Berberine inhibits p53-dependent cell growth through induction of apoptosis of prostate cancer cells.

Berberine has anti-tumor properties in some cancer cells including prostate cancer, but the exact mechanisms and in vivo effects are unclear. We investigated anti-cancer activity of berberine in vitro and in vivo, and possible mechanisms in prostate cancer cells. Berberine treatment inhibited cell cancer growth in a concentration (0-50 microM) and time- (0-48 h) dependent manner without any growth inhibition in normal human prostate epithelial PWR-1E cells. However, the p53 expressing LNCaP cells were more susceptible against berberine than the p53 lacking PC-3 cells. The cell arrest in G0/G1 phase, apoptotic cell death and the expression of apoptotic cell death proteins Bax and caspase-3 was much higher in berberine-treated LNCaP cells than those in PC-3 cells. Exploration of p53 siRNA or pifithrin-alpha, a p53 inhibitor to the LNCaP cells, suppressed berberine-induced cell death and expression of apoptosis-related proteins. In xenograft in vivo studies, berberine reduced tumor weights and volumes accompanied with apoptotic cell death and increased expression of apoptotic cell death proteins, however, the extent of inhibitory effect was more significant in LNCaP cell-bearing mice. Therefore, these results indicated that berberine inhibited p53-dependent prostate cancer cell death.

Berberine inhibits human neuroblastoma cell growth through induction of p53-dependent apoptosis.

Berberine, an alkaloid, has anti-tumor properties in some cancer cells, but action mechanisms are not clear yet. We here investigated the anticancer activity of berberine and possible mechanisms in human neuroblastoma SK-N-SH and SK-N-MC cells. The p53-expressing cells, SK-N-SH (IC50=37 microM) were more susceptible to berberine than the p53-deficient cells, SK-N-MC (IC50 > or =100 microM) without cytotoxic effect on the cortical neuronal cells. Berberine caused cell cycle arrest in G0/G1 phase and apoptotic cell death, and these effects were much greater in SK-N-SH cells than those in SK-N-MC cells. Berberine much greatly decreased G0/G1 phase-associated cyclin and cyclin-dependent kinase (cyclin D1, cyclin E, Cdk2, and Cdk4) expression, and increased apoptotic gene expression and activation of caspase-3 in SK-N-SH cells. Exploration of p53 siRNA or pifithrin-alpha (PFT-alpha), a p53 inhibitor, in the SK-N-SH cells resulted in increase of IC50 values for cell viability, and decreased apoptotic cell death, expression of p53 and activation of caspase-3. Therefore, these results showed that berberine causes p53-dependent apoptotic death of neuroblastoma cells, and suggested that berberine may be useful as an anticancer agent for neuroblastoma.

Increase of collagen synthesis by obovatol through stimulation of the TGF-beta signaling and inhibition of matrix metalloproteinase in UVB-irradiated human fibroblast.

BACKGROUND: Alterations of the extracellular matrix (ECM) is critical in the photo and age-damaged skin. Thus any compounds keep ECM can protected from photo and aged-damaged skin. ECM is predominantly composed of type I and type III collagens in the dermis. Transforming growth factor (TGF-beta)s play important roles in cellular biosynthesis of extracellular matrix. Activator protein 1 (AP-1) and Smad are significant factors that mediate TGF-beta. OBJECTIVE: We have investigated increasing effects of obovatol, a biphenolic compound isolated from leaves of Magnolia obovata on the collagen synthesis through stimulation of the TGF-beta signaling and inhibition of matrix metalloproteinase, thereby protect against from UV damages via maintain of collagen in the UVB irradiated human fibroblast cells. METHODS: The fibroblasts were pretreated with obovatol for 24h and then the cells were irradiated with UVB. UVB-exposed cells were further cultured for 24h. Type I procollagen, MMP-3, TGF-beta and Smad as well as phosphorylation of MAPK family expression were determined by Western blot. The activation of AP-1 was investigated using EMSA. The released type I procollagen and TGF-beta into cell culture medium were determined by Western blot after concentration of these proteins. RESULTS: The results showed that obovatol stimulated type I procollagen, TGF-beta, and Smad expression and inhibited matrix metalloproteinase-3 (MMP-3) in dose-dependent manner (1-5muM) in UVB-irradiated human fibroblast cells. Obovatol also inhibited UVB-induced activation of AP-1 and MAP kinases. CONCLUSION: These results suggest that obovatol increases collagen synthesis through stimulation of the TGF-beta signaling and inhibition of matrix metalloproteinase in UVB-irradiated human fibroblast, thus obovatol could be effective against photo-damaged skin.

Inhibitory effect of obovatol on nitric oxide production and activation of NF-kappaB/MAP kinases in lipopolysaccharide-treated RAW 264.7cells.

The components of Magnolia obovata are known to have many pharmacological activities. In this study, we investigated the effects of obovatol, a neolignan compound isolated from the leaves of M. obovata, on nitric oxide (NO) production and NF-kappaB activity in lipopolysaccharide (LPS)-activated RAW 264.7 cells. The results show that obovatol (1-5 microM) significantly inhibited LPS-induced NO production in a concentration-dependent manner (IC(50): 0.91 microM). Consistent with the inhibitory effect on NO production, obovatol inhibits the expression of inducible nitric oxide synthase and cyclooxygenase-2 expression. Furthermore, obovatol suppressed NF-kappaB (p50 and p65) translocation to the nucleus as well as IkappaB release resulting in the inhibition of the DNA binding activity of the NF-kappaB. Obovatol also inhibited c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) signal, which are the most significantly involved signal in NO production and NF-kappaB activation. When the cells were treated with the combination of obovatol with U0126 (an ERK inhibitor) or SP600125 (a JNK inhibitor) as well as with SC-514 (an IKK2 inhibitor), much more inhibition of NO production was observed than that by obovatol alone. The present results suggest that obovatol has an inhibitory effect on NO production through the inhibition of NF-kappaB/MAPK activity, and thus can be used as an anti-inflammatory agent.

Gene expression analysis in human gastric cancer cell line treated with trichostatin A and S-adenosyl-L-homocysteine using cDNA microarray.

Trichostatin A (TSA) and S-adenosyl-L-homocysteine (AdoHcy) have been reported to affect histone modifications. To investigate the effects of two drugs that can reportedly affect chromatin remodeling, we analyzed the gene expression profiles of TSA and AdoHcy in a gastric cancer cell line using 14 K cDNA microarray. The significant analysis of microarray (SAM) identified 98 and 43 differentially expressed genes in TSA and AdoHcy treated sets, respectively, and selected genes were functionally classified. In the gastric cancer cell line, genes related to cell communication, cell growth/maintenance, and morphogenesis were highly expressed with TSA, and genes with cell growth/maintenance, metabolism, oxidoreductase activity were upregulated with AdoHcy. Genes downregulated with TSA included those controlling the cell cycle, cell growth/proliferation, DNA binding, and metabolism, whereas genes involved in calcium signaling, cell growth/proliferation, and metabolism were downregulated with AdoHcy. Furthermore, we identified the genes commonly expressed in both drug treatments. Compared to TSA, AdoHcy did not induce apoptosis in the SNU-16 gastric cancer cell line, and RT-PCR was performed for selective genes to confirm the microarray data. This gene expression profile analysis with TSA and AdoHcy should contribute to a greater understanding of the molecular mechanism of chromatin remodeling and cancer, and provide candidate genes for further studies involving the roles of histone modifications in gastric cancer.