Antidepressants such as Prozac are usually prescribed for the treatment of mental health disorders, but new research suggests that they could also protect against severe infections and life -threatening sepsis. Scientists at the Salk Institute have now revealed how drugs are able to regulate the immune system and defend infectious diseases that could lead to a new generation of therapies for salvation and enhance global readiness for future Pandemics.
The Salk study follows the recent findings that users of selective serotonin reuptake inhibitors (SSRIs) such as Prozac had less severe COVID-19 infections and were less likely to develop long Covid. Another study found that prozac-also known as fluoxetine-efficient in protecting mice from sepsis, a life-threatening condition in which the body’s immune system exceeds in an infection and can cause multiple organs deficiency or even death . By identifying a mechanism to explain the amazing effects of fluoxetine defense, Salk researchers brought fluoxetine and possibly other SSRIs closer to clinical trials for use against infections and immunological disorders.
Findings were published in Scientific progress on 14 February 2025.
In the treatment of an infection, the optimal treatment strategy would be the one that kills bacteria or virus, while protecting our tissues and organs. Most medicines we have in our toolbox kill pathogens, but we were excited to find that fluoxetine can protect tissues and organs. Playing virtually an offense and The defense, which is ideal and particularly exciting to see in a drug we already know is safe to use people. ”
Professor Janelle Ayres, holder of the legacy chair of the Salk Institute and Howard Hughes Medical Institute Investator
While our immune system pays the best possible to protect us from infections, they can sometimes react too much. In septicemia, the inflammatory response revolves so out of control that it begins to destroy the tissues and organs of a person at the point of failure. The same excessive reaction is also characteristic of the severe Covid-19 disease.
An obvious solution would probably be to suppress the inflammatory response, but this can really make patients more vulnerable to their initial infection-and more sensitive to new ones. Time is also critical, as immunosuppressive drugs should be administered before any tissue damage.
Instead, an ideal treatment could preventively control the intensity and duration of immune response to prevent any bodily harm and 2) to kill the infection that endangers the body at risk.
To understand what the SSRIs can do in this context, the researchers studied mice with bacterial infections and were divided into two categories: one pre -treatment with fluoxetine and the other not. Enthusiastically, they saw that mice that had been pre -treated with fluoxetine were protected from sepsis, multiple organs damage and death. The team then started a series of tracking experiments to understand these results.
First, they measured the number of bacteria in each mouse population eight hours after infection. The mice that were treated with fluoxetine had fewer bacteria at this stage, indicating a less severe infection. The findings showed that fluoxetine had antimicrobial properties, which allowed it to limit the growth of bacteria.
The researchers then measured the levels of different inflammatory molecules in each group. They saw more anti-inflammatory IL-10 in their pre-processed populations and suggests that IL-10 prevented hypertylycemia-induced septylelycemia-a condition in which blood contains too many fatty triglycerides. This allowed the heart to maintain the correct metabolic condition, protecting mice from morbidity and mortality caused by infection.
The group disconnected this IL-10-dependent protection against multiple organs damage and death from the previous discovery of antimicrobial effects of fluoxetine, in turn revealing the dual-user’s dual user capabilities in 1) kill pathogens and 2) relieve the damage caused by infection in the body.
To understand how the effect of fluoxetine on serotonin levels can contribute to these results, the researchers also examined two new mice: both of them had previously been processed with fluoxetine, but someone had been released serotonin while The other didn’t. The circulation of serotonin is a small chemical messenger who travels to the brain and body to regulate things such as mood, sleep and pain and is the main objective of the effects of Fluoxetine mental health. Found that the positive effects of fluoxetine health were completely unrelated to the circulation of serotoninRegardless of whether mice had serotonin in circulation, they presented the same defense infection from fluoxetine.
“This was really unexpected, but also really exciting,” says first writer Robert Gallant, a former postgraduate researcher in Ayres. “Knowing of fluoxetine can regulate the immune response. Protect the body from infection, and You have an antimicrobial effect-all completely regardless of the circulation of serotonin-it is a huge step towards developing new solutions for life-threatening infections and diseases. It really goes to show how much more there is to find out about SSRIs. ”
Ayres and Gallant say their next step is to explore fluoxetine dosage shapes suitable for septic people. They are also willing to see if other SSRIs can have the same results.
“Fluoxetine, one of the most prescription drugs in the United States, promotes cooperation between host and pathogen to defend the disease and mortality caused by infection,” says Ayres, also head of molecular laboratories and physiology Systems in Salk. “Finding duplicate protective and defensive results in a reassistable drug is really exciting.”
Other writers include Karina Sanchez, Emeline Joulia and Christian Metallo of Salk and Jessica Snyder of the University of Washington.
The project was supported by the National Institutes of Health (DPI AI144249, R01 AI14929, F31 AI169988, T32 GM007240-43, T32 GM133351, NCI CCSG: P30CA014195) and the foundations Nomis.
Source:
Magazine report:
Gallant, RM, et al. (2025) Fluoxetine promotes metabolic defenses dependent on IL-10. Scientific progress. doi.org/10.1126/sciadv.adu4034.
