Biosynthesis of ZnO Nanoparticles Using Capsicum chinense Fruit Extract and Their In Vitro Cytotoxicity and Antioxidant Assay

Exploring the Biomedical Frontiers of Plant-Derived Nanoparticles: Synthesis and Biological Reactions

As contemporary technology advances, scientists are striving to identify new approaches to managing several diseases. Compared to the more popular physiochemical synthesis, the plant-derived combination of metallic nanoparticles using plant secondary metabolites as a precursor has a number of benefits, including low expenses, low energy consumption, biocompatibility, and medicinal usefulness. This study intends to explore the impacts of using plant-derived synthetic materials including metallic nanoparticles (NPs), emphasizing the benefits of their broad use in next-generation treatments for cancer, diabetes, Alzheimer's, and vector diseases. This comprehensive analysis investigates the potential of plant-derived remedies for diseases and looks at cutting-edge nanoformulation techniques aimed at addressing the function of the nanoparticles that accompany these organic substances. The purpose of the current review is to determine how plant extracts contribute to the synthesis of Silver nanoparticles (AgNPs), Gold nanoparticles (GtNPs), and platinum nanoparticles (PtNPs). It provides an overview of the many phytocompounds and their functions in biomedicine, including antibacterial, antioxidant, anticancer, and anti-inflammatory properties. Furthermore, this study placed a special focus on a range of applications, including drug delivery systems, diagnostics and therapy, the present benefits of nanoparticles (NPs), their biomedical uses in medical technology, and their toxicities.

Phytochemical Profile, Antioxidant and Cytotoxic Potential of Capsicum annuum (L.) Dry Hydro-Ethanolic Extract

Capsicum annuum (L.) is one of the essential spices most frequently used in our daily routine and has remarkable ethnobotanical and pharmacological properties. Its fruits are rich in vitamins, minerals, carotenoids, and numerous other phenolic metabolites with a well-known antioxidant activity. Regular consumption of chili fruits may have a positive influence on human health. Therefore, we investigated a commercially available chili fruit powder in the present study, extracting it with 50% ethanol. The dried hydro-ethanolic extract (CAE) was thoroughly analyzed using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS/MS), and 79 bioactive phenolic constituents were identified. Then, we quantified the main phenolic compounds and found a polyphenol content of 4.725 ± 1.361 mg Eq tannic acid/100 g extract and a flavonoid amount of 1.154 ± 0.044 mg Eq rutin/100 g extract. Phenolic secondary metabolites are known for their dual redox behavior as antioxidants/pro-oxidants, underlying their numerous benefits in health and disease. Thus, the antioxidant potential of CAE was evaluated using three methods; our results could explain the protective effects of chili fruits: IC50DPPH = 1.669 mg/mL, IC50ABTS = 0.200 mg/mL, and EC50FRAP = 0.561 mg/mL. The pro-oxidant potential of phenolic compounds could be a basis for CAE cytotoxicity, investigated in vitro on tumor cell lines and in vivo on Daphnia sp. Results demonstrated the dose- and time-dependent CAE's cytotoxic activity; the highest antiproliferative activity was recorded on colon (LoVo) and breast (MDA-MB-231) cancer cell lines after 48 h of exposure (IC50 values < 200 µg/mL). In vivo testing on Daphnia sp. reported a potent CAE cytotoxicity after 48 h and embryonic developmental delays. Extensive data analyses support our results, showing a significant correlation between the CAE's concentration, phenolic compound content, antioxidant activity, exposure time, and the viability rate of different tested cell lines.

Biosorption of Escherichia coli Using ZnO-Trimethyl Chitosan Nanocomposite Hydrogel Formed by the Green Synthesis Route

In this study, we tested the biosorption capacity of trimethyl chitosan (TMC)-ZnO nanocomposite (NC) for the adsorptive removal of Escherichia coli (E. coli) in aqueous suspension. For the formation of ZnO NPs, we followed the green synthesis route involving Terminalia mantaly (TM) aqueous leaf extract as a reducing agent, and the formed ZnO particles were surface-coated with TMC biopolymer. On testing of the physicochemical characteristics, the TM@ZnO/TMC (NC) hydrogel showed a random spherical morphology with an average size of 31.8 ± 2.6 nm and a crystal size of 28.0 ± 7.7 nm. The zeta potential of the composite was measured to be 23.5 mV with a BET surface area of 3.01 m² g^-1. The spectral profiles of TM@ZnO/TMC NC hydrogel on interaction with Escherichia coli (E. coli) revealed some conformational changes to the functional groups assigned to the stretching vibrations of N-H, C-O-C, C-O ring, and C=O bonds. The adsorption kinetics of TM@ZnO/TMC NC hydrogel revealed the pseudo-second-order as the best fit mechanism for the E. coli biosorption. The surface homogeneity and monolayer adsorption of the TM@ZnO/TMC NC hydrogel reflects majorly the entire adsorption mechanism, observed to display the highest correlation for Jovanovic, Redlich-Peterson, and Langmuir's isotherm models. Further, with the use of TM@ZnO/TMC NC hydrogel, we measured the highest adsorption capacity of E. coli to be 4.90 × 10 mg g^-1, where an in-depth mechanistic pathway was proposed by making use of the FTIR analysis.

Removal of hydrocarbons and heavy metals from petroleum water by modern green nanotechnology methods

Considered heavy metals, such as As(III), Bi(II), Cd(II), Cr(VI), Mn(II), Mo(II), Ni(II), Pb(II), Sb(III), Se(-II), Zn(II), and contaminating chemical compounds (monocyclic aromatic hydrocarbons such as phenolic or polycyclic derivatives) in wastewater (petrochemical industries: oil and gas production plants) are currently a major concern in environmental toxicology due to their toxic effects on aquatic and terrestrial life. In order to maintain biodiversity, hydrosphere ecosystems, and people, it is crucial to remove these heavy metals and polluting chemical compounds from the watery environment. In this study, different Nanoparticles (α-Fe₂O₃, CuO, and ZnO) were synthesized by green synthesis method using Portulaca oleracea leaf extract and characterized by UV-Vis spectrophotometers, FTIR spectroscopy, X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) techniques in order to investigate morphology, composition, and crystalline structure of NPs, these were then used as adsorbent for the removal of As(III), Bi(II), Cd(II), Cr(VI), Mn(II), Mo(II), Ni(II), Pb(II), Sb(III), Se(-II), and Zn(II) from wastewater, and removal efficiencies of were obtained 100% under optimal conditions.

Green Fabrication, Characterization of Zinc Oxide Nanoparticles Using Plant Extract of Momordica charantia and Curcuma zedoaria and Their Antibacterial and Antioxidant Activities

In recent years, the rapid increase in the resistance of microorganisms to antibiotics has produced major health issues. Novel applications for these compounds have been developed by integrating modern technologies such as nanotechnology and material science with the innate antibacterial activity of metals. The current study demonstrated the synthesis of zinc oxide nanoparticles (ZnO NPs) from Momordica charantia and Curcuma zedoaria plant extracts, as well as their antibacterial properties. The synthesis of ZnO NPs was confirmed via UV-visible spectroscopy, showing clear peaks at 375 and 350 nm for M. charantia and C. zedoaria, respectively. Scanning electron microscopy (SEM) analysis revealed crystals of irregular shapes for the majority of the nanoparticles synthesized from both plants. The existence of ZnO NPs was confirmed using X-ray diffraction while the particle size was calculated using Scherrer's equation, which was 19.65 for C. zedoaria and 17.02 for M. charantia. Different functional groups were detected through Fourier transform infrared spectroscopy analysis. The antibacterial activity of the ZnO NPs at three different concentrations (250, 500, and 1000 µg/ml) was assessed against three different bacterial strains, i.e., Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa), using disc diffusion methods. The ZnO nanoparticles showed promising antibacterial activity against bacterial strains. For C. zedoaria, the highest growth inhibition was observed at a concentration of 1000 µg/ml, which was 18, 19, and 18 mm as compared to antibiotics (15, 11, and 15.6 mm) against E. coli, P. aeruginosa, and S. aureus, respectively. Similarly, at 1000 µg/ml of NPs, M. charantia showed the highest growth inhibition (18, 15, and 17 mm) as compared to antibiotics (15, 11, and 14.6 mm) against E. coli, P. aeruginosa, and S. aureus, respectively. In conclusion, compared to pure plant extract and antibiotics, ZnO NPs at a higher concentration (1000 µg/ml) exhibited a significant difference in zone of inhibition against all the bacterial strains. Different concentrations of ZnO using M. charantia and C. zedoaria caused increments in the scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The nanoparticles extracted using C. zedoaria exhibited higher antioxidant activity than M. charantia. Greenly synthesized ZnO nanoparticles have remarkable antibacterial properties and antioxidant activity, making them a promising contender for future pharmaceutical application.