Monday December 2 2013
Algae are a rich source of the fatty acids that scientists tested
"Scientists in Scotland believe marine algae could help fight spots," reports the Mail Online. The news comes from a study that suggests that fatty acids found in marine algae such as seaweed could be an effective additional treatment against some strains of bacteria associated with acne.
Researchers were interested in whether certain acids known as long-chain polyunsaturated fatty acids (LC-PUFAs), which are found in marine algae, had antibacterial properties.
Acne and many other skin infections are related to strains of bacteria that normally live harmlessly on the skin – usually Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus).
As the researchers say, there is a need for alternative topical treatments (those applied directly to the skin) as the treatments used currently are either not very effective, or cause undesirable side effects such as skin irritation or dryness.
The study found that when applied to bacterial cultures in the laboratory, LC-PUFAs were most effective at preventing growth of P. acnes and less effective against S. aureus. When tested in combination, standard treatments and LC-PUFAs seemed to work well together.
So far the preparations have only been tested on bacterial cultures in the laboratory, not on people. Further research is needed to see whether a LC-PUFA preparation could be developed that would be a safe and effective acne treatment.
If you have poorly controlled acne, talk to your GP. Many treatments that could work well for you are only available on prescription.
Where did the story come from?
The study was carried out by two researchers from the School of Natural Sciences at the University of Stirling in Scotland and was published in the peer-reviewed open access scientific journal Marine Drugs. The study can be read free online or downloaded as a PDF (PDF, 593kb).
It was funded by Dignity Sciences Ltd, a company reported to be pursuing the use of LC-PUFAs to treat acne. The researchers state that Dignity Sciences had no influence on the study design, data collection or analysis.
The Mail Online's reporting of the study was accurate, although it could have been been made clearer that this is very early stage research and no treatments based on LC-PUFAs have been developed yet.
What kind of research was this?
This was a laboratory study that aimed to investigate whether LC-PUFAs were effective at preventing the growth of the bacteria that cause acne and other skin infections. The researchers also wanted to see whether LC-PUFAs could potentially be used in treatments for these skin conditions.
The researchers say that LC-PUFAs have been demonstrated to have anti-inflammatory and antimicrobial properties, and have been attracting attention as topical treatments for skin infections.
In this study, researchers investigated the activity of LC-PUFAs against P. acnes and S. aureus. Both of these bacteria are present on everyone's skin. In people who are prone to an oily build-up on the skin, P. acnes can multiply, leading to the inflamed spots characteristic of acne. S. aureus is also associated with many different types of skin infection, such as boils, abscesses, impetigo and cellulitis, as well as sometimes causing serious infection of the body.
Current topical treatments for acne include the application of benzoyl peroxide, salicylic acid and certain antibiotics, while topical treatments for S. aureus infections include the application of fusidic acid, mupirocin, neomycin and polymyxin B. However, there are problems with some of these skin treatments either not being effective or causing side effects such as irritation or drying of the skin.
What did the research involve?
The researchers first investigated whether LC-PUFAs could prevent bacterial growth of P. acnes and S. aureus, and then looked at how they interacted with other drugs used to treat these skin infections.
They looked at the effects of six LC-PUFAs:
- dihomo-γ-linolenic acid (DGLA)
- docosahexaenoic acid (DHA)
- eicosapentaenoic acid (EPA)
- γ-linolenic acid (GLA)
- 15-hydroxyeicosatrienoic acid (HETrE)
- 15-hydroxyeicosapentaenoic acid (15-OHEPA)
In the laboratory, the researchers prepared alcohol solutions of the LC-PUFAs and then treated bacteria cultures with them. They used cultures of P. acnes and 10 different strains of S. aureus, including three isolates of MRSA (methicillin-resistant S. aureus) – two that caused community-acquired infection and one that caused hospital-acquired infection – and two isolates of S. aureus with resistance to vancomycin, an antibiotic usually used to treat MRSA.
They also treated the bacteria with two solutions of alcohol to demonstrate that the solvents used to prepare the LC-PUFA solutions were having no effect.
The researchers examined the minimum concentration of LC-PUFAs required to inhibit growth of the bacteria and the minimum concentration of LC-PUFAs required to kill the bacteria.
They then carried out a different type of test that allowed them to look at how the six LC-PUFAs interacted with both benzoyl peroxide and salicylic acid when treating P. acnes, both of which are widely used topical treatments for acne.
The researchers also looked at the interaction of the LC-PUFAs with benzoyl peroxide, salicylic acid, fusidic acid, mupirocin, neomycin and polymyxin B when treating S. aureus.
What were the basic results?
The researchers found that HETrE and DHA were the most effective LC-PUFAs for preventing the growth of P. acnes, with the minimum concentration required to prevent growth being 32mg/l. This was followed by GLA at a concentration of 64mg/l. However, although they inhibited growth, none of the LC-PUFAs were able to kill P. acnes up to the maximum concentration tested of 4,096mg/l.
The LC-PUFAs were generally less effective against S. aureus. Overall, the minimum concentration required for each LC-PUFA to prevent growth of S. aureus (non-MRSA) was up to eight times higher than for P. acnes. DHA and EPA were the most effective at preventing growth of S. aureus, with a minimum concentration required of 128mg/l.
However, in contrast to P. acnes, the LC-PUFAs were able to kill S. aureus at the same concentration needed to prevent growth, or double that concentration.
Against the stronger MRSA and vancomycin-resistant strains, the best LC-PUFA was DHA, followed by EPA, GLA, HETrE, 15-OHEPA and DGLA.
The effectiveness of benzoyl peroxide and salicylic acid at preventing the growth of P. acnes was similar to the LC-PUFAs (minimum required concentration of 64mg/l). Neither of these agents were able to kill P. acnes up to the maximum concentration tested of 4,096mg/l. They were less effective against S. aureus and needed higher concentrations to prevent growth.
Fusidic acid and mupirocin were the most potent against S. aureus, needing a minimum of 0.25mg/l to prevent growth, while neomycin and polymyxin B were less effective. However, all six of the agents were able to kill S. aureus.
None of the LC-PUFAs had an inhibitory effect on any of the standard treatments for P. acnes and S. aureus. When combined with benzoyl peroxide, three LC-PUFAs (15-OHEPA, DGLA and HETrE) were actually found to have a synergistic effect and were more effective against the bacteria when working together.
How did the researchers interpret the results?
The researchers concluded that, "LC-PUFAs warrant further evaluation as possible new agents to treat skin infections caused by P. acnes and S. aureus, especially in synergistic combinations with antimicrobial agents already used clinically."
This laboratory study investigated the effects of six long-chain polyunsaturated fatty acids (LC-PUFAs) found in high levels in marine organisms when used against the bacteria that cause acne (P. acnes) and various other skin infections (S. aureus).
As the researchers say, there is a need for alternative topical treatments for these skin conditions, as the treatments used currently tend to be either not very effective, or cause undesirable side effects such as skin irritation or dryness. LC-PUFAs have previously been demonstrated to have antimicrobial and anti-inflammatory properties.
This research demonstrated that LC-PUFAs were most effective at preventing the growth of P. acnes, but were less effective against S. aureus. However, the LC-PUFAs were able to kill S. aureus bacteria but not P. acnes.
LC-PUFAs had a similar effect to the commonly used topical treatment benzoyl peroxide against the acne-causing bacteria. Importantly, the LC-PUFAs did not inhibit the activity of the standard treatments when used in combination, and some even seemed to have a beneficial effect and worked well together.
This was exploratory research – so far, the preparations have only been tested on bacterial cultures in the laboratory, not on real people. Further research is needed to see whether a LC-PUFA preparation could be developed for the topical treatment of acne or skin infections in people. It would then need further trials to test that it is effective and, most importantly, safe.
Acne may not be life threatening, but it can be extremely distressing. Any new effective treatment that can be used topically and does not involve the use of antibiotics would be welcome.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter.