Final Blog Post

Although antibiotics have saved many lives and are an essential contribution to medicine, bacteria have developed a strong resistance to them. This resistance will put many more patients at risk of death due to bacterial infection from serious, common procedures such as organ transplants and chemotherapy. The antibiotic resistance crisis is only becoming more dire due to several causes. Antibiotics are overused immensely and this increases the resistance to them. The administration and distribution of antibiotics have also greatly contributed to the antibiotic resistant strains of bacteria that are seen today, such as tuberculosis and MRSA. Antibiotics are often used agriculturally to increase yields of meat produced by livestock, but these antibiotics are transferred to humans through the consumption of these products. One solution to decrease the rate at which bacteria are growing resistant to the only method we have to fight them is to create new antibiotics. However, new antibiotics have not been developed in the last thirty-five years. Antibiotics are no longer the most profitable drug, so companies do not want to invest in the development of them. For companies that do want to invest in this, it is still a challenge, as obtaining approval for antibiotic development is difficult.

One way to combat the resistance is to use naturally derived substances, such as honey. Honey is known to contain antibacterial properties. There are many different kinds of honey and each one possesses different antimicrobial properties. In general, they can be separated into two categories, peroxide honeys and non-peroxide honeys. Hydrogen peroxide is a result of the glucose oxidase enzyme, which plays a role in the bee’s digestion of the nectar, which when treated with heat, or light may be inactive. The gluconic acid, also a result of this enzyme, contributes to the low pH of the honey, along with other acids in the substance. The low pH is also a factor in the antimicrobial property. Due to different activity levels of this enzyme, the amount of hydrogen peroxide varies by type of honey, which could account for the varying antimicrobial efficiency in peroxide honeys (Nanda, 2015). Non-peroxide honeys have other properties that make up for the lack of this property. They contain the compound methylglyoxal in very high concentrations. All honeys have this compound, but most contain a very low concentration of it, aside from non-peroxide honeys. Methylglyoxal is antibacterial and is formed from sugars when heated or stored for long periods of time. This compound is derived, specifically, from dihydroxyacetone, which is heavily concentrated in the nectar of the flowers from which non-peroxide honey is derived (Kwakman, 2011). The antibacterial component of this compound comes from the fact that it alters the structure of the bacteria, so that it cannot survive under the conditions.(Rabie, 1).

Essential oils are also known to be antibacterial. Many of the antimicrobial properties of essential oils are due to their structural components, which are largely characterized as phenols. These compounds are also found in honey. A mixture of honey and essential oils would presumably work synergistically to provide a stronger antimicrobial agent than either of the two alone, which is what this project aimed to show.

Over the course of this project, it was shown that honey and oil do, in fact, show greater antimicrobial properties when mixed. Many different types of honey and oil were tested in varying concentrations. Before mixing any substances, the honey samples were tested alone. Both peroxide and non-peroxide honeys were tested. Non-peroxide honeys exhibited a much greater inhibition of bacterial growth. This was determined through examining the zone of inhibition when the bacteria were placed on plates with the honey samples. Various oils were also tested. The oil that was shown to have the highest antibacterial resistance was cinnamon cassia. Once the best honey and oil samples were determined, they were mixed in varying concentrations in efforts to find the best antibacterial surface.

At first, when mixing the honey and oil, it was determined that another substance would have to be added in order to make a homogeneous mixture. In efforts to keep the substance natural, aloe vera gel was used to do so. Once added, the substances were able to mix due to the hydrophilic head and hydrophobic tail of the aloe. The non-peroxide honey used, which was Manuka honey, and the cinnamon cassia oil showed the most resistance to bacterial growth, so they were mixed together and showed the highest resistance out of all of the formulations. Once this was determined, the concentration of the oil was increased to see if the bacterial effect would be greater, which it was.

Now that it has been determined which surfaces work the best, we will examine various types of Manuka honey and cinnamon cassia oil. Manuka honey has something called a “manuka factor” which varies among different types/brands. This factor will be examined to determine whether a higher manuka factor will exhibit a higher resistance to bacterial growth. Cinnamon cassia oil is relatively similar among different brands, but may still vary slightly in its properties, so future elaborations of this project will examine this. Lastly, plant powders will also be added to the formulations. These powders will add to the antibacterial effect of the surfaces. The most effective pairings of all three substances will be examined.

The opportunity to conduct this research has allowed me to gain experience that I could not otherwise have obtained. I will be able to take the skills I have developed over the course of this project and apply them in my career. In the beginning of April I was able to present this research in Orlando at the American Chemical Society National Conference, which allowed me to present in a professional setting. I was also able to develop a close relationship with my mentor, Dr. Jaimelee Rizzo, as I had to consult her about my results often. Although it took a lot of time and dedication, I am grateful that I was able to conduct this research.

Blog Post 3

It is widely known that honey is antimicrobial. However, there are many different kinds of honey and the antimicrobial properties differ amongst them. Dr. Rizzo and I have been experimenting to determine the best honey to focus our research on. We sent out samples containing both raw honey and Manuka honey to LIU Post, where the antimicrobial factors of the samples are tested using the zone diameter of inhibition technique. When tested alone, the raw honey gave a value of 1.1 for the diameter, which is the minimum diameter needed to be considered antimicrobial. This showed us that raw honey itself was not as effective as Manuka honey, so we are now starting to focus on using different brands of Manuka Honey. In order to understand why there was such a difference in the effects of the pure honey samples, I conducted a literature search. The reason for the difference in antimicrobial effectiveness between these two honeys comes from their composition. Raw honey is a peroxide honey, while Manuka honey is non-peroxide. For peroxide honey, peroxide and polyphenols contribute most to the antimicrobial properties of the honey. For honey that is non-peroxide, the main antimicrobial component is methylglyoxal, with polyphenols also being important. Although it is present in all honeys, methylglyoxal is much more concentrated in Manuka honey, which has stronger antimicrobial properties than peroxides.

In addition to determining the most effective honey, we have also been experimenting to find the most effective essential oil to mix the honey with. It has been determined that cinnamon cassia is definitely the most effective among the oils. In the first set of samples I prepared and had tested, I mixed a 3:1:1 ratio of honey, oil, and aloe vera gel, respectively. This gave values of 3.5 and 2.2 when tested against the growth of S. aureus and E. Coli. I consulted Dr. Rizzo with these results and we decided to test the effect when we increased the concentration of the cinnamon cassia oil, and thus the aloe vera gel. In the next set of samples, I prepared a sample of a 3:2:2 ratio of manuka honey to cinnamon cassia oil to aloe, respectively. This gave values of 4 for S. aureus and 3.6 for E. Coli, both of which show a very high antimicrobial factor.

We are still working on testing the longevity of these surfaces. I made a large amount of one sample and sent a potion to LIU Post. I have some stored in the research lab, which we will be sending out in increments each month. This data will give us information on the integrity and antimicrobial efficacy of the material over time. We are also beginning to test the change in antimicrobial effects when different oils are mixed into one sample. In addition, the use of plant powders will also be implemented into the samples.

Blog Post 2

In making my first samples, there were a few problems we ran into. We had previously determined that we needed to add aloe Vera gel in order to create a homogeneous mixture. Once we determined this, we needed to analyze the effect of its addition of the results of UV radiation and antimicrobial activity. The results showed that the higher the amount of aloe Vera gel, the more UV was able to penetrate the surface, which is not ideal. In order to reduce the effect of the aloe Vera gel, I experimented with adding lower concentrations. The concentration had to be high enough to still create a homogeneous mixture, but low enough to not effect the UV too extensively. It was found that for some samples, adding half of the amount of aloe still allowed the honey and oils to mix effectively, but for other samples, changing the amount of aloe did not allow for the separate layers to mix. We are still doing literature searches on the structure of the oils, honey, and aloe to further understand the interaction of the aloe with different oils and why lowering the concentration is allowed for some samples, but not others.

The surfaces we are creating are meant to have a longer shelf life and this aspect of our research had not been tested for this particular project. Dr. Rizzo and I devised a plan to test this. I made samples that were tested right away, but I kept part of these samples to be tested progressively throughout the semester. The UV radiation did not appear to change with the time the samples sat. However, we are still waiting for the antimicrobial results.

 

UGR Blog Post 1: Manuka Honey and Beeswax as a Natural Antibacterial Wound Dressing

Dr. Rizzo and I are studying the use of Manuka Honey and Beeswax as a Natural Antibacterial Wound Dressing.  We are creating a flexible wound dressing with these materials by infusing a variety of natural oils and powders. Our laboratory has previously demonstrated antimicrobial efficacy of a formulation utilizing other natural butters and oils against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa.  Our goal is to demonstrate that these novel materials will prevent skin infections and possibly serve to heal an already infected wound. Through this project, I will have the opportunity to present at a national conference for the American Chemical Society, where I will be able to discuss my research with many established scientists

My methods include measuring out certain volumes of essential oils and infusing them with various types of honey as well as beeswax. The types of honey include Manuka honey, Raw honey, and Raw unfiltered honey. The addition of aloe vera gel has proven to be necessary as well, due to the fact that the honey and oils do not mix together by themselves. The aloe allows all of the materials to combine into the same layer for testing. Once the sample is made, its resistance to ultraviolet radiation is tested as well as its antibacterial effect.