Nobiletin, a polymethoxylated flavonoid from citrus, shows anti-angiogenic activity in a zebrafish in vivo model and HUVEC in vitro model

Traditional Chinese medicinal herbs are a rich source of compounds with reported anti-inflammatory and anti-carcinogenic effects. Growing evidence shows the codependence of chronic inflammation and angiogenesis, and the potential benefits of targeting angiogenesis in the treatment of chronic inflammation and targeting inflammation in the treatment of diseases with impaired angiogenesis. We hypothesized that the anti-inflammatory activity of the natural compounds may owe at least some of its efficacy to their anti-angiogenic activity and hence we investigated the anti-angiogenic activity of these compounds in vivo in zebrafish embryos and in vitro in human umbilical vein endothelial cells (HUVECs). Nobiletin, a polymethoxylated flavonoid from citrus fruits, showed anti-angiogenic activity in both assays. Nobiletin inhibited the formation of intersegmental vessels (ISVs) in live transgenic zebrafish embryos expressing green fluorescent protein (GFP) in the vasculature. Cell cycle analysis of dissociated zebrafish embryo cells showed that nobiletin induced G0/G1 phase accumulation in a dose-dependent manner in GFP-positive endothelial cells. Nobiletin also dose-dependently induced VEGF-A mRNA expression. In HUVECs, nobiletin inhibited endothelial cell proliferation and, to a greater extent, tube formation in a dose-dependent manner. As in the in vivo study, nobiletin induced G0/G1 cell cycle arrest in HUVECs. However, this arrest was not accompanied by an increase in apoptosis, indicating a cytostatic effect of nobiletin. This study, for the first time, identifies nobiletin as having potent anti-angiogenic activity and suggests that nobiletin has a great potential for future research and development as a cytostatic anti-proliferative agent.     

Furanodiene enhances tamoxifen-induced growth inhibitory activity of ERa-positive breast cancer cells in a PPARγ independent manner

Herbal plants are enriched with compounds with a wide range of biological activities. Furanodiene is a sesquiterpene isolated from Rhizoma Curcumae. Growing evidence shows furanodiene exhibits diversified activities of hepatoprotection, anti-inflammation, anti-angiogenesis, and anti-tumor. However, its biological activities against breast cancer have not been deeply understood, and its potential as an anti-breast cancer agent combined with tamoxifen (TAM) has not been evaluated so far. This study describes the combined effects of furanodiene and TAM in human breast cancer cells in vitro. The results showed that ERa-negative MDA-MB-231 cells were much more sensitive than ERa-positive MCF-7 cells to the growth inhibition due to furanodiene. Combined administration of furanodiene and TAM led to marked increase in growth inhibition, cell cycle arrest and pro-apoptotic activity in ERa-positive cells compared to individual agent, and enhanced the down-regulation of p-cyclin D1, cyclin D1, CDK2, CDK6, p-Rb, Rb and p-p44, and the up-regulation of p27, Bax and Bad, but did not show increased cytotoxicity in ERa-negative MCF-10A non-tumorigenic breast epithelial cells. Co-incubation induced the typical PARP cleavage or caspase 9 cleavages compared to individual agent. In addition, PPARγ activity inhibition by its antagonist T0070907 did not significantly reverse the enhanced effect of furanodiene and TAM suggesting that anti-cancer properties of combination were PPARγ independent. Our data indicated that furanodiene could enhance the growth inhibitory and pro-apoptotic activity of TAM by inducing cell cycle arrest and cell apoptosis via CDKs-cyclins and mitochondria-caspases-dependent, and PPARγ-independent signaling pathways in breast cancer cells, without contributions to the cytotoxicity of TAM.     

Circadian clock genes period and cycle regulate photoperiodic diapause in the bean bug Riptortus pedestris males

The photoperiodic response is crucial for many insects to adapt to seasonal changes in temperate regions. It was recently shown that the circadian clock genes period (per) and cycle (cyc) are involved in the photoperiodic regulation of reproductive diapause in the bean bug Riptortus pedestris females. Here, we investigated the involvement of per and cyc both in the circadian rhythm of cuticle deposition and in the photoperiodic diapause of R. pedestris males using RNA interference (RNAi). RNAi of per and cyc disrupted the cuticle deposition rhythm and resulted in distinct cuticle layers. RNAi of per induced development of the male reproductive organs even under diapause-inducing short-day conditions, whereas RNAi of cyc suppressed development of the reproductive organs even under diapause-averting long-day conditions. Thus, the present study suggests that the circadian clock operated by per and cyc governs photoperiodism of males as that of females.     

Molecular characterization and distribution of CYCLE protein from Athalia rosae

cDNA encoding CYCLE (CYC) from the coleseed sawfly, Athalia rosae (Hymenoptera, Symphyta), was amplified by PCR. This is a first determination of hymenopteran CYC structure. ArCYC had an overall identity of 66% with CYC of Anopheles gambiae and ca. 60% of Drosophila melanogaster. Structural investigation revealed that ArCYC contained characteristic motifs of: bHLH, PAS A, PAS B, PAC and BCTR. Detailed analysis indicated high conservation of these regions among insects. Northern blot analysis showed that the mRNA of ca. 3 kb was transcribed both in the head and in the rest of the body. Southern blot analysis suggested the presence of a single copy of the gene in the genome. Western blot indicates that the quantity of CYC protein does not fluctuate under LD 12:12 in either the head or the rest of the body. Immunocytochemical examination revealed CYC-like antigen in the pars intercerebralis, dorsolateral protocerebrum, dorsal optic tract, tritocerebrum of the brain and the subesophageal ganglion.