I did try serrapeptase, quite a few years ago, as well as the enzyme supplements bromelain and papain, but did not notice any improvements in anxiety. Not all anti-inflammatories target brain inflammation; they may just act on inflammation in the body.
However, there are circumstances where
inflammation in the body can trigger inflammation in the brain, and in these cases, you may be able to successfully reduce brain inflammation (and thus anxiety) by reducing inflammation in your body (systemic inflammation as it is called). For example, if you have some gut problems, like an imbalance of good and bad bacteria in your intestines, this can cause some inflammation in your intestines. This can then kick off neuroinflammation via the vagus nerve.
The
vagus nerve, which runs from gut to brain, is designed to detect inflammation in the organs of the body, including the intestines. The vagus does this by sensing the presence of the inflammation cytokine IL-1beta. When the vagus senses inflammation in the body, it will send a nerve signal to the brain, which then triggers an increase in inflammation in the brain. So because of this vagus nerve gut-to-brain communication, any inflammation in your gut can get translated into increased inflammation in the brain as well.
So by improving gut and digestive health, you may be able to reduce anxiety levels. I have IBS, and found that taking prebiotics and probiotics (friendly bacteria) had a powerful anxiety-reducing effect. In fact this was one of the earliest successes I had in terms of finding solutions for my severe generalized anxiety disorder. I started a thread on the anxiolytic effect of prebiotics/probiotics
here.
Likewise, the
trigeminal nerve, which runs from your nasal and sinus cavities to the brain, is another nerve which senses inflammation in the body. When the trigeminal nerve senses inflammation in the sinuses, it will send a signal to the brain to instigate increased brain inflammation. So nasal or sinus inflammation may trigger brain inflammation, which in turn may cause anxiety symptoms.
I suffer from nasal and sinus congestion and inflammation (due to a chronic viral infection). I noticed that when my sinuses were more inflamed, my anxiety was much worse. So then I started to search for supplements that would decrease my nasal and sinus inflammation (sinusitis). The supplements that I found effectively cleared my sinusitis are listed in
this post. These all helped significantly reduce my anxiety levels.
So certainly there are situations where chronic infection or inflammation in the body (systemic inflammation) can trigger neuroinflammation via the vagus or trigeminal nerves, and in these cases, reducing the infection or inflammation can greatly reduce anxiety levels. If you are interested in reading about the vagus nerve and its job of triggering brain inflammation,
this article may be of interest.