Investigating the Antimicrobial Activity and Pigmentation of the Extract of Rhazya stricta Plant Against Human Bacteria

Background: Due to the increasing resistance of pathogenic bacteria to common antibiotics, researchers are looking for antimicrobial agents of plant origin as alternative drugs. Objectives: This study aimed to investigate the antimicrobial activity and pigmentation of the extract of the Rhazya stricta plant against human bacteria. Methods: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) in six concentrations were evaluated by the dilution method in a liquid medium on the determined bacteria. The pink color of the plant extract was assessed using ELISA. Results: The results of the diameter of the inhibition zone showed that the maximum diameter of the inhibition zone for ethyl acetate (2 mm), aqueous (7 mm), ethanolic (8 mm), methanolic (9 mm), and hydroalcoholic (10 mm) extracts was against Staphylococcus aureus. The smallest diameter of the inhibition zone was related to the ethyl acetate extract of R.stricta against methicillin-resistant strains of Staphylococcus aureus (MRSA) (2 mm), while the largest diameter of the inhibition zone was related to the methanolic extract of R.stricta (8 mm). Conclusions: The results of the study showed that different medicinal plant solvents inhibit the growth of pathogenic bacteria at different concentrations, which can be used in the treatment of infections caused by these bacteria. Additionally, this medicinal plant can be used in the dyeing industry due to its pigmentation properties.