Ameliorative effect of edible Halopteris scoparia against cadmium-induced reproductive toxicity in male mice: A biochemical and histopathologic study

Cadmium (Cd) is a toxic metal affecting the reproductive system. Halopteris scoparia (brown algae) is generally consumed as a salad in the Far East countries. This study was conducted to compare and determine the possible protective effects of H. scoparia and vitamin E and C combination (VEC) against cadmium chloride (CdCl₂)-induced reproductive toxicity. A total of 36 male mice were equally divided into as control, CdCl₂ (2 mg/kg), CdCl₂ + H. scoparia (900 mg/kg), CdCl₂ + VEC (200 mg/kg), H. scoparia alone and VEC alone groups. Blood and testis samples were taken for biochemical, histochemical and immunohistochemical analyses. H. scoparia was also examined for antioxidant activity (by DPPH assay) and mineral/trace element content (by ICP-MS method). CdCl₂ exposure caused a significant deterioration in body weight, sperm parameters (count, motility, viability and morphology) (p < .001), histopathology, immunoreactivity and testosterone levels. However, H. scoparia improved CdCl₂-induced deterioration effects more successfully than VEC-treated group. The present study suggests that edible H. scoparia can be used as a natural protective agent against Cd-induced testicular damage by possibly enhancing essential element levels or increasing antioxidant defence system.     

Induction of reactive oxygen species in chlamydomonas reinhardtii in response to contrasting trace metal exposures

The toxicity of metals to organisms is, in‐part, related to the formation of reactive oxygen species (ROS) in cells and subsequent oxidative stress. ROS are by‐products of normal respiration and photosynthesis processes in organisms, but environmental factors, like metal exposure, can stimulate excess production. Metals involved in several different mechanisms such as Haber‐Weiss cycling and Fenton‐type reactions can produce ROS. Some metals, such as Cd, may contribute to oxidative stress indirectly by depleting cellular antioxidants. We investigated the measurement of ROS as a sensitive biomarker of metal toxicity (that could possibly be implemented in a biotic ligand model for algae) and we compared ROS induction in response to several contrasting transition metals (Cu, V, Ni, Zn, and Cd). We also compared the ROS response to glutathione and growth toxicity endpoints measured in a previous study. The cell‐permeable dye, 2′7′dichlorodihydrofluorescein diacetate, was used as a probe to detect formation of ROS in Chlamydomonas reinhardtii cells. Metal‐exposed cells were incubated with the fluorescent dye in a 96‐well plate and monitored over 5.5 h. A dose‐response of ROS formation was observed with Cu exposure in the range of 20–500 nM. Cu produced more ROS compared with either Zn or Cd (both nonredox active metals). The redox‐active metal V produced increased ROS with increased concentration. The measurement of ROS may be a useful indicator of Cu toxicity, but the signal to noise ratio was better for the glutathione endpoint assay. © 2011 Wiley Periodicals, Inc. Environ Toxicol 28: 516–523, 2013.     

Ecotoxicity and uptake of polymer coated gold nanoparticles

Abstract

Bioconjugated gold nanoparticles (Au NPs) are a promising tool for pharmaceutical applications. However, the ecotoxicity of these types of NPs has hardly been studied. We investigated the ecotoxicity and uptake of 4–5 nm Au NPs to which two types of polymer coatings were attached. One coating was an amphiphilic polymer only and the other an amphiphilic coating to which 10 kDa polyethylene glycol chains were attached. In both 72 h algal growth inhibition tests with the alga Pseudokirchneriella subcapitata and in 24 h resazurin cytotoxicity tests with the rainbow trout gill cell line RTGill-W1, the pegylated Au NPs were found less toxic compared to the amphiphilic coated particles. No uptake or direct interaction between particles and algal cells was observed. However, uptake/adsorption in fish gill cells reached up to >10⁶ particles/cell after 1 h and particles were eliminated for ≥96% after 24 h depuration. Both particle types were found within membrane enclosed vesicles in the cytoplasm of RTgill-W1 cells.     

褐藻某些化学组分研究新进展

从褐藻中分离出许多化学结构新颖的新化合物，一些具有独特的生物活性。本文按萜类，类脂，甾醇，酚类，其他化合物等化学结构类型概述了1993－2000年间报道的新的褐藻化学成分。     

饮用天然矿泉水淡水藻类污染研究进展

本文概述了有关研究报告的矿泉水水源及瓶装成品水的藻类污染发生情况，检出种类，检验方法，污染途径及可能造成的危害。从控制污染的观点考察，列出重要的环节。针对淡水藻类的特点，结合瓶装矿泉水的水源，水处理，灌装，包装材料，管理等生产工艺，介绍并分析了国内外学者提出的控制措施和研究趋势。     

Edible Microalgae and Their Bioactive Compounds in the Prevention and Treatment of Metabolic Alterations

Marine and freshwater algae and their products are in growing demand worldwide because of their nutritional and functional properties. Microalgae (unicellular algae) will constitute one of the major foods of the future for nutritional and environmental reasons. They are sources of high-quality protein and bioactive molecules with potential application in the modern epidemics of obesity and diabetes. They may also contribute decisively to sustainability through carbon dioxide fixation and minimization of agricultural land use. This paper reviews current knowledge of the effects of consuming edible microalgae on the metabolic alterations known as metabolic syndrome (MS). These microalgae include Chlorella, Spirulina (Arthrospira) and Tetraselmis as well as Isochrysis and Nannochloropsis as candidates for human consumption. Chlorella biomass has shown antioxidant, antidiabetic, immunomodulatory, antihypertensive, and antihyperlipidemic effects in humans and other mammals. The components of microalgae reviewed suggest that they may be effective against MS at two levels: in the early stages, to work against the development of insulin resistance (IR), and later, when pancreatic -cell function is already compromised. The active components at both stages are antioxidant scavengers and anti-inflammatory lipid mediators such as carotenoids and -3 PUFAs (eicosapentaenoic acid/docosahexaenoic acid; EPA/DHA), prebiotic polysaccharides, phenolics, antihypertensive peptides, several pigments such as phycobilins and phycocyanin, and some vitamins, such as folate. As a source of high-quality protein, including an array of bioactive molecules with potential activity against the modern epidemics of obesity and diabetes, microalgae are proposed as excellent foods for the future. Moreover, their incorporation into the human diet would decisively contribute to a more sustainable world because of their roles in carbon dioxide fixation and reducing the use of land for agricultural purposes.     

Lobster Supply Chains Are Not at Risk from Paralytic Shellfish Toxin Accumulation during Wet Storage

Lobster species can accumulate paralytic shellfish toxins (PST) in their hepatopancreas following the consumption of toxic prey. The Southern Rock Lobster (SRL), Jasus edwardsii, industry in Tasmania, Australia, and New Zealand, collectively valued at AUD 365 M, actively manages PST risk based on toxin monitoring of lobsters in coastal waters. The SRL supply chain predominantly provides live lobsters, which includes wet holding in fishing vessels, sea-cages, or processing facilities for periods of up to several months. Survival, quality, and safety of this largely exported high-value product is a major consideration for the industry. In a controlled experiment, SRL were exposed to highly toxic cultures of Alexandrium catenella at field relevant concentrations (2 × 10⁵ cells L⁻¹) in an experimental aquaculture facility over a period of 21 days. While significant PST accumulation in the lobster hepatopancreas has been reported in parallel experiments feeding lobsters with toxic mussels, no PST toxin accumulated in this experiment from exposure to toxic algal cells, and no negative impact on lobster health was observed as assessed via a wide range of behavioural, immunological, and physiological measures. We conclude that there is no risk of PST accumulation, nor risk to survival or quality at the point of consumption through exposure to toxic algal cells.