Antibacterial, cytotoxic, analgesic and diuretic activities of <i style="mso-bidi-font-style:normal">Rhizophora mucronata</i> Lam. bark

Abstract

229-232<i style="mso-bidi-font-style: normal">Rhizophora mucronata Lam., locally known as ‘Garjon or Jhanna’ in Bangladesh is a mangrove plant of Rhizophoraceae family. Different parts of this plant have got applications in folk medicine from the ancient time. In the present study, attempts have been made for a detailed phytochemical study of the bark of the plant for antibacterial, cytoxic, analgesic and diuretic activites. Disc diffusion method was used for the screening of antibacterial activity and cytotoxicity study was performed by brine shrimp lethality bioassay. Acetic acid induced writhing method was employed to assess the analgesic potentiality of the extract. Diuretic property of the bark extract was studied by Lipschitz method. The ethanolic extract of the barks of R. mucronata Lam. showed moderate antibacterial activity against both Gram-positive and Gram-negative strains. Marked inhibitory effects were found with Escherichia coli and Staphylococus epidermidis at a concentration of 500 µg/disc. The extract showed very high level of general toxicity in the brine shrimp lethality bioassay having an LC50 value of 0.5 µg/mL. The extract of <i style="mso-bidi-font-style: normal">R. mucronata Lam. bark at concentrations of 250 mg/kg and 500 mg/kg exhibited significant (P<0.01) inhibition of writhing reflex by 36.96% and 50%, respectively while the standard diclofenac inhibition was found to be 65.21% at a dose of 50 mg/kg body weight. The extract also showed very high response to diuresis in a dose-dependent manner