Silver nanoparticle biosynthesis utilizing Ocimum kilimandscharicum leaf extract and assessment of its antibacterial activity against certain chosen bacteria

The use of plants in the biological production of silver nanoparticles for antibacterial applications is a growing field of research. In the current work, we formulated Ocimum kilimandscharicum extracts using silver nanoparticles, and evaluated its potential antibacterial activity. Aqueous and methanol plant extracts were used to reduce silver nitrate at different time intervals (30 to 150 minutes) and pH (2 to 11). The UV-visible absorption spectrum recorded for methanol and aqueous extracts revealed a successful synthesis of AgNPs for methanol and aqueous extracts. The antimicrobial activity of the AgNPs was evaluated against Escherichia coli ATCC 25922, Salmonella choleraesuius ATCC 10708, and Staphylococcus aureus ATCC 25923 The best inhibition zone for the methanol and aqueous-mediated AgNPs, ranging from 12 ± 1 to 16 ± 1mm. Additionally, the methanol and aqueous extract silver nanoparticles had the same Minimum Inhibitory Concentration (6.25 ± 0.00 mg/ml), whereas the Minimum Bactericidal Concentrations were 12.5 ± 0.00 and 25 ± 0.00 mg/ml, respectively. The highest inhibition zone of 16 ± 1 mm was observed against Salmonella choleraesuius with 50 ± 0.00 mg/ml aqueous silver nanoparticles. The results show that the silver nanoparticles made with Ocimum kilimandscharicum have antibacterial action against those microorganisms.

Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Catharanthus roseus Extract: A Novel Approach

BACKGROUND

Nanotechnology enables precise manipulation of matter at the molecular level, with nanoparticles offering diverse applications in medicine and beyond. Green synthesis methods, utilizing natural sources like plant extracts, are favored for their eco-friendliness. Zinc oxide (ZnO) nanoparticles are recognized for their ability to combat microbes and reduce inflammation, which holds promise for biomedical applications. Catharanthus roseus, renowned for its medicinal properties, warrants further exploration in oral health management due to its anti-inflammatory and antioxidant attributes.

AIM

The current study aimed to synthesize Catharanthus roseus-mediated ZnO nanoparticles and to evaluate their anti-inflammatory and antioxidant activity.

MATERIALS AND METHODS

Catharanthus roseus powder (1 g) was dissolved in distilled water (100 ml), heated at 60°C for 15-20 minutes, and filtered to obtain 20 ml extract. ZnO nanoparticles were synthesized by adding 0.594 g ZnO powder to 50 ml water, mixed with plant extract, and stirred for 72 hours, and the resulting solution was centrifuged. Nanoparticles were collected and analyzed for Fourier-transform infrared spectroscopy (FTIR) using Bruker's Alpha II FTIR spectrometer (Bruker, Billerica, Massachusetts, United States), antioxidant, and anti-inflammatory activities.

RESULTS

FTIR analysis revealed characteristic peaks indicative of functional groups present in Catharanthus roseus-mediated ZnO nanoparticles, including O-H, N-O, C-O, C=C, and C≡C-H. Anti-inflammatory activity evaluation showed inhibition ranging from 48% to 89%, with the maximum inhibition at 50 μL concentration. Similarly, antioxidant activity ranged from 62% to 88%, with the maximum inhibition also seen at 50 μL concentration.

CONCLUSION

Both assays effectively showcased the superior anti-inflammatory and antioxidant activity of the Catharanthus roseus-incorporated ZnO nanoparticles extract compared to the control. This suggests their potential as a viable therapeutic agent for further evaluation.

In-Vivo Bactericidal Potential of Mangifera indica Mediated Silver Nanoparticles against Aeromonas hydrophila in Cirrhinus mrigala

The present study reports the green synthesis of silver nanoparticles from leaves' extract of Mangifera indica (M. indica) and their antibacterial efficacy against Aeromonas hydrophila (A. hydrophila) in Cirrhinus mrigala (C. mrigala). The prepared M. indica mediated silver nanoparticles (Mi-AgNPs) were found to be polycrystalline in nature, spherical in shapes with average size of 62 ± 13 nm. C. mrigala (n = ±15/group) were divided into six groups i.e., G1: control, G2: A. hydrophila challenged, G3: A. hydrophila challenged + Mi-AgNPs (0.01 mg/L), G4: A. hydrophila challenged + Mi-AgNPs (0.05 mg/L), G5: A. hydrophila challenged + Mi-AgNPs (0.1 mg/L) and G6: A. hydrophila challenged + M. indica extract (0.1 mg/L). Serum biochemical, hematological, histological and oxidative biomarkers were evaluated after 15 days of treatment. The liver enzyme activities, serum proteins, hematological parameters and oxidative stress markers were found to be altered in the challenged fish but showed retrieval effects with Mi-AgNPs treatment. The histological analysis of liver, gills and kidney of the challenged fish also showed regaining effects following Mi-AgNPs treatment. A CFU assay from muscle tissue provided quantitative data that Mi-AgNPs can hinder the bacterial proliferation in challenged fish. The findings of this work suggest that M. indica based silver nanoparticles can be promising candidates for the control and treatment of microbial infections in aquaculture.

Biosynthesis, characterization and anthelmintic activity of silver nanoparticles of Clerodendrum infortunatum isolate

Over the past few decades, the green synthesis of nanoparticles has gained importance for their therapeutic efficacy and eco-friendly nature. Integrating green chemistry principles into multidisciplinary nanoscience research has paved the way for developing environmentally benign and sustainable methods for synthesizing gold and silver nanoparticles. In the present study, the flowers obtained from Clerodendrum infortunatum (L.), belonging to the family Verbenaceae, have been used for biosynthesizing silver nanoparticles (AgNPs) to evaluate the anthelmintic potential. UV-Vis spectroscopy, XRD, FTIR, SEM and TEM analyses were performed to ascertain the formation of AgNPs. Clerodendrum-derived AgNP (CLE-AgNP) has significantly affected the normal physiological functions of the poultry parasite Raillietina spp., a menace to the livestock industry. Our study manifests that CLE-AgNPs cause considerable distortion of the surface tegument of this cestode parasite leading to changes in the host-parasite interface. The histochemical localization studies of the tegument-associated enzymes viz. AcPase, AlkPase, ATPase and 5'-Nu, exposed to the drug, showed a substantial activity decline, thus establishing the anthelmintic potential of the CLE-AgNPs.

Effect of size on physicochemical, antibacterial, and catalytic properties of Neolamarckia cadamba (burflower-tree) synthesized silver/silver chloride nanoparticles

Aqueous extract of Neolamarchia cadamba leaves were used in the synthesis of silver/silver chloride nanoparticles (Ag/AgCl NPs). Further they were separated based on their using step-wise centrifugation approach at 09,000, 12,000, and 15,000 rpm. Thus obtained NPs were characterized for their physicochemical features. NPs showed maximum absorbance at 455 nm, 415 nm, and 402 nm. All the NPs were found to be crystalline in nature with average crystallite size (nm) of 58.31, 23.43, and 09.56. Particle size distribution (nm) of NPs was observed to 435.43, 276.75, and 105.49, Surface charge (-mV) of NPs was observed to be 14.59, 23.90, and 32.17. Ag/AgCl NPs-rpm@15,000 showed antibacterial activity against Escherichia coli, coagulase-negative Staphylococci, and Staphylococcus aureus with zone of inhibition (mm) of 16.65, 13.69, and 14.02 at 50 µg per well, respectively. Ag/AgCl NPs-rpm@15,000 showed excellent catalytic activity in degradation of methyl red, methylene blue, rhodamine-B, and methyl orange dyes in the presence of sodium borohydride under 4, 6, 5, and 4 min with pseudo-first order rate constant (min^-1) of 0.981 (96.4%), 0.666 (97.1%), 0.905 (98.1%), and 1.032 (96.6%), respectively. Furthermore, Ag/AgCl NPs-rpm@15,000 showed good catalytic efficiency even under different dye combinations. Total combination was degraded under 18 min.

Comparative assessment of the biological activity of the green synthesized silver nanoparticles and aqueous leaf extract of Perilla frutescens (L.)

Green synthesized nanoparticles (GSNPs) display fascinating properties compared to physical and chemical synthesized ones. GSNPs are currently used in numerous applications such as food packaging, surface coating agents, environmental remediation, antimicrobial, and medicine. In the present study, the aqueous leaf extract of Perilla frutescens L. having suitable capping, reducing, and stabilizing compounds was used for green synthesis of silver nanoparticles (Pf-AgNPs). The bioreductant capacity of aqueous leaf extract of P. frutescens for Pf-AgNPs was determined by different confirmatory techniques including UV-Visible spectroscopy, XRD, FESEM, EDX, zeta potential, DLS, SERS, and FTIR analysis. The results exhibited that Pf-AgNPs had optimal size (< 61 nm), shape (spherical), and stability (- 18.1 mV). The antioxidant activity of Pf-AgNPs with both DPPH and FRAP assays was significantly higher compared to P. frutescens extract. Furthermore, Pf-AgNPs had high antimicrobial activity against Escherichia coli and Staphylococcus aureus (MIC = 0.78 mg/mL), and Candida albicans (MIC = 8 mg/mL) while the plant extract showed low antimicrobial activity against both bacterial strains and the fungus tested. Pf-AgNPs and P. frutescens extract also exhibited moderate toxicity on MCF-7 cancer cells with IC₅₀ values of 346.2 and 467.4 µg/mL, respectively. The results provide insights into using the biosynthesized Pf-AgNPs as an eco-friendly material for a wide range of biomedical applications.

Novel Biocompatible Green Silver Nanoparticles Efficiently Eliminates Multidrug Resistant Nosocomial Pathogens and Mycobacterium Species

Bacterial infection is a major crisis of 21st era and the emergence of multidrug resistant (MDR) pathogens cause significant health problems. We developed, green chemistry-based silver nanoparticles (G-Ag NPs) using Citrus pseudolimon fruit peel extract. G-Ag NPs has a spherical shape in the range of ~ 40 nm with a surface charge of - 31 Mv. This nano-bioagent is an eco-friendly tool to combat menace of MDR. Biochemical tests prove that G-Ag NPs are compatible with human red blood cells and peripheral blood mononuclear cells. There have been many reports on the synthesis of silver nanoparticles, but this study suggests a green technique for making non-cytotoxic, non-hemolytic organometallic silver nanoparticles with a high therapeutic index for possible use in the medical field. On the same line, G-Ag NPs are very effective against Mycobacterium sp. and MDR strains including Escherichia coli, Klebsiella species, Pseudomonas aeruginosa, and Acinetobacter baumannii isolated from patient samples. Based on it, we filed a patent to Indian Patent Office (reference no. 202111048797) which can revolutionize the prevention of biomedical device borne infections in hospital pre/post-operated cases. This work could be further explored in future by in vivo experimentation with mice model to direct its possible clinical utility.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-023-01061-0.

New frontiers of invasive plants for biosynthesis of nanoparticles towards biomedical applications: A review

Above 1000 invasive species have been growing and developing ubiquitously on Earth. With extremely vigorous adaptability, strong reproduction, and spreading powers, invasive species have posed an alarming threat to indigenous plants, water quality, soil, as well as biodiversity. It was estimated that an economic loss of billions of dollars or equivalent to 1 % of gross domestic product as a consequence of lost crops, control efforts, and damage costs caused by invasive plants in the United States. While eradicating invasive plants from the ecosystems is practically infeasible, taking advantage of invasive plants as a sustainable, locally available, and zero-cost source to provide valuable phytochemicals for bionanoparticles fabrication is worth considering. Here, we review the harms, benefits, and role of invasive species as important botanical sources to extract natural compounds such as piceatannol, resveratrol, and quadrangularin-A, flavonoids, and triterpenoids, which are linked tightly to the formation and application of bionanoparticles. As expected, the invasive plant-mediated bionanoparticles have exhibited outstanding antibacterial, antifungal, anticancer, and antioxidant activities. The mechanism of biomedical activities of the invasive plant-mediated bionanoparticles was insightfully addressed and discussed. We also expect that this review not only contributes to efforts to combat invasive plant species but also opens new frontiers of bionanoparticles in the biomedical applications, therapeutic treatment, and smart agriculture.

Biogenic Synthesis of Silver Nanoparticles Using Catharanthus roseus and Its Cytotoxicity Effect on Vero Cell Lines

Background: Type 2 diabetes mellitus (DM2) is a chronic and sometimes fatal condition which affects people all over the world. Nanotherapeutics have shown tremendous potential to combat chronic diseases—including DM2—as they enhance the overall impact of drugs on biological systems. Greenly synthesized silver nanoparticles (AgNPs) from Catharanthus roseus methanolic extract (C. AgNPs) were examined primarily for their cytotoxic and antidiabetic effects. Methods: Characterization of C. AgNPs was performed by UV−vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and atomic force microscopy (AFM). The C. AgNPs were trialed on Vero cell line and afterwards on an animal model (rats). Results: The C. AgNPs showed standard structural and functional characterization as revealed by FTIR and XRD analyses. The zetapotential analysis indicated stability while EDX analysis confirmed the formation of composite capping with Ag metal. The cytotoxic effect (IC50) of C. AgNPs on Vero cell lines was found to be 568 g/mL. The animal model analyses further revealed a significant difference in water intake, food intake, body weight, urine volume, and urine sugar of tested rats after treatment with aqueous extract of C. AgNPs. Moreover, five groups of rats including control and diabetic groups (NC1, PC2, DG1, DG2, and DG3) were investigated for their blood glucose and glycemic control analysis. Conclusions: The C. AgNPs exhibited positive potential on the Vero cell line as well as on experimental rats. The lipid profile in all the diabetic groups (DG1-3) were significantly increased compared with both of the control groups (p < 0.05). The present study revealed the significance of C. AgNPs in nanotherapeutics.

Remediation of heavy metal(loid) contaminated soil through green nanotechnology

Modern industrialization is progressively degrading soil quality due to heavy metal contamination. Heavy metal (HM) contamination of agricultural soil has gained considerable attention due to its rapidly increasing levels. Nanoparticles (NPs) have unique physicochemical properties that make them effective stress relievers. Material science has recently been emphasizing “green” synthesis as a reliable, environmentally friendly, and sustainable method of synthesizing different kinds of materials, such as alloys, metal oxides, hybrids, and bioinspired materials. Therefore, green synthesis can be viewed as an effective tool to reduce the detrimental effects of the traditional nanoparticle synthesis methods commonly used in laboratories and industries. The review briefly describes the biosynthesis of NPs, the use of nanobiotechnology to remediate heavy metal-contaminated soil, the effect that NPs have on growth and development of plants, the behavior of NPs within plants when exposed to pollutants and the mechanisms used to alleviate HM stress. In addition, a broad overview of the major types of nanomaterials used so far in bioremediation of toxic heavy materials, recent advances regarding HM stress and the possible mechanisms by which NPs and HM interact in the agricultural system are also discussed.

Non-Thermal Plasma Reduction of Ag+ Ions into Silver Nanoparticles in Open Atmosphere under Statistically Optimized Conditions for Biological and Photocatalytic Applications

An environmentally friendly non-thermal DC plasma reduction route was adopted to reduce Ag+ ions at the plasma−liquid interface into silver nanoparticles (AgNPs) under statistically optimized conditions for biological and photocatalytic applications. The efficiency and reactivity of AgNPs were improved by statistically optimizing the reaction parameters with a Box−Behnken Design (BBD). The size of the AgNPs was chosen as a statistical response parameter, while the concentration of the stabilizer, the concentration of the silver salt, and the plasma reaction time were chosen as independent factors. The optimized parameters for the plasma production of AgNPs were estimated using a response surface methodology and a significant model p < 0.05. The AgNPs, prepared under optimized conditions, were characterized and then tested for their antibacterial, antioxidant, and photocatalytic potentials. The optimal conditions for these three activities were 3 mM of stabilizing agent, 5 mM of AgNO3, and 30 min of reaction time. Having particles size of 19 to 37 nm under optimized conditions, the AgNPs revealed a 82.3% degradation of methyl orange dye under UV light irradiation. The antibacterial response of the optimized AgNPs against S. aureus and E. coli strains revealed inhabitation zones of 15 mm and 12 mm, respectively, which demonstrate an antioxidant activity of 81.2%.

Phytoantioxidant Functionalized Nanoparticles: A Green Approach to Combat Nanoparticle-Induced Oxidative Stress

Nanotechnology is gaining significant attention, with numerous biomedical applications. Silver in wound dressings, copper oxide and silver in antibacterial preparations, and zinc oxide nanoparticles as a food and cosmetic ingredient are common examples. However, adverse effects of nanoparticles in humans and the environment from extended exposure at varied concentrations have yet to be established. One of the drawbacks of employing nanoparticles is their tendency to cause oxidative stress, a significant public health concern with life-threatening consequences. Cardiovascular, renal, and respiratory problems and diabetes are among the oxidative stress-related disorders. In this context, phytoantioxidant functionalized nanoparticles could be a novel and effective alternative. In addition to performing their intended function, they can protect against oxidative damage. This review was designed by searching through various websites, books, and articles found in PubMed, Science Direct, and Google Scholar. To begin with, oxidative stress, its related diseases, and the mechanistic basis of oxidative damage caused by nanoparticles are discussed. One of the main mechanisms of action of nanoparticles was unearthed to be oxidative stress, which limits their use in humans. Secondly, the role of phytoantioxidant functionalized nanoparticles in oxidative damage prevention is critically discussed. The parameters for the characterization of nanoparticles were also discussed. The majority of silver, gold, iron, zinc oxide, and copper nanoparticles produced utilizing various plant extracts were active free radical scavengers. This potential is linked to several surface fabricated phytoconstituents, such as flavonoids and phenols. These phytoantioxidant functionalized nanoparticles could be a better alternative to nanoparticles prepared by other existing approaches.