Phytosynthesis of Nickel Oxide Nanoparticles and Their Antioxidant and Antibacterial Efficacy Studies.

 Multidrug-resistant (MDR) bacteria are widely acknowledged as a significant and pressing public health concern. Tribulus terrestris has been used as a health tonic in traditional medicine since ancient Vedic times. It was also utilized to synthesize small, well-dispersed metal nanoparticles (NPs). The biosynthesized nickel oxide nanoparticles (NiO-NPs) have a broad spectrum of biomedical uses.  The objective of the research was to utilize a green synthesis method to synthesize NiO-NPs using Tribulus terrestris, subsequently characterize, and this study aimed to assess the antioxidant and antibacterial effectiveness of these NPs against wound isolates that are resistant to multiple drugs.  The synthesis of NiO-NPs was achieved through the titration method, which is a green synthesis approach, and it was characterized by using techniques such as ultraviolet-visible spectroscopy (UV), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and energy dispersive X-ray (EDX). The antioxidant activity of the NPs was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and antibacterial activity was done using the agar well diffusion method. IBM SPSS Statistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States) is used for statistical analysis.  The biosynthesized NiO-NPs exhibited a color change from dark brown to dark green, indicating the successful reduction of the NPs. UV analysis peaks were observed at 310-350 nm, while FT-IR analysis showed the peaks at various wavelengths such as 629.31cm-1 (halo compound; C-Br stretching), 957.80cm-1(aromatic phosphates; P-O-C stretch), 1004.65cm-1 (aliphatic phosphates; P-O-C stretch), 1094.93cm-1 (organic siloxane or silicone; Si-O-Si), 1328.38cm-1 (dialkyl/aryl sulfones), 1604.88cm-1 (open-chain azo-N=N-), 2928.68cm-1 (methylene C-H asym/sym stretch), 3268.65cm-1 (normal polymeric "OH" stretch). The crystallinity of the NPs was determined to be 24.7%, while the remaining 75.6% exhibited an amorphous structure. The SEM image revealed a spherically agglomerated structure of the nano-ranged size NiO-NPs. The EDX analysis indicated the presence of elemental compositions Ni (7.4%), O (39.4%), and C (53.3%) in the biosynthesized NiO-NPs. These NPs demonstrated significant antibacterial activity against Pseudomonas aeruginosa and Klebsiella pneumoniae, moderate antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), and the lowest antibacterial activity against Enterococcus faecalis.  Our in vitro results demonstrate that the biosynthesized NiO-NPs exhibit significant antioxidant and antibacterial activity. These NPs can be used as a future antimicrobial medication, particularly against MDR clinical wound isolates of K. pneumoniae, P. aeruginosa, and MRSA.

Suresh L ，Snega R ，Geetha Sravanthy P ，Saravanan M ... -  《Cureus》

One-Pot Synthesis of Silver/Zirconium Nanoparticles Using Sargassum tenerrimum for the Evaluation of Their Antibacterial and Antioxidant Activities.

The global health threat posed by worldwide antimicrobial resistance necessitated immediate multisectoral action by the scientific community to achieve sustainable development goals. Silver and zirconium nanoparticles (Ag/ZrO-NPs), known for their antimicrobial properties, have the potential to combat pathogens effectively, making them versatile for various applications across different fields.  This study aims to synthesize and characterize Sargassum tenerimum-mediated Ag/ZrO-NPs and evaluate their antioxidant and antibacterial efficacy against multidrug resistant (MDR) pathogens. The synthesis of Ag/ZrO-NPs using the one-pot green synthesis method was conducted and followed by using characterization techniques, namely, UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), and energy-dispersive X-ray analysis (EDX). The antibacterial activity was assessed using the agar well diffusion method, and antioxidant activity was determined using the DPPH(2,2-diphenyl-1-picrylhydrazyl) method. Statistical analysis was analyzed using the IBM SPSS Statistics for Windows, version 21.0 (released 2012, IBM Corp., Armonk, NY). The green-synthesized Ag/ZrO-NPs exhibited a color change from dark brown to creamy white, indicating the successful reduction of the nanoparticles. UV-analysis peaks were observed at 310-330 nm, while the FT-IR analysis showed the peaks at various wavelengths, such as 648.9 cm-1 (alkyne C-H bond), 1041.14 cm-1 (aliphatic fluoro compounds, C-F stretch), 1382.54 cm-1 (dimethyl -CH3), 1589.6 cm-1 (primary amine, N-H bond), and 3353.8 cm-1 (aliphatic secondary amine, N-H stretch). The crystallinity of the nanoparticles was determined to be 59.5%, while the remaining 40.5% exhibited an amorphous structure. The SEM image revealed the spherically agglomerated structure of the nano-ranged size Ag/ZrO-NPs. The EDX analysis indicated the presence of elemental compositions Zr (16.2%), Ag (18.8%), and C (28.7%) in the green-synthesized Ag/ZrO-NPs. These nanoparticles demonstrated significant antibacterial activity against Pseudomonas aeruginosa, Enterococcus faecalis, and Methicillin-resistant Staphylococcus aureus (MRSA). The moderate antibacterial activity against E. coli showed thesignificant antioxidant activity in a dose-dependent manner. The green-synthesized Ag/ZrO-NPs showed notable antibacterial and antioxidant activity. In future aspects, it may be used as a potential drug after completion of in-vivo and in-vitro studies.

Putluru S ，Snega R ，Geetha Sravanthy P ，Saravanan M ... -  《Cureus》

Green Synthesis of Molybdenum Nanoparticles From Solanum xanthocarpum and Evaluation of Their Antimicrobial and Antioxidant Activity Against Multidrug-Resistant Wound Isolates.

In recent years, antimicrobial drug resistance has emerged as a serious global public health concern, according to the World Health Organization data. The emergence of pathogens resistant to multiple drugs has been linked to an increase in morbidity and mortality from microbial infections. The study's main goal is to explore the efficacy of using Solanum xanthocarpum in the green synthesis of molybdenum nanoparticles (Mo NPs) for antibacterial and antioxidant properties. An eco-friendly method of synthesizing Mo NPs was accomplished using an aqueous extract of Solanum xanthocarpum. Characterization of the synthesized nanoparticles was done by UV-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). After that, antibacterial and antioxidant activity was further evaluated. The UV-visible spectrophotometer analysis confirmed the presence of synthesized Mo NPs showing a peak around 320 nm. The presence of functional compounds like C-CI, C-H, C=C, and O=C=O was confirmed by FT-IR spectrum analysis. The positions of diffraction peaks in Mo NP patterns were identified using XRD analysis; they were more crystalline (82.7%) and less amorphous (17.3%). The presence of the elements molybdenum (Mo), carbon (C), and oxygen (O) was confirmed by the EDX spectrum and irregular shapes shown in the SEM images. Further, the antimicrobial study results showed the formation of an inhibition zone against 27 mm for Klebsiella pneumoniae, 24 mm for Pseudomonas aeruginosa, 22 mm for Staphylococcus aureus, and 24 mm for Enterococcus faecalis, respectively, at a high concentration 80 μg/ml of Mo NPs. The maximum antioxidant activity at 100 μg/ml was 73.49%, compared to the standard ascorbic acid (74.25%). Additionally, the moderate activity at 60 μg/ml was 53.21%, compared to the standard (56.5%), and the minimal activity at 20 μg/ml was 30.21%, compared to the standard (36.89%). The environmentally friendly synthesized Mo NPs from Solanum xanthocarpum exhibited antioxidant activity. Furthermore, the findings show that Mo NPs mediated by Solanum xanthocarpum can inhibit antibiotic-resistant bacteria, especially methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecalis. In order to understand further how nanoparticles work against bacteria that are resistant to many drugs, additional research and clinical studies would be needed.

Bharathidasan P ，Surya M ，Geetha Sravanthy P ，Saravanan M ... -  《Cureus》

Green synthesis of cerium oxide nanoparticles usingTribulus terrestris: characterization and evaluation of antioxidant, anti-inflammatory and antibacterial efficacy against wound isolates.

Multi-drug resistance (MDR) infections are a significant global challenge, necessitating innovative and eco-friendly approaches for developing effective antimicrobial agents. This study focuses on the synthesis, characterization, and evaluation of cerium oxide nanoparticles (CeO2NPs) for their antioxidant, anti-inflammatory, and antibacterial properties. The CeO2NPs were synthesized using aTribulus terrestrisaqueous extract through an environmentally friendly process. Characterization techniques included UV-visible spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), x-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive x-ray (EDX) analysis. The UV-vis spectroscopy shows the presence of peak at 320 nm which confirms the formation of CeO2NPs. The FT-IR analysis of the CeO2NPs revealed several distinct functional groups, with peak values at 3287, 2920, 2340, 1640, 1538, 1066, 714, and 574 cm-1. These peaks correspond to specific functional groups, including C-H stretching in alkynes and alkanes, C=C=O, C=C, alkanes, C-O-C, C-Cl, and C-Br, indicating the presence of diverse chemical bonds within the CeO2NPs. XRD revealed that the nanoparticles were highly crystalline with a face-centered cubic structure, and SEM images showed irregularly shaped, agglomerated particles ranging from 100-150 nm. In terms of biological activity, the synthesized CeO2NPs demonstrated significant antioxidant and anti-inflammatory properties. The nanoparticles exhibited 82.54% antioxidant activity at 100 μg ml-1, closely matching the 83.1% activity of ascorbic acid. Additionally, the CeO2NPs showed 65.2% anti-inflammatory activity at the same concentration, compared to 70.1% for a standard drug. Antibacterial testing revealed that the CeO2NPs were particularly effective against multi-drug resistant strains, includingPseudomonas aeruginosa,Enterococcus faecalis, and MRSA, with moderate activity againstKlebsiella pneumoniae. These findings suggest that CeO2NPs synthesized viaT. terrestrishave strong potential as antimicrobial agents in addressing MDR infections.

Choudary MRP ，Surya M ，Saravanan M 《Biomedical Physics & Engineering Express》

Green Synthesis of Aluminum Oxide Nanoparticles Using Clerodendrum phlomidis and Their Antibacterial, Anti-inflammatory, and Antioxidant Activities.

 Clerodendrum phlomidis plays a significant role in many indigenous medical systems, and it can be mostly found in Southeast Asia. The objective of the study was to synthesize and characterize the biosynthesized aluminum oxide nanoparticles (AlO-NPs) using C. phlomidis and analyze their antibacterial (bactericidal), antioxidant, and anti-inflammatory activities. The extract was prepared by the autoclave-assisted method, and the AlO-NPs were synthesized by the green synthesis method. The biosynthesized AlO-NPs were characterized by ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray (EDX) analysis. The antibacterial property was assessed by the Kirby-Bauer well diffusion method, and the antioxidant activity was checked by DPPH (2,2-diphenyl-1-picrylhydrazyl) activity compared with the control L-ascorbic acid. Anti-inflammatory activity was evaluated by an albumin denaturation assay, and diclofenac was used as a control. IBM SPSS Statistics for Windows, Version 21.0 was used for the statistical analysis.  Results: An absorption peak at a wavelength of 380 nm was detected by UV-Vis spectroscopy analysis. It proves that AlO-NPs have been successfully produced by the green synthesis method. The results of the FT-IR study demonstrated the existence of numerous chemicals and functional groups in the 500-3500 cm-1 range. AlO-NPs from the plant extract were subjected to FE-SEM analysis, which revealed an aggregated or spherically cluster-like structure. The sample's elemental makeup, which revealed that it included 38% aluminum and 28% oxygen, was identified with the help of the EDX, and this verified the high purity of the AlO-NPs. The results of the antibacterial activity of AlO-NPs revealed that there was a zone of inhibition for Enterococcus faecalis; however, there was no zone of inhibition for Streptococcus mutans. The synthesized AlO-NPs exhibit strong antioxidative (DPPH activity) and anti-inflammatory (albumin denaturation assay) action. In this work, the in vitro antioxidant activity of C. phlomidis was assessed using the standard, L-ascorbic acid, as a measure of DPPH activity. At a maximum concentration of 500 µg/ml, the obtained results showed the incredible antioxidant properties of the investigated AlO-NPs synthesized from the plant extracts and demonstrated 90% inhibition. AlO-NPs that were biosynthesized showed effective anti-inflammatory activity at a higher concentration of 100 µg/ml and demonstrated 89% inhibition in contrast to the drug diclofenac sodium. According to the study's findings, AlO-NPs made using a greener synthesis approach have the potential to be used in a variety of industries and are also an affordable and sustainable way to effectively act as anti-inflammatory and antioxidant agents.

Thanaraj S ，Mitthun ANK ，Geetha Sravanthy P ，Carmelin DS ，Surya M ，Saravanan M ... -  《Cureus》