Boswellia Serrata is a gum resin extracted from a tree, which is sometimes burnt (the entire species of Boswellia is commonly known as Frankinsence) as an aromatic or otherwise administered as medicine. It has most usage for medicine in Ayurvedic medicine, some reading into Traditional Chinese Medicine, and its usage extends to the Middle East and other tropical regions.
Boswellia Serrata, via its active boswellic acids, appears to be a novel inhibitory of a pro-inflammatory enzyme called 5-Lipoxygenase and may possess other anti-inflammatory effects (such as nF-kB inhibition, which are not as novel). These anti-inflammatory effects have been investigated for their benefits in osteoarthritis (OA), and it appears that oral Boswellia supplements can suppress pain and immobility associated with OA quite significantly with the effects taking as little as a week to occur. The studies are well conducted, but funded by the producers of the tested supplements. There are limited non-funded interventions with Boswellic for this claim, but they seem to agree with the battery of funded study in effect size.
Remarkably, Boswellia appears to be quite anti-cancer that appears to be more anti-proliferative rather than apoptotic (the latter meaning to induce regulated cell death) since it is a potent inhibitor of angiogenesis and cell invasiveness. There are not a large battery of studies on these claims, but preliminary mouse and rat evidence where the rodents are injected with tumors suggest that Boswellia can potently suppress tumor growth (Pancreatic, Colorectal) and in some cases actually outright prevent tumor growth (Prostatic, Glioma). Boswellia appears to be a very promising anti-cancer herb due to the potency it exhibits in animals, with one study noting this after oral administration (100mg/kg of the main boswellic acid in animals). The potency has been replicated in other cancer cell lines in vitro (including breast, cervical, myeloma and leukemia) but these cancers do not yet have animal interventions yet.
Boswellia appears to be fairly nontoxic, has a history of usage as a phytopharmaceutical for brain edema associated with radiotherapy (a cancer treatment), and the general anti-inflammatory and anti-cancer effects make it a fairly interesting herb relative to others that have subpar evidence.