Effects of curcumin-based photodynamic treatment on the storage quality of fresh-cut apples.

Photodynamic treatment (PDT) is an innovative technology with non-thermal and environmentally sound merits, but the evaluation on the storage qualities of fresh produce was scarce. In this study, the effects of curcumin-based PDT on the quality of fresh-cut 'Fuji' apple slices during storage at 4 °C were investigated. The impacts on the survival of Escherichia coli, color and weight loss were examined under different curcumin concentrations, illumination time or incubation time. Curcumin-based photodynamic inactivation of E. coli on the surface of apple slices reached 0.95 log. Curcumin-based PDT was proven to prevent browning and weight loss. Additionally, PDT significantly reduced the activity of polyphenol oxidase and peroxidases to 48% and 51%, respectively. Moreover, there were few negative changes in total phenolic, ascorbic acid content and anti-oxidant activity of the treated apples. These results indicated that curcumin-based PDT was a viable and promising non-thermal technology to preserve the quality of fresh produce.

Effect of photodynamic inactivation of Escherichia coli by hypericin.

The present study has focused on the effects of hypericin (Hyp) based photodynamic inactivation (PDI) of Escherichia coli (E. coli). To evaluate the efficiency of Hyp based PDI of E. coli, single factor experiments and response surface optimization experiment were conducted to obtain the optimum parameter values (36 µM Hyp, 5.9 J cm-2 light dose: 16.4 mW cm-2, 60 W, 260 s, 590 nm and 68 min incubation time) and finally achieved a 4.1 log CFU mL-1 decrease of E. coli. Cell-Hyp interaction and intracellular reactive oxygen species (ROS) level were detected by fluorescence spectrometric photometer. Data indicated that Hyp possessed a strong ability to bind with cells. In addition, a significant increase was observed in intracellular ROS level after Hyp-based photosensitization treatment. Therefore, Hyp-based photosensitization seems to be a promising method to efficiently inactivate E. coli. It is expected to be a safe, efficient, low cost and practical method which can be applied in the field of food safety.

Electroacupuncture for older adults with mild cognitive impairment: study protocol for a randomized controlled trial.

BACKGROUND: Mild cognitive impairment is an intermediary state between normal aging and clinical Alzheimer's disease. Early intervention of mild cognitive impairment may be an important strategy in the management of Alzheimer's disease. The proposal aims to evaluate if electroacupuncture would optimize cognitive function in subjects with mild cognitive impairment and understand the role of electroacupuncture in the treatment of Alzheimer's disease. METHODS/DESIGN: A randomised patient- and assessor-blind sham-controlled trial is designed to assess whether electroacupuncture intervention decreases the rate of cognitive decline amongst older adults with mild cognitive impairment. One hundred and fifty subjects aged 65 years of age or over with a diagnosis of mild cognitive impairment are recruited from the community and elderly centre in Hong Kong. All subjects are randomly allocated into two groups (75 subjects each group): the electroacupuncture group and sham control. Participants in the electroacupuncture group receive electroacupuncture stimulation by sterile, disposable acupuncture needles inserted to the acupoints with a depth of 1 to 3 cm. The acupuncture needles are subjected to 2 Hz electroacupuncture with an intensity of 5 to 10 mA. Each participant receives electroacupuncture for 8 weeks (once a day, 3 days a week) and the treatment lasts for 30 minutes each time. For sham electroacupuncture, needles are inserted to a depth of 1 to 2 mm, and connected to the electroacupuncture device without any current passing through. Outcome measures (including primary and secondary outcome measures) are collected at baseline, at the end day of intervention, and months 4 and 6 after intervention. The primary outcome is measured by the Alzheimer Disease Assessment Scale-Cognitive subscale. Secondary outcomes are measured by the mini-mental state examination, category fluency text and the Short Form 12. DISCUSSION: The study will provide evidence for evaluating and understanding the role of electroacupuncture in the treatment of Alzheimer's disease. TRIAL REGISTRATION: This trial is registered with chictr.org (registration number: ChiCTR-TRC-12002414 . Registration date: 11 August 2012.

Hypocrellin B enhances ultrasound-induced cell death of nasopharyngeal carcinoma cells.

Hypocrellin B, a natural pigment from a traditional Chinese herb, has been attracting extensive attention. The present study aims to investigate whether hypocrellin B can enhance cell death induced by ultrasound sonification on nasopharyngeal carcinoma cells in vitro. The sonodynamic action of hypocrellin B was investigated on nasopharyngeal carcinoma cell line CNE2 cells as tumor model cells. In the experiments, the hypocrellin B concentration was kept constant at 2.5 microM and the cells were subject to ultrasound exposure for 15 s at an intensity of 0.65 W/cm(2). Cytotoxicity was investigated 24 h after ultrasound sonification. Apoptosis was evaluated using flow cytometry with annexin V-FITC and propidium iodine staining and nuclear staining with Hoechst 33258. Cell ultrastructure morphology was observed using transmission electron microscopy (TEM). No significant dark cytotoxicity of hypocrellin B in the CNE2 cells was observed at the concentration of 2.5 microM. The cell death rate induced by ultrasound sonification was significantly higher in the presence of hypocrellin B than in the absence of hypocrellin B. Flow cytometry showed that ultrasound exposure in the presence of hypocrellin B significantly increased the early and late apoptotic rate, 18.64% and 22.57%, respectively, compared with the controls. Nuclear condensation was observed in the nuclear staining and swollen mitochondria and more vacuolar and broken cell membrane were found in TEM after the treatment of hypocrellin B and ultrasound. Our findings demonstrated that the presence of hypocrellin B significantly enhanced the cytotoxicity of ultrasound radiation in CNE2 cells, suggesting that hypocrellin B is a novel sonosensitizer and hypocrellin B-mediated sonodynamic therapy is a potential therapeutic modality in the management of malignant tumors.

Transfection efficiency of TDL compound in HUVEC enhanced by ultrasound-targeted microbubble destruction.

The aim of the present study was to explore the gene transfection efficiency of Tat peptide/plasmid DNA/ liposome (TDL) compound combined with ultrasound-targeted microbubble destruction (UTMD) in human umbilical vein endothelial cell (HUVEC). Tat peptide, plasmid DNA (pIRES2-EGFP-HGF) and Lipofectamine 2000 were used to prepare the TDL compound. Microbubbles were prepared using mechanic vibration. The expression of the report gene enhanced green fluorescent protein (EGFP) was observed using fluorescent microscopy and flow cytometry. The viability of HUVEC was measured by MTT assay. mRNA and protein of HGF was analyzed by reverse transcription-polymerase chain reaction and Western Blot. The intensity of green fluorescence and the gene transfection efficiency of TDL compound + microbubbles + ultrasound group were higher than those of other groups, and no significantly different viability was found between TDL compound + microbubbles + ultrasound group and the other groups. The HGF mRNA and HGF protein of TDL compound + microbubbles + ultrasound group were higher than those of other groups. Our finding demonstrated that UTMD could enhance the transfection efficiency of TDL compound without obvious effects on the cell viability of HUVEC, suggesting that the combination of UTMD and TDL compound might be a useful tool for the gene therapy of ischemic heart disease.

Relationship between myocardial ultrasonic integrated backscatter and mitochondria of the myocardium in dogs.

OBJECTIVE: This study aimed to explore the relationship between integrated backscatter (IBS) and mitochondria in arrested myocardium. METHODS: Twelve open-chest dogs were randomly divided into two groups: one group with cardiac arrest in systole and the other with cardiac arrest in diastole. IBS images at parasternal papillary muscle short-axis view were stored at different time frames (0, 30, and 60 min after cardiac arrest). The values of ultrasonic IBS were obtained using the acoustic densitometry technique. After ultrasound examination, tissue samples of corresponding times were harvested and observed under the transmission electron microscope. The microscopic images were analyzed using a computer imaging analysis system to obtain the stereological parameters of mitochondria. The correlation between IBS and the stereological parameters was analyzed. RESULTS: After cardiac arrest, swollen mitochondria with electron-lucent matrix could be observed in some myofibers following the progression of time. The alteration of IBS correlated well with that of mitochondrial stereological parameters, such as volume density (Vv), surface density (Sv), average volume (v), average surface area (s), and specific surface (Rsv, ratio between surface and volume). CONCLUSION: Mitochondria might be an important scatterer in the myocardium for IBS.

Photodynamic effects of pyropheophorbide-a methyl ester in nasopharyngeal carcinoma cells.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is one of the most common cancers, and exploring novel therapeutic modalities will improve the clinical outcomes. It has been confirmed that photodynamic therapy can efficiently deactivate malignant cells. The aim of the present study was to explore the photodynamic effects of pyropheophorbide-a methyl ester (MPPa) in CNE2 nasopharyngeal carcinoma cells. MATERIAL/METHODS: CNE2 cells were subjected to photodynamic therapy with MPPa, in which the drug concentration was 0.25 to 4 microM and light energy 1 to 8 J/cm(2). Photodynamic toxicity was investigated 24 h after treatment. Apoptosis was determined using flow cytometry with annexin V-FITC and propidum iodine staining and with nuclear staining with Hoechst 33258. The mitochondrial membrane potential (DeltaPsim) was evaluated by Rhodamine 123 assay. RESULTS: There was no dark cytotoxicity of MPPa in the CNE2 cells at doses of 0.25-4 microM, and MPPa resulted in dose- and light-dependent phototoxicity. The apoptotic rate 8 h after PDT with MPPa (2 microM) increased to 16.43% under a light energy of 2 J/cm(2). Mitochondrial membrane potential (DeltaPsim) collapsed when the CNE2 cells were exposed to 2 microM MPPa for 20 h and then 2 J/cm(2) irradiation. CONCLUSIONS: Photodynamic therapy with MPPa significantly enhanced apoptosis and the collapse of DeltaPsim. This can be developed for treating nasopharyngeal carcinoma.