Harnessing the pharmaceutical potential of noni fruit extract: antibacterial and antifungal effects against antibiotic-resistant microorganisms and oral pathogens.

Abstract

The escalating threat of antibiotic-resistant microorganisms necessitates innovative therapeutic approaches. This study explores the pharmaceutical potential of Noni Fruit Extract (NFE), derived from Morinda citrifolia, as a promising solution against antibiotic-resistant strains and oral pathogens. NFE exhibited robust antibacterial activity, rivaling conventional antibiotics. The investigation encompassed a spectrum of microorganisms, including Gram-positive (Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis), Gram-negative (Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, Salmonella typhimurium, Klebsiella pneumoniae), antibiotic-resistant strains (Vancomycin-Resistant Enterococci (VRE), Methicillin-Resistant Staphylococcus aureus (MRSA)), a fungal pathogen (Candida albicans), and oral pathogens (Streptococcus mutans, Streptococcus mitis). The disk diffusion method determined NFE's inhibition zone diameters against these pathogens. NFE displayed potent antibacterial activity against both Gram-negative and Gram-positive microorganisms. At 5mg/mL, NFE produced a 10 mm inhibition zone against Pseudomonas aeruginosa, reaching 19.3 mm at 100mg/mL. Proteus vulgaris exhibited zones of 10.3, 12.7, 27.3, 33.7, and 44.7 mm at NFE concentrations from 5 to 100 mg/mL. Escherichia coli displayed the largest inhibition zone of 61.7 mm at 100 mg/mL NFE. Similar trends were observed for Salmonella typhimurium and Klebsiella pneumoniae. NFE also demonstrated strong antifungal activity against Candida albicans. Against antibiotic-resistant strains, NFE significantly affected VRE at 100mg/mL, yielding a 42.3 mm zone. MRSA displayed an 8.3 mm zone at 5 mg/mL NFE and 51.3 mm below 100 mg/mL, underscoring NFE's efficacy against antibiotic-resistant strains. NFE exhibited robust antibacterial activity against oral pathogens, with notable inhibition zones at higher concentrations on Streptococcus mutans and Streptococcus mitis. Following EN 1276:2019 methodology, time-dependent antibacterial efficacy assessment revealed significant log reductions in microbial load, indicating NFE's potent antibacterial effect at various concentrations and contact times. In conclusion, NFE displayed potent antibacterial and antifungal activities against various microorganisms, including antibiotic-resistant strains and oral pathogens. These findings suggest NFE's promise as an alternative therapeutic agent in combatting antimicrobial resistance.