Estimation of bacterial growth inhibition and antibiofilm activity of Hibiscus Sabdariffa plant extracts against standard pathogenic bacteria

Abstract

Present study was aimed to find the bacterial growth inhibition and antibiofilm activity of different polarity extracts of Hibiscus sabdariffa calyx. Dried calyx of H. sabdariffa plant were extracted using two different solvents petroleum ether represented organic fraction (OF), furthermore the dried marc have been introduced for second extraction process using (70%) ethanol represented hydrolacholic fraction (HF). Both fraction have been estimated for their efficacy for inhibiting bacterial growth and biofilm formation using macrodilution and modified crystal violet methods respectively. The results showed significant bacterial growth inhibition percentage of Streptococcus pneumonia bacteria by hydroalcholic fraction about (93.423±2.913%) while lowest activity exhibited by the organic fraction against similar bacteria (9.22±1.0252 %). Generally greater activity toward gram negative bacteria have been reported for both fractions. Significant antibioflim activity have been expressed by both fraction at (50mg\ml) concentration against which increase in a dose dependent manner. Low concentrations (3.125mg/ml) of both fractions showed promoting bacterial biofilm formation. Both fractions exhibited strong antibacterial and antibiofilm activity toward tested bacterial strains.