Planta Med. 2000 Mar;66(2):110-3.
Concentration-dependent potentiating and inhibitory effects of Boswellia extracts on 5-lipoxygenase product formation in stimulated PMNL.
Safayhi H,
Boden SE,
Schweizer S,
Ammon HP.
Department of Pharmacology, University of Tuebingen, Germany.
hasan.safayhi@uni-tuebingen.de
Preparations from the gum of Boswellia spec. have been used in the traditional medicine for the treatment of inflammatory diseases. Extracts from B. serrata gum were shown to inhibit leukotriene biosynthesis by impairing the 5-lipoxygenase (5-LO) activity. In order to identify the minimal effective concentrations of extracts in vitro we studied the effects of ethanolic extracts from commercially available resins from two regions (B. serrata gum from India and Olibanum in granis from Arabia) on the 5-LO product formation from endogenous substrate in calcium and ionophore stimulated neutrophils in a defined concentration range. Both extracts inhibited 5-LO product formation in vitro in concentrations greater than 10 to 15 micrograms/ml as reported previously for an ethanolic B. serrata extract. In contrast, lower concentrations of extracts (1 to 10 micrograms/ml) even potentiated 5-LO product formation, especially the biosynthesis of 5(S)-HETE. The in vitro data underline the major importance of drug standardization when Boswellia resin containing preparations are used for the treatment of diseases.
PMID: 10763581 [PubMed - indexed for MEDLINE]
Biochem Pharmacol. 2008 Jun 1;75(11):2112-21. Epub 2008 Mar 15.
Inhibitory effect of acetyl-11-keto-beta-boswellic acid on androgen receptor by interference of Sp1 binding activity in prostate cancer cells.
Yuan HQ,
Kong F,
Wang XL,
Young CY,
Hu XY,
Lou HX.
Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, Shandong 250012, China.
Androgen receptor (AR)-mediated signaling is crucial for the development and progression of prostate cancer (PCa). Naturally occurring phytochemicals that target the AR signaling offer significant protection against this disease. Acetyl-11-keto-beta-boswellic acid (AKBA), a compound isolated from the gum-resin of Boswellia carterii, caused G1-phase cell cycle arrest with an induction of p21(WAF1/CIP1), and a reduction of cyclin D1 as well in prostate cancer cells. AKBA-mediated cellular proliferation inhibition was associated with a decrease of AR expression at mRNA and protein levels. Furthermore, the functional biomarkers used in evaluation of AR transactivity showed suppressions of prostate-specific antigen promoter-dependent and androgen responsive element-dependent luciferase activities. Additionally, down-regulation of an AR short promoter mainly containing a Sp1 binding site suggested the essential role of Sp1 for the reduction of AR expression in cells exposed to AKBA. Interruption effect of AKBA on Sp1 binding activity but not Sp1 protein levels was further confirmed by EMSA and transient transfection with a luciferase reporter driven by three copies of the Sp1 binding site of the AR promoter. Therefore, anti-AR properties ascribed to AKBA suggested that AKBA-containing drugs could be used for the development of novel therapeutic chemicals.
PMID: 18430409 [PubMed - indexed for MEDLINE]