The Detection of Phytochemical Properties from Freeze Dried Ottochloa nodosa (Kunth) Dandy Extracts and Its Potential as a Bacterial Inhibitor

Abstract

This study aimed to detect the secondary metabolites and chemical components in the freeze-dried extract of Ottochloa nodosa (Kunth) Dandy. In addition, discovering the extract could have potential as a bacterial inhibitor by determination of the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) carried out in extracts. Determination of antimicrobial potential of freeze-dried extracts was conducted through phytochemical screening, gas chromatography-mass spectrometry (GC-MS) test, agar disc diffusion and broth dilution methods. The study shows this extract has bacterial inhibitors’ potential since it contained phytochemical compounds such as alkaloid, saponin, flavonoid and tannin, while 9 chemical components have been displayed through GC-MS analysis. The disc diffusion method was done at different concentrations, at 25, 50 and 100 mg/ml. The result also shows that the extracts are able to inhibit the gram-positive and gram-negative bacteria. Freeze-dried extract presented significant differences in 100 mg/ml and 50 mg/ml, p=0.05. The MIC value was found at 2.0 mg/ml in the agar plate containing methicillin-resistant S. aureus (MRSA), Aeromonas hydrophila and Staphylococcus aureus, while Vibrio parahaemolyticus was at 5.0 mg/ml. While the MBC value showed 2.0 mg/ml in MRSA and S. aureus (since the plates containing A. hydrophila and V. parahaemolyticus had bacterial growths, thus, it demonstrated that the plant extracts were only able to inhibit the bacterial growth but could not kill them). In conclusion, the freeze-dried method can be applied for water removal during plant extraction and possess bacterial inhibition activity. This study implicated that O. nodosa extract is a natural source of antibiotic substances for bacterial infection treatment.