Phytochemical Composition and Comparative Evaluation of Antimicrobial Activities of the Juice Extract of <i>Citrus Aurantifolia</i> and its Silver Nanoparticles

Abstract

Background: Citrus aurantifolia juice has been useful for the treatment of various infections and green synthesis of silver nanoparticle using lime juice may offer added advantages.
Objective: The phytochemical composition and comparative evaluation of antimicrobial activities of the crude juice extract and biosynthesized Silver nanoparticle (SNPs) from Citrus aurantifolia juice was investigated.
Materials and methods: Phytochemical, antimicrobial evaluation (agar well diffusion) and biosynthesis of SNPs was done using Crude extract of Citrus aurantifolia. The SNPs were characterized by colour changes, spectroscopy and Fourier-Transform Infrared (FTIR) Spectroscopy.
Results: The juice extract contained bioactive compounds such as flavonoids (710mg/100g), tannins (525mg/100g), phenols (65mg/100g) and terpenes (56mg/100g). Changes in colour, UV-Vis Spectroscopy at 300-550nm ranges and FTIR revealed the functional groups present in the biosynthesized SNPs. The crude extract and SNPs exhibited varying antimicrobial activities against some selected pathogens including Streptococcus pyogenes ATCC 19615, Klebsiella pneumoniae ATCC 10031, Bacillus sp, Actinobacillus sp., Pseudomonas aeruginosa and Staphylococcus aureus. The crude extract has more antibacterial potential against the tested pathogens than the biosynthesized SNPs. The crude extract also had higher antimicrobial activities against Streptococcus pyogenes which were resistant to ciprofloxacin. The result revealed that the crude extract was more effective than the SNPs produced and the Minimum Inhibitory concentration (MIC) also showed increasing activities with an increase in the concentration of the juice extract and SNPs.
Conclusion: Crude extract of Citrus aurantifolia contain bioactive compound with potent antimicrobial potential and the extract was more effective than the biosythesized SNPs.

Keywords: Citrus aurantifolia juice, Silver nanoparticle, phytochemical, antimicrobial activities, minimum inhibitory concentration.