Antibacterial and biofilm inhibition activities of Melastoma malabathricum stem bark extract against Streptococcus mutants
- Author:
Rohazila Mohamad Hanafiah
;
Wan Syaidatul Aqma
;
Wan Ahmad Yaacob
;
Zulfahmi Said
;
Nazlina Ibrahim
- Publication Type:Journal Article
- Keywords:
Antibacterial;
biofilm;
Melastoma malabathricum;
Streptococcus mutans
- From:Malaysian Journal of Microbiology
2015;11(2):199-206
- CountryMalaysia
- Language:English
-
Abstract:
Aim: This study was to determine the antibacterial activity of Melastoma malabathricum stem bark acetone extract
(MMSBAE) against Streptococcus mutans.
Methodology and results: Antibacterial activity of the extract was determined by minimal inhibitory concentration
(MIC), minimal bactericidal concentration (MBC), biofilm formation, adherence inhibition, time kill studies and effect on S.
mutans membrane integrity. MIC and MBC values of MMSBAE were 1.25 and 5 mg/mL, respectively. Time kill studies
showed that reduction of colony forming unit in treated cells is 3 log10 after 10 h of treatment (p ˂ 0.05). The extracts
reduced 50% biofilm and adherence activity of S. mutans at 1.88 mg/mL. The effect on S. mutans membrane integrity
after exposure to MMSBAE for 90 and 120 min was determined by measuring leakage of cell content at 2 different
wavelengths of 260 nm and 280 nm. In leakage assay, the percentage of absorbance (260 nm) in treated cell material
showed 57% at 90 min and 60% at 120 min which is higher than negative control (<20%) but less than positive control
(100%). The percentage absorbance of treated cell material (280 nm) was 61% at 90 min and 63% at 120 min.
Identification of compound in MMSBAE was done by gas chromatography mass spectrometry (GCMS). Ten compounds
were identified in the MMSBAE with some of them important in antimicrobial activity such as ethyl ester, undecene, and
gamma sitosterol.
Conclusion, significance and impact of study: MMSBAE showed excellent bactericidal and antibacterial activities
against S. mutans. The antibacterial mode of action of MMSBAE is suggested to be the disruption of the S. mutans
membrane structure. The MMSBAE significantly inhibited biofilm and adherence activities of S. mutans in dose
dependent manner (p ˂ 0.05). MMSBAE has potential in the development of antibacterial agent with anti-biofilm and
anti-adherence activities.
- Full text:P020150716484038273118.pdf
