Systematic Evaluation of Antioxidant Efficiency and Antibacterial Mechanism of Bitter Gourd Extract Stabilized Silver Nanoparticles

Abstract

In this study, we accentuate the facile and green synthesis of ecologically viable silver nanoparticles (AgNPs) using aqueous (A-BGE) and ethanolic (E-BGE) dried bitter gourd (Momordica charantia) fruit extract as reducing and capping agents. Although AgNPs synthesized using BGEs have been reported earlier in fundamental antimicrobial studies, the possible antioxidant activity, antibacterial efficacy against superbugs, and a potential antimicrobial mechanism are still lacking. The characterization of as-prepared AgNPs was studied through UV-vis, TEM, Zeta-potential, FT-IR, XRD, and XPS analysis. The antioxidant ability of BG-AgNPs was extensively evaluated through DPPH and FRAP assays, which showed that A-BG-AgNPs possessed higher scavenging ability and superior reducing power due to the high phenolic content present in the BG extract. Furthermore, A-BG-AgNPs were highly stable in various physiological media and displayed excellent antibacterial activity against drug-resistant bacterial strains (i.e., MIC value of 4 µg/mL). The generation of reactive oxygen species evidenced that the possible antimicrobial mechanism was induced by BG-AgNPs, resulting in bacterial cell damage. Within the minimal hemolysis, the BG-mediated AgNPs possessed synergistic antioxidant and antibacterial agents and open another avenue for the inhibition of the growth of pathogens.

Synergistic actions of phytonutrient capped nanosilver as a novel broad-spectrum antimicrobial agent: unveiling the antibacterial effectiveness and bactericidal mechanism

“…Compared to A-DE-AgNPs, using A-BL-AgNPs as an antibacterial reagent not only showed similar S. aureus (Gram-positive bacteria) killing activity but also exhibited twofold higher antimicrobial efficiency against Gram-negative bacteria. A-BL-AgNPs also showed a better antibacterial efficiency against the wild-type and two drug-resistant A. baumannii strains (MIC = 2 mg mL À1 ) than the bitter melon extract-mediated AgNPs from our previous report, 47 which might be due to the CGE-mediated AgNPs releasing more Ag + ions. Several plant extract mediated AgNPs against multi-drug resistant bacterial pathogens have been explored recently due to the widespread antibiotic resistance around the world.…”

Evaluating Antioxidant Performance, Biosafety, and Antimicrobial Efficacy of Houttuynia cordata Extract and Microwave-Assisted Synthesis of Biogenic Silver Nano-Antibiotics

“…The most important antioxidant components are polyphenolic compounds (including flavonoids) that deactivate free radicals due to their hydrogen-donating ability. A linear relationship between the total phenolic and flavonoid content and antioxidant capacity has been reported in several literature publications [39][40][41].…”

Phytochemical-Based Nanomaterials against Antibiotic-Resistant Bacteria: An Updated Review

“…AgNPs inhibited the growth of both tested Gram-negative and Gram-positive multi-drug-resistant (MDR) strains with MIC and MBC values ranging between 0.019–0.156 and 0.039–0.625 mg/mL, respectively. Moorthy et al (2021) produced AgNPs using aqueous and ethanolic bitter gourd ( M. charantia ) extracts (A-BG-AgNPs and E-BG-AgNPs, respectively) [ 152 ]. They found that E-BG-AgNPs were much smaller in size and showed greater agglomeration than the aqueous ones.…”