E. coli

In Ayurvedic and Unani medicine, Justicia adhatoda is a well-known medicinal herb. It is commonly known that higher plants contain antibacterial agents. The antimicrobial potential of Justicia adhatoda, alone makes a major contribution. An indicator of an antimicrobial agent's relative potential is the formation of a growth inhibition zone, which is a clear area surrounding the original agent and indicates the efficacy of the agent. The present study aimed to evaluate antimicrobial activity of at different concentrations (25, 50, 75 & 100 μg/ml) of methanol, pet ether and water extract of leaf, stem, root and flower part of J. adhatoda against Gram-negative (E. coli and P. syringe) and gram-positive (B. cereus and S. aureus) bacterial strains. Antibiotic was used as standard. Based on the data presented here in; for root, the largest zone of inhibition was found to be against B. cereus (13mm) in water extracts at 100 μg/ml concentration followed by against all other three bacteria with 12mm inhibition zone in methanol extract. For stem, the largest zone of inhibition was found to be against E. coli (17mm) in methanol extracts followed by against S. aureus with 16mm inhibition zone in methanol and water extracts (100 μg/ml concentration). In case of flower, the maximum inhibition Zone (IZ) was 17 mm against E. coli (in water extract) and S. aureus (in methanol extract) followed by P. syringe (methanol extract) with 15mm inhibition zone. For leaves, highest IZ was 17 mm against E. coli (in water extract) followed by S. aureus (in methanol and pet ether extract) with IZ of 15mm. So, this study provided referential information about the antimicrobial activity of different extracts of different parts of Justicia adhatoda L. It may be effective in identifying a new bioactive compound for the development of novel medications.