A dual-purpose silver nanoparticles biosynthesized using aqueous leaf extract of Detarium microcarpum: An under-utilized species

Green Synthesis of Silver Nanoparticles from Diospyros villosa Extracts and Evaluation of Antioxidant, Antimicrobial and Anti-Quorum Sensing Potential

The biosynthesis of silver nanoparticles (AgNPs) from Diospyros villosa leaves and stem bark extracts is described. The stem bark AgNPs of D. villosa synthesized at 80 °C (S80) showed good scavenging activity with a lower IC50 value of 8.75 µg·mL−1 compared to ascorbic acid (9.58 µg·mL−1). The total phenol content of the S80 AgNPs was measured and found to be 10.22 ± 0.14 mg.g−1 gallic acid equivalence (GAE). Bacterial growth inhibition (% GI) and violacein inhibition (% VI) of 10.08% and 58.83%, respectively, was observed against C.subtsugae CV017 with leaf AgNPs synthesized at 80 °C (L80) at 80 μg·mL−1. Stem bark AgNPs synthesized at room temperature (SRT) also indicated % GI of 13.83% and % VI of 65.97% against C. subtsugae CV017 at 160 μg·mL−1. Leaf AgNPs of D. villosa synthesized at room temperature (LRT), showed % GI of 29.07% and % VI of 56.53%, respectively, against C. violaceum ATCC 12472 at 320 μg·mL−1. The L80 and SRT at 160 μg·mL−1 and LRT at 320 μg·mL−1 may be considered as potential QS inhibitors following their activity against C. subtsugae CV017 and C. violaceum ATCC 12472, respectively. Therefore, D. villosa represents a potential source of antioxidants as well as an anti-quorum sensing therapeutic candidate for the control of Gram-negative bacterial infections.

Modified Alginate Beads with Ethanol Extraction of Cratoxylum formosum and Polygonum odoratum for Antibacterial Activities

Bacteria contaminations in water are concerned as environmental effects including human health, so water treatment is required before use. Although using extracted plant is interesting because of their good chemical compounds for bacterial inhibitions, no study has applied the extracted plant in bead materials for disinfection in wastewater. The current research attempted to extract Cratoxylum formosum and Polygonum odoratum for the synthesis of C. formosum beads (CFB) and P. odoratum beads (POB), and their antibacterial efficiencies were investigated by agar diffusion tests, antibacterial batch tests, adsorption isotherm and kinetics, and material reusability. C. formosum and P. odoratum leaves were ethanol-extracted, and their bead materials (CFB and POB) were synthesized. Furthermore, their characterizations of surface area, chemical compositions, and chemical functional groups were investigated. For field emission scanning electron microscopy and focused ion beam (FESEM-FIB) analysis, CFB and POB had spherical shapes with coarse surfaces. Energy-dispersive X-ray spectrometry (EDX) analysis of CFB and POB illustrated five main chemical compositions, which were carbon (C), oxygen (O), calcium (Ca), chlorine (Cl), and sodium (Na), whereas Fourier transform infrared (FTIR) spectroscopy analysis identified seven main chemical functional groups, which were O-H, C-H, C=O, C=C, N-H, C-O, and C-Cl. Agar diffusion tests confirmed the abilities of CFB and POB to inhibit both Staphylococcus aureus and Escherichia coli, and batch experiments examined high antibacterial efficiencies of CFB of almost 100% on both bacterial types. The adsorption isotherm of CFB corresponded to the Freundlich model, which is related to the physiochemical adsorption process with multilayer or heterogeneous adsorption, and the adsorption kinetics of CFB was correlated to the pseudo-second-order kinetic model, which involved chemisorption relating to physiochemical interaction. Moreover, the desorption experiment confirmed the reusability of CFB. Therefore, CFB is a potential material to possibly apply for disinfection of wastewater.

Biosynthesized Silver Nanoparticles by Aqueous Stem Extract of Entada spiralis and Screening of Their Biomedical Activity

Silver nanoparticles (Ag-NPs) have been established as antibacterial nanoparticles and have been innovatively developed to overcome the occurrence of antibiotic resistance in the environment. In this study, an environmentally friendly and easy method of the biosynthesis of Ag-NPs plants, mediated by aqueous extract stem extract of Entada spiralis (E. spiralis), was successfully developed. The E. spiralis/Ag-NPs samples were characterized using spectroscopy and the microscopic technique of UV-visible (UV-vis), X-ray Diffraction (XRD), Field Emission Transmission Electron Microscope (FETEM), zeta potential, and Fourier Transform Infrared (FTIR) analyses. Surface Plasmon Resonance (SPR) absorption at 400-450 nm in the UV-vis spectra established the formation of E. spiralis/Ag-NPs. The crystalline structure of E. spiralis/Ag-NPs was displayed in the XRD analysis. The small size, around 18.49 ± 4.23 nm, and spherical shape of Ag-NPs with good distribution was observed in the FETEM image. The best physicochemical parameters on Ag-NPs biosynthesis using E. spiralis extract occurred at a moderate temperature (~52.0°C), 0.100 M of silver nitrate, 2.50 g of E. spiralis dosage and 600 min of stirring reaction time. The antibacterial activity was tested against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Proteus vulgaris using an antibacterial disk diffusion assay. Based on the results, it is evident that E. spiralis/Ag-NPs are susceptible to all the bacteria and has promising potential to be applied in both the industry and medical fields.

Inhibitory Effect of Eco-Friendly Naturally Synthesized Silver Nanoparticles from the Leaf Extract of Medicinal Detarium microcarpum Plant on Pancreatic and Cervical Cancer Cells

BACKGROUND

Recently, nanoparticle synthesis by eco-friendly methods has received tremendous attention due to the method advantages and also because of the application of the nanoparticles in cancer research. Therefore, in this study, we synthesized silver nanoparticles from Detarium microcarpum leaf phytochemicals and evaluated its inhibitory effect on pancreatic and cervical cancer cells.

MATERIALS AND METHODS

Silver nanoparticles (dAgNps) were synthesized by reacting phytochemicals of D. microcarpum leaves with silver nitrate for 12 hours. Cell viability assay was carried out to investigate the cytotoxic effect of dAgNps on HeLa and PANC-1 cells.

RESULTS

Scanning electron microscopy (SEM) and transmission electron microscopy(TEM) results revealed the average sizes of dAgNps are 81 nm and 84 nm respectively. The x-ray diffraction (XRD) pattern of dAgNps was similar to that of face centered cubic(fcc) structure of silver as reported by joint committee on powder diffraction standards (JCPDS) and fourier-transform infrared spectroscopy (FTIR) analysis showed that some phytochemicals of D. microcarpum such as polyphenols and flavonoids were likely involved in the reduction of Ag+ to form nanoparticles. Finally, cell viability assay revealed dAgNps inhibited PANC-1 and HeLa cell proliferations with IC50 values of 84 and 31.5 µg/ml respectively.

CONCLUSION

In conclusion, the synthesized nanoparticles from D. microcarpum leaves (dAgNps) have inhibitory effect on pancreatic and cervical cancer cells.

Incorporated plant extract fabricated silver/poly-D,l-lactide-co-glycolide nanocomposites for antimicrobial based wound healing

Polymeric nanocomposites have gained extensive attention in modern nanotechnology by reason of its design, flexibility, sole applications and lower life cycle costs. Preparation of composites using spreading of inorganic metal nanoparticles in organic polymeric matrices has plenty of scope and applications in the biomedical field. Poly-D,l-lactide-co-glycolide (PLGA) is an appreciated polymer for composites preparation because of its non-toxic and promising biodistribution. The consideration of metal nanoparticles has extended rapidly with the presence of new nanocomposites into a range of products and technologies. Compared to bulk materials the synthesized metal nanoparticles have unique character and biomedical uses due to its shape, size, and huge surface to volume ratio. Among different inorganic metal nanoparticles, silver nanoparticles (Ag NPs) have dominated in the biomedical field owing to its diverse potential applications including imaging, sensor, diagnosis and disease treatment. Further, medicinal plant extract mediated Ag NPs shown superior advantages and its antimicrobial based wound healing prospective has been established. However, not much information on plant extract mediated Ag NPs integrated PLGA nanocomposites wound healing applications. In the present review, we discussed necessity, preparation, characterization and antimicrobial based wound healing mechanism of incorporated plant extract mediated silver/PLGA nanocomposites.

Seasonal variation’s effect on antidiabetic activity of silver nanoparticles

The present work develops an eco-friendly protocol that was adopted to synthesize silver nanoparticles (AgNPs) from the aqueous extract of Corchorus depressus collected in three different seasons. Visually, the formation of AgNPs was confirmed by the change in the color of extracts to reddish brown and the AgNPs were further characterized by ultraviolet–visible studies of the absorption band at 435–450 nm that is due to surface plasmon resonance of AgNPs. The functional groups that behave as a reducing agent and those that act as a capping agent were determined by the FTIR. The particle size was determined by scanning electron microscopy and the amount of capping agents (organic contents at the surface of AgNPs) was estimated by thermogravimetric analysis. AgNPs showed a remarkable inhibitory activity against α-glucosidase compared to their respective aqueous extracts. Extraction of plant material collected in the month of January and their AgNP formation showed the smallest particle size of 4 ± 2 nm. Moreover, an augmented remarkable inhibitory activity against the carbohydrate-digesting enzyme α-glucosidase with IC50 of 2·48 ± 0·56 μg/ml was also observed compared to other extracts.

Microorganism Assisted Synthesized Nanoparticles for Catalytic Applications

Metal and metalloid nanoparticles (NPs) have attracted substantial attention from research communities over the past few decades. Traditional methodologies for NP fabrication have also been intensely explored. However, drawbacks such as the use of toxic agents and the high energy consumption involved in chemical and physical processes hinder their further application in various fields. It is well known that some bacteria are capable of binding and concentrating dissolved metal and metalloid ions, thereby detoxifying their environments. Bioinspired fabrication of NPs is environmentally friendly and inexpensive and requires only low energy consumption. Some biosynthesized NPs are usually used as heterogeneous catalysts in environmental remediation and show higher catalytic efficiency because of their enhanced biocompatibility, stability and large specific surface areas. Therefore, bacteria used as nanofactories can provide a novel approach for removing metal or metalloid ions and fabricating materials with unique properties. Even though a wide range of NPs have been biosynthesized, and their synthetic mechanisms have been proposed, some of these mechanisms are not known in detail. This review focuses on the synthesis and catalytic applications of NPs obtained using bacteria. The known mechanisms of bioreduction and prospects in the design of NPs for catalytic applications are also discussed.

Detarium microcarpum: A novel source of nutrition and medicine: A review

Detarium microcarpum is a plant indigenous to Africa, which occurs naturally in many African countries, particularly in savannah regions. Its leaves and fruits are used mainly as food and as folk medicine. It has anti-diabetic, antioxidant, and hepatitis C inhibitor properties and has been traditionally utilised in cancer treatment. This review examines published work on the nutritional, pharmacological, and traditional uses of Detarium microcarpum. This plant may become valuable if the fruit, stems, roots, and leaves are extracted for nutraceutical purposes.

Evaluation of antidiabetic activity of biologically synthesized silver nanoparticles using Pouteria sapota in streptozotocin-induced diabetic rats

BACKGROUND

Medicinal plants and green synthesis of silver nanoparticles (AgNPs) have proven to be good sources of agents effective in the treatment of diabetes mellitus. The present study focused on the green synthesis of AgNPs from the aqueous leaf extract of Pouteria sapota in order to evaluate the in vitro and in vivo antidiabetic properties of this extract and the synthesized AgNPs.

METHODS

The AgNPs were biologically synthesized under ambient conditions from an aqueous leaf extract of P. sapota using the hot percolation method and were characterized using spectroscopic methods, X-ray diffraction, and scanning electron microscopy. The in vitro antidiabetic activity of the aqueous leaf extract and AgNPs was confirmed by non-enzymatic glycosylation of hemoglobin, glucose uptake by yeast cells following exposure of cells to 5 or 10 mmol/L glucose solution, and inhibition of α-amylase. Further, in vivo antidiabetic activity was assessed in streptozotocin-induced rats. Rats were treated with aqueous leaf extract (100 mg/kg) or AgNPs (10 mg/kg) for 28 days. Following treatment, rats were killed for biochemical and histopathological analysis of kidney and liver samples.

RESULTS

A significant reduction in blood sugar levels was noted in rats treated with leaf extract or AgNPs. Results of in vitro and in vivo analyses in rats treated with leaf extract or AgNPs show that both the extract and the biologically synthesized AgNPs have antidiabetic activity.

CONCLUSION

The aqueous leaf extract of P. sapota and AgNPs exhibited efficient antidiabetic activity in the rat model of diabetes and therefore could have potential for development for medical applications in the future.