Effect of alcoholic extract of oleander leaves and flowers on some pathogenic bacteria

Abstract

Abstract

 This study aimed to demonstrate the antibacterial activity of crude leaf and flower extracts of oleander (Nerium oleander), a medicinal plant traditionally used to treat infections. Given the increasing resistance of pathogenic bacteria to antibiotics, particularly multidrug-resistant strains (MDRs), this study aimed to evaluate the efficacy of oleander extracts against selected Gram-positive and Gram-negative bacteria and compare it to antibiotics commonly used in healthcare settings. Plant material was collected, dried, and then extracted using 70% ethanol. Different concentrations (10%, 30%, and 50%) were tested using the disc diffusion method.. Results showed that many bacterial isolates, particularly E. coli and Enterococcus, were resistant to multiple antibiotics. In contrast, oleander extracts demonstrated inhibitory effects, especially at 50% concentration. The leaf extract was more effective than the flower extract, producing larger inhibition zones against Streptococcus, E. coli, Enterobacter, and Pseudomonas. The findings suggest that Nerium oleander possesses significant antibacterial potential, especially against resistant strains, and may serve as a natural alternative in antimicrobial therapy. Further research is recommended to isolate and identify the active phytochemicals responsible for this activity.