Evaluation Of Antimicrobial Activity Of Methanolic And Ethanolic Extracts Of Three Varieties Of Nerium Oleander

Abstract

Background: Humans have utilized medicinal plants for health purposes since ancient times, notably the widespread usage of raw extracts of various components of medicinal plants to cure human ailments. Moreover, the occurrence of antibacterial and antifungal ingredients contributes to health properties. The purpose of this research was to assess the antifungal and antibacterial activities of three Nerium oleander cultivars (red, pink, and white). Materials and Methods: For this purpose, the researchers gathered flowers from several regions in Gaza City, Palestine. The extraction process was carried out utilizing a Soxhlet apparatus with 250 ml of 70% ethanol and methanol,  subsequently extract concentrations of 50, 100, 200, 300, and 500 mg/ml was generated using DMSO. Meanwhile, the researchers investigated the antibacterial properties of flower extracts against gram-positive bacteria (Staphylococcus aureus and Streptococcus group A) and gram-negative bacteria (Escherichia coli) as well as Candida albicans, using the well-agar diffusion technique. The Chi square test was then utilized to evaluate the statistical relationship between the extracts' antimicrobial activity and the type of solvent. Results: The findings of this investigation revealed that all flower extracts demonstrated no antibacterial activity against E. coli at all concentrations tested using both ethanolic and methanolic extracts. Nonetheless, the other two bacteria were sensitive to these extracts, with only the ethanolic red variant displaying antibacterial activity against Streptococcus spp. with inhibition zones of 5 and 7 mm at 100 and 300 mg/ml, respectively. While an ethanolic extract of all three flowers at 300 mg/ml inhibited S. aureus, the red flowers had the strongest impact, with an inhibition zone of 6 mm. The methanolic extract of white flowers, on the other hand, had no impact on S. aureus; however, the methanolic extracts of pink and red flowers each had a noticeable antibacterial effect, with an inhibition zone of 4 mm for both. Surprisingly, merely the ethanolic extract of the red flower exhibited antifungal activity against Candida spp, whereas the ethanolic extracts of all three-flower varieties showed activity at a concentration of 300 mg/ml. Nevertheless, there was a statistically significant relationship between antimicrobial activity and extract type. Conclusion: Overall, the current investigation demonstrated variations in findings between the three cultivars as well as this study revealed the antibacterial and antifungal activities of N. oleander flower extracts.