Antibacterial effect of ethanolic extract of Mirabilis jalapa (Alsaa Arbaa) seeds against some bacteria

Abstract

An indigenous medicinal plant Mirabilis jalapa (family: Nyctaginaceae) was widely used as a traditional medicine in many parts of the world for treatment of various diseases: antiviral, antibacterial, antifungal, anti tumours, anti-nociceptive, anti-inflammatory agent, laxative, dysentery, muscular pain and abdominal colic. The research indicates the effectiveness of the seeds of 4-O’clock plant against Staphylococcus aureus and Escherichia coli. The seeds of the plant were collected, air dried, powdered and (100 gm.) subjected to gradient extraction using soxhlate apparatus. Ethanol 70% was used as a solvent. Three concentrations presenting 50% (500 mg/ml), 25% (250 mg/ml) and 12.5% (125 mg/ml) were prepared. In-vitro antibacterial assay of the ethanolic extract of the plant seeds was performed using agar wells diffusion method, disc diffusion method and dilution method with distilled water as negative control. The seeds of the plant exhibited significant antibacterial effect against Staphylococcus aureus and Escherichia coli. The greatest zone of inhibition was displayed by well diffusion method against Staphylococcus aureus at 500 mg/ml was 29 mm, at 250 mg/ml was 18 mm and at 125 mg/ml was 12 mm. But at same concentrations when were used disc diffusion method the result were displayed are 24 mm at 500 mg/kg, 9mm at 250 mg/ml and 7 mm at 125 mg/ml against Staphylococcus aureus. And 20 mm at 500 mg/ml, 14.3 mm at 250 mg/ml and 8.3 mm at 125 mg/ml against Escherichia coli. Keywords: Mirabilis jalapa, Seeds, Staphylococcus aureus, Escherichia coli, Disc diffusion, Well diffusion