Stimulation of osteogenic activity in human osteoblast cells by edible Uraria crinita.

Uraria crinita is an edible herb used as a natural food for childhood skeletal dysplasia. Ethyl acetate, n-butanol, and aqueous fractions of a 95% ethanol crude extract of U. crinita were obtained and the active ingredients isolated and purified using a bioguided method. In this manner, we isolated and identified a new active flavone glycoside, apigenin 6-C-ß-d-apiofuranosyl(1→2)-α-d-xylopyranoside (3) and 10 known components with stimulatory activity on human osteoblast cells. The new compound 3 at 100 µM significantly increased alkaline phosphatase activity (114.10 ± 4.41%), mineralization (150.10 ± 0.80%), as well as osteopontin (1.39 ± 0.01-fold), bone morphogenetic protein-2 (BMP-2, 1.30 ± 0.04-fold), and runt-related transcription factor 2 (Runx2, 1.43 ± 0.10-fold) mRNA expression through the activation of the BMP-2/Runx2 pathway. Two other components, dalbergioidin (1) and byzantionoside B (9), displayed similar effects. These results show that U. crinita and its active compounds may have the potential to stimulate bone formation and regeneration.

Chrysin: a histone deacetylase 8 inhibitor with anticancer activity and a suitable candidate for the standardization of Chinese propolis.

Chinese propolis (CP) is a natural product collected by honeybees and a health food raw material. Previous studies have shown that CP exhibits a broad spectrum of biological activities including anticancer, antioxidant, antibacterial, anti-inflammatory, and antiviral activities. The focuses of the present study were the standardization of CP and the possible mechanisms of its active anticancer ingredients. Nine samples of CP were collected from different locations in China. Analyses of the CP samples revealed that all 9 had similar chemical compositions. Parameters analyzed included the CP extract dry weight, total phenolic content, and DPPH free radical scavenging activities. The active anticancer ingredient was isolated, characterized against human MDA-MB-231 breast cancer cells, and identified as chyrsin, a known potent anticancer compound. Chrysin is present at high levels in all 9 of the CP samples, constituting approximately 2.52% to 6.38% of the CP extracts. However, caffeic acid phenethyl ester (CAPE), another potent active ingredient is present in low levels in 9 samples of CP, constituting approximately 0.08% to 1.71% of the CP extracts. Results from analyses of enzymatic activity indicated that chrysin is a histone deacetylase inhibitor (HDACi) and that it markedly inhibited HDAC8 enzymatic activity (EC(50) = 40.2 µM). In vitro analyses demonstrated that chrysin significantly suppressed cell growth and induced differentiation in MDA-MB-231 cells. In a xenograft animal model (MDA-MB-231 cells), orally administered chrysin (90 mg/kg/day) significantly inhibited tumor growth. Despite the geographical diversity of the 9 samples' botanical origins, their chemical compositions and several analyzed parameters were similar, suggesting that CP is standardized, with chrysin being the major active ingredient. Overall, in vitro and in vivo data indicated that chrysin is an HDAC8 inhibitor, which can significantly inhibit tumor growth. Data also suggested that chrysin might represent a suitable candidate for standardization of CP.

Growth and cell cycle regulation by isoflavones in human breast carcinoma cells.

The isoflavones daidzein and biochanin A induced a biphasic growth response in T-47D human breast cancer cells. At growth stimulatory concentrations, daidzein increased the percentage of cells entering the S phase, while at a growth inhibitory concentration, daidzein obstructed the progression of the cell cycle in the G2/M phase. Biochanin A regulated the cell cycle progression in a similar manner and showed a delay in the progression from the S phase to the G2/M phase at growth inhibitory concentrations. The levels of a cell cycle regulatory protein, P53, in response to the treatment of isoflavones, were also determined. Cells that became de-attached and floated in the medium after treatment with growth inhibitory concentrations of daidzein or biochanin A, showed higher P53 levels than cells that remained attached. These results suggest that daidzein and biochanin A influence T-47D cell proliferation and cell cycle progression, and that the underlying mechanisms might be associated with the P53 protein levels.