Viola betonicifolia-Mediated Biosynthesis of Silver Nanoparticles for Improved Biomedical Applications

Biosynthesis, characterization, and antifungal activity of plant-mediated silver nanoparticles using Cnidium monnieri fruit extract

The present study describes a novel method for green synthesis of silver nanoparticles using Cnidium monnieri (CM-AgNPs). Cnidium monnieri fruit is an excellent anti tinea drug that can be used externally to treat superficial fungal infections in the human body. The aqueous ethanolic extract of Cnidium monnieri fruit was prepared and employed in the synthesis of stable silver nanoparticles via biological reduction method. The synthesis conditions of CM-AgNPs was systematically optimized using Box-Behnken design. CM-AgNPs were well characterized by UV-spectroscopy and X-ray powder diffraction (XRD), and it was confirmed that the synthesized particles were AgNPs. The possible functional groups required for the reduction and stabilization of CM-AgNPs in the extract were identified through FTIR spectrum. The size of CM-AgNPs structure was confirmed to be approximately 44.6 nm in polydisperse spherical shape through scanning electron microscopy (SEM), transmission electron microscopy (TEM), and laser dynamic light scattering (DLS). Further, the minimum inhibitory concentration 90% (MIC90) ratios values of Cm-AgNPs against Trichophyton rubrum (7 d), T. mentagrophytes (7 d) and Candida albicans (24 h) were 3.125, 3.125, and 0.78125 μg/mL, respectively, determined by the broth micro dilution method. Finally, the result was concluded that the synthesized AgNPs could be further evaluated in large scale as a potential human topical antifungal agent.

Green Biosynthesis of Silver Nanoparticles Using Aqueous Extracts of Ageratum Conyzoides and Their Anti-Inflammatory Effects

The NLRP3 inflammasome, which plays a central role in innate immunity, is linked to a variety of inflammatory diseases, and thus it may provide a new target for the treatment of those diseases. Biosynthesized silver nanoparticles (AgNPs), particularly those synthesized using medicinal plant extracts, have recently been shown to be a promising therapeutic option. Herein, the aqueous extract of Ageratum conyzoids was used to prepare a series of sized AgNPs (AC-AgNPs), in which the smallest mean particle size was 30 ± 1.3 nm with a polydispersity of 0.328 ± 0.009. The ζ potential value was -28.77 with a mobility of -1.95 ± 0.24 cm2/(v·s). Its main ingredient, elemental silver, accounted for about 32.71 ± 4.87% of its mass, and other ingredients included amentoflavone-7,7⁗-dimethyl ether, 1,3,5-tricaffeoylquinic acid, kaempferol 3,7,4'-triglucoside, 5,6,7,3',4',5'-hexamethoxyflavone, kaempferol, and ageconyflavone B. In LPS+ATP-stimulated RAW 264.7 and THP-1 cells, AC-AgNPs significantly inhibited the release of IL-1β, IL-18, TNF-α, and caspase-1, indicating that AC-AgNPs can inhibit the activation of the NLRP3 inflammasome. The mechanistic study revealed that AC-AgNPs could decrease the phosphorylation levels of IκB-α and p65, resulting in decreased expression of NLRP3 inflammasome-related proteins, including pro-IL-1β, IL-1β, procaspase 1, caspase 1P20, NLRP3, and ASC, and also scavenge the level of intracellular ROS to prevent NLRP3 inflammasome assembly. Furthermore, AC-AgNPs attenuated the in vivo expression of inflammatory cytokines by suppressing NLRP3 inflammasome activation in a peritonitis mouse model. Our study provides evidence that the as-prepared AC-AgNPs can inhibit the inflammatory process by suppressing NLRP3 inflammasome activation and might be used to treat NLRP3 inflammasome-driven inflammatory diseases.

Helicobacter Pylori-Induced Gastric Infections: From Pathogenesis to Novel Therapeutic Approaches Using Silver Nanoparticles

Helicobacter pylori is the first formally recognized bacterial carcinogen and the most important single digestive pathogen responsible for the induction of gastroduodenal diseases such as gastritis, peptic ulcer, and, finally, gastric neoplasia. The recently reported high rates of antimicrobial drug resistance hamper the current therapies of H. pylori, with therapeutic failure reaching up to 40% of patients. In this context, new treatment options and strategies are urgently needed, but the successful development of these new therapeutic tools is conditioned by the understanding of the high adaptability of H. pylori to the gastric acidic environment and the complex pathogenic mechanism. Due to several advantages, including good antibacterial efficiency, possible targeted delivery, and long tissular persistence, silver nanoparticles (AgNPs) offer the opportunity of exploring new strategies to improve the H. pylori therapy. A new paradigm in the therapy of H. pylori gastric infections using AgNPs has the potential to overcome the current medical limitations imposed by the H. pylori drug resistance, which is reported for most of the current organic antibiotics employed in the classical therapies. This manuscript provides an extensive overview of the pathology of H. pylori-induced gastritis, gastric cancer, and extradigestive diseases and highlights the possible benefits and limitations of employing AgNPs in the therapeutic strategies against H. pylori infections.