[Polydatin induces human cervical cancer cell apoptosis via PI3K/AKT/mTOR signaling pathway].

To observe the effect of polydatin on proliferation and apoptosis of cervical cancer HeLa cells and explore its possible mechanism. The growth inhibitory effect was detected with MTT assay. After HeLa cells were treated with different concentrations (50, 100, 150 µmol•L⁻¹) of polydatin, MTT assay was used to detect the inhibitory effect of polydatin on proliferation of HeLa cells; Acridine orange/ethidium bromide staining was used for morphological changes in apoptotic HeLa cells； Annexin/propidium iodide staining was applied to detect HeLa cell apoptotic rate. In addition, flow cytometry was employed to analyze apoptosis and cell cycle distribution； RT-PCR and Western blot assay were used to detect PI3K, AKT, mTOR, and P70S6K mRNA and protein expression levels. The results showed that polydatin significantly inhibited HeLa cells proliferation in a dose-dependent manner. Polydatin can cause S phase arrest for HeLa cells, promote cell apoptosis and decrease the mRNA and protein expression levels of PI3K, AKT, mTOR and P70S6K. It indicated that polydatin could inhibit proliferation and induce apoptosis of cervical cancer HeLa cells, and the mechanism may be associated with inhibiting the PI3K/AKT/mTOR signaling pathway and suppressing downstream gene expression.

Catalpol ameliorates diabetic atherosclerosis in diabetic rabbits.

Catalpol, isolated from the roots of Rehmanniaglutinosa, Chinese foxglove, is an iridoid glycoside with antioxidant, anti-inflammatory and anti-hyperglycemic agent. The present study was to investigate the effects of catalpol on diabetic atherosclerosis in alloxan-induced diabetic rabbits. Diabetes was induced in rabbits by a hyperlipidemic diet and intravenous injection of alloxan (100 mg/kg). Rabbits were treated for 12 weeks. The fasting blood glucose, insulin, homeostasis model of insulin resistance, total cholesterol and triglyceride were measured. The thoracic aorta was excised for histology. The plasma and vascular changes including some markers of oxidative stress, inflammatory cytokines and fibrosis factors were examined. Plasma levels of fasting blood glucose, insulin and homeostasis model of insulin resistance were significantly decreased in catalpol group. Catalpol treatment ameliorated diabetic atherosclerosis in diabetic rabbits as demonstrated by significantly inhibited neointimal hyperplasia and macrophages recruitment. Catalpol treatment also enhanced the activities of superoxide dismutase, glutathione peroxidase, and increased the plasma levels of total antioxidant status, meanwhile reduced the levels of malondialdehyde, protein carbonyl groups and advanced glycation end product. Furthermore, catalpol also reduced circulating levels of tumor necrosis factor-α, monocyte chemotactic protein-1 and vascular cell adhesion molecule-1. Catalpol also decreased transforming growth factor-ß1 and collagen IV mRNA and protein expressions in the vessels. Catalpol exerts an ameliorative effect on atherosclerotic lesion in alloxan-induced diabetic rabbits. The possible mechanisms may be related to inhibition of oxidative stress inflammatory response and anti-fibrosis and reduced aggregation of extracellular matrix.

Cytoproliferative and Cytoprotective Effects of Striatisporolide A Isolated from Rhizomes of Athyrium multidentatum (Doell.) Ching on Human Umbilical Vein Endothelial Cells.

OBJECTIVES: The aim of this study was to investigate the proliferative and protective effects of striatisporolide A (SA) obtained from the rhizomes of Athyrium multidentatum (Doell.) Ching on human umbilical vein endothelial cells (HUVECs). METHODS: Cell viability was measured by the MTT method. Cell apoptosis was determined by flow cytometry. Intracellular ROS was measured by the 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe. RESULTS: The viability rate in cells treated with 100 µM SA alone was increased to 128.72% ± 0.19% and showed a significant difference compared with the control group (p < 0.05). Meanwhile, SA augmented the cell viabilities in H2O2-treated HUVECs, and the cell viability was enhanced to 56.94% ± 0.13% (p < 0.01) when pre-incubated with 50 µM SA. The cell apoptosis rates were reduced to 2.17% ± 0.20% (p < 0.05) and 3.1% ± 0.34% (p < 0.01), respectively, after treatment with SA alone or SA/H2O2. SA inhibited the overproduction of reactive oxygen species (ROS) in HUVECs induced by H2O2 and the fluorescent intensity was abated to 9.47 ± 0.61 after pre-incubated with 100 µM SA. CONCLUSIONS: The biological activities of SA were explored for the first time. Our results stated that SA exhibited significant cytoproliferative and minor cytoprotective effects on HUVECs. We presume that the mechanisms of the proliferation and protection actions of SA involve interference with the generation of ROS and the cell apoptosis. These findings provide a new perspective on the biological potential of butenolides.

Amelioration by catalpol of atherosclerotic lesions in hypercholesterolemic rabbits.

The aim of the present study was to evaluate the effects of catalpol administration on atherosclerosis. Atherogenesis was induced by a high-cholesterol chow in male New Zealand White rabbits that were randomly assigned to receive atorvastatin (5 mg/kg/day), catalpol (5 mg/kg/day), or vehicle by oral gavage for 12 weeks. The rabbits were sacrificed after 12 weeks, and the thoracic aorta and serum were collected for further pathological and molecular biological analysis. Catalpol administration resulted in significantly attenuated atherosclerotic lesions. Total cholesterol, triglycerides, and low-density lipoprotein cholesterol were remarkably reduced, and high-density lipid cholesterol was elevated in the catalpol-treated group. Catalpol reduced the levels of tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, soluble vascular cell adhesion molecule-1, and soluble intercellular adhesion molecule-1 in the serum, as well as vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, tumor necrosis factor-α protein, inducible nitric oxide synthase, matrix metalloproteinases-9, and nuclear factor-κB protein65 in the aortic arch. In addition, catalpol treatment reduced the lipid peroxidation levels, while elevating antioxidant capacity. Catolpol pretreatment inhibited the nuclear translocation and DNA binding activity of nuclear factor-κB protein in oxygenized low-density lipoprotein-stimulated EA.hy926 cells. Furthermore, catolpol pretreatment activated nuclear factor erythroid 2-related factor 2 and upregulated the expression of its downstream antioxidant enzyme heme oxygenase. In summary, catalpol attenuated atherosclerotic lesions by the inhibition of inflammatory cytokines and oxidative stress status in a rabbit atherosclerotic model and enhanced the antioxidant capacity in oxygenized low-density lipoprotein-stimulated EA.hy926 cells. These results suggest that catalpol may be used to prevent and attenuate atherosclerosis.

[Expression of cyclooxygenase-2 mRNA and identification of its spliceriant in human myometrium obtained from women in labor].

OBJECTIVE: To investigate the expression of cyclooxygenase-2 (COX-2) in human lower segments of myometrium obtained from women in labor and those not in labor and identify the splice variant of COX-2. METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) was used for investigating the expression of COX-2. According to the sequence of rat COX-2 splice variant, the primers were designed and synthesized, then the splice variant of COX-2 in human myometrium from woman in labor was identified, cloned into vector and sequenced. RESULTS: The results showed that (1) The Expression of COX-2 mRNA was lower in human myometrium obtained from women who were not in labor than those in labor. (2) A new band of COX-2 was obtained in myometrium from a woman in labor. The fragment includes an unspliced intron, which locates between exons 7 and 8. CONCLUSION: COX-2 gene is not only expressed highly in human myometrium from women in labor, but also produced splicing variant by alternative splicing.