Antibacterial Potential of Gold Nanoparticles Synthesized From Leaf Extract of Syzygium cumini Against Multidrug-Resistant Urinary Tract Pathogens

Metallic nanoparticles: a promising novel therapeutic tool against antimicrobial resistance and spread of superbugs

In recent years, antimicrobial resistance (AMR) has become an alarming threat to global health as notable increase in morbidity and mortality has been ascribed to the emergence of superbugs. The increase in microbial resistance because of harboured or inherited resistomes has been complicated by the lack of new and effective antimicrobial agents, as well as misuse and failure of existing ones. These problems have generated severe and growing public health concern, due to high burden of bacterial infections resulting from scarce financial resources and poor functioning health systems, among others. It is therefore, highly pressing to search for novel and more efficacious alternatives for combating the action of these super bacteria and their infection. The application of metallic nanoparticles (MNPs) with their distinctive physical and chemical attributes appears as promising tools in fighting off these deadly superbugs. The simple, inexpensive and eco-friendly model for enhanced biologically inspired MNPs with exceptional antimicrobial effect and diverse mechanisms of action againsts multiple cell components seems to offer the most promising option and said to have enticed many researchers who now show tremendous interest. This synopsis offers critical discussion on application of MNPs as the foremost intervening strategy to curb the menace posed by the spread of superbugs. As such, this review explores how antimicrobial properties of the metallic nanoparticles which demonstrated considerable efficacy against several multi-drugs resistant bacteria, could be adopted as promising approach in subduing the threat of AMR and harvoc resulting from the spread of superbugs.

A Comprehensive Review on Exploring the Potential of Phytochemicals and Biogenic Nanoparticles for the Treatment of Antimicrobial-Resistant Pathogenic Bacteria

Antimicrobial resistance (AMR) is an escalating global health concern that results in approximately 700,000 deaths annually owing to drug-resistant infections. It compromises the effectiveness of conventional antibiotics, as well as fundamental medical procedures, such as surgery and cancer treatment. Phytochemicals, natural plant constituents, and biogenic nanoparticles synthesized through biological processes are pharmacological alternatives for supplementing or replacing traditional antibiotics. These natural compounds exhibit a diverse range of bioactive properties, including antibacterial, anti-inflammatory, and antioxidant activities, and have the potential to overcome bacterial resistance mechanisms. However, their limited solubility, bioavailability, and stability have limited their therapeutic potential. Nanotechnology, particularly the utilization of biogenic nanoparticles, offers the potential to overcome these limitations by enhancing the biosafety, stability, and controlled release of phytochemical compounds, thereby enabling a more effective combination of resistant pathogens. This review examines current research on the combinatorial application of phytochemicals and biogenic nanoparticles, with emphasis on their capacity to address AMR. This study presents a novel perspective on the concurrent utilization of phytochemicals and biogenic nanoparticles, which may enhance antibacterial efficacy while mitigating toxicity. This review provides specific and innovative insights into the novelty, sustainability, and eco-friendly aspects of these approaches to address multidrug-resistant infections, highlighting their role in emerging as a transformative strategy for AMR management through the integration of natural and biogenic resources.

Bio-Inspired Synthesis of Gold Nanoparticles Using Leaf Extract of Jamun and Research on Its Biomedical Potential

Background

Bio-based synthesis of metallic nanoparticles has garnered much attention in recent times owing to their non-toxic, environmentally friendly, and cost-effective nature.

Methods

In this study, gold nanoparticles (S4-GoNPs) were synthesized by a simple and environmentally friendly technique using an aqueous extract of jamun leaves (JLE) as an effective capping, stabilizer, and reducing agent. JLE was screened for the presence of phytochemicals followed by synthesis, characterization, and evaluation of their antibacterial, antidiabetic, antioxidant, and photocatalytic degradation potentials using standard established procedures.

Results

The phytochemical profile of JLE was found to be rich in flavonoids, tannins, terpenoid phenols, anthraquinones, and cardiac glycosides. Its GC-MS analysis revealed the presence of compounds majorly of them as the (1R)-2,6,6-Trimethylbicyclo[3.1.1]hept-2-ene (5.141%), 2(10)-pinene (4.119%), α-cyclopene (5.274%) α,α-muurolene (7.525%), naphthalene, 1,2,3,4,4a,5,6,8a-octahydro-7-methyl-4-methylene-1-(1-methylethyl)-(1.alpha.,4a.beta.,8a.alpha) (8.470%), delta-cadinene (23.246), α-guajene (3.451%), and gamma-muurolene (4.379%). The visual morphology and UV-Vis spectral surface plasmon resonance at 538 nm confirmed the successful synthesis of S4-GoNPs. The average particle size was determined as 120.5 nm with Pdi = 0.152, and -27.6 mV zeta potential. Using the Scherrer equation, the average crystallite size was calculated as 35.69 nm. S4-GoNPs displayed significant antidiabetic properties, with 40.67% of α-amylase and 91.33% of α-glucosidase inhibition activity. It also exhibited promising antioxidant potential in terms of the DPPH (91.56%) ABTS (76.59%) scavenging. It displayed 31.04% tyrosinase inhibition at 0.1 mg/mL. Moreover, it also demonstrated encouraging antibacterial effects with zones of inhibition ranging from 11.02 - 14.12 mm as compared to 10.55-16.24 mm by the reference streptomycin (at 0.01 mg/disc). In addition, S4-GoNPs also showed potential for the photocatalytic degradation of the industrial dye, methylene blue.

Conclusion

In conclusion, these results suggest the promising applicability of green-synthesized S4-GoNPs in various sectors, including the biomedical, cosmetic, food, and environmental waste management industries.

Preparation of Herbal Nano-Formulation-Assisted Mouth Paint Using Titanium Dioxide Nanoparticles and Its Biomedical Applications

Background Mouth paint is a liquid oral care solution applied topically to the mouth, formulated to address oral health concerns like bacterial infections, inflammation, and bad breath. To improve the effectiveness of oral healthcare, nanomaterials are utilized in many dental products. Titanium dioxide nanoparticles (TiO2NPs) exert their antimicrobial effects through mechanisms like producing reactive oxygen species and direct interaction with microbial cells. The current study explored the antimicrobial, anti-inflammatory, and cytotoxic effects of the mouth paint prepared using TiO2NPs using an aqueous formulation of lemongrass and dry ginger. Methods Mouthpaint prepared using TiO2NPs synthesized using lemongrass and ginger was prepared and tested for potential applications. The antimicrobial activity of the prepared TiO2NPs-mediated mouth paint at different concentrations (25, 50, and 100 µL) against oral pathogens (Streptococcus mutans, Enterococcus faecalis, Staphylococcus aureus, and Candida albicans) was evaluated using the Agar well diffusion method. The anti-inflammatory activity of the produced mouth paint was examined using a bovine serum albumin denaturation assay and an egg albumin denaturation assay. The cytotoxic effect of the produced mouthpaint was analyzed using a brine shrimp lethality assay.  Results Green synthesized TiO2NPs showed potent antimicrobial activity against the tested oral pathogens by exhibiting a zone of inhibition of 11 mm on Petriplate against Staphylococcus aureus and Candida albicans at 100 μL concentration. The prepared nanoparticles-mediated mouth paint possesses significant anti-inflammatory activity by effectively preventing the denaturation of bovine serum albumin, with a 74% inhibition at a concentration of 50 μL. The egg albumin denaturation assay showed a percentage inhibition of 80% at 50 μL. At the lowest concentration of 5 μL of the prepared mouth paint, 90% of the nauplii (egg-to-larvae stage of brine shrimp) remained alive after 48 hours. Conclusion The results showed that mouthpaint prepared using titanium dioxide nanoparticles synthesized using lemongrass and dry ginger formulations possessed significant antimicrobial activity and also displayed potential anti-inflammatory activity. The prepared mouth paint also displayed less toxicity, and hence, it can be used as an alternative to the commercially available synthetic mouth paint, which has more side effects.