What are Antimicrobial Peptides (AMPs)? Think of them as Your Body’s “Natural Soldiers”.

Antimicrobial peptides, AMPs for short, are like small soldiers that our body produces naturally. They are made up of even smaller fragments called amino acids and represent the organism’s first line of defense against “bad” bacteria that can make us sick.

How Do These “Natural Soldiers” Fight Infections?

The main way AMPs work is by directly attacking bacteria. Imagine that bacteria have a kind of protective “shield” (cell membrane) which has a certain electrical charge (negative). AMPs have an opposite charge (positive), which makes them attracted to bacteria like a magnet.

Once they reach the bacterium, AMPs can:

• Puncture the bacterial shield: They disrupt and destroy the bacterium’s cell membrane, like popping a balloon.
• Attack from within: Some AMPs can penetrate inside the bacterium and affect other important parts, such as genetic material (DNA).

This multi-front attack strategy makes them very effective in destroying bacteria. Ordinary antibiotics, on the other hand, often have only one specific target.

Why Don’t We Use These “Natural Soldiers” More Often as Medicines? Existing Challenges.

Although AMPs are very promising, there are several challenges that limit their widespread use as medicines:

• They can also affect “good” cells: One of the main problems is that sometimes AMPs don’t clearly differentiate between “bad” bacteria and our body’s healthy cells. This means that if they were administered throughout the body (systemically, for example, by pill or injection), they could also affect healthy tissues.
• Localized action: Naturally, our body produces AMPs exactly where they are needed, for example, at the site of a skin infection. However, it is precisely this localized action that has made it difficult to develop them as drugs that circulate throughout the body. Past clinical trials have not always had the expected results when their widespread use has been attempted.

What Are Researchers Doing to Overcome These Challenges?

Scientists are working hard to turn AMPs into safe and effective treatments:

• Creating “smarter” AMPs: They are trying to modify the structure of AMPs to make them more effective against bacteria and less harmful to human cells.
• Administration methods: Most experimental AMPs must be administered intravenously (directly into the vein) because they are not well absorbed if taken orally (as pills). Solutions for this problem are also being sought. Interestingly, some antibiotics we already use, such as colistin and daptomycin, are quite similar to AMPs in their mode of action.

A Great Advantage: It’s Hard for Bacteria to Become Resistant to AMPs

One of the biggest advantages of AMPs is that bacteria develop resistance to them much more slowly compared to conventional antibiotics. Because AMPs attack bacteria in multiple ways, especially their membrane, it is difficult for bacteria to adapt and survive. Studies show that bacteria need much longer to become resistant to AMPs.

However, we must be careful. Excessive use of AMP-like antibiotics, such as colistin in veterinary medicine (for animals), has shown that bacteria can eventually develop resistance, and this resistance can spread.

New Ways to Use AMPs: Innovations in Treatment

Researchers are continuously exploring new strategies:

• Combined treatment with antibiotics: AMPs could be used together with regular antibiotics. This combination could help old antibiotics regain effectiveness against bacteria that have become resistant to them.
• Artificial Intelligence (AI) to the rescue: Scientists are now using AI to design and discover new AMPs much faster and more efficiently. AI can help identify compounds that selectively attack resistant bacteria, offering new hope in treating difficult infections.

Another Possible Use: Fighting Cancer

A very interesting research area is the potential of AMPs to target and destroy cancer cells. It seems that cancer cells have similar characteristics on their surface to those of bacteria (a certain negative electrical charge). This could pave the way for new cancer treatments that selectively attack tumors without affecting healthy cells.

What’s Next? The Future of AMPs

Researchers continue to seek new solutions:

• Smaller compounds from natural sources: Smaller antibacterial compounds derived from fungi are being studied, which could be easier to administer orally. Of course, these must be rigorously tested to ensure they are safe and effective.
• Smart strategies: Exploring new AMPs and finding the best ways to include them in current treatments is a very promising direction in our fight against dangerous bacteria and the growing problem of antibiotic resistance.

In short, antimicrobial peptides are powerful natural “weapons” of our body. While there are still challenges to overcome, scientists are making significant progress to turn them into new medicines that can help us combat infections and perhaps even cancer, especially as more and more bacteria become resistant to the antibiotics we currently have.

Source Medscape