Boswellic acids: a group of medicinally important compounds

Boswellic acid inhibits expression of acid sphingomyelinase in intestinal cells

Background

Boswellic acid is a type of triterpenoids with antiinflammatory and antiproliferative properties. Sphingomyelin metabolism generates multiple lipid signals affecting cell proliferation, inflammation, and apoptosis. Upregulation of acid sphingomyelinase (SMase) has been found in several inflammation-related diseases such as inflammatory bowel diseases, atherosclerosis, and diabetes.

Methods

The present study is to examine the effect of 3-acetyl-11-keto-β-boswellic acids (AKBA), a potent boswellic acid, on acid SMase activity and expression in intestinal cells. Both transformed Caco-2 cells and non-transformed Int407 cells were incubated with AKBA. After incubation, the change of acid SMase activity was assayed biochemically, the enzyme protein was examined by Western blot, and acid SMase mRNA was quantified by qPCR.

Results

We found that AKBA decreased acid SMase activity in both intestinal cell lines in dose and time dependent manners without affecting the secretion of the enzyme to the cell culture medium. The effect of AKBA was more effective in the fetal bovine serum-free culture medium. Among different types of boswellic acid, AKBA was the most potent one. The inhibitory effect on acid SMase activity occurred only in the intact cells but not in cell-free extract in the test tubes. At low concentration, AKBA only decreased the acid SMase activity but not the quantity of the enzyme protein. However, at high concentration, AKBA decreased both the mass of acid SMase protein and the mRNA levels of acid SMase in the cells, as demonstrated by Western blot and qPCR, respectively. Under the concentrations decreasing acid SMase activity, AKBA significantly inhibited cell proliferation.

Conclusion

We identified a novel inhibitory effect of boswellic acids on acid SMase expression, which may have implications in human diseases and health.

Structure-activity relationship (SAR) of parthenin analogues with pro-apoptotic activity: Development of novel anti-cancer leads

Analogues of parthenin were synthesized by substitutions at different reaction centres to establish a structure-activity relationship (SAR). Some of the molecules have displayed significant cytotoxicity in human cervical carcinoma (HeLa) and human myeloid leukemia (HL-60) cells. A few of the compounds also induced apoptosis in HL-60 cells measured in terms of sub-Go/G1 DNA fraction. Also one of the lead molecules has been shown to be the inhibitor of both telomerase and topoisomerase-II.