are there any herbs, vitamins out there that help out with asthma??

although I am still feeling strong from the aminos, I have a slight case of breathing trouble, mainly due to a really bad cough i had a few years back, and a case of bronchitis when i was younger, and rhinitis when younger. but moreover my father, and specifically my grandma(smoker) has COPD. My grandma is on medication for it but my father is not.

So is there anything out there besides NAC that could help with this condition? I have heard of coleus forskohlin being used, not sure how much though? but besides that?