Cinnamon investigated

Dr. Sanjida Topa and her colleagues at Swinburne University of Technology in Australia have been investigating traditional medicines. Most recently, they looked at cinnamon.

They focused on this particular spice because, as Dr. Topa explains, “many previous studies have reported antimicrobial activity of cinnamon essential oil, [but] it is not widely used in the pharmaceutical industry.”

In particular, they concentrated on a component of cinnamon oil called cinnamaldehyde (CAD), which is responsible for cinnamon’s distinctive taste and aroma. Their findings were published recently in the journal Microbiology

The researchers wanted to test whether CAD could break up biofilms, which are sticky layers that are often responsible for persistent infections that even antibiotics cannot touch. The most well-known example of a biofilm is the plaque found on teeth.

In order to congregate and form into biofilms, bacteria must communicate with each other to build this complex structure. The researchers wondered whether CAD might disrupt this highly orchestrated event.

“We hypothesized that using natural antimicrobials, such as essential oils, might interfere in biofilm formation. Thus, we focused on the impact of different concentrations of cinnamaldehyde in different biofilm development stages.”

Breaking up biofilms

For their experiments, they used Pseudomonas aeruginosa, a bacterium commonly responsible for infections in people with reduced immune systems, such as individuals with cancer, diabetes, or cystic fibrosis.

When CAD was tested against bacterial biofilms, it was shown to break them down in over three quarters of cases. It also appeared to hinder the formation of biofilms and prevent bacteria from spreading.

Biochemical analysis showed that the disruption of biofilm genesis was likely due to reduced levels of a second messenger called bis-(3′–5′)-cyclic dimeric guanosine monophosphate, which is known to be important in their formation.

“These findings definitely contribute to the search for novel antimicrobials. […] Fabrication of cinnamaldehyde for surface treatments, for example [to treat] skin infections, could be the first direct application.”