Antibacterial activity of different types of P. odorata leaf extracts was evaluated in combination with
standard antibiotics. Persicaria. odorata leaves were extracted with n-hexane (n-hex), dichloromethane
(DCM) and methanol (MeOH). Each extract was applied on vancomycin (30µg), erythromycin (15µg) and
gentamicin (10µg) discs, respectively. Disk diffusion method was used to evaluate the synergistic activity of
each combination on Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes,
Streptococcus pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, and Escherichia coli. Minimum
inhibitory concentration (MIC) and gas chromatography mass spectrometry (GCMS) analysis was performed on
the active extract. Synergistic effects seen were mainly from the n-hex+antibiotics combinations, mainly on
the Gram-positive bacteria (7 additive, 5 antagonistic), with MIC range from 50 µg/ml to 100 µg/ml, as well
as Gram-negative bacteria (2 additive, 2 indifferent, 5 antagonistic). In particular, synergism showed by the
combination of n-hex+van were all additive against the susceptible bacteria. DCM extract combination
showed synergistic effects on three Gram-positive species (S. aureus, S. epidermidis, S. pyogenes).
Meanwhile, MeOH+antibiotics combination showed significant additive synergistic effects (p
Hydroxychavicol (HC) is a phenolic compound of betel leaf (Piper betle). It has been reported to have antifungal properties against dermatophytes including T. rubrum. The aim of this study was to identify the effects of the HC against T. rubrum. Broth dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the HC. Microscopic study of the treated fungus was done by transmission electron microscope (TEM). Cytotoxicity study using pre-adipocyte (3T3-L1) cell line was performed by means of MTT cell proliferation assay. The MIC and MFC results of the HC were both 0.49 µg/ml. Microscopic study revealed the destruction of the fungal cell wall and organelles. Cytotoxicity study showed HC to be non-toxic to the tested human cell line. In conclusion, HC may potentially be used as an alternative therapeutic agent against T. rubrum infections.
Trichophyton rubrum is a common pathogenic fungal species that is responsible for causing infection on
human skin, hair and nail. The antifungal-resistant strains complicate the treatment regime.
Hydroxychavicol (HC) is one of the main compounds from Piper betel leaf that have antifungal potential and
its mechanism of action has not been studied yet. The objective of this preliminary study to determine the
antifungal properties of HC against T. rubrum using transmission electron microscope (TEM) on gross and
ultrastructure of T. rubrum hypha. T. rubrum was treated with HC and miconazole (MI) at concentrations of
1.25, 2.5, 5 and 10 mg/mL for 1, 3, 5 and 7 days continuously. Generally, fungi structures became more
severely damaged at increasing treatment duration. Microscopically, the fungi’s cell wall treated with HC
showed a rough surface, shrinkage and demolition similar to the MI treated group. The fungi organelles were
also demolished and disorganized. This study revealed that HC has the ability to inhibit T. rubrum growth
and has potential to be an antifungal agent for skin infections.