BackgroundThere is a growing interest in the green synthesis of silver nanoparticles (AgNPs) using plant extract because the technique is cost effective, eco-friendly and environmentally benign. This is phasing out the use of toxic and hazardous chemical earlier reported. Tithonia diversifolia is a wild sunflower that grows widely in the western part of Nigeria with a proven medicinal benefit. However, several studies carried out have left doubts on the basic operational parameters needed for the green synthesis of AgNPs. The objective of this work was to carry out green synthesis of AgNPs using T. diversifolia extract via an eco-friendly route through optimization of various operational parameters, characterization, and antimicrobial studies.MethodGreen synthesis of TD-AgNPs was done via bottom-up approach through wet chemistry technique using environmentally benign T. diversifolia plant extract as both reducing and stabilizing agent. Phytochemical Screening of the TD plant extract was carried out. Experimental optimization of various operational parameters—reaction time, concentration, volume ratio, and temperature was investigated. TD-AgNPs were characterized by UV–Vis spectroscopy, FTIR Spectroscopy, SEM/energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Antimicrobial studies against multi drug resistant microorganisms (MDRM) were studied using the agar well diffusion method.ResultsThis study reveals the importance of various operational parameters in the synthesis of TD-AgNPs. Excellent surface plasmon resonance peaks (SPR) were obtained at optimum experimental factors of 90 min reaction time under room temperature at 0.001M concentration with the volume ratio of 1:9 (TD extract:Ag ion solution). The synthesis was monitored using UV–Vis and maximum wavelength obtained at 430 nm was due to SPR. The morphology and elemental constituents obtained by TEM, SEM, and EDX results revealed a spherical shape of AgNPs with prominent peak of Ag at 3.0 kV in EDX spectrum. The crystallinity nature was confirmed by XRD studies. FTIR analysis proved presence of biomolecules functioning as reducing, stabilizing, and capping agents. These biomolecules were confirmed to be flavonoid, triterpenes, and saponin from phytochemical screening. The antimicrobial studies of TD-AgNPs were tested against MDRM—Escherichia coli, Salmonella typhi, Salmonella enterica, and Bacillus subtilis.DiscussionThe variation of reaction time, temperature, concentration, and volume ratio played substantive and fundamental roles in the synthesis of TD-AgNPs. A good dispersion of small spherical size between 10 and 26 nm was confirmed by TEM and SEM. A dual action mechanism of anti-microbial effects was provided by TD-AgNPs which are bactericidal and membrane-disruption. Based on the antimicrobial activity, the synthesized TD-AgNPs could find good application in medicine, pharmaceutical, biotechnology, and food science.

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Background: This study sought to investigate the antimicrobial activity of six plants used in traditional medicine in Africa. Methods: The antimicrobial activity of the six medicinal plant extracts (aqueous and ethanol) were evaluated against Proteus mirabilis (ATCC 21784), Pseudomonas aeruginosa (ATCC27856) were Aspergillus fumigatus using the agar-well diffusion protocol. The activities of these extracts were compared with the positive controls chloramphenicol and griseofulvin. Similarly, the phytochemicals from the extracts were qualitatively assayed and their percentage yield calculated by standard methods. Results: The bacterial organisms used, P. mirabilis and P. aeruginosa, were slightly-to-highly susceptible to aqueous and ethanolic extracts from the various test plants, while A. fumigatus was insensitive to the treatments. The ethanolic extracts of the sampled plants showed superior inhibitory performance on the target bacteria to the aqueous extracts. Aqueous and ethanolic extracts of Aframomum melegueta, Moringa oleifera and Cola nitida showed inhibitory consistency against the target bacteria. Superior inhibitory activity was observed for ethanol extracts of A. melegueta seed and M. oleifera pod against P. mirabilis and P. aeruginosa. Variations in phytochemicals were noticed across solvents and plant parts for all plants. Phenols were detected in the aqueous and ethanolic extracts of C. nitida and Cola acuminate, but relatively appeared denser in extracts of A. melegueta seed and Chrysophyllum albidium fruits. The extracts of C. nitida, C. acuminate and A. melegueta tested positive for the presence of flavonoids, which were undetected in C. albidium and M. oleifera seed and pod extracts. None of the extracts showed the presence of every phytochemical assayed during the study. Conclusions: Extracts of the medicinal plants assessed in this study showed antibacterial potential. Developing new methodologies that preserve the bioactive potency of phyto-extracts for optimal microbicidal activity is promising for development of safe, non-reactive pharmaceuticals.

Background: Plants in traditional healthcare services in West Africa were selected based on ethnobotanical data for this study. Aqueous and ethanol extracts from these plants’ parts were comparatively screened for phytochemicals and in vitro antimicrobial activity. Methods: The antimicrobial activity of five medicinal plants’ extracts (aqueous and ethanol) were evaluated against Proteus mirabilis (LHC201), Pseudomonas aeruginosa (LHC181) and Aspergillus fumigates (LUML56) using the agar-well diffusion protocol. Retailed chloramphenicol and griseofulvin were used as positive controls respectively. Phytochemicals and percentage yield were determined by modified standard methods. Results: The target bacteria showed varied degrees of susceptibility to both aqueous and ethanol extracts. A. fumigates was insensitive to the treatments. The ethanol extracts of the sampled plants’ parts showed better inhibitory performance against the target bacteria compared to aqueous extracts. Aqueous and ethanol extracts of Aframomum melegueta, Moringa oleifera and Cola nitida showed marginal difference in inhibitory activity with higher inhibition zones observed for the ethanol extracts of A. melegueta seed and M. oleifera pod against the target bacteria. Phytochemicals composition and density observed in extractants and plants’ parts also varied. Phenols were detected in both the aqueous and ethanolic extracts of C. nitida and C. acuminata, but appeared relatively richer in extracts of A. melegueta seeds and C. albidium fruits. C. nitida, C. acuminate and A. melegueta extracts were positive for flavonoids which were undetected in C. albidium fruits, M. oleifera seeds and pod extracts. No single extract had all the phytochemicals assayed. Conclusions: Screened extracts of medicinal plants’ parts used for this study showed promise antibacterial and resource for developing safer pharmaceutics. Optimization of the antibacterial potential of the extracts for commercial exploitation requires further studies. This study has provided information on the antibacterial property of C. albidum fruits which was hitherto underutilized for traditional medicine purpose.

Background: Plants in traditional healthcare services in West Africa were selected based on ethnobotanical data for this study. Aqueous and ethanol extracts from these plants’ parts were comparatively screened for phytochemicals and in vitro antimicrobial activity. Methods: The antimicrobial activity of five medicinal plants’ extracts (aqueous and ethanol) were evaluated against Proteus mirabilis (LHC201), Pseudomonas aeruginosa (LHC181) and Aspergillus fumigates (LUML56) using the agar-well diffusion protocol. Retailed chloramphenicol and griseofulvin were used as positive controls respectively. Phytochemicals and percentage yield were determined by modified standard methods. Results: The target bacteria showed varied degrees of susceptibility to both aqueous and ethanol extracts. A. fumigates was insensitive to the treatments. The ethanol extracts of the sampled plants’ parts showed better inhibitory performance against the target bacteria compared to aqueous extracts. Aqueous and ethanol extracts of Aframomum melegueta, Moringa oleifera and Cola nitida showed marginal difference in inhibitory activity with higher inhibition zones observed for the ethanol extracts of A. melegueta seed and M. oleifera pod against the target bacteria. Phytochemicals composition and density observed in extractants and plants’ parts also varied. Phenols were detected in both the aqueous and ethanolic extracts of C. nitida and C. acuminata, but appeared relatively richer in extracts of A. melegueta seeds and C. albidium fruits. C. nitida, C. acuminate and A. melegueta extracts were positive for flavonoids which were undetected in C. albidium fruits, M. oleifera seeds and pod extracts. No single extract had all the phytochemicals assayed. Conclusions: Screened extracts of medicinal plants’ parts used for this study showed promise antibacterial and resource for developing safer pharmaceutics. Optimization of the antibacterial potential of the extracts for commercial exploitation requires further studies. This study has provided information on the antibacterial property of C. albidum fruits which was hitherto underutilized for traditional medicine purpose.