The search for novel antimicrobial compounds continues as the world seeks to combat the growing rise of antimicrobial resistant bacteria. Such organisms pose a particular challenge to the hospital environment and to patients with wreaked immune systems.
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Novel areas of antimicrobial research include the application of ‘smart’ polymers, the use of biomedical and electrochemical technologies, and the so-called poison arrow (a new method to break through the bacterial cells wall).
Another area being examined is ethnobotany. This is the study of the interrelationship between people and plants, especially the role of plants in human culture and practices, including how people represent plants in their systems of knowledge. This involves examining natural plant products like alkaloids, tannins, saponosids, essential oil, oleoresin, and assessing secondary metabolites.
With the antimicrobial space, this concerns, according to Biotechniques, the examination of plant natural products. Plants present a generally untapped resource for discovering bioactive compounds. Some of these have the potential to address the antimicrobial drug development pipeline.
The basis for this is summed up nicely in a research paper, which reads: “plants can develop different constitutive and inducible mechanisms for the protection from pathogenic infection via morphological barriers, secondary metabolites or antimicrobial peptides.”
The potential for natural products from plants relates to their rich and unique chemodiversity, their worldwide distribution and ease of access, their various antibacterial modes of action, and the proven clinical effectiveness of plant extracts from which they are isolated.
As an example, one research team has studied natural berberine-hybridized benzimidazoles for use as potential antibacterial agents in order to treat Staphylococcus aureus infection. S. aureus is prone to developing resistance to several antibiotics and this has proved particularly challenging in the hospital environment.
Other studies have demonstrated similar efficacy, together with low cytotoxicity, and strong antibacterial activities against multidrug-resistant Escherichia coli.
Several comparisons have also been run against conventional antibiotics, such as Streptomycin and Tetracycline, where equal or better results have been obtained. Examples of promising agents include ethanolic extract of Azadirachta indica and aqueous and ethanolic extracts of Eucalyptus globulus and Bergenia ciliata and ethanolic extract of Punica granatum.
Researchers are now seeking to assess the various antibacterial activities of these products and to establish a more robust selection criteria in order to identify the best candidate products to be used in antimicrobial clinical trials.