Comparative antimicrobial activities of organic acid extract of hibiscus sabdariffa linn red calyxes on bacterias namely staphylococcus aureus and escherichia coli / Esmalinda Mohamad

Emergence of Multidrug Resistance organisms is an alarming situation. The intervention of novel antibiotic from medicinal plants that scientifically known as Hibiscus sabdariffa Linn (Roselle), might be the key for this problem. Roselle is a multi-purpose plant, in which the outer leaves (calyx) is reported by previous studies to have antimicrobial properties, subjected to its phytochemical contents and polarity of the biochemical compounds that is best extracted by using polar extraction solvent. The present study was conducted to compare the efficacy of organic acid (polar solvents) extracts of H. sabdariffa Linn. red calyxes as antimicrobial agent. Antimicrobial Sensitivity Testing (AST) and Antimicrobial Assay (MIC and MBC) was implied in attempt to achieve the objective of the study. Powder form of dry Roselle red calyx was soaked in three different vinegars (extraction solvent) with ratio of 1:2 for 24 hours extracted by using Maceration technique. The 50% concentration extracts were tested on Staphylococcus aureus and Escherichia coli. The antimicrobial efficacy were determined through technique of agar diffusion and broth microdilution method. Good inhibitory effect were shown against S. aureus compared to E.coli in all 3 tested organic acid extracts. There is probability that the extracts may be effective against Gram Positive bacteria. Out of three extracts, Distilled white vinegar-Roselle extracts shows most prominent antimicrobial effect with almost twice zone of inhibition yield by others. However, there is possibility that it is due to synergistic effect with the Distilled white vinegar since the vinegar itself revealed antimicrobial effect upon preliminary test against Gram positive organism. All extracts interpreted ‘Clear’ up to fifth well as tested against S. aureus while against E.coli, no visible growth seen in fifth well and sixth well for the ACV-R and DWV-R;RV-R, respectively. MIC value reported at 3.13% and 1.56% for 5th and 6th wells, respectively. MBC value displayed similar inhibitory patterns like MIC results with slight increase one concentration above on all tested extracts. Bactericidal effects (No growth on subculture medium) indicating MBC breakpoints. The study managed to prove the antimicrobial potencies of organic acid extracts of H. sabdariffa red calyx.