Synthesis and enhanced antibacterial using plant extracts with silver nanoparticles: Therapeutic application

Mechanism of Action of Green-Synthesized Silver Nanoparticle-Incorporated Dental Varnish Against Candida albicans

INTRODUCTION

 Candida albicans, a common fungal pathogen, is often associated with oral infections such as denture stomatitis. Dental varnishes, especially those incorporating antimicrobial agents, have shown promise in preventing C. albicans colonization. This study investigates the antifungal efficacy of a dental varnish incorporating green-synthesized silver nanoparticles (AgNPs) using Ocimum gratissimum and Ocimum tenuiflorum extracts.

MATERIALS AND METHODS

AgNPs were synthesized via a green synthesis method using Ocimum extracts. The AgNPs were then incorporated into a dental varnish. The antifungal efficacy of the AgNP-incorporated varnish was evaluated against C. albicans using various assays, including agar well diffusion, time-kill curve, protein leakage, and cytoplasmic leakage analyses.

RESULTS

The AgNP-incorporated dental varnish demonstrated significant antifungal activity against C. albicans. The agar well diffusion assay showed a dose-dependent increase in the zone of inhibition, with the highest concentration (100 µg/mL) achieving a zone of 23 mm. The time-kill curve assay indicated a concentration-dependent reduction in colony-forming units (CFU) of C. albicans, with the highest concentration resulting in a CFU reduction to below 103 within five hours. Both protein and cytoplasmic leakage analyses confirmed membrane disruption, showing increased optical density readings at higher concentrations of AgNPs.

DISCUSSION

The results suggest that the antifungal activity of the AgNP-incorporated dental varnish is mediated through multiple mechanisms, including membrane disruption, increased permeability leading to protein and cytoplasmic leakage, and possibly the generation of reactive oxygen species (ROS). The varnish's efficacy was comparable to that of commercial antifungal dental varnishes, highlighting its potential as a viable alternative in dental applications.

CONCLUSION

Green-synthesized AgNPs, when incorporated into dental varnish, exhibit potent antifungal activity against C. albicans. The study demonstrates that this approach can effectively disrupt fungal cells, suggesting its potential use in preventing and treating oral fungal infections. Future research should explore the in vivo efficacy, safety, and long-term stability of AgNPs in dental varnish formulations.

Valorization and characterization of corn by-product polyphenols through green extraction technologies

The amount of food waste throughout the world has become quite alarming and is contributing to lower food resources. The study aimed to extract and characterize the polyphenols from corn silks at immature and mature stages through conventional and green extraction techniques. Purposely, corn silks, which are some of the by-products of corn, (Zea mays L.) were collected and subjected to proximate analysis including moisture, ash, protein, fiber, and minerals. Secondly, the antioxidants from both immature and mature corn silks were extracted by techniques involving supercritical and ultrasound extraction alongside conventional extraction. The results displayed a promising quantity of protein and fiber along with calcium, magnesium, sodium potassium, and copper. Among the extraction techniques, supercritical extraction at 3,000 Pa acquired the highest total phenolic contents (TPC), total flavonoids (TF), 2, 2-diphenylpicrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP) activities as 128.08 ± 3.74 mg GAE/100 g, 86.73 ± 2.75 mg CE/100 g, 106.73 ± 5.10%, and 73.52 ± 2.33 μM Fe + 2/g, respectively, followed by the ultrasound and conventional extraction techniques. Between the immature and mature corn silks, the highest antioxidant activity was displayed by immature corn silks.