Bioactive flavonoids of the flowers of Butea monosperma

Chemopreventive and anti-cancer properties of the aqueous extract of flowers of Butea monosperma

ETHNOPHARMACOLOGICAL RELEVANCE

Butea monosperma (Lam.) (Fabaceae) popularly known as 'flame of the forest' has been widely used in the traditional Indian medical system of 'Ayurveda' for the treatment of a variety of ailments including liver disorders.

AIM OF THE STUDY

To evaluate the antioxidative, anti-inflammatory, hepatoprotective and anti-cancer activities of the aqueous extract of Butea monosperma flowers.

MATERIALS AND METHODS

Dried flowers of Butea monosperma were extracted with water. The extract was tested for its anti-proliferative, pro-apoptotic and anti-carcinogenic effects in hepatoma cell lines. The chemopreventive and anti-angiogenic effects of the extract were evaluated by its daily oral administration in a HBV-related X15-myc mouse model of hepatocellular carcinoma (HCC).

RESULTS

Treatment with the aqueous extract inhibited cell proliferation and accumulation of cells in G1 phase. This was accompanied by a marked reduction in the levels of activated Erk1/2 and SAPK/JNK and induction of apoptotic cell death. Oral administration of the extract in transgenic mice conferred hepatoprotection as is evident from normal serum ALT levels and improved liver histopathology and lowered serum VEGF level.

CONCLUSIONS

The ability of aqueous extract of Butea monosperma flowers to impose growth arrest and trigger pro-apoptotic death in cell culture strongly correlated with its strong chemopreventive effect in vivo when given orally.

Butrin, isobutrin, and butein from medicinal plant Butea monosperma selectively inhibit nuclear factor-kappaB in activated human mast cells: suppression of tumor necrosis factor-alpha, interleukin (IL)-6, and IL-8

Activation of mast cells in rheumatoid synovial tissue has often been associated with tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-8 production and disease pathogenesis by adjacent cell types. Butea monosperma (BM) is a well known medicinal plant in India and the tropics. The aim of this study was to examine whether a standardized extract of BM flower (BME) could inhibit inflammatory reactions in human mast cells (HMC) using activated HMC-1 cells as a model. Four previously characterized polyphenols--butrin, isobutrin, isocoreopsin, and butein--were isolated from BME by preparative thin layer chromatography, and their purity and molecular weights were determined by liquid chromatography/mass spectrometry analysis. Our results showed that butrin, isobutrin, and butein significantly reduced the phorbol 12-myristate 13-acetate and calcium ionophore A23187-induced inflammatory gene expression and production of TNF-alpha, IL-6, and IL-8 in HMC-1 cells by inhibiting the activation of NF-kappaB. In addition, isobutrin was most potent in suppressing the NF-kappaB p65 activation by inhibiting IkappaBalpha degradation, whereas butrin and butein were relatively less effective. In vitro kinase activity assay revealed that isobutrin was a potent inhibitor of IkappaB kinase complex activity. This is the first report identifying the molecular basis of the reported anti-inflammatory effects of BME and its constituents butrin, isobutrin, and butein. The novel pharmacological actions of these polyphenolic compounds indicate potential therapeutic value for the treatment of inflammatory and other diseases in which activated mast cells play a role.