https://pubmed.ncbi.nlm.nih.gov/17474862/ (Paywalled, abstract only)
https://zero.sci-hub.se/3428/d8f5b3d4ccd98f680daab1f55150cdc1/kwak2006.pdf (full document)
EDIT:
The extract mentioned is from the following species:
https://en.m.wikipedia.org/wiki/Pinus_densiflora
[known as: Japanese red pine, the Japanese pine, or Korean red pine]
EDIT 2:
The bark of the same species contains neuroprotective compounds:
https://www.jmb.or.kr/journal/view.html?doi=10.4014/jmb.1801.01053
“Taken together, these results suggest that [Korean red pine bark extract] and its constituent antioxidative phenolics are potent neuroprotective agents that can maintain cell viability under oxidative stress and inhibit cholinesterase activity.”
I also have copd. I also had Lung surgery in 3/2020 removing a part of my left lung. I should be winded and it should be harder for me to breath but infact It hasn't been this good for decades!!But Bronchitis sucks big time!! Do you work in an office with no fresh air circulation? Also, you should if you don't have one get a Nebulizer for home. Ask your doctor. It's a life savor to have one on hand when you feel it coming on use it for the day or 2. What you need is not only the emergency inhaler but the maintenance one. Not sure if you have both. Beleive me the maintenance one for me helps big time! Drink the pine needle tea at least once a day or 3 to 5 times a week. To help boost your respiratory system. For a couple of months. Then use as needed. Everyday take your zinc and vit c. You need to get to a stable point before it starts to get better with less and less bouts of bronchitis, until there is none. Good luck.
Hey thanks for taking the time to go into details , fortunately I’m seldom doing office work I do a lot of field base stuff , I ditched my trade 20 years ago as a boilermaker and pipe welder for health reasons - no more metal dust and welding fumes , I’m using inhalers but they have limited affect I’ll take your advise and get myself a nebuliser, smoking never helped either but I gave up 10 years ago but has left me with mild COPD