Volume 34 Number 4 (2025)
Antibacterial effect of Nigella sativa (Kalojira) against Staphylococcus aureus and Escherichia coli
Tusher SM1 , Tusher SM2 , Sultana S3 , Paul SK4 , Farhana F5 , Adneen Z6 , Salma MU7 , Khanom TA8
Mymensingh Med J 2025 Oct; 34 (4): 1151-1156
PMID: 41024554
Abstract
Bacterial infection is one of the biggest causes of morbidity and mortality worldwide. Pathogens have also gradually developed resistance to the miracle drug, antibiotics. That’s why interest in searching for effective alternatives for the current antibiotics with different mode of action on microbes is increasing. In this regard, one of the reputed medicinal plants, Nigella sativa (Kalojira) was investigated for potential antibacterial effect against commonly encountered pathogens (Staphylococcus aureus and Escherichia coli). Both aqueous and ethanolic extract of Kalojira was found active against Staphylococcus aureus and Escherichia coli in disc diffusion method. Zone of inhibitions of aqueous extract at 100.0% (1000µg/ml) concentrations were 25mm against Staphylococcus aureus, 24mm against Escherichia coli. Zone of inhibitions of ethanolic extract were 32mm against Staphylococcus aureus and 32mm against Escherichia coli at 100.0% concentration. The broth dilution technique was performed to determine the MICs of Aqueous kalojira extract (AKE), EKE and Amikacin. The MICs of AKE were 500µg/ml and 600µg/ml against Staphylococcus aureus and Escherichia coli respectively. The MICs of EKE were 400µg/ml and 400µg/ml against aforesaid organism respectively. The MIC of Amikacin was 1.5µg/ml against Staphylococcus aureus and 1µg/ml against Escherichia coli. The MIC of Amikacin was lowest in comparison to MICs of AKE and EKE for the test organisms. The subculture study showed the same results with that of previous experiments.
Keywords: Antibacterial activity, Kalojira, Staphylococcus aureus, Escherichia coli, Zone of Inhibition (ZOI), Minimum inhibitory concentration (MIC), Broth dilution and disc diffusion, Aqueous Kalojira Extract (AKE) and Ethanolic Kalojira extract (EKE)
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