ADVERTISEMENT

Capsaicin, The Pungent Ingredient In Chili Peppers, Has Antidepressant-Like Properties

Depression is a mental illness that affects nearly 320 million people around the world. It is the second-highest cause of work disability, and some projection analyses predict it could become the first by 2020. Depression is a devastating condition for the person who suffers from it and also for the people around them.

Although there are several medications for depression, ~30% of patients have little response to these treatments. Moreover, all the medications for depression have undesirable side effects to some degree. Thus, the search for new and more efficient treatments for this disease is highly desirable.

ADVERTISEMENT

In this respect, researchers from Mexico’s universities have recently found that capsaicin, the pungent ingredient of chili peppers, exhibits antidepressant-like properties. As is commonly known, chili is a fruit widely used in the gastronomy of many countries in the world, among which Mexico is one of the main consumers.

Using an animal model broadly employed for the screening of potential antidepressant drugs, a forced swimming test in rats, the researchers discovered that low doses (50 to 250 µg/kg)  of capsaicin reduced the immobility time (the index of antidepressant-like behavior) of the rats subjected to this test. These low doses of capsaicin were as effective as a saturating dose of amitriptyline, which is a tricyclic antidepressant drug used for the treatment of depression.  Moreover, ineffective low doses of capsaicin (1 pg/kg, and 1 ng/kg) were indeed effective when they were combined with a small dose of amitriptyline.

Capsaicin is a physiological agonist of the transient receptor potential cation channel subfamily V member 1 (TRPV1). This type of cell membrane receptors was discovered not long ago, and they were almost exclusively attributable to the transmission of noxious information. However, TRPV1 channels were found to be extensively expressed in many areas of the brain, especially in those structures involved in the control of emotions (limbic system).

In the study performed by the Mexican researchers, a non-pungent agonist for the TRPV1 channels, named palvanil, showed similar antidepressant-like properties as the pungent compound, capsaicin. This result could be potentially relevant for people who not tolerate the pungent flavor of capsaicin.  Likewise, the researchers found that capsaicin did not have stimulating effects on the muscle, and the general locomotor activity, suggesting that its antidepressant-like effects were exclusively on the nervous system, where antidepressant drugs act.

ADVERTISEMENT

Finally, unlike many antidepressant drugs used nowadays, capsaicin did not induce anxiogenic-like behaviors. It is certainly premature to consider capsaicin as an antidepressant treatment; however, this investigation offers promising results. More investigation is needed to determine if capsaicin is as effective in humans as it was in rodents. Assuming that capsaicin has antidepressant properties in humans, it would be a favorable improvement in the treatment of depression because the low doses employed in this compound envision much lesser collateral side effects than those provoked by antidepressant drugs currently used. Perhaps the good mood of Mexican people is in part a result of the ingestion of chili. 

The results of this investigation were published in the article entitled Capsaicin produces antidepressant-like effects in the forced swimming test and enhances the response of a sub-effective dose of amitriptyline in rats, published in the journal Physiology & Behavior. The research was conducted by Miriam E. Reyes-Mendez, Luis A. Castro-Sánchez, Adán Dagnino-Acosta, Irving Aguilar-Martínez, Azucena Pérez-Burgos, Clemente Vázquez-Jiménez, Eloy G. Moreno-Galindo, from the University of Colima, Fernando J. Álvarez-Cervera, José L. Góngora-Alfaro, from University of Yucatan; Ricardo A. Navarro-Polanco, and the leading author Javier Alamilla, from CONACYTUniversity of Colima.

Comments

READ THIS NEXT

Cellular Stress And Ampk Activators Including Metformin And The Anesthetic Drug Propofol Promote Restoration Of Human Consciousness

The neural mechanisms that give rise to human consciousness have been described as one of the greatest and most profound […]

IQ Scores And Levels: Range And Meaning

IQ stands for “intelligence quotient”—a composite score of various tests meant to measure human intelligence. A person’s IQ score is […]

The Backside Of Paintings: Why It’s Time For The Back Of Paintings To Get A Regeneration Process

When looking at paintings at the museum, the observer’s attention is literally captured by the colors, the forms, the feelings […]

What’s The Unintended Consequence Of Electric Cars?

Ozone. No, not the ‘good’ ozone up in the stratosphere that protects us from cosmic rays. I mean the ‘bad’ […]

How Many Countries Are There?

How many countries are there? Officially there are 195 countries in the world, with 44 countries in Europe, 23 countries […]

Dating Old Crocs: What Fossil Chemistry Reveals About Earth History

Published by Stephanie Greene Department of Earth and Atmospheric Sciences, University of Alberta The findings described in this article are […]

Overweight: Growing Influence Of Genes With Aging

Researchers have shown that the influence of genes changes during the first years of life. In childhood, there are other […]

Science Trends is a popular source of science news and education around the world. We cover everything from solar power cell technology to climate change to cancer research. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. Want to know more?