Hong Kong Baptist University

About: Hong Kong Baptist University is a education organization based out in Hong Kong, China. It is known for research contribution in the topics: Population & China. The organization has 7811 authors who have published 18919 publications receiving 555274 citations. The organization is also known as: Hong Kong Baptist College & HKBU.

Antidiabetic properties of dietary flavonoids: a cellular mechanism review

Abstract: Natural food products have been used for combating human diseases for thousands of years. Naturally occurring flavonoids including flavones, flavonols, flavanones, flavonols, isoflavones and anthocyanidins have been proposed as effective supplements for management and prevention of diabetes and its long-term complications based on in vitro and animal models. To summarize the roles of dietary flavonoids in diabetes management and their molecular mechanisms. Tremendous studies have found that flavonoids originated from foods could improve glucose metabolism, lipid profile, regulating the hormones and enzymes in human body, further protecting human being from diseases like obesity, diabetes and their complications. In the current review, we summarize recent progress in understanding the biological action, mechanism and therapeutic potential of the dietary flavonoids and its subsequent clinical outcomes in the field of drug discovery in management of diabetes mellitus.

AtMKK1 mediates ABA-induced CAT1 expression and H2O2 production via AtMPK6-coupled signaling in Arabidopsis.

Abstract: Catalase controls cellular H 2 O 2 and plays important roles in the adaptation of plants to various stresses, but little is known about the signaling events that lead to the expression of CAT1 and the production of H 2 O 2 . Here we report the dependence of CAT1 expression and H 2 O 2 production on a mitogen-activated protein kinase (MAPK) cascade. CAT1 transcript was induced in an ABA-dependent way and the induction was abolished in the T-DNA insertion mutant mkkl (SALK_015914), while AtMKK1 overexpression significantly enhanced the ABA-induced CAT1 expression and H 2 O 2 production. AtMPK6, another component in the MAPK cascade, was also involved: mpk6 mutant blocked and overexpressing AtMPK6 enhanced the ABA-dependent expression of CAT1 and H 2 O 2 production. The activity of AtMPK6 was increased by ABA in an AtMKK1-dependent manner. These data clearly suggest an ABA-dependent signaling pathway connecting CAT1 expression through a phosphorelay including AtMKK1 and AtMPK6. In further support of this view, mkkl mutant reduced both the sensitivity to ABA during germination and the drought tolerance of seedlings, whereas the AtMKKI overexpression line showed the opposite responses when compared with the wild type. The data suggest AtMKK1-AtMPK6 to be a key module in an ABA-dependent signaling cascade causing H 2 O 2 production and stress responses.

Involvement of plasma-membrane NADPH oxidase in abscisic acid- and water stress-induced antioxidant defense in leaves of maize seedlings.

Abstract: The roles of the plasma-membrane (PM) NADPH oxidase in abscisic acid (ABA)- and water stress-induced antioxidant defense were investigated in leaves of maize ( Zea mays L.) seedlings. Treatment by exogenous ABA (100 micro M ABA) or osmotic stress (-0.7 MPa induced by polyethylene glycol) significantly increased the activity of the PM NADPH oxidase, the production of leaf O(2)(-), the activities of several antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase), and the contents of antioxidant metabolites (ascorbate and reduced glutathione). Pretreatment with three different inhibitors of NADPH oxidase (diphenylene iodonium, imidazole and pyridine) or an inhibitor of ABA biosynthesis (tungstate) reduced the increase in the activity of the PM NADPH oxidase and the production of leaf O(2)(-), and the capacity of antioxidant defense systems mediated by ABA. The inhibitory effects above caused by tungstate were reversed by exogenous ABA. These data indicate that NADPH oxidase is involved in the ABA-induced production of active oxygen species (AOS), and our results depict a minimal chain of events initiated by water stress-induced ABA accumulation, which then triggers the production of AOS by membrane-bound NADPH oxidase, resulting in the induction of antioxidant defense systems against oxidative damage in plants.

Benchmarking Organic Micropollutants in Wastewater, Recycled Water and Drinking Water with In Vitro Bioassays

Abstract: Thousands of organic micropollutants and their transformation products occur in water Although often present at low concentrations, individual compounds contribute to mixture effects Cell-based bioassays that target health-relevant biological endpoints may therefore complement chemical analysis for water quality assessment The objective of this study was to evaluate cell-based bioassays for their suitability to benchmark water quality and to assess efficacy of water treatment processes The selected bioassays cover relevant steps in the toxicity pathways including induction of xenobiotic metabolism, specific and reactive modes of toxic action, activation of adaptive stress response pathways and system responses Twenty laboratories applied 103 unique in vitro bioassays to a common set of 10 water samples collected in Australia, including wastewater treatment plant effluent, two types of recycled water (reverse osmosis and ozonation/activated carbon filtration), stormwater, surface water, and drinking water Sixty-five bioassays (63%) showed positive results in at least one sample, typically in wastewater treatment plant effluent, and only five (5%) were positive in the control (ultrapure water) Each water type had a characteristic bioanalytical profile with particular groups of toxicity pathways either consistently responsive or not responsive across test systems The most responsive health-relevant endpoints were related to xenobiotic metabolism (pregnane X and aryl hydrocarbon receptors), hormone-mediated modes of action (mainly related to the estrogen, glucocorticoid, and antiandrogen activities), reactive modes of action (genotoxicity) and adaptive stress response pathway (oxidative stress response) This study has demonstrated that selected cell-based bioassays are suitable to benchmark water quality and it is recommended to use a purpose-tailored panel of bioassays for routine monitoring