Antibacterial Effects of Extract of Hedge Nettle and Purslane Plants on Staphylococcus aureus: In Vitro and Animal Model

Antibacterial Effects of Extract of Hedge Nettle and Purslane Plants on Staphylococcus aureus: In Vitro and Animal Model
Nader Kazemi,^1,* Zahra Asadi,²
1. Department of Microbiology, Biology Research Center, Zanjan Branch, Islamic Azad University, Zanjan, Iran
2. Department of Microbiology, Biology Research Center, Zanjan Branch, Islamic Azad University, Zanjan, Iran
Introduction: Infectious diseases are one of the most common diseases around the world which impose enormous financial burden on society. Staphylococcus aureus is an important causes of nosocomial infections and multi drug resistance. Although synthetic antibiotics have been able to play an important role in treatment of infectious diseases in past decades, however problems related to microbial resistance of antibiotics have caused that the medical plants to be considered as an alternative. On the other hand, medical properties of the extracts and essential oils against microbial as well as non microbial diseases have been known since ancient times and many studies have been performed on medical properties of the different plant species and their essential oil or extracts effects on microorganisms.
Methods: In this study, aqueous and ethanolic extracts were prepared from dried leaves of the Stachys schtschegleevi and Portulaca oleracea, then anti-bacterial activities of the extracts for Staphylococcus aureus were experimented, first by the method of well diffusion in agar, and later the amount of the MIC and MBC of the extracts were measured by broth dilution method. In animal model study, first 5×105 CFU/ml of bacteria was intraperitoneally injected and after 24 hours, 0.5ml (as MBC concentration of each the extracts) of extracts, to female BALB/c mice was intrapertioneally injected. Then, the counting of bacterial clonies in spleen were determined with cultivation on Mueller Hinton agar after 7 days as the standard protocol.
Results: The experiment results concerning the determination of growth inhibition diameter in agar showed that the maximum of growth inhibition diameter is related to the ethanolic extract of Stachys schtschegleevi (20 mm), and the minimum of growth inhibition diameter is related to ethanolic extract of Portulaca oleracea (10 mm) at the highest concentration (400 mg/ml). The results of broth microdilution method on Staphylococcus aureus showed that the amount of MIC and MBC in ethanolic extract for Stachys schtschegleevi were 52.5 mg/ml and 125 mg/ml respectively, while this amounts for ethanolic and aqueous extracts of Purtulaca oleracea and Stachys schtschegleevi were the same and equal to 125 mg/ml and 250 mg/ml. The aqueous extract of the Portulaca oleracea did not show any antimicrobial activity. In conditions of in vivo, after 48 hours spleen supernatant cultivation, the average number of bacteria for ethanolic extracts of the Stachys schtschegleevi and Portulaca oleracea were 1.8×103 CFU/ml and 6.6×103 CFU/ml respectively and for aqueous extract of Stachys schtschegleevi was 14.6×103 CFU/ml. These results showed significantly decrease in number of bacteria in all experimental groups (p˂0.5) compared to control group.
Conclusion: In general, the results of evaluations in experimental conditions and the animal model showed that ethanolic and aqueous extracts of Stachys schtschegleevi and ethanolic extract of Portulaca oleracea have the effective antibacterial activity against mentioned bacteria and can be useful to treatment of nosocomial infections.
Keywords: Antimicrobial, Portulaca oleracea, Stachys schtschegleevi, Staphylococcus aureus