 ± 0.03) against E. coli. Conclusion. The results of the present investigation suggest that the leaf latex of A. weloensis can be used as potential leads to discover new drugs to control some bacterial infections.


2015 ◽  
Vol 761 ◽  
pp. 402-406 ◽  
Author(s):  
Siti Aishah Mohd Hanim ◽  
Nik Ahmad Nizam Nik Malek ◽  
Zaharah Ibrahim ◽  
Mashitah Mad Salim ◽  
Nur Isti'anah Ramli ◽  
...  

The antibacterial activity of functionalized zeolite NaY (CBV100) with different concentrations of 3-aminopropyltriethoxysilane (APTES) (0.01, 0.05, 0.20 and 0.40 M) was studied against Staphylococcus aureus ATCC 6538 (Gram positive) and Escherichia coli ATCC 11229 (Gram negative) through disc diffusion technique (DDT). The characterization of functionalized zeolite NaY with fourier transform infrared (FTIR) spectroscopy indicated the attachment of APTES on zeolite NaY. Through DDT, the inhibition zone of functionalized zeolite NaY increased proportionally to the amount of the amine-functional group attached onto zeolite NaY. Functionalized zeolite NaY showed higher antibacterial activity against Gram-positive compared to Gram-negative bacteria. It can be concluded from this study that amine-functionalized zeolite NaY shows evidence of antibacterial activities.


2013 ◽  
Vol 2 (1) ◽  
pp. 147-152 ◽  
Author(s):  
AM Bukar ◽  
MA Isa ◽  
HS Bello ◽  
AS Abdullahi

The phytochemical screening and antibacterial activity of ethanolic and Methanolic leaves extract of Vernonia amygdalina against five clinical isolates (Staphylococcus aureus, E. coli, Pseudomonas species, Salmonella species and Proteus species) was determined using standard method of analysis. The results of the antibacterial activity of ethanol, methanol and aqueous extract of leaves of V. amygdalina have diameters ranging between 0.4 to 10mm. The plant extracts from the plants had profound activities against gram-positive than gram negative bacteria. From the above studies, it has clearly indicated that V. amygdalina extract may represent new sources of antibacterial drug, if the phytoactive components are purified and proper dosage are determined for administration. International Journal of Environment, Volume-2, Issue-1, Sep-Nov 2013, Pages 147-152 DOI: http://dx.doi.org/10.3126/ije.v2i1.9217


2021 ◽  
Vol 16 (1) ◽  
pp. 115-125
Author(s):  
Razafiarimanga Zara Nomentsoa ◽  
Randriamampianina Lovarintsoa Judicael ◽  
Randrianarivo Hanitra Ranjàna ◽  
Ralitera Andrianirina Manampisoa ◽  
Rakoto Danielle Aurore Doll ◽  
...  

The present work aimed to study the composition and antibacterial properties of the essential oils (EO) of Ocotea zahamenensis leaves (LEO), stem (SEO) and root (REO) barks from two harvest periods (March and June). All EOs were extracted by hydrodistillation from fresh plant parts with yields up to 4.5%. They are colourless, clear, with a strong odour, heavy, levogyre, with a low acid index and an ester index up to 14.89. Gas chromatography/flame ionisation detection analysis of these EOs identified 5 to 12 components representing 96.06 to 99.96% of the overall composition. Safrole was by far the most predominant constituent with contents ranging from 77.45% (SEO, June) to 97.05% (REO, March). The antibacterial activity was tested against eight pathogenic bacteria including 4 Gram (-) and 4 Gram (+) using microdilution assays. With Minimum Inhibitory Concentration (MIC) values of less than 1 mg/mL, all EOs showed antibacterial activity which varied according to the strain. There was not much difference between the activities of March and June Eos, and in both cases SEO were slightly more effective than LEO and REO. All EOs had bacteriostatic action on Bacillus cereus and Vibrio fischeri and bactericidal on almost other strains. When administered orally to mice at 0.5 mg/kg body weight, all EOs caused symptoms of intoxication. Their LD50 varied from 1.019 to 2.73 g/kg body weight. These EOs could be a new source of safrole and could be used for various purposes with further toxicological studies.


Copper (II) complex of naphthaldehyde thiosemicarbazone (L) has been synthesized and characterized by melting points, conductance, magnetic, infrared, and ESI-MS spectral measurements in addition to elemental analysis. A tetrahedral structure is suggested for the complex. The antibacterial activities of the complex and ligand were evaluated by the disc diffusion technique. Pure bacteria cultures of Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) were used to check the antibacterial activities of the synthesized compounds. Antibacterial activities were compared by measuring the inhibition zone diameter and chloramphenicol was used as a reference. Both the compounds showed significant antibacterial activity in different range against gram-positive & gram-negative bacteria. The antibacterial activity data also show that the Cu(II) complex to be more effective than the parent ligand. Molecular geometry of the complex has been optimized by ChemDraw Ultra 12.0 and then MM2 calculation has been done.


2020 ◽  
Vol 83 (2) ◽  
pp. 331-337
Author(s):  
WENYUE WANG ◽  
RUI WANG ◽  
GUIJU ZHANG ◽  
FANGLI CHEN ◽  
BAOCAI XU

ABSTRACT Naturally occurring monoglyceride esters of fatty acids have been associated with a broad spectrum of antimicrobial activities. We used an automated turbidimetric method to measure the MIC and assess the antimicrobial activity of five monoglycerides (monocaprin, monolaurin, monomyristin, monopalmitin, and monostearin) against pathogenic strains of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli. The antibacterial activity of monocaprin was highest because its carbon chain is shorter than those of other monoglycerides. The MICs of monocaprin against S. aureus, B. subtilis, P. aeruginosa, and E. coli were 0.32, 0.32, 2.5, and 2.5 mg/mL, respectively. Monocaprin had antibacterial activity under neutral and alkaline conditions (pH 7.0 to 9.0) but had no inhibitory effect on S. aureus, B. subtilis, and E. coli under weakly acidic conditions (pH 6.0). The antibacterial mechanism of monocaprin against gram-positive strains (S. aureus and B. subtilis) resulted from destruction of the cell membrane. In contrast, the antibacterial activity of monocaprin against gram-negative strains (P. aeruginosa and E. coli) was attributed to damage to lipopolysaccharides in the cell walls. Because of its inhibitory effect on both gram-positive and gram-negative bacteria, monocaprin could be used as an antibacterial additive in the food industry. HIGHLIGHTS


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