Researchers studied whether a type of leech called Poecilobdella manillensis could help treat atherosclerosis, a disease where fatty deposits build up in arteries and restrict blood flow. Using both animal models and lab tests, scientists found that this leech extract lowered cholesterol levels, reduced dangerous blood clots, and decreased inflammation in blood vessels. The treatment appeared to work by stopping a harmful process called cell death that damages the inner lining of arteries. While these early results are promising, this research is still in the laboratory and animal testing phase, so much more work is needed before it could be used in humans.

The Quick Take

  • What they studied: Whether an extract from a specific leech species could reduce artery damage and inflammation caused by atherosclerosis (clogged arteries)
  • Who participated: The study used rabbits fed a high-fat diet to mimic human artery disease, plus laboratory-grown blood vessel cells exposed to harmful cholesterol particles
  • Key finding: The leech extract reduced cholesterol levels, decreased dangerous inflammation markers, and protected blood vessel cells from damage in both animal and lab experiments
  • What it means for you: This suggests a natural treatment might one day help prevent or slow artery disease, but it’s very early research. Don’t expect leech treatments at your doctor’s office anytime soon—much more testing in humans is needed first

The Research Details

This research combined two different approaches to test the leech extract. First, researchers gave rabbits a high-fat diet and injured their neck arteries to create atherosclerosis, then treated some rabbits with different doses of the leech extract (0.1, 0.4, or 0.8 grams per day). They measured changes in cholesterol, blood clots, and artery damage.

Second, they grew human blood vessel cells in the lab and exposed them to oxidized cholesterol (the type that damages arteries). They then treated these cells with blood serum from the rabbits that had received the leech extract to see if it protected the cells.

This two-part approach—testing in living animals and in isolated cells—helps researchers understand both whether something works and how it might work in the body.

Using both animal models and lab cell studies provides stronger evidence than either approach alone. The animal studies show real-world effects in a living system, while the cell studies help identify the specific biological mechanisms involved. This combination helps researchers understand if the treatment is truly effective and why.

This study has some limitations worth noting: the sample size of animals isn’t specified, which makes it harder to assess statistical reliability. The research is preliminary and hasn’t been tested in humans yet. The journal is relatively new (Atherosclerosis Plus), so it may not have the same established reputation as older journals. These early-stage results are interesting but require confirmation through larger, more rigorous human studies before any medical claims can be made.

What the Results Show

In the rabbit studies, the leech extract produced several beneficial effects. It lowered blood cholesterol levels and reduced the formation of dangerous blood clots, both key problems in atherosclerosis. When researchers examined the rabbits’ neck arteries, they found less fatty buildup and less damage to the smooth muscle cells that make up artery walls.

In the lab cell experiments, cells treated with serum from leech-treated rabbits showed improved health markers. These cells produced more energy (ATP), had higher survival rates, and showed less of the harmful inflammation that damages arteries. The researchers measured multiple inflammatory markers and found that the leech extract reduced most of them significantly.

The research identified specific biological pathways that appear to be involved in how the leech extract works. It reduced several inflammation-promoting proteins and blocked a harmful cell death process called pyroptosis. The extract also improved how well cells could produce energy and reduced oxidative stress (cellular damage from harmful molecules). These findings suggest the leech extract works through multiple protective mechanisms rather than just one.

This research builds on traditional medicine practices that have used leeches for centuries. Previous studies have suggested that leech extracts have anti-inflammatory and blood-thinning properties. This study is more specific, focusing on the molecular mechanisms and testing against a particular disease model. The findings align with growing scientific interest in natural compounds that might protect blood vessels, though most such compounds remain in early research stages.

Several important limitations should be considered: the exact number of animals tested wasn’t clearly specified, making it hard to judge statistical strength. The research only tested rabbits, not humans, so results may not translate directly to people. The study used isolated lab cells, which don’t fully replicate the complexity of a living body. Long-term effects weren’t studied, so we don’t know if benefits persist over time. Finally, the optimal dose for humans (if this ever reaches human testing) remains completely unknown.

The Bottom Line

Based on current evidence, this leech extract cannot be recommended for human use yet. This is very early-stage research (laboratory and animal testing only). Anyone interested in preventing or treating atherosclerosis should follow established medical advice: maintain a healthy diet, exercise regularly, manage stress, avoid smoking, and work with their doctor on cholesterol management. If this research progresses to human trials and shows promise, that would be the time to consider it as a potential treatment option.

This research is most relevant to cardiovascular researchers, pharmaceutical companies developing new treatments, and people interested in natural medicine approaches. People with atherosclerosis or high cholesterol should continue following their doctor’s current treatment plans. This finding doesn’t change any current medical recommendations. Scientists studying inflammation and cell death mechanisms may also find this research interesting.

This research is in the very early stages. If it progresses normally, it would take many years before human trials could begin, and several more years of testing before any potential treatment could reach patients. Realistic timeline: 5-10+ years minimum before this could potentially be available as a medical treatment, if it continues to show promise through additional research.

Want to Apply This Research?

  • Users interested in heart health could track their established cardiovascular risk factors: weekly cholesterol levels (if monitored), daily steps walked, servings of vegetables consumed, and stress levels. This creates a baseline for monitoring heart health while waiting for future research developments.
  • Users could use the app to build and maintain proven heart-healthy habits: following a Mediterranean-style diet, exercising 150 minutes weekly, managing stress through meditation, and taking prescribed medications as directed. These evidence-based practices provide real protection while experimental treatments like this leech extract continue research.
  • Set up long-term tracking of cardiovascular health markers that users can discuss with their doctor: blood pressure, cholesterol levels (if available), exercise consistency, diet quality, and stress management. This creates accountability and helps users see the impact of lifestyle changes on their heart health over months and years.

This research is preliminary and has only been tested in animals and laboratory cells, not in humans. The leech extract (Poecilobdella manillensis) is not approved for human use and should not be used to treat any medical condition without explicit guidance from a qualified healthcare provider. If you have atherosclerosis, high cholesterol, or other cardiovascular concerns, continue following your doctor’s treatment recommendations. Do not attempt to obtain or use leech extracts based on this research. Always consult with your healthcare provider before making any changes to your treatment plan or starting any new supplements or alternative therapies.