Composition and Antibacterial Activity of the Essential Oils of Orthosiphon stamineus Benth and Ficus deltoidea Jack against Pathogenic Oral Bacteria

Abstract

In this study, the essential oils of Orthosiphon stamineus Benth and Ficus deltoidea Jack were evaluated for their antibacterial activity against invasive oral pathogens, namely Enterococcus faecalis, Streptococcus mutans, Streptococcus mitis, Streptococcus salivarius, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. Chemical composition of the oils was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of the oils and their major constituents were investigated using the broth microdilution method (minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)). Susceptibility test, anti-adhesion, anti-biofilm, checkerboard and time-kill assays were also carried out. Physiological changes of the bacterial cells after exposure to the oils were observed under the field emission scanning electron microscope (FESEM). O. stamineus and F. deltoidea oils mainly consisted of sesquiterpenoids (44.6% and 60.9%, respectively), and β-caryophyllene was the most abundant compound in both oils (26.3% and 36.3%, respectively). Other compounds present in O. stamineus were α-humulene (5.1%) and eugenol (8.1%), while α-humulene (5.5%) and germacrene D (7.7%) were dominant in F. deltoidea. The oils of both plants showed moderate to strong inhibition against all tested bacteria with MIC and MBC values ranging 0.63–2.5 mg/mL. However, none showed any inhibition on monospecies biofilms. The time-kill assay showed that combination of both oils with amoxicillin at concentrations of 1× and 2× MIC values demonstrated additive antibacterial effect. The FESEM study showed that both oils produced significant alterations on the cells of Gram-negative bacteria as they became pleomorphic and lysed. In conclusion, the study indicated that the oils of O. stamineus and F. deltoidea possessed moderate to strong antibacterial properties against the seven strains pathogenic oral bacteria and may have caused disturbances of membrane structure or cell wall of the bacteria.

Seasonal Effect on the Chemical Composition, Insecticidal Properties and Other Biological Activities of Zanthoxylum leprieurii Guill. & Perr. Essential Oils

“…Dendrolasin was present in significant amounts (4-16.4%) in all months except in May. This last molecule has well-known antimicrobial and antibacterial properties, and is also used in the treatment of cancer [42][43][44]. We also noticed the presence of thymol, an oxygenated monoterpene, at 13.30% in August.…”

An Overview of Phytochemical and Biological Activities

“…Results showed mild-to-powerful inhibition with MIC and MBC values ranging from 0.63 to 2.5mg/mL, although none on monospecies biofilms displayed any inhibition. [ 29 30 ] Suryati et al [ 21 ] recorded an antibacterial compound lupeol from F. deltoidea leaves that check the growth of E. coli , B. subtilis , and S. aureus at minimum inhibition concentration.…”

Pengaruh Efektivitas Antibakteri Ekstrak Daun Kumis Kucing Terhadap Bakteri Streptococcus Mutans

“…Aktivitas antibakteri terbaik dari ekstrak daun kumis kucing terhadap Staphylococcus aureus. Kekuatan antibakteri yang dimiliki oleh minyak esensial dari daun kumis kucing (Orthosiphon stamineus) adalah kuat (Azizan et al, 2017). Oleh karena itu, peneliti merasa tertarik untuk melakukan penelitian tentang "Uji Efektivitas Antibakteri Ekstrak Daun Kumis.…”