What is Arnica?
In short, arnica (Arnica montana, along with a few other species) is a plant with a reputation for healing in traditional medicines.
I first learned about arnica aka mountain tobacco aka wolfsbane (what?) as a plant extract useful in soothing bruises. Apparently pole dancers frequently use arnica gels to speed bruise healing (!), and it's known as a folk remedy used throughout the ages for soothing inflamed joints and muscles.
Intrigued, I wanted to see what sort of science may underlie these uses. Naturally, many of the papers on this subject are behind a paywall that even my institution doesn't have access to, but here's what I *was* able to find with relative ease.
A quick literature search shows that the science behind the use of Arnica to treat inflammation is largely lacking (source), but there is some support for how it might work in vitro, through a compound it contains called helenalin.
However, at least one abstract I came across indicated that topical arnica treatment does not alleviate pain (source).
It's important to note the tiny size of this study, and I found it interesting that while most of the articles I came across did not report significant findings suggesting the medical use of arnica, they all called for further investigation (seemingly based on the promise from traditional medicine, and hints at molecular mechanism from the in vitro studies connecting helenalin to NF-KB).
