Plant-based supplement shown to reduce anxiety in mice
Although depression is a common disorder, its frequent companion, anxiety, can be at least as serious. There may be new hope for anxiety disorder sufferers, however, in the form of an existing natural supplement.
Led by Dr. Nicolas Panayotis, scientists at Israel's Weizmann Institute of Science had previously discovered that when subjected to stress, mice lacking a nerve cell protein known as importin alpha-five exhibited less anxiety than a control group of mice with normal amounts.
The researchers found that the lack of the protein was linked to a specific pattern of gene expression, involving approximately 120 genes within the hippocampus of the animals' brains. With that in mind, the team more recently set about searching an international genomic database for compounds that might produce the same pattern.
After five potential candidates were tested on mice, one was found to be particularly effective at reducing anxiety in behavioral tests. The plant-derived substance is called beta-sitosterol, and it's already sold as a dietary supplement that's claimed to reduce cholesterol levels.
After having received the compound, mice were found to be much more likely to walk into the brightly lit center of an enclosure, instead of sticking to the "safer" darker areas around the sides. The effect was increased significantly when the beta-sitosterol was combined with the anti-anxiety drug fluoxetine, better known as Prozac.
It's still not clear exactly what effect the supplement is having, such as whether or not it is in fact reducing importin alpha-five levels in the brain. It should also be noted that although the neural pathways examined in the study are known to be associated with regulating anxiety in both mice and humans, further research is needed to show whether these results would translate to humans.
Eventually, the scientists hope that beta-sitosterol could ultimately be administered either on its own or along with Prozac, boosting the anxiety-reducing effect so that less of the latter drug is needed. This smaller dosage would in turn reduce unwanted side effects.
The research is described in a paper that was recently published in the journal Cell Reports Medicine.
Source: Weizmann Institute of Science