Does boswellia serrata reduce Crohn's symptoms?

"Therapy of active Crohn disease with Boswellia serrata extract H 15" in Z Gastroenterol (2001)
"The study confirms that therapy with H15 is not inferior to mesalazine. This can be interpreted as evidence for the efficacy of H15 according to the state of art in the treatment of active Crohn's disease with Boswellia serrata extract, since the efficacy of mesalazine for this indication has been approved by the health authorities. Considering both safety and efficacy of Boswellia serrata extract H15 it appears to be superior over mesalazine in terms of a benefit-risk-evaluation."

"Dietary Factors in the Modulation of IBD: Boswellia Serrat/Indian Frankincense" from Medscape Today News
"A randomized, double-blind controlled study comparing Boswellia serrata extract H15 with mesalamine in patients with Crohn's disease demonstrated no statistical difference in the Crohn's Disease Activity Index, indicating that Boswellia serrata may play a helpful role in Crohn's disease. Other studies have shown possible effectiveness of Boswellia serrata gum resin in patients with ulcerative colitis. Proposed mechanisms of effect of Boswellia serrata include inhibition of 5-lipoxygenase."

"Effects of Boswellia serrata in mouse models of chemically induced colitis" in Am J Physiol Gastrointest Liver Physio (2004) [link is for a full text version]
"The most striking finding in our studies was increased liver size and clear evidence of steatosis, particularly in mice fed the higher dose of methanolic extract of B. serrata. This observation was further confirmed in vitro with human HepG2 cells as a model. Although microarray analyses of hepatic gene expression cannot fully explain this phenomenon, it gives important clues to the potential hepatotoxic effects of Boswellia. ...

Although the results presented in this short report may or may not directly translate into human pathophysiology, this compelling evidence should be a cause for concern and will hopefully prompt more scrupulous toxicological assessment of liver functions in patients participating in clinical trials with B. serrata. Contrary to the widespread popular view that "because it is natural, it is safe," herbal therapy carries more risks and produces more serious side effects than any other form of alternative therapy. Unfortunately, there are no formal data on the ineffectiveness of certain compounds and on the incidence even of acute, severe side effects, such as liver failure, after taking certain herbal medications. This is primarily due to the approach of investigators to negative data and to the skewed peer review process, which favors positive and promising results. Although the pharmaceutical industry recently agreed to give physicians and patients full access to both positive and negative results of clinical trials, a systematic reporting of the collection of ineffective trials and adverse responses to herbs is still missing." [emphases mine]

Boswellia serrata in Alternative Medicine Review (2008)