Boswellia

Boswellia (a.k.a. Frankincense) has been used to treat arthritic pain and inflammation for thousands of years.  Modern clinical studies have found that this effect is primarily from the inhibition of 5-lipoxygenase, which is different from typical anti-inflammatory drugs like Ibuprofen or Aspirin.  The effectiveness of Boswellia for osteoarthritis has been demonstrated in clinical studies.

Boswellia in the treatment of Osteoarthritis:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2575633/

Boswellia in Chronic Inflammatory Diseases:
https://www.ncbi.nlm.nih.gov/pubmed/17024588
https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-2006-947227.pdf

Boswellia, An Overview:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3309643/