The search for new antibiotics goes on and the accepted norm seems to be keeping our eyes narrowly focused on the bacteria that pervade our lives day in and day out. That’s a great idea, of course. Bacteria out number us probably along an order of 1 billion to 1. But what if there are other sources of antibacterial agents in the world, ones that haven’t been played out, and ones which just might provide new and/or unique mechanisms of action against the diseases that plague us?

For several years now, Luis Kanzaki’s team has been looking very closely into the jungle that surrounds them. With so much of the Amazon still to be “discovered” by Western science, it can still be very beneficial to look to their local, indigenous remedies for clues to new chemicals or drugs that may prove efficacious against some of our more dangerous pests. Every few years, researchers from Kanzaki’s lab in Brazil have published antimicrobial studies using locally known plants and trees which have typically been used to treat maladies from arthritis to sore throats to malaria. António Correia wrote papers in 2008, in which they found numerous, potentially new sources of antibiotics from plant extracts which were effective against several multi-drug resistant bacteria and again in 2010, where they discovered the presence of many of these same bacteria playing a part in the corrosion of metals of local dams and were able to inhibit their growth using similar plant extracts.

More recently, Amanda Oliveira et al. found more Amazonian medicinal plant extracts to search for antimicrobial activity. Running a type of Kirby-Bauer diffusion assay (click here to find a GoldBio instructional video), they tested their extracts against gram-positive (such as E. coli, Salmonella enterica and Pseudomonas aeruginosa) and gram-negative (such as Staphylococcus aureus and Enterococcus faecalis) bacterial strains as well as the yeast C. albicans. Their results are striking! Several of their extracts performed 40-50% as efficacious as the control drug, Ciprofloxacin, a second generation fluoroquinolone antibiotic. One extract, Ptychopetalum olacoides, outperformed the control against Klebsiella ozaenae, a multidrug resistant, gram-negative bacteria. That’s an amazing success if you consider that these are crude extracts going up against a widely used, synthetic, broad-spectrum antibiotic.

Of course, the active ingredients in these extracts still need to be teased out, tested and optimized. So it’s not as if these are ready to use antibiotics. Regardless though, opportunities like these don’t come around every day. And in our current world in which more bacteria are becoming resistant and less antibiotics are making it to market, it makes me wonder what other discoveries await us if we were to but look around our own little jungles for something interesting.

Oliveira, A. A., Segovia, J. F., Sousa, V. Y., Mata, E. C., Gonçalves, M. C., Bezerra, R. M., Junior, P. O., & Kanzaki, L. I. (2013). Antimicrobial activity of amazonian medicinal plants. SpringerPlus, 2(1), 1-6.

Correia, A. F., Segovia, J. F. O., Gonçalves, M. S. A., De Oliveira, V. L., Silveira, D., Carvalho, J. C. T., & Kanzaki, L. I. B. (2008). Amazonian plant crude extract screening for activity against multidrug-resistant bacteria. Eur Rev Med Pharmacol Sci, 12(6), 369-380.

Correia, A. F., Segoviae, J. F. O., Bezerra, R. M., Gonçalves, M. C. A., Ornelas, S. S., Silveira, D., Carvelho, J. C., & Kanzaki, L. I. B. (2010). Aerobic and facultative microorganisms isolated from corroded metallic structures in a hydroeletric power unit in the amazon region of Brazil.

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