A Carbon Nanodot Based Near-Infrared Photosensitizer with a Protein-Ruthenium Shell for Low-Power Photodynamic Applications.

Near-infrared (NIR) light-activated photosensitization represents an encouraging therapeutic method in photodynamic therapy, especially for deep tissue penetration. In this context, two-photon activation, i.e., utilization of photons with relatively low energy but high photon flux for populating a virtual intermediate state leading to an excited state, is attractive. This concept would be highly advantageous in photodynamic therapy due to its minimal side effects. Herein, we propose that the combination of plasma protein serum albumin (HSA) containing several Ru complexes and NIR two-photon excitable carbon nanodots (Cdots), termed HSA-Ru-Cdots, provides several attractive features for enhancing singlet oxygen formation within the mitochondria of cancer cells stimulated by two-photon excitation in the NIR region. HSA-Ru-Cdot features biocompatibility, water solubility, and photostability as well as uptake into cancer cells with an endosomal release, which is an essential feature for subcellular targeting of mitochondria. The NIR two-photon excitation induced visible emission of the Cdots allows fluorescence resonance energy transfer (FRET) to excite the metal-to-ligand charge transfer of the Ru moiety, and fluorescence-lifetime imaging microscopy (FLIM) has been applied to demonstrate FRET within the cells. The NIR two-photon excitation is indirectly transferred to the Ru complexes, which leads to the production of singlet oxygen within the mitochondria of cancer cells. Consequently, we observe the destruction of filamentous mitochondrial structures into spheroid aggregates within various cancer cell lines. Cell death is induced by the long-wavelength NIR light irradiation at 810 nm with a low power density (7 mW/cm2), which could be attractive for phototherapy applications where deeper tissue penetration is crucial.

Gene expression profile associated with Asmt knockout-induced depression-like behaviors and exercise effects in mouse hypothalamus.

Sleep disorder caused by abnormal circadian rhythm is one of the main symptoms and risk factors of depression. As a known hormone regulating circadian rhythms, melatonin (MT) is also namely N-acetyl-5-methoxytryptamine. N-acetylserotonin methyltransferase (Asmt) is the key rate-limiting enzyme of MT synthesis and has been reportedly associated with depression. Although 50-90% of patients with depression have sleep disorders, there are no effective treatment ways in the clinic. Exercise can regulate circadian rhythm and play an important role in depression treatment. In the present study, we showed that Asmt knockout induced depression-like behaviors, which were ameliorated by swimming exercise. Moreover, swimming exercise increased serum levels of MT and 5-hydroxytryptamine (5-HT) in Asmt knockout mice. In addition, the microarray data identified 10 differentially expressed genes (DEGs) in KO mice compared with WT mice and 29 DEGs in KO mice after swimming exercise. Among the DEGs, the direction and magnitude of change in epidermal growth factor receptor pathway substrate 8-like 1 (Eps8l1) and phospholipase C-ß 2 (Plcb2) were confirmed by qRT-PCR partly. Subsequent bioinformatic analysis showed that these DEGs were enriched significantly in the p53 signaling pathway, long-term depression and estrogen signaling pathway. In the protein-protein interaction (PPI) networks, membrane palmitoylated protein 1 (Mpp1) and p53-induced death domain protein 1 (Pidd1) were hub genes to participate in the pathological mechanisms of depression and exercise intervention. These findings may provide new targets for the treatment of depression.

Selenium regulates the mitogen-activated protein kinase pathway to protect broilers from hexavalent chromium-induced kidney dysfunction and apoptosis.

Hexavalent chromium [Cr (VI)] is a common environmental pollutant. Although selenium (Se) can antagonize the toxicity of Cr (VI), the specific underlying mechanism has not been identified. To investigate this mechanism, we used potassium dichromate (K2Cr2O7) and selenium-rich yeast (SeY) to construct single Cr (VI)- and combined Se/Cr (VI)-exposed broiler models during a 42-day period. Broilers were randomly assigned to the control (C), SeY (Se), SeY + Cr (VI) (Se/Cr), and Cr (VI) (Cr) groups. The antagonistic mechanisms of Se and Cr (VI) were evaluated using histopathological evaluation, serum and tissue biochemical tests, real-time fluorescence quantitative polymerase chain reaction, and western blotting. The results suggested that Se alleviated the morphological and structural damage to renal tubules and glomeruli, while reducing the organ index, creatinine levels, and blood urea nitrogen levels in the kidneys of Cr (VI)-exposed broilers. Furthermore, Cr (VI) reduced the levels of superoxide dismutase and glutathione, and increased the levels of malondialdehyde, in broiler kidney tissues. However, Se alleviated Cr (VI)-induced oxidative stress by increasing the levels of superoxide dismutase and glutathione, and decreasing the levels of malondialdehyde, within a certain range. Compared to the C group, the levels of p38, JNK, p-p38, p-JNK, p-p38/p38, and p-JNK/JNK significantly increased, whereas those of ERK, p-ERK, and p-ERK/ERK decreased, in the Cr group. Compared to the Cr group, the levels of p38, JNK, p-p38, p-JNK, p-p38/p38, and p-JNK/JNK significantly decreased, whereas those of ERK, p-ERK, and p-ERK/ERK increased, in the Se/Cr group. Furthermore, the levels of p53, c-Myc, Bax, Cyt-c, caspase-9, and caspase-3 significantly increased, and those of Bcl-2 and Bcl-2/Bax significantly decreased, following Cr (VI) exposure, while Se restored the expression of these genes. In conclusion, our findings suggest that SeY can protect against Cr (VI)-induced dysfunction and apoptosis by regulating the mitogen-activated protein kinase pathway activated by oxidative stress in broiler kidney tissues.

The Role of Nitric Oxide in the Antidepressant Actions of 5-Aminoimidazole-4-Carboxamide-1-ß-D-Ribofuranoside in Insulin-Resistant Mice.

OBJECTIVE: Depression and Type 2 diabetes mellitus are interrelated conditions, but the underlying neurobiology is insufficiently understood. The current study compared the effects of a pharmacological manipulation with 5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranoside (AICAR) that targets neurobiological processes by adenosine 5'-monophosphate-activated protein kinase activation versus exercise on depression-like behavior and nitric oxide (NO)-related measures. METHODS: A mouse model of a depression-like and insulin-resistant state, induced by the co-treatment of high-fat diet and corticosterone administration, was used to examine the antidepressant action of AICAR and exercise. RESULTS: Data showed that AICAR was a putative antidepressant in the depression-like and insulin-resistant mice (total ambulatory distance in the open-field test was 5120.69 ± 167.47 cm, mobility duration in the forced swim test was 17.61 ± 1.54 seconds, latency to feed in the novelty suppressed feeding test was 255.67 ± 37.80 seconds; all p values < .05). Furthermore, the antidepressant actions of AICAR required endothelial nitric oxide synthase activity with increased NO production in the prefrontal cortex, whereas corticosterone-induced expression of neuronal nitric oxide synthase and NO production may increase the risk of depression. In contrast to the traditional antidepressants such as ketamine and imipramine, AICAR interfered with the effects of insulin in skeletal muscle in the context of high-fat diet, consistent with the potential antidepressant effects of AICAR. Exercise also resulted in activation of adenosine 5'-monophosphate-activated protein kinase, nitric oxide synthase, and NO production (all p values < .01), which in turn may be implicated in the antidepressant effects of exercise. CONCLUSIONS: These findings suggest that NO is an essential signal mediating the antidepressant actions of AICAR. Ultimately, the concurrent effects of AICAR on brain insulin action and mitochondrial function suggest a potential of neural insulin resistance, which may contribute to our understanding of the comorbidity of depression and Type 2 diabetes.

Lactobionic acid-modified dendrimer-entrapped gold nanoparticles for targeted computed tomography imaging of human hepatocellular carcinoma.

Development of novel nanomaterial-based contrast agents for targeted computed tomography (CT) imaging of tumors still remains a great challenge. Here we describe a novel approach to fabricating lactobionic acid (LA)-modified dendrimer-entrapped gold nanoparticles (LA-Au DENPs) for in vitro and in vivo targeted CT imaging of human hepatocellular carcinoma. In this study, amine-terminated poly(amidoamine) dendrimers of generation 5 pre-modified with fluorescein isothiocyanate and poly(ethylene glycol)-linked LA were employed as templates to form Au nanoparticles. The remaining dendrimer terminal amines were subjected to an acetylation reaction to form LA-Au DENPs. The prepared LA-Au DENPs were characterized via different methods. Our results reveal that the multifunctional Au DENPs with a Au core size of 2.7 nm have good stability under different pH (5-8) and temperature (4-50 °C) conditions and in different aqueous media, and are noncytotoxic to normal cells but cytotoxic to the targeted hepatocarcinoma cells in the given concentration range. In vitro flow cytometry data show that the LA-Au DENPs can be specifically uptaken by a model hepatocarcinoma cell line overexpressing asialoglycoprotein receptors through an active receptor-mediated targeting pathway. Importantly, the LA-Au DENPs can be used as a highly effective nanoprobe for specific CT imaging of hepatocarcinoma cells in vitro and the xenoplanted tumor model in vivo. The developed LA-Au DENPs with X-ray attenuation property greater than clinically employed iodine-based CT contrast agents hold a great promise to be used as a nanoprobe for targeted CT imaging of human hepatocellular carcinoma.

Improved oral bioavailability of glyburide by a self-nanoemulsifying drug delivery system.

AIM: The present study aimed at the development and characterisation of self-nanoemulsifying drug delivery system (SNEDDS) to improve the oral bioavailability of poorly soluble glyburide. METHODS: The solubility of glyburide was determined in various oils, surfactants and co-surfactants which were grouped into two different combinations to construct ternary phase diagrams. The formulations were evaluated for emulsification time, droplet size, zeta-potential, electrical conductivity and stability of nanoemulsions. RESULT: The optimised SNEDDS loading with 5 mg/g glyburide comprised 55% Cremophor® RH 40, 15% propanediol and 30% Miglyol® 812, which rapidly formed fine oil-in-water nanoemulsions with 46 ± 4 nm particle size. Compared with the commercial micronised tablets (Glynase®PresTab®), enhanced in vitro release profiles of SNEDDS were observed, resulting in the 1.5-fold increase of AUC following oral administration of SNEDDS in fasting beagle dogs. CONCLUSIONS: These results indicated that SNEDDS is a promising drug delivery system for increasing the oral bioavailability of glyburide.

Application of complexation high-speed counter-current chromatography in the separation of 5-hydroxyisoflavone isomers from Belamcanda chinensis (L.) DC.

A novel separation technique of complexation high-speed counter-current chromatography (HSCCC) using copper ion as a complexation agent was first developed to isolate 5-hydroxyisoflavone isomers from Belamcanda chinensis (L.) DC. According to the partition coefficient and separation factor, the two-phase solvent system composed of light petroleum-ethyl acetate-methanol-water (3:5:3:5, v/v) and copper nitrate (0.10mol/L in the lower phase) was selected. 9.2mg isoirigenin (1), 46.4mg irigenin (2) and 1.2mg 5,7,4'-trihydroxy-6,3',5'-trimethoxyisoflavone (3) were simultaneously purified from 100mg crude extract by HSCCC with the purity of 95.06%, 96.98% and 93.69%, respectively. As evidenced by the results of UV-Vis spectroscopy, the stoichiometries of the copper ion with the three 5-hydroxyisoflavones were all 1:1 and their chelating power was 3>2>1. Those explained the complexation HSCCC behavior. It is the first report that includes the practical application of complexation HSCCC and explanation of its chromatographic behavior.

[Quantitative analysis of steroidal saponins in Chinese material medica Rhizoma Paridis by HPLC-ELSD].

OBJECTIVE: The several species of the genus Paris called as Rhizoma Paridis were famous traditional Chinese medica. To develop the quantitative analysis method of the steroidal saponins in some species of the genus Paris and commercially available Rhizoma Paridis samples by HPLC-ELSD. METHOD: The contents of 11 steroidal saponins in Rhizoma Paridis samples were dectected with a Kromasil C18(4.6 mm x 150 mm, 5 microm) column which was deluted with acetonitrile-water (30:70-60:40) at a flow rate of 1 mL x min(-1) by HPLC-ELSD. RESULT: All the authentic samples could be separated and calibration curves of 11 saponins were prepared. 11 steroidal saponins in 16 Rhizoma Paridis samples were detected in 30 min. The recovery for the assay of saponins was between 95% and 97%. The precision and stability of samples (RSD) were below 3%. CONCLUSION: The method was shown to be accurate and convenient, and suitable for the quantitative analysis of these 11 steroidal saponins in the commercially available Rhizoma Paridis samples.

Determination of piceid in rat plasma and tissues by high-performance liquid chromatographic method with UV detection.

A rapid, sensitive and selective HPLC method was developed and validated for determination of piceid in rat plasma and tissues. The drug was isolated from plasma and tissues by a simple protein precipitation procedure. Chromatographic separation was performed on a C(18) column with acetonitrile-water (26:74, v/v) as mobile phase. The method was successfully applied to the pharmacokinetics and tissue distribution research after oral administration of a 50 mg/kg dose of piceid to healthy male Wistar rats. The pharmacokinetic parameters showed that piceid was quickly absorbed, distributed and eliminated within 4 h after oral administration. The tissue distribution results showed that, at 10 min, the concentrations of piceid in most tissues reached peak level except in heart and testis. The highest level of piceid was found in stomach, then in small intestine, spleen, lung, brain, testis, liver, kidney and heart. The amount of piceid in testis and heart reached the peak level at 30 min. At 120 min, the amount of piceid in all tissues decreased to a low percentage of the initial concentration. Piceid was absorbed throughout the gastrointestinal tract with considerable absorption taking place in the stomach and small intestine. There was no long-term accumulation of piceid in rat tissues.

[Study on pharmacokinetics of emodin in Rhizoma Polygontum Cuspidatum and its compound].

OBJECTIVE: To study the difference in the pharmacokinetics of emodin in Zhiganning capsules and Rhizoma Polygontum Cuspidatum by nonaqueous RP-HPLC. METHOD: The rats were orally administered with the extraction of Rhizoma Polygontum Cuspidatum and Zhiganning capsules. After hydrolysis and extraction, the content of emodin in the plasma is determined by Nonaqueous RP-HPLC. RESULT: The concentration-time profiles of emodin fit two-compartment model. The pharmacokinetics parameters including, t1/2alpha, AUC(0-infinity), CL(s) and C(max) of emodin in the group of Rhizoma Polygontum Cuspidatum were significantly different from these in the group of its compounds. CONCLUSION: There is a significant difference in pharmacokinetics of emodin between zhiganning capsules and the extraction of Rhizoma Polygontum Cuspidatum.