Browsing by Author "Ahmed, Risikat Nike"
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Item Antibacterial Action of Silver Nanoparticles of Extract of Leaf of Thevetia nerifolia(Society for the Conservation of Phytofuels and Sciences, 2015) Ahmed, Risikat Nike; Abdullahi, M.A; Zakariyah, Rahmat Folashade; Gambari-Ambali, Rabiat. O; Adeyemi, Sherif D; Afonja, A.I; Adebisi, O.OSilver nanoparticles (AgNPs) were synthesized using a combination of aqueous extract of Thevetia nerifolia and 1mM of silver nitrate (AgNO3) solution to obtain concentrations of 100mg/ml–400mg/ml. Characterization of the particles was done by UV–Vis spectroscopy Fourier transform infrared (FTIR). Antibacterial activity was investigated against Staphylococcus aureus, Escherichia coli and Psedomonas aeruginosa using standard agar well diffusion method. Gentamicin and tetracycline were used as reference antibiotics. The Minimum Inhibitory Concentration (MIC) was achieved by microbroth dilution technique. Minimum Bactericidal Concentration (MBC) was done by plate assay. The mode of action of the particles was evaluated by direct exposure of the cells of selected isolates to the nanoparticles. The presence of phytochemical constituents was examined using standard methods. The total yield of AgNPs of the plant extract was 0.6g. Characterization by UV-visible spectrometry revealed peak absorbance of 0.465 at 452.0nm, while FTIR showed the presence of two (2) functional groups. According to the antibacterial sensitivity assay, the four concentrations exhibited considerable effects against all test isolates. At 400mg/ml, the highest inhibitory activities were observed with S. aureus and E. coli with zones of inhibition measuring 22mm and 20mm respectively. The activity of synthesized particle compared favourably with reference antibiotics. The MIC was obtained at 40mg/ml while MBC was at a higher concentrations. The mode of action showed disruption of cellular components as a result of increased permeability of cell membrane. Following the results of the phytochemical analysis, a total of five (5) bioactive constituents were obtained. It is evident from this study that AgNPs synthesized could be a good candidate in the treatment of conditions caused by the test isolates.Item Antibacterial Evaluation of Extracts of Seed Kernel and Leaf of Moringa Oleifera Against Bacteria from Raw Cow Milk(Nigerian Journal of Microbiology, 2016) Zakariyah, Rahmat Folashade; Sani, Al-hassan; Odebisi-Omokanye, Mutiat Busayo; Ahmed, Risikat NikeMoringa oleiferahas been found very useful in a lot of health related problems owing to its medicinal components and values, these has led to research on its antibacterial activity against food borne pathogens. Aqueous and acetone extracts of Moringa oleifera seed kernel and leaf were evaluated for antibacterial activity against Bacillus cereus, Staphylococcus aureus and Escherichia coli isolated from raw cow milk. The antibacterial assay was carried out at concentrations of 250, 125, 62.5 and 31.25mg/ml using modified agar well diffusion method. Aqueous extract inhibited the growth of test isolates at varying degrees. Aqueous extract of seed kernel was highly inhibitory on Staphylococcus aureus with a zone of inhibition (23.33±1.20mm) at concentration of 250mg/ml. Minimum Inhibitory Concentration showed that both extracts inhibited the growth of Bacillus cereus, Staphylococcus aureus and Escherichia coli at concentrations ranging from 125 to 21.25mg/ml. The antibacterial effect of standard antibiotics was performed and it was observed that Gentamycin inhibited growth of the three test isolates. Preliminary phytochemical screening revealed the presence of alkaloids, flavonoids, steroids, saponin, tannin, phenols, glycosides and carbohydrates compound in the extracts. From the present study, Moringa oleifera seed kernel and leaf can be a promising source of phytochemical components and further studies is therefore recommendedItem Extraction and Antibacterial Activity of Essential Oils from Eucalyptus globulus(Ilorin Journal of Science, 2016) Ahmed, Risikat Nike; Sule, Ismaila Olawale; Zakariyah, Rahmat Folashade; Gambari-Ambali, Rabiat O; Jimoh, Fausat AbimbolaThe essential oil of Eucalyptus globulus obtained by hydrodistillation (Fever tree) was investigated for activity against two bacteria (Staphylococcus aureus and Klebsiella pneumoniae). The oil was extracted using a Clevenger-type apparatus. Separation, identification and determination of percentage composition of compounds present in the oil were carried out by Gas Chromatography Mass Spectrometry. The antibacterial activity was investigated by agar diffusion technique using various concentrations of the essential oil: 100% v/v, 75% v/v, 50% v/v, 25% v/v, 15% v/v. Minimum inhibitory concentration was determined using turbidimetric assay by taking the absorbance with the aid of a spectrophotometer. Minimum bactericidal concentration was by plate assay. Gas Chromatography Mass Spectrometry revealed the presence of seven compounds, all amounting to 90.4% with globulol having the highest percentage composition of 30.1%. The evaluation of sensitivity of the oil revealed the highest activity at 100% v/v against both isolates. Minimum inhibitory concentration was obtained at 25% v/v when assayed against K. pneumoniae with no activity at all against S. aureus at the same concentration. Oil showed no bactericidal activity at all concentrations, suggesting only bacteristatic activity of the oil. Investigation from this work revealed that the essential oil of E. globulus exhibit activity against the tested isolates and can thus be employed in the treatment of infections caused by them.Item Green Synthesis and Antibacterial Activity of Silver Nanoparticles From Extract of Leaves of Croton Zambesicus(Nigerian Journal of Microbiology, 2016) Ahmed, Risikat Nike; Sani, Al-hassan; Oluwo, N.O; Sule, Ismaila Olawale; Zakariyah, Rahmat FolashadeSilver nanoparticles (AgNPs) was synthesized using a combination of aqueous extract of Croton zambesicus and silver nitrate (AgNO3) solution to obtain various concentrations of 100mg/ml, 200mg/ml, 300mg/ml and 400mg/ml at 10mM. Characterization of the synthesized silver nanoparticle was done by UV-visible spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). Antimicrobial activity against four bacterial isolates was determined by standard method of agar-well diffusion assay. The activity of two standard antibiotics was compared with the AgNPs of C. zambesicus using the disc diffusion method. The Minimum Inhibitory Concentration (MIC) was achieved using microbroth dilution technique. Test tubes that showed low turbidity in the MIC assays were reinoculated on sterile agar plates and this was taken as Minimum Inhibitory Concentration (MBC). The presence of phytochemical constituent was examined using standard methods. The total yield of the AgNPs of the plant extract was 10.94g. The characterization by UV-visible revealed that at a wavelength of 429.0nm the particle has peak absorbance of 2.003, while the FTIR showed the presence of five (5) functional groupsE. coli demonstrated reduction in activity as concentration increased with zone diameter of 24mm at 100mg/ml and 10mm at 400mg/ml. The analysis of MIC and MBC revealed inhibitory and bactericidal effects at the same concentration of 30mg/ml. The mode of action of the AgNPs at 100mg/ml showed a total cell lysis of all test isolates. Following the results of the phytochemical analysis, the presence of six phytochemicals were observed. It is evident from this study that AgNPs synthesized from extract of leaf of C. zambesicus is a very effective antibacterial agent that can compare favourably with conventional antibiotics, hence considering it as an alternative in the elimination of the tested isolates and infections caused by themItem A review of the ethnomedicinal, antimicrobial, and phytochemical properties of Musa paradisiaca (plantain)(2021) Ajijolakewu, Kamoldeen Abiodun; Ayoola, Saheed Abiodun; Agbabiaka, Tariq Oluwakunmi; Zakariyah, Rahmat Folashade; Ahmed, Risikat Nike; Oyedele, Julius Olusegun; Sani, Al-hassanBackground: More people—in both developing and developed countries—now use, and are favourably disposed to, traditional medicine. Musa paradisiaca (plantain) is used extensively in traditional medicine across continents. In this review, we investigated the scientifc justifcation of this extensive usage. Main body: Generally, several studies validate usage in infectious diseases, but limited antiviral and in vivo reports exist. The mechanistic elicitation of antimicrobial activity has similarly not been ascertained. Contrarily, data abound from rigorous studies on physiological conditions. Activity across categories is tied to the potent phytosterols duo of stigmasterol and β-sitosterol; and the triterpenes viz. cycloeucalenone, 24-methylene-cycloartanol, and 31-norcy clolaudenone; present in plantain. Toxicity studies, while fnite, suggest general safety and tolerance. Conclusions: Findings in the studies reviewed projects plantain as a veritable source for drug bioprospecting that will be of beneft to scientifc research and pharmaceutical industriesItem SCREENING OF Prosopis africana FOR ANTIMICROBIAL ACTIVITY AGAINST SELECTED ORAL PATHOGENS(Nigeria Journal of Pure and Applied Sciences, 2017) Zakariyah, Rahmat Folashade; Sani, Al-hassan; Odebisi-Omokanye, Mutiat Busayo; Ahmed, Risikat Nike; Jimoh, Fausat Abimbola; Badmus, Simbiat AtinukeProsopis africana, a chewing stick popularly used in the South Western part of Nigeria was examined for antimicrobial activity against Lactobacillus casei ATCC 334, Staphylococcus aureus ATCC 35218, Candida albicans ATCC 10231, Escherichia coli ST2747 and Streptococcus mutans using agar well diffusion method. Extraction was done using ethanol and distilled water. The plant was screened for its phytochemical components. Gas chromatography mass spectrometry analysis was done to detect the secondary metabolites. All the extracts showed antimicrobial activity against the organisms with zones of inhibition ranging from 3.33±0.29 - 13.83±1.61mm except Staphylococcus aureus ATCC 35218 which was resistant to aqueous extract of the dried sample. Statistical analysis of data showed that there was no significant difference in the antimicrobial effects of ethanolic and aqueous extracts of the plant samples at 95% confidence intervals. The phytochemical screening result showed that phenols, alkaloids, sterols, triterpenes and saponins are components of the chewing stick. Also, fatty acids such oleic, palmitic and stearic acids were chemical constituents detected in the plant extracts by GC-MS. The results obtained in this study indicate that P. africana will be useful in the treatment of oral infections.