MicroRNA828 negatively regulates lignin biosynthesis in stem of Populus tomentosa through MYB targets.

Lignin biosynthesis in the sclerenchyma cells is strictly controlled by a complex network of genetic and environmental signals. In the last decades, the transcriptional regulation of lignin synthesis in woody species has been established. However, the role of microRNA-mediated post-transcriptional modulation in secondary cell wall biosynthesis remains poorly understood. Here, we identified a microRNA, miR828, involved in the regulation specific to lignin biosynthesis during stem development in Populus tomentosa Carr. miR828 is preferentially expressed in the secondary vascular tissues during stem development. Two MYB genes (MYB171 and MYB011) were validated as direct targets of miR828 by degradome analysis and green fluorescent protein signal detection. Overexpression of miR828 in poplar downregulated genes for lignin biosynthesis, resulting in reduced lignin content in cell walls. Conversely, suppression of miR828 in plants by the short tandem target mimics elevated the expression of lignin biosynthetic genes and increased lignin deposition. We further revealed that poplar MYB171, as the most abundant miR828 target in the stem, is a positive regulator for lignin biosynthesis. Transient expression assays showed that both MYB171 and MYB011 activated PAL1 and CCR2 transcription, whereas the introduction of miR828 significantly suppressed their expression that was induced by MYB171 or MYB011. Collectively, our results demonstrate that the miR828-MYBs module precisely regulates lignin biosynthesis during the stem development in P. tomentosa through transcriptional and post-transcriptional manners.

Controlled release of resveratrol and xanthohumol via coaxial electrospinning fibers.

Synergistic delivery of two drugs is a desirable choice to overcome drug resistance. Resveratrol (RES) and xanthohumol (XAN) which are both new drugs originated from plants exhibit great potential in the treatment of cancer, but there are few studies on combining them in a delivery system. In this work, a new core/shell fiber mesh containing RES and XAN was designed out via coaxial electrospinning, and the effect of drug content on the medicated fibers was discovered. RES/polyethylene oxide (PEO) could be well combined with XAN/Poly(lactide-glycolide) (PLGA) to make core/shell fibers, but fibrous morphology worsened with increasing drug content of the core or shell to some extent. The core/shell was amorphous nature, and changing drug content had little influence on the wetability of the core/shell fibers. The release accelerated with drug content increasing in the fibers, and RES and XAN showed gradient release, which the release rate of RES was slower than XAN. These two drugs could sustain release for 350 h. When the blend ratios of RES/PEO and XAN/PLGA were 50/50 and 10/90 in the fibers, the fiber mesh showed the best mechanical properties, of which the tensile strength and elongation at break were 2.85 ± 0.10 MPa and 55.23 ± 2.53%, respectively. The medicated fibers presented good characteristics of inhibiting breast cancer cell activity.

Preparation of alginate oligosaccharide nanoliposomes and an analysis of their inhibitory effects on Caco-2 cells.

The conditions were optimised for preparing Alginate oligosaccharide (AOS) nanoliposomes, and Caco-2 cell experiments were carried out to examine their antitumour effects. The optimal formulation of AOS nanoliposomes was as follows: a phosphatidylcholine-to-cholesterol ratio of 5.12, AOS concentration of 8.44 mg/mL, Tween 80 concentration of 1.11%, and organic phase to aqueous phase ratio of 5.25. Under the above conditions, the experimental encapsulation efficiency was 65.84%, and the AOS nanoliposomes exhibited a small particle size of 323 nm. After Caco-2 cells were treated with AOS liposomes and AOS for 24 h, AOS nanoliposomes inhibited the growth of Caco-2 cells to a greater extent than AOS at concentrations of 0.0625, 0.125, 0.25, 0.5 and 1 mg/mL (P < 0.01). LDH leakage exhibited a concentration-dependent increase following treatment with 0.5-1 mg/mL AOS nanoliposomes, and the inhibitory effect of AOS nanoliposomes exhibited a more significant difference than AOS (P < 0.01). Cells treated with 0.5 mg/mL and 1 mg/mL AOS nanoliposomes displayed a substantial and significant increase in activity compared with AOS (P < 0.01). Based on these results, AOS nanoliposomes exerted a more significant effect on inhibiting Caco-2 cell proliferation than AOS.

Protective effects of dehydrocostuslactone on rat hippocampal slice injury induced by oxygen­glucose deprivation/reoxygenation.

The present study aimed to investigate the protective effects of dehydrocostuslactone (DHL) against rat hippocampal slice injury caused by oxygen­glucose deprivation/reoxygenation (OGD/R). Rat hippocampal slice injury was induced by OGD/R in vitro, and the degree of injury was evaluated through a lactate dehydrogenase (LDH) assay and 2,3,5­triphenyltetrazolium chloride (TTC) staining. The protein expression levels of B­cell lymphoma-2 (Bcl­2), Bcl­2­associated X protein (Bax), cytochrome c (cyt­c), apoptotic protease activating factor 1 (apaf­1), caspase­9, caspase­7, caspase­3, sequestosome 1 (SQSTM1) and microtubule­associated protein 1 light chain 3 (LC3) were analyzed through western blot analysis. The results showed that 1, 5 and 10 µM DHL decreased the levels of LDH (P<0.05) and increased the A490 value of TTC (P<0.05). Furthermore, the expression of Bcl­2 was enhanced, and the protein expression levels of Bax, cyt­c, apaf­1, caspase­9, caspase­7, caspase­3, SQSTM1 and LC3 were significantly inhibited (P<0.05), compared with those in the OGD/R group. These results suggested that DHL elicited protective effects against hippocampal OGD/R injury, and its underlying mechanism may be associated with inhibiting apoptosis.

Syringin prevents bone loss in ovariectomized mice via TRAF6 mediated inhibition of NF-κB and stimulation of PI3K/AKT.

BACKGROUND: Syringin, also called eleutheroside B, is a main bioactive phenolic glycoside in Acanthopanax senticosus (Rupr. et Maxim.) Harms. Based on the "kidney dominates bone" theory of TCM, A. senticosus can strengthen bone and Syringin may be one of the responsibilities. PURPOSE: The objectives of this study were to estimate the osteoporotic activity of Syringin and reveal the possible molecular mechanisms in vivo. METHODS: Sixty female ICR mice were randomly assigned into sham operated group (SHAM, treated with vehicle) and five ovariectomized subgroups (n = 10 each), treated with vehicle as OVX group, estradiol valerate (EV, 1 mg/kg/day) as positive group, and Syringin (10, 20 and 40 mg/kg/day) as low, moderate and high dosage groups. The therapeutic effect of Syringin against osteoporosis was systematically analyzed by determining the bone mineral density (BMD), bone biomechanical properties, bone microarchitecture and serum biochemical parameters, and the molecular mechanism was also evaluated. RESULTS: After three months of orally administrated intervention, Syringin (10, 20 and 40 mg/kg/day) significantly improved the BMD, bone maximum load and trabecular bone microarchitecture in ovariectomized mice, evidenced by the increased bone mineral content, tissue mineral content, tissue mineral density, trabecular thickness and trabecular number, as well as the decreased trabecular separation in OVX mice. Meanwhile, the activities of tartrate-resistant acid phosphatase, deoxypyridinoline and cathepsin K in OVX mice were also inhibited by Syringin, while the increased body weight and decreased uterus weight seemed not influenced by Syringin administration. Concerning the underlying molecular mechanisms, Syringin significantly downregulated the expression of tumor-necrosis factor receptor-associated factor 6 (TRAF6), nuclear factor kappa B (NF-κB) and receptor activator of nuclear factor kappa B ligand (RANKL) proteins levels, upregulated the expression of osteoprotegerin (OPG), phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) levels, suggesting that Syringin prevented bone lost by TRAF6-mediated inhibition of NF-κB and stimulation of PI3K/AKT, and subsequently increasing the OPG/RANKL ratio and inhibiting the osteoclastogenesis, finally promoting bone formation. CONCLUSIONS: All of the data implied Syringin possessed the potent anti-osteoporosis activity on ovariectomized mice, and the underlying molecular mechanism may be related to the NF-κB and PI3K/AKT signaling pathways.

Therapeutic Effect of Cistanoside A on Bone Metabolism of Ovariectomized Mice.

Cistanoside A (Cis A), an active phenylethanoid glycoside isolated from Cistanche deserticola Y. C. Ma, has received our attention because of its possible role in the treatment of osteoporosis. In the present study, we evaluated the effects of Cis A on an ovariectomized (OVX) mice model and investigated its underlying molecular mechanisms of action. After 12 weeks of orally-administrated intervention, Cis A (20, 40 and 80 mg/kg body weight/day) exhibited significant antiosteoporotic effects on OVX mice, evidenced by enhanced bone strength, bone mineral density and improved trabecular bone microarchitecture. Meanwhile, the activities of bone resorption markers, including tartrate-resistant acid phosphatase (TRAP), deoxypyridinoline (DPD) and cathepsin K, were decreased, and the bioactivity of bone formation marker alkaline phosphatase (ALP) was increased. Mechanistically, Cis A inhibited the expression of TNF-receptor associated factor 6 (TRAF6), an upstream molecule that is shared by both nuclear factor kappa-light chain enhancer of activated B cells (NF-κB) and phosphatidylinositol 3-kinase (PI3K)/Akt pathways and subsequently suppressed the levels of receptor activators of nuclear factor kappaB ligand (RANKL), downregulated the expression of NF-κB and upregulated osteoprotegerin (OPG), PI3K and Akt, which means Cis A possessed antiosteoporotic activity in ovariectomized mice via TRAF6-mediated NF-kappaB inactivation and PI3K/Akt activation. Put together, we present novel findings that Cis A, by downregulating TRAF6, coordinates the inhibition of NF-κB and stimulation of PI3K/Akt pathways to promote bone formation and prevent bone resorption. These data demonstrated the potential of Cis A as a promising agent for the treatment of osteoporosis disease.

[Identification of Volatile Chemical Constituents from Hui Formula "Ha Hei Lili" by GC-MS].

OBJECTIVE: The volatile components of the Hui formula "Ha Hei Lili" were extracted by steam distillation extraction (SD) and supercritical CO2 fluid extraction, and the structures were analyzed and identified by GC-MS. METHODS: The GC-MS conditions were set as follows: Rxi-5Sil MS quartz capillary column (30 m x 0.25 mm, 0.25 µm), the initial temperature of 50 degrees C to keep 1 min, to 10 degrees C/min heating to 120 degrees C, maintained 3 min, then to 3 degrees C/min heating to 200 degrees C, maintained 3 min, and then to 5 degreesC/min heating to 290 degrees C, maintained until completion of analysis; helium as the carrier gas, column flow rate 1.0 ml/min, split ratio 25: 1, inlet temperature 250 degrees C, EI ionization source 70 eV, ion source temperature 230 degrees C, scan range of m/z 35 - 500. RESULTS: Yield of volatile oil were 0.21% and 5.44% extracted by SD and SFE methods, respectively; and for SD method, 36 kinds of compounds were identified, accounted for 87.02% of total mass of volatile oil; for SFE method, 38 kinds of constituents were identified, accounted for 97.47% of total mass of volatile oil. CONCLUSION: The type of constituents contained in the volatile oil extracted by SD and SFE methods are totally different; and GC-MS can be used to identify the structures and relative content of volatile components, the results of this study can provide an experimental basis for development and utilization of Hui formula "Ha Hei Lili".