The in vitro evaluation of some South African plant extracts for minimum inhibition concentration and minimum bactericidal concentration against selected bacterial strains

Author(s):  
Bongani A. Nkala ◽  
Hlengiwe P. Mbongwa ◽  
Tozama Qwebani-Ogunleye
Author(s):  
Abdulrahman M. Elbagory ◽  
Christopher N. Cupido ◽  
Mervin Meyer ◽  
Ahmed Hussein

The preparation of gold nanoparticles (AuNPs) involves a variety of chemical and physical methods. These methods use toxic and environmentally harmful chemicals. Consequently, the synthesis of AuNPs using green chemistry has been under investigation to develop eco-friendly nanoparticles. One method to achieve this is the use of plant-derived phytochemicals capable of reducing gold ions to produce AuNPs. The aim of this study was to implement a facile microtitre-plate method to screen a large number of aqueous plant extracts to determine the optimum concentration (OC) to bio-synthesize the AuNPs. Several AuNPs of different sizes and shapes were successfully synthesized and characterized from seventeen South African plants. The characterization was done using Ultra Violet-Visible Spectroscopy, Dynamic Light Scattering, High Resolution Transmission Electron Microscopy and Energy-Dispersive X-ray Spectroscopy. We also studied the effects of temperature on the synthesis of the nanoparticles and measured its effect on the particle size of the synthesized AuNPs and the data showed that changes in temperatures affect the size and dispersity of the generated AuNPs. Further, some of the synthesized AuNPs were stable upon incubation with different biological solutions in vitro.


2016 ◽  
Vol 5 (10) ◽  
pp. 4986
Author(s):  
Muhammad Nadeem* ◽  
Sayed Abdullah

Multi Drugs Resistance (MDR) bacteria are mostly resistant to most of antibiotics, this leads to several severe infections and diseases. Thus the desire of new antibiotic sources are required which direct to the screening of new medicinal plants and use against MDR pathogenic bacteria. In our study, the antibacterial activity of three different plant extracts are utilized against pathogenic bacteria in-vitro to treat the infection and disease cause by pathogenic bacteria. The extracts were isolated from Mallotus philippensis, Silybum marianum and Stachys parviflora Benth in four different solvents extracts and were tested against eight pathogenic MDR bacterial strains (Brucella abortus, Escherichia coli, Enterobacter sakazakii, Proteus vulgaris, Klebsiella pneumoniae, Providencia stuartii, Pseudomonas aeruginosa (gram negative) and Staphylococcus aureus (gram positive) through well diffusion and disc diffusion. It was found that the extracts of selected plants showed maximum activity against all bacterial strains. The recorded zones of inhibition were 8.0-26.33mm for methanolic, 6.0-17.66mm for chloroform extracts and 8.01-2.33mm for ethyl acetate extracts.  So, it is cleared from the results that the tested plant extracts have great potential as antibacterial compounds against bacteria. However, further research is required to isolate and identify the active ingredients are vital for further pharmacological evaluation. Also screening of these plants for Anticancer and Anti-diabetic activity will be significant. 


Author(s):  
Abul KMS Kabir ◽  
Sarkar MA Kawsar ◽  
Mohammad MR Bhuiyan ◽  
Md Safiqur Rahman ◽  
Bilkiss Banu

Some acylated derivatives of methyl 4,6-O-cyclohexylidene-?-D-glucopyranoside, including the precursor, were employed as test compounds for in vitro antimicrobial functionality test against ten human pathogenic bacteria and six phytopathogenic fungi. For comparative studies, biological activity of standard antibiotics, Ampicillin and Nystatin were also carried out against these microorganisms. The study revealed that the tested samples exhibited moderate to good antibacterial and antifungal activities. It was also observed that the test substances were more effective against fungal phytopathogens than those of the bacterial strains. Encouragingly, a good number of test compounds exhibited better antimicrobial activity than the standard antibiotics employed. Minimum Inhibition Concentration (MIC) test of methyl 4,6-O-cyclohexylidene-3-Odecanoyl- 2-O-octanoyl-?-D-glucopyranoside was conducted against INABA ET (Vibrio) and MIC was found to be 12.5 ?g/disc. DOI: http://dx.doi.org/10.3329/cujbs.v3i1.13406 The Chittagong Univ. J. B. Sci.,Vol. 3(1&2):53-64, 2008


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