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In this study, seven strains of bacteria with polyhydroxyalkanoates (PHA)-producing ability (i.e.Bacillus cereus,Pseudomonas putida,Bacillus pumilus,Pseudomona huttiensis,Yersinia frederiksenii,Aeromonas ichthiosmia, andSphingopyxis terrae) were isolated from various waste treatment plants in Hong Kong. Simultaneous wastewater treatment and PHA accumulation were successfully achieved in the bioreactors using isolated bacteria from different sludges. At the organic loading less than 13,000 ppm, more than 95% of chemical oxygen demand (COD) was removed by the isolated strains before the decrease of PHA accumulation. In addition, more than 95% of nitrogen removal was achieved by all isolated strains. In the bioreactors inoculated with single strains, the highest yields of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxyvalerate) (PHV) were obtained inA. ichthiosmia(84 mg PHB/g) andB. cereus(69 mg/g), respectively. For the mixed culture, the highest yields of PHB and PHV were increased by 55% and 45% in the system inoculated withB. pumilusandA. ichthiosmia. The biologically synthesized PHA also showed the potential applications in drug delivery and tissue engineering. PHA-nanoparticles loaded with pyrene were successfully prepared by recombinantEscherichia coli. The results ofin vitrodrug release and biocompatibility tests revealed that nanoparticles could be used as safer dray carriers with high loading capacity and efficiency. After 20 days, the cells successfully grew on 90% of the PHA-aortic valve. [ABSTRACT FROM PUBLISHER]

Context: Natural products are good sources of natural dietary antioxidants that are believed to protect the body against hepatotoxic effect induced by oxidative stress.Hedyotis diffusaWilld (Rubiaceae) (HDW) is a traditional Chinese medicinal herb that has been shown to possess a variety of antioxidant properties. Objective: The present study examines and explains the cell protective property of HDW water extract (WEHDW). Materials and methods: 2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) assay was used to measure the free radical scavenging property of WEHDW (0.001–10 mg/mL). The protective effect of WEHDW (0.3–10 mg/mL 2 h pretreatment) against hydrogen peroxide (H2O2,200 μM for 6 h) induced cytotoxicity in human hepatic cells, LO2, was evaluated using cell viability assay and nuclear staining. The molecular pathway of WEHDW's effect was investigated by using Western blot assay. Results: WEHDW had a 50% scavenging concentration (SC50) at 0.153 mg/mL in the DPPH assay. Exposure of LO2cells to H2O2resulted in apoptosis which could be markedly attenuated by pre-treating WEHDW in a concentration-dependent manner (0.5, 1, 3, 5, or 10 mg/mL) (all withp < 0.001, versus control). Moreover, Hoechst (nuclear) staining showed that 1 mg/mL WEHDW could protect LO2cells by attenuating apoptotic cell death mediated by H2O2. It was found that WEHDW reversed H2O2-induced activation of MEK/ERK pathway and H2O2-induced inhibition of P13-K/AKT/GSK3β pathway in LO2cells. Discussion and conclusion: WEHDW may help to improve the antioxidant defense system, resulting in prevention of oxidative stress-related fatty liver diseases. [ABSTRACT FROM AUTHOR]

Oxidative stress is considered an important factor that promotes cell death in response to a variety of pathophysiological conditions. This study investigated the antioxidant properties of allicin, the principle ingredient of garlic, on preventing oxidative stress-induced injury. The antioxidant capacities of allicin were measured by using 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay and hydrogen peroxide (H2O2)-induced cell damage on H9c2 cardiomyoblasts. Allicin (0.3-10 μM) pre-incubation could concentration-dependently attenuate the intracellular reactive oxygen species (ROS) increase induced by H2O2 on H9c2 cells. It could also protect H9c2 cells against H2O2-induced cell damage. However, the DPPH free radical scavenging activity of allicin was shown to be low. Therefore, it is believed that the protective effect of allicin on H9c2 cells could inhibit intracellular ROS production instead of scavenging extracellular H2O2 or free radicals. For the observed protective effect on H9c2 cells, allicin might also be effective in reducing free radical-induced myocardial cell death in ischemic condition. [ABSTRACT FROM AUTHOR]

Context: The poor prognostic outcome of breast cancer is largely due to its resistance to cancer therapies. Development of therapeutic agents that can inhibit growth and induce apoptosis in breast cancer cells can help solve the problem. Emodin is an active anthraquinone that has been reported to have diverse biological effects. Objective: In this study, the anticancer effects of emodin on growth inhibition, apoptosis induction and the expression of apoptosis-related genes in MCF-7 cells were investigated. Materials and methods: Growth inhibition induced by emodin was investigated by the MTS assay and the colony formation assay; while emodin-induced apoptosis was determined by the COMET assay and DNA fragmentation detection. Emodin (35 μM)-induced alterations in the expression of apoptotic-related genes were detected by using real-time PCR. Results: Emodin had significant growth inhibitory effects on MCF-7 cells with IC50 = 7.22 µg/ml (∼30 μM). It also exerted a concentration-dependant inhibitory effect on the colony-forming ability of MCF-7 cells with IC50 = 7.60 µg/ml (∼30 µM). Hallmarks of apoptosis, such as single-strand DNA breakage and DNA fragmentation, were observed in emodin-treated MCF-7 cells. The gene expression of Fas ligand ( FASL) was up-regulated ( p < 0.01) but those of MCL1, CCND1 and C-MYC were down-regulated ( p < 0.05) in emodin-treated MCF-7 cells. Discussion and conclusion: This study indicated that emodin could induce growth inhibition and apoptosis in MCF-7 cells through the modulation of the expression of apoptosis-related genes. The growth inhibitory effects of emodin might involve both the intrinsic and the extrinsic apoptotic pathways and cell cycle arrest. [ABSTRACT FROM AUTHOR]

Context: Apoptotic neuronal cell death plays an important role in Parkinson's disease (PD), a progressive neurodegenerative disorder. Luteolin, a flavonoid, has been shown to possess various pharmacological properties including strong antioxidant capacity. Objective: This study investigated the neuroprotective effect of luteolin against cytotoxicity induced by 6-hydroxy-dopamine (6-OHDA) (250 µM) in rat pheochromocytoma (PC12) cell line. Materials and methods: The neuroprotective effect of luteolin against 6-OHDA-induced cytotoxicity in PC12 was evaluated by using cell viability test, nuclear staining and flow cytometry. In addition, the apoptotic role of luteolin was unveiled by monitoring mRNA expression of proapoptotic and anti-apoptotic genes. Results: Pretreatment with luteolin (3.13, 6.25, 12.5, 25 or 50 µM) could markedly attenuate 6-OHDA-induced PC12 cell viability loss in a concentration-dependent manner. Cell morphologic analysis and nuclear staining assays showed that luteolin (3.13, 12.5 or 50 µM) protected the cells from 6-OHDA-induced damage. As shown in the flow cytometry assay, the increased apoptotic rate induced by 6-OHDA could be significantly ( p < 0.001) suppressed by luteolin (12.5 or 50 µM) pretreatment. The protection of luteolin (50 µM) against 6-OHDA-induced cell damage was shown to be through suppressing the over-expression of Bax gene ( p < 0.01), inhibiting the reduction of Bcl-2 gene expression ( p < 0.05) and markedly depressing the enhanced Bax/Bcl-2 ratio. Luteolin also downregulated the gene expression level of p53. Discussion and conclusion: Luteolin has protective effects against 6-OHDA-induced cell apoptosis and might be a potential nutritional supplement which could be used to prevent neurodegenerative diseases such as PD. [ABSTRACT FROM AUTHOR]

Panax ginseng (Ginseng), Rhodiola rosea (Hong Jing Tian) and Schisandra chinensis (Wu Wei Zi) are well-known herbs in traditional Chinese medicine (TCM). Recently, there have been a number of studies on these three herbs. This review discusses their active components and major pharmacological effects. For P. ginseng, it has been shown to have an anti-inflammatory activity, affects pulmonary function and erectile dysfunction, improves cognition in patients with Alzheimer's disease and promotes sexual arousal in menopausal women as well as prevents cancer. For R. rosea, its effectiveness in alleviating depression and reducing fatigue is summarized in this review. Additionally, anti-cancer and other clinical effects of S. chinensis are also discussed. These three herbs are considered as adaptogens as they bear multiple functions and their effects were found to be very different in patients depending on the circumstances (age, gender, environment, diet, season, etc.). Thus, in most cases, the art of the TCM practitioner is to prescribe these herbs after a complete evaluation of overall heath status of the patients. [ABSTRACT FROM AUTHOR]

Although zebrafish has become a popular animal model for drug discovery and screening, drug metabolism in zebrafish remains largely unknown. In this study, we probed the metabolic capability of zebrafish larvae with calycosin, one of the major isoflavone constituents of Radix Astragali that was previously demonstrated to be angiogenic in the zebrafish model. The metabolism of calycosin and accumulation of its metabolites in zebrafish larvae were determined using an LC–MS/MS method. Calycosin showed a slow but steady decrease from the culture medium as well as a steady accumulation in zebrafish larvae. Calycosin underwent major conjugation and minor oxidation in zebrafish larvae. A total of ten calycosin metabolites formed from glucuronidation, glucosylation, sulfation, oxidation or a combination of two of these metabolisms were identified, most of which were reported for the first time. Most metabolites increased steadily in the larvae over 24-h experimental period. The dominant phase II conjugation of calycosin in zebrafish larvae matched well with existing knowledge of isoflavone metabolism in mammalians. The findings shed a light in certain degree of similarity of phase II drug metabolism between zebrafish larvae and mammals and warrant further investigation on feasibility of adopting the zebrafish larvae as a whole-organism model for examining drug metabolism. [ABSTRACT FROM AUTHOR]

Context: Grifola frondosa (Polyporaceae), maitake, is a widely consumed edible mushroom in some Asian countries. The fruit bodies and mycelia of maitake have shown different bioactive compounds with anticancer and other therapeutic properties. Objective: This study evaluated three chemically modified maitake polysaccharide-peptides' (MPSP) adjuvant effect ( in vivo) and anticancer activity ( in vitro growth inhibitory effect) compared with crude MPSP from G. frondosa. Materials and methods: We investigated the possibility of enhancing the adjuvant effect and anticancer effect of crude MPSP by using simple chemical modification methods to convert crude MPSP to phosphorylated, acetylated or esterified MPSPs. The adjuvant effect and growth inhibitory effect were evaluated by C6 cell inoculated rat model with cyclophosphamide (CPA) treatment and in vitro cell viability assay, respectively. Results: All four tested MPSPs showed significant adjuvant effect to CPA treatment on rats inoculated with C6 cancer cells. In addition, an obvious growth inhibitory effect was observed in C6 cancer cells but not in normal brain cells treated with various forms of MPSPs. Only phosphorylation could significantly ( p < 0.05) improve the adjuvant effect ( in vivo) and growth inhibitory effect. A same rank order (phosphorylated MPSP > esterified MPSP ≥ acetylated MPSP ≥ crude MPSP) of efficacy was observed in both the in vivo and in vitro assays. Discussion and conclusion: This study showed chemical phosphorylation could markedly enhance both adjuvant effects and growth inhibitory effects. This study demonstrated the feasibility of enhancing the efficacy of MPSP by using a simple chemical modification method, and this provides a foundation for future study in this area. [ABSTRACT FROM AUTHOR]

A validated high performance liquid chromatographic (HPLC) method with dual wavelength detection was developed and applied to the determination of chlorogenic acid in rat plasma. Elution was performed on C18 column at 27°C with acetronitrile-water (0.2% phosphoric acid, pH = 2.0) at different proportions according to a time scheduled programme and pumped at a flow rate of 1.0 mL min-1. The eluent was detected at 325 nm for chlorogenic acid and 370 nm for the internal standard, kaempferol. The intra-day and inter-day precisions were better than 3.58% and 3.66%, respectively. The standard curve for chlorogenic acid was linear (r2 = 0.9993) in the concentration range of 0.1-15 μg mL-1. Accuracy in the measurement of samples ranged from 91.97 to 101.81%. The limit of detection and the limit of quantification for chlorogenic acid in plasma were 30 and 90 ng mL-1, respectively. This assay has been successfully applied in the pharmacokinetic study of chlorogenic acid through oral and intravenous administration in rats. It showed that the low bioavailability of chlorogenic acid and an intravenous administration route is a better dosage regimen. It is a simple and sensitive analytical method with good accuracy and reproducibility. The current method also demonstrated that an internal standard with different optimal UV absorbance from that of the analyte can also be used in an analytical method. [ABSTRACT FROM AUTHOR]

Scutellaria baicalensis Georgi (Labiatae) (“huang qin”), Ligusticum chuanxiong Hort. (Umbelliferae) (“chuang xiong”), Panax notoginseng (Burk.) F.H. Chen (Araliaceae) (“san qi”), Uncaria rhynchophylla (Miq.) Jackson. (Rubiaceae) (“gou teng”), Rhokiola rosea L. (Crassulaceae) (“hong jing tian”) and Stephania tetrandra S. Moore (Menispermaceae) (“fang ji”) are commonly used traditional Chinese medicine (TCM) for hypertensive patients. The pharmacologically active compounds found in these TCMs are baicalin, ligustrazine, notoginsenoside R1, rhynchophylline, salidroside and tetrandrine, respectively, which possess antihypertensive properties with diverse cellular mechanisms. In this study, we attempted to evaluate a possible correlation of the antioxidative activities (using the DPPH assay) and the vaso-relaxation effects (using rat isolated thoracic aorta) of these compounds. In the antioxidative study, a relative order of free radical scavenging capacity (SR%) of baicalin ≥ tetradrine >> salidroside ≥ ligustrazine ≥ rhynchophylline ≈ notoginsenoside R1 was demonstrated. In the vaso-relaxing study, a relative order of the maximum relaxation response (at 3 mM) of tetradrine > baicalin >> ligustrazine > notoginsenoside R1 ≈ rhynchophylline > salidroside was recorded. A positive correlation (R2 = 0.7741) between the antioxidative activity and the vascular relaxation effect of the compounds evaluated was illustrated. In contrast, ascorbic acid only elicited a free radical scavenging activity with no apparent relaxation effect, whereas nifedipine (a Ca2+ channel blocker) caused a marked vascular relaxation with no obvious free radical scavenging activity. Hence, our results suggest, for the first time, that the therapeutic effect (e.g., antihypertensive) of these TCM-oriented drugs, unlike western medicine, are probably correlated with the unique antioxidative potential of these compounds. [ABSTRACT FROM AUTHOR]

A high performance liquid chromatographic method was developed and applied to the simultaneous determination of puerarin and danshensu in a traditional Chinese medicinal preparation containing Pueraria lobata and Salvia miltiorrhiza as its major herbal constituents. Elution was performed on a C18 column at 27°C with acetonitrile-water (0.5% acetic acid) at different proportions according to a time scheduled programme, and pumped at a flow rate of 1.0 mL/min. Indomethacin was used as an internal standard. High resolution was obtained between the analytes and the internal standard. The intra-day and inter-day precisions were better than 1.9% and 2.2%, respectively. The coefficient of determination for each analyte was above 0.997. It is a simple and sensitive analytical method with good accuracy and reproducibility. [ABSTRACT FROM AUTHOR]

Lobeliae chinensis Herba ("ban bian lian"), Rheum officinale Baill. ("da huang"), Sanguisorba officinalis Linn. ("di yu"), Agrimonia pilosa Ledeb. ("xian he cao"), and Paris polyphylla Smith ("zhi hua tou") are well-known traditional Chinese medicines. They are commonly used in traditional Chinese medicine formulae against cancer. In this study, the antioxidant and anticancer effects of water extracts of these herbs were investigated. In the antioxidant and anticancer studies, water extracts of di yu, xian he cao, and da huang were show to be the most antioxidative and had the highest growth inhibitory effect on human lung adenocarcinoma A549 cell and human breast cancer MCF-7 cell. By comparing their percentage free radical scavenging capacity (SR%) and percentage growth inhibition on A549 and MCF-7 cells, a positive linear relationship between antioxidant activity and anticancer effect of the five herbal water extracts was found. This suggested that the antioxidants of the herbal water extracts might contribute to their anticancer effects on A549 and MCF-7 cells. [ABSTRACT FROM AUTHOR]