Dehong Tan

Blueberry Anthocyanins-Enriched Extracts Attenuate Cyclophosphamide-Induced Cardiac Injury

We sought to explore the effect of blueberry anthocyanins-enriched extracts (BAE) on cyclophosphamide (CTX)-induced cardiac injury. The rats were divided randomly into five groups including normal control, CTX 100 mg/kg, BAE 80mg/kg, CTX+BAE 20mg/kg and CTX+BAE 80mg/kg groups. The rats in the three BAE-treated groups were administered BAE for four weeks. Seven days after BAE administration, rats in CTX group and two BAE-treated groups were intraperitoneally injected with a single dose of 100 mg/kg CTX. Cardiac injury was assessed using physiological parameters, Echo, morphological staining, real-time PCR and western blot. In addition, cardiotoxicity indices, inflammatory cytokines expression and oxidative stress markers were also detected. Four weeks 20mg/kg and 80mg/kg dose of BAE treatment following CTX exposure attenuated mean arterial blood pressure, heart rate and activities of heart enzymes, improved cardiac dysfunction, left ventricular hypertrophy and fibrosis. Importantly, BAE also attenuated CTX-induced LV leukocyte infiltration and inflammatory cytokines expression, ameliorated oxidative stress as well as cardiomyocyte apoptosis. In conclusion, BAE attenuated the CTX-induced cardiac injury and the protective mechanisms were related closely to the anti-inflammatory, antioxidant and anti-inflammatory characteristics of BAE.

Antibacterial Activity of Juglone against Staphylococcus aureus: From Apparent to Proteomic

The proportion of foodborne disease caused by pathogenic microorganisms is rising worldwide, with staphylococcal food poisoning being one of the main causes of this increase. Juglone is a plant-derived 1,4-naphthoquinone with confirmed antibacterial and antitumor activities. However, the specific mechanism underlying its antibacterial activity against Staphylococcus aureus remains unclear. To elucidate the mechanism underlying its antibacterial activity, isobaric tags for relative and absolute quantitation methods of quantitative proteomics were applied for analysis of the 53 proteins that were differentially expressed after treatment with juglone. Combined with verification experiments, such as detection of changes in DNA and RNA content and quantification of oxidative damage, our results suggested that juglone effectively increased the protein expression of oxidoreductase and created a peroxidative environment within the cell, significantly reducing cell wall formation and increasing membrane permeability. We hypothesize that juglone binds to DNA and reduces DNA transcription and replication directly. This is the first study to adopt a proteomic approach to investigate the antibacterial mechanism of juglone.

In vitro inhibitory activities of six gypenosides on human liver cancer cell line HepG2 and possible role of HIF-1α pathway in them

During our phytochemical investigation of Gynostemma pentaphyllum (Thunb.) Makino, six gypenosides (compounds 1-6) were isolated and determined, including two with a 21,23-epoxy group (1, 2), two with a 21,23-lacton skeleton (3, 4), and two with usual side-chain (5, 6). In this research, we studied their possible in vitro inhibitory activities on cancer cell line HepG2 under hypoxic conditions, explored the role of HIF-1α pathway in them and discussed the potential antitumor gradients and conduct analysis of structure-activity relationships (SAR). They and gensenoside-Rg3 were tested for different assays. Compounds 1-4 showed moderate antitumor activities against HepG2 by MTT assay, inhibited HIF-1α mRNA expression, as well as disturbing HepG2 migration and invasion, superior to Rg3. Correlations were found for gypenosides with different side chain on inhibiting HepG2 proliferation activity, the ones have epoxy structure showed the highest effect. These results supported the potential application of G. pentaphyllum as a functional food for hepatoprotection.

Protective effects of grape seed extract fractions with different degrees of polymerisation on blood glucose, lipids and hepatic oxidative stress in diabetic rats

The purpose of this study was to evaluate the effect of grape seed procyanidin (GSPE) fractions with different degrees of polymerisation (DPs) on blood glucose, lipids and hepatic oxidative stress in diabetic rats. Diabetic rats received a daily oral supplement of GSPE with different DPs for 6 weeks. During this period, blood glucose, body weight and food intake were assessed weekly. At the end of the experiment, serum lipid and hepatic oxidative stress were assessed compared with those of rats that did not receive GSPE. GSPE significantly decreased blood glucose, serum lipids and hepatic oxidative stress. Moreover, these effects were significantly better in the groups administered the oligomeric rather than the polymeric forms. These results demonstrate that GSPE has a positive effect on diabetes in rats, and the oligomeric form of GSPE may be more protective than other forms.

Effect of epigallocatechin-3-gallate on acrylamide-induced oxidative stress and apoptosis in PC12 cells

Acrylamide (ACR) is a chemical intermediate utilized in industry. ACR is also formed during heating of foods containing carbohydrates and amino acids. Therefore, humans are widely exposed to ACR, and ACR neurotoxicity in humans is a significant public health issue attracting wide attention. In this study, we investigated the potential neuroprotective effects of epigallocatechin-3-gallate (EGCG), the most abundant polyphenolic compound in green tea, in PC12 cells treated with ACR. ACR-treated PC12 cells pretreated with various concentrations of EGCG (2.5, 5 and 10 μM) for 24 h had increased viability and acetylcholinesterase activity and reduced apoptosis and necrosis compared to cells exposed to ACR alone. EGCG reduced the expression of bax mRNA, decreased cytochrome c release, reduced intracellular calcium levels, inactivated caspase 3 and increased mitochondrial membrane potential, suggesting that EGCG prevents ACR-induced apoptosis through a mitochondrial-mediated pathway. In addition, EGCG inhibited the formation of reactive oxygen species and lipid peroxidation while enhancing superoxide dismutase activity and glutathione levels, thereby reducing oxidative stress. Our results indicate that pretreatment of PC12 cells with EGCG attenuates ACR-induced apoptosis by reducing oxidative stress. Therefore, drinking green tea may reduce nerve injury induced by ACR.

Blueberry anthocyanins-enriched extracts attenuate the cyclophosphamide-induced lung toxicity

The influence of blueberry anthocyanins-enriched extracts (BAE) on cyclophosphamide (CTX)-induced lung damage was investigated. BAE (20 and 80mg/kg/d) were orally dosed to rats 7d both before and after CTX administration (100mg/kg, intraperitoneal injection, single dose). The results showed CTX treatment induced obvious pathological pulmonary injury with raised injury score and lung/body weight ratio. In CTX group, the activity of lysosomal proteases, lung permeability and the number of neutrophil infiltrates all elevated. On the other hand, claudin-4 and zonula occluden-1 protein levels decreased. And also changes of oxidative stress and inflammatory cytokines parameters together with nuclear factor-κB activation were shown. Improvement of all above-mentioned physiological and biochemical parameters was exhibited in BAE groups, with a dose-dependent manner. In conclusion, BAE attenuate the CTX-induced lung toxicity, antioxidant and anti-inflammatory characteristics are involved in the protective mechanism of BAE.

Rhodamine B induces long nucleoplasmic bridges and other nuclear anomalies in Allium cepa root tip cells.

The cytogenetic toxicity of rhodamine B on root tip cells of Allium cepa was investigated. A. cepa were cultured in water (negative control), 10xa0ppm methyl methanesulfonate (positive control), and three concentrations of rhodamine B (200, 100, and 50xa0ppm) for 7xa0days. Rhodamine B inhibited mitotic activity; increased nuclear anomalies, including micronuclei, nuclear buds, and bridged nuclei; and induced oxidative stress in A. cepa root tissues. Furthermore, a substantial amount of long nucleoplasmic bridges were entangled together, and some nuclei were simultaneously linked to several other nuclei and to nuclear buds with nucleoplasmic bridges in rhodamine B-treated cells. In conclusion, rhodamine B induced cytogenetic effects in A. cepa root tip cells, which suggests that the A. cepa root is an ideal model system for detecting cellular interactions.

Preparation and Functional Exploration of Cysteine Peptides from Fresh Garlic Scales for Improving Bioavailability of Food Legume Iron and Zinc

Abstract Two γ-glutamyl-cysteine peptides (γ-GCPs), ( S C2 R C7)-γ- L -glutamyl- S -allyl- L -cysteine ( 1 ) and ( S C2 R C7)-γ- L -glutamyl- S -propyl- L -cysteine ( 2 ) were isolated from fresh garlic scales using ion-exchange chromatography and preparative HPLC. Their molecular structures were identified by HPLC-MS, CD, 1 H NMR, 13 C NMR, and specific rotation, and confirmed by using corresponding standard compounds. The influence of exogenously adding 1 and 2 on the bioavailability of iron and zinc from food legume was examined with soybean and mung bean, at the level of 0.01 mmol/5 g of legume respectively. The enhancing effect of the two γ-GCPs on bioavailability of iron was generally evidenced in the case of soybean (from 1.88% to 6.73% and 4.42%) and mung bean (from 2.52% to 12.04% and 9.38%). The two γ-GCPs similarly enhanced the bioavailability of zinc from the food legume, with the extent of increase in soybean ranging from 13.37% to 23.95% and 20.58%, and in mung bean from 15.98% to 28.44% and 27.05%. Obviously, both 1 and 2 had a promoting effect on the bioavailability of iron and zinc from food legumes. These findings are of practical value in a food-based strategy to enhance the bioavailability of trace minerals for human health.

Cytotoxic triterpenes from the acid hydrolyzate of Gynostemma pentaphyllum saponins

Abstract One new dammarane-type triterpene, gypsapogenin A (1), was isolated from the acid hydrolyzate of total saponins from Gynostemma pentaphyllum (Thunb.) Makino, together with two known compounds, (20S,24S)-3β,20,21β,23β,25-pentahydroxy-21,24-cyclodammarane (2) and (23S)-3β-hydroxydammar-20,24-dien-21-oic acid 21,23-lactone (3). Its structural elucidations were accomplished mainly on the basis of the interpretation of spectroscopic data, such as IR, HR-TOF-MS, and NMR. The cytotoxic activities were evaluated against HepG2 and A549 human cancer cell lines.

Blueberry anthocyanins ameliorate radiation-induced lung injury through the protein kinase RNA-activated pathway

The purpose of this study was to explore the effect of blueberry anthocyanins (BA) on radiation-induced lung injury and investigate the mechanism of action. Seven days after BA(20 and 80 mg/kg/d)administration, 6 weeks old male Sprague-Dawley rats rats were irradiated by LEKTA precise linear accelerator at a single dose of 20 Gy only once. and the rats were continuously treated with BA for 4 weeks. Moreover, human pulmonary alveolar epithelial cells (HPAEpiC) were transfected with either control-siRNA or siRNA targeting protein kinase R (PKR). Cells were then irradiated and treated with 75 μg/mL BA for 72 h. The results showed that BA significantly ameliorated radiation-induced lung inflammation, lung collagen deposition, apoptosis and PKR expression and activation. In vitro, BA significantly protected cells from radiation-induced cell death through modulating expression of Bcl-2, Bax and Caspase-3. Suppression of PKR by siRNA resulted in ablation of BA protection on radiation-induced cell death and modulation of anti-apoptotic and pro-apoptotic proteins, as well as Caspase-3 expression. These findings suggest that BA is effective in ameliorating radiation-induced lung injury, likely through the PKR signaling pathway.