Modified photoanode by in situ growth of covalent organic frameworks on BiVO4 for oxygen evolution reaction.

The development of efficient oxygen evolution reaction (OER) catalysts is of great significance because the water oxidation reaction at the photoanode is the rate-determining step in photoelectrocatalytic (PEC) water splitting. Herein, two hybrid photoanodes named BiVO4/COF-Azo and BiVO4/COF-Ben were prepared by in situ solvothermal growth on a modified BiVO4 photoanode. Characterization results revealed that the Azo and Ben COFs could match with BiVO4 well to form heterojunctions, which could effectively enhance the separation efficiency of photogenerated carriers. Also, the smaller impedance of the composite photoanodes and faster kinetics of the water oxidation reaction promoted the charge transmission and enhanced the reaction efficiency of the surface-reaching holes, respectively. As a result, the composite photoanodes exhibited a larger photocurrent and more negative onset potential compared to the pristine BiVO4. This work not only provides a new strategy to construct efficient hybrid photoanodes, but also expands the applications of COFs.

Anti-Breast Cancer Effect of 2-Dodecyl-6-Methoxycyclohexa-2,5-Diene-1,4-Dione in vivo and in vitro Through MAPK Signaling Pathway.

BACKGROUND: 2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) has been reported to inhibit a variety of cancer cell lines. The purpose of this study was to investigate the effects of DMDD on 4T1 breast cancer cells and the effects of DMDD on 4T1 breast cancer in mice and its molecular mechanisms. METHODS: 4T1 breast cancer cells were treated with different concentrations of DMDD, and their proliferation, apoptosis, cell-cycle distribution, migration, and invasion were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT, Acridine orange and ethidium bromide dual staining analysis (AO/EB) dual staining, flow cytometry, scratch test, and the Transwell assay. Relative quantitative real-time qPCR analysis and Western blot were applied to examine the expression levels of related genes and proteins. In animal experiments, we established a xenograft model to assess the anti-breast cancer effects of DMDD by evaluating the inhibition rate. The apoptotic activity of DMDD was evaluated by hematoxylin-eosin (HE) staining, transmission electron microscope (TEM) analysis and TdT-mediated dUTP nick end labeling (TUNEL) assays. The mRNA expression levels of MAPK pathway components were detected by relative quantitative real-time qPCR. In addition, the protein expression levels of MAPK pathway components were assessed through immunohistochemical assays and Western blotting. RESULTS: Experiments showed that DMDD could inhibit the proliferation, migration, invasion of 4T1 cells and induce cellular apoptosis and G1 cell cycle arrest. Moreover, DMDD down-regulated the mRNA expressions of raf1, mek1, mek2, erk1, erk2, bcl2, and up-regulated the mRNA expression of bax. DMDD reduced the protein expressions of p-raf1, p-mek, p-erk, p-p38, Bcl2, MMP2, MMP9 and increased the protein expressions of Bax and p-JNK. The results showed that DMDD can effectively reduce the tumor volume and weight of breast cancer in vivo, up-regulate the expression of IL-2, down-regulate the expression of IL-4 and IL-10, induce the apoptosis of breast cancer cells in mice, and regulate the expression of genes and proteins of the MAPK pathway. CONCLUSION: Our study indicates that DMDD can inhibit proliferation, migration, and invasion and induces apoptosis and cell-cycle arrest of 4T1 breast cancer cells. Also, our findings indicate that DMDD induces the apoptosis of breast cancer cells and inhibits the growth in mice. Its mechanism may be related to the MAPK pathway.

Protective Effect of Benzoquinone Isolated from the Roots of Averrhoa carambola L. on Streptozotocin-Induced Diabetic Mice by Inhibiting the TLR4/NF-κB Signaling Pathway.

BACKGROUND: Studies have demonstrated that the roots of Averrhoa carambola L. (Oxalidaceae), a traditional Chinese medicine, can be used to treat diabetes and diabetes-related diseases. Nevertheless, the potential beneficial effects and mechanism of benzoquinone isolated from the roots of Averrhoa carambola L. (BACR) on diabetes remain unclear. METHODS: Diabetic Kunming mice were injected with STZ (120 mgkg-1) in the tail vein. Fasting blood glucose (FBG) and the change of body weight were measured after oral administration of BACR (120, 60, 30 mg/kg/d) every week. The levels of the total cholesterol (TC), triglyceride (TG), free fatty acids (FFA), glucosylated hemoglobin (GHb), fasting insulin (FINS), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured. The histological examination of pancreatic tissues and the TLR4/NF-κB pathway was analyzed by RT-PCR, immunohistochemistry and Western blot. RESULTS: The study found that clearly the BACR obviously reduced the blood glucose, serum lipids, GHb and FINS. In addition, BACR treatment markedly reduced the release of inflammatory factors, including IL-6 and TNF-α, and down-regulated the expression of the TLR4/NF-κB pathway. CONCLUSION: BACR has potential benefits for the treatment of diabetes by ameliorating metabolic functions and attenuating the inflammatory response via inhibition of the activation of theTLR4/NF-κB pathway.

2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione, isolated from the root of Averrhoa carambola L., protects against diabetic kidney disease by inhibiting TLR4/TGFß signaling pathway.

OBJECTIVE: Diabetic kidney disease (DKD) is the leading cause of death and disability of diabetes mellitus. However, there is still a lack of specific drugs for the treatment of DKD. The chief aim of this research is to investigate the role and mechanism of 2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) for DKD. METHODS: Wild type and TLR4 knockout mice were induced to diabetes. After 4-week treatment with DMDD, blood sugar, renal function, blood lipid and pathological changes were assessed. Real-time PCR, western blotting, and immunohistochemistry were employed to detect the expressions of TLR4, TGFß1 and Smad2/3 in the renal tissue. RESULTS: DMDD improved the serum lipid and decreased fasting blood glucose levels in diabetic mice. CysC and urinary albumin levels increased markedly in the diabetic group, and they were obviously decreased after 4 weeks of DMDD treatment. Compared with the WT diabetic mice, the urinary albumin and CysC in the TLR4-/- mice were expressed at lower levels. HE and Masson's staining revealed that DMDD clearly ameliorated pathological changes and renal fibrosis. When TLR4 gene was knock out, the pathological was improved. Mechanistically, TLR4, TGF-ß1 and Smad2/3 were obvious up-regulation in the renal tissues of diabetic mice. The expressions of these proteins were significantly down-regulated after DMDD treatment (p < 0.05). In the TLR4-/- mice, mRNA and protein levels of TGF-ß1 and Smad2/3 were obviously lower than those in the WT mice. In addition, IHC revealed that a strong in situ expressions of TLR4, TGF-ß1 and Smad2/3 were seen in the kidney tissues of diabetic mice, which were distinctly weakened in the DMDD-treated mice. In the TLR4-/- mice, however, expressions of TGF-ß1 and Smad2/3 were not remarkable increase in the diabetic mice compared with normal mice. CONCLUSIONS: These results strongly indicate that TLR4 is essential for DMDD protection against renal dysfunction in diabetic mice. Its hypoglycemic and anti-fibrosis effects were likely mediated by the TLR4/TGFß signaling pathway.

Extract of Averrhoacarambola L. (Oxalidaceae) roots ameliorates carbon tetrachloride-induced hepatic fibrosis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The root of Averrhoa carambola L. (Oxalidaceae), a traditional Chinese medicine, was mainly used in ancient times in the treatment of urinary calculi, recurrent headache and joint pain. AIM OF THE STUDY: Our aims were to explore the potential therapeutic effect of the extract of Averrhoa carambola L. (Oxalidaceae) roots (EACR) against hepatic fibrosis in CCl4-treated rats and to understand the underlying molecular mechanism. MATERIALS AND METHODS: Six groups of male Sprague Dawley rats were treated as follows: vehicle (olive oil), CCl4 alone, CCl4+colchicine, CCl4+EACR 1.0 g/kg, CCl4+EACR 0.5 g/kg and CCl4+EACR 0.25 g/kg. At the end of the 12th week, biomarkers of liver function, liver fibrosis, hepatic oxidative stress and antioxidant status were assayed, and histopathological and immunohistochemical evaluation of liver tissue were conducted to investigate the liver damage and fibrosis degree. Furthermore, expressions of COL-1a1, α-SMA, TGF-ß1, Smad2, smad3, Smad4 and TIMP2 were examined by qPCR and/or western blot. The expressions of apoptosis-related proteins were also detected using western blot analysis. RESULTS: EACR treatment markedly reduced the CCl4-induced elevation of serum aminotransferase activities, liver fibrosis indexes, and the extent of oxidative stress. EACR treatment also significantly reduced the accumulation of collagen and the immunostaining of α-SMA, TGF-ß1 and Smad2, 4 and 7 in the liver of CCl4 treated rats. In addition, EACR treatment markedly reversed the CCl4-induced increase in mRNA expression of COL-1a1, α-SMA, TIMP2, TGF-ß1, Smad2 and Smad4 and suppressed the expressions of α-SMA, TIMP2, TGF-ß1, smad2, 3 and 4, BAX and cleaved caspase-3 proteins. Meanwhile, EACR treatment also significantly elevated the mRNA expression of Smad7 and the protein expression of Smad7 and Bcl-2. CONCLUSION: These results suggest that EACR has protective activity against liver fibrosis. The anti-fibrotic activity of EACR in vivo is associated with enhanced antioxidant, apoptosis-inhibition and increased MMP-2/TIMP-2 expression ratio, and with modulation of TGF-ß1/Smad signaling pathway.

2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione isolated from Averrhoa carambola L. root ameliorates diabetic nephropathy by inhibiting the TLR4/MyD88/NF-κB pathway.

BACKGROUND: Averrhoa carambola L. is a traditional medicinal herb that has long been used to treat diabetes. Our previous studies found that 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) isolated from A. carambola L. roots could ameliorate diabetic nephropathy (DN), but its exact mechanism remains unclear. METHODS: A DN model was established by streptozotocin (STZ, 100 mg/kg body weight) in TLR4 knockout (TLR4-/-, KO) mice and wild-type (WT) mice. Body weight and blood glucose were evaluated after oral administration of DMDD (12.5, 25, 50 mg/kg body weight/d) in diabetic mice. The levels of serum lipids, including TC, TG, HDL, and LDL and kidney function indexes Scr and BUN, were detected by biochemical equipment. The levels of inflammatory cytokines including IL-6 and TNF-α, were determined by ELISA kits. Furthermore, changes in renal ultrastructure were observed by electron microscopy. Western blot analysis and RT-PCR were used to assess the protein expression and mRNA levels of TLR4, MyD88 and NF-κB. RESULTS: DMDD treatment attenuated diabetic nephropathy, as a result of a decline in blood glucose, serum creatinine, and blood urine nitrogen levels and an increase in the quantity and density of podocytes, combined with improved dyslipidaemia. DMDD treatment inhibited the inflammatory response and downregulated the expression of the TLR4/MyD88/NF-κB pathway in diabetic mice, and these changes were significantly different in TLR4-/- mice. CONCLUSION: DMDD alleviates diabetic nephropathy by mitigating kidney damage and inflammation via the inhibition of the TLR4/MyD88/NF-κB signalling pathway.

[Effect of enhanced UV-B radiation on polyamine metabolism and endogenous hormone contents in rice (Oryza sativa L.)].

The results showed that the activities of Agrinine decarboxylase(ADC), Ornithine decarboxylase(ODC) and s-Adenosylmethionine decarboxylase(SAMDC) were increased by 165.74%, 104.60% and 89.60% in the leaves of Shan You63(Sy63) and by 59.91%, 41.30% and 23.68% in the leaves of Nancheum(NC). Only ADC and ODC activities were increase by 115.93%, 14.45%, but SAMDC activity was decreased by 33.01% in the leaves of IR65600-85 respectively in the exposure to enhanced UV-B radiation for 7-14 days. In late treatment time course(21-28 d), the activities of ADC and ODC were increased by 89.72% and 3.71% in the leaves of Sy63 exposed to UV-B radiation for 21-28 days and by 73.95% and 27.38% in the leaves of NC. The activity of ADC was also increased by 94.41%, but ODC activity was decreased by 13.57% in the leaves of IR65600-85 compared with the controls. As far as SAMDC was concerned, the enzymic activities in the leaves of Sy63, NC and IR65600-85 were reduced by 40.06%, 19.20% and 38.21% respectively in the exposure to enhanced UV-B radiation for 21-28 days. The reverse was true in the case of Polyamine Oxidase (PAO), this in turn resulted in increased contents of Polyamine(PA) especially putrescine(Put). In addition, the result also indicated that the contents of IAA and GA1/3 were significantly reduced in all rice cultivars used for this experiments with enhanced UV-B radiation treatments for 7-28 days, in which the contents of IAA and GA1/3 were decreased by 58.92% and 45.48% in the leaves of Sy63, by 43.31% and 56.20% in the leaves of NC, and by 38.60% and 47.33% in the leaves of IR65600-85. The contents of ZRs in the leaves of the three cultivars concerned were lower in earlier treatment time courses (7-14 d), but much higher in late courses(21-28 d) compared with the their counterparts. With regard to the endogenous hormone of ABA, the content was significantly increased by 14.4%, 99.6% and 56.7% respectively in the three rice cultivars concerned exposed to enhanced UV-B radiation for 7-28 days, thereby led to decreased values of IAA/ABA, GA1/3/ABA and ZRs/ABA, consequently suppressed growth and development of rice.

[Effects of enhanced ultraviolet-B radiation on growth development and yield formation in rice (Oryza sativa L.)].

Effect of enhanced ultraviolet-B radiation (280-320 nm) on growth, development and yield formation in the three rice cultivars (Oryza sativa L.) under pot conditions were investigated. The results showed that enhanced ultraviolet-B radiation decreased rice height, tiller number, total leaf area and biomass, but the inhibitory rate varied in different cultivars and developmental stages. Plant height was decreased by 9.4%-12.2% in seedling stage, plant shoot and root of dry matter were decreased by 45.3%-59.8% and 54.9%-59.0% respectively in tillering period. The leaf emergence delayed, resulting in delayed time of flowering in Shanyou 63, Nanchuan and IR65600-85 by 2d, 3d and 7d, prolonged total growth period by 3d, 4d and 9d. Net photosynthesis rate of Shanyou 63, Nanchuan and IR65600-85 were decreased by 11.9%, 12.8% and 29.7%, respectively. Attributed to decreased contents of chlorophyll a, b, carotenoid and induction kinetics parameters of Fv, Fv/Fm and Fv/Fo. Effective panicle per plant, total grain number per panicle, filled grain rate and 1000-grain weight were decreased by enhanced UV-B radiation. Consequently the grain yields were reduced by 25.2%-31.1%.