Antioxidants in the black mussel (Mytilus galloprovincialis) as an indicator of Black Sea coastal pollution

Blue Mussel (Mytilus edulis) Water Extract Ameliorates Inflammatory Responses and Oxidative Stress on Osteoarthritis in Obese Rats

Purpose

To investigate the effects of Mytilus edulis water extract (MWE) on an anterior cruciate ligament transection and a partial medial meniscectomy surgery to induced osteoarthritis (OA) with the high-fat diet (HFD)-induced obese rats.

Methods

The male Sprague-Dawley rats were fed with HFD for 4 weeks before surgery. The OA rats were orally administered with MWE (108.5, 217.0, and 542.5 mg/kg) for 6 weeks.

Results

The administration of MWE affected weight loss, triglycerides content, and total cholesterol level. MWE also enhanced the activity of superoxide dismutase and decreased lipid peroxidation degree. Moreover, MWE reduced proinflammatory cytokines level, alleviated inflammation and swelling of the osteoarthritic knee, and reduced loss of proteoglycan in articular cartilage tissue.

Conclusion

MWE suppressed proinflammatory mediators and attenuated the cartilage degradation and pain in osteoarthritis rats under obesity condition. Therefore, MWE has the potential to act as an alternative for osteoarthritis treatment.

Multiple biomarker responses in caged benthic gastropods Bellamya aeruginosa after in situ exposure to Taihu Lake in China

BACKGROUND

Freshwater sediments have been recognized as a long-term sink and potential source for environmental pollutants released into the aquatic ecosystems. In this study, the sediment quality of Taihu Lake, which is susceptible to anthropogenic contamination, was assessed by a combination of chemical analytical and biological end points. Specifically, the snail Bellamya aeruginosa was caged in situ at two locations representing different pollution levels for different exposure times (7, 14 and 21 days). At each of these time points, biochemical parameters, i.e., phase I biotransformation enzymes ethoxyresorufin-O-deethylase (EROD), the antioxidant enzymes superoxide dismutase and catalase, reactive oxygen species, protein carbonyl content and lipid peroxidation, were evaluated in the hepatopancreas of snails. In addition, surface sediments were collected for analysis of contaminants of concern, including inorganic pollutants, organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers.

RESULTS

Chemical analyses revealed that sediments from Taihu Lake were contaminated with trace elements and organic pollutants. Concentrations of trace elements (Cu, Ni and As) and organochlorinated pesticides (4,4'-DDE) exceeded their corresponding threshold effect level according to the sediment quality assessment values for freshwater ecosystems in Canada, indicating that adverse biological effects may occur. All biomarkers, except EROD activity, were induced in snails during all exposure times. The integrated biomarker response index (IBR) indicated that during the initial exposure phase (7 days), B. aeruginosa were subjected to significant environmental stress, which diminished during later sampling time points.

CONCLUSIONS

Results showed that IBR correlated well with the levels of environmental contaminants, demonstrating the applicability of this biomonitoring approach to complex environmental exposure scenarios.

Trace metals and oxidative status in soft tissues of caged mussels (Aulacomya atra) on the North Patagonian coastline

This study investigated metal accumulation and oxidative effects in mantle, gill and digestive gland of the ribbed mussel Aulacomya atra from the Argentinean North Patagonian coastline. Mussels were transplanted over an 18-month period from a site with low anthropogenic impact to a harbor site with higher seawater concentration of aluminum, chromium, copper, manganese, nickel and zinc. Total trace metal concentration in seawater did not change throughout the 18-month transplant in either site. A. atra bioaccumulated metals in digestive gland, gills and mantle at different levels. Digestive gland had the highest concentration of metals, especially towards the end of the transplant experiment in the harbor area. Mussels transplanted to the harbor site experienced an upregulation in their antioxidant system, which likely explains the lack of oxidative damage to lipids despite higher metal accumulation. These results demonstrate that A. atra selectively accumulates metals from the water column and their prooxidant effects depend on the tissue antioxidant defenses and the exposure time.

Nitric oxide synthesis inhibition and cytotoxicity of Korean horse mussel Modiolus modiolus extracts on cancer cells in culture

The Korean horse mussel extract was purified and fractionated by a bioassay-guided purification step. The final fraction contained seven steroid and one polycyclic aromatic compounds, in which cholest-7-en-3-ol, (3β,5α)- (58.7 %) was a main component followed by ergosta-7,22dien-3-ol (3β,5α,22E) (13.0 %). This extract exhibited strong anti-inflammatory activity determined solely through the nitric oxide inhibition assay in a dose-dependant manner with the IC50 value of 9.6 µg/mL and no cytotoxic effect on the macrophages. Moreover, it also exhibited strong cytotoxicity with the IC50 values of 21.4, 36.4, and 37.1 µg/mL against AGS, DLD-1, and HeLa cells, respectively. These results indicated that the horse mussel extract might be a functional ingredient in the prevention of inflammation and human cancers.

Effect of seasonality on oxidative stress responses and metal accumulation in soft tissues of Aulacomya atra, a mussel from the South Atlantic Patagonian coast

This study investigated the effects of pollution and its interaction with temperature on the oxidative status of the ribbed mussel Aulacomya atra in the southern Atlantic Patagonian coast. Animals were collected from four sites with different degree and type of human activity impact, during the summer and winter of 2011. Seawater chromium, copper, manganese, nickel and zinc concentrations were measured, as well as metal accumulation, lipid peroxidation, protein oxidation, reduced glutathione levels, and enzymatic activities of superoxide dismutase and glutathione-S-transferase in gills and digestive glands. Metal bioaccumulation and oxidative stress responses in both tissues were generally higher in mussels from harbor areas. Water temperature had a remarkable effect on gill SOD activity and protein oxidation during winter in mussels from all locations. Methodologically, we conclude that measuring both metal bioaccumulation and oxidative stress responses allowed for a more accurate assessment of the biological effects of metal present in seawater.

Lipid peroxidation and antioxidant defense enzymes in Clarias gariepinus as useful biomarkers for monitoring exposure to polycyclic aromatic hydrocarbons

The toxicological evaluations of crude oil, xylene, toluene and benzene were carried out against juvenile stages of Clarias gariepinus. On the basis of LC(50) value, benzene (0.017 ml/l) was found to be the most toxic followed by xylene (0.086 ml/l), toluene (0.398 ml/l) and crude oil (2.219 ml/l) was the least toxic. The results of the lipid peroxidation assay showed that the level of malonaldehyde (MDA) in liver and gills of fish exposed to all the test chemicals increased significantly (P < 0.05) when compared to control. Measurement of activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) in liver and gill of fishes exposed to sublethal concentration of the test chemicals over a 28-day period was found to decrease significantly (P < 0.05) when compared to control. The observed reduction in the activities of antioxidant defense enzymes such as SOD, CAT and GST in conjunction with an increase in MDA levels in the gill and liver tissues of test animals exposed to aromatic hydrocarbon compounds were recommended as a good battery of biomarkers for early detection of pollution during biomonitoring programmes.

Role of oxidative stress in the antitumoral action of a new vanadyl(IV) complex with the flavonoid chrysin in two osteoblast cell lines: relationship with the radical scavenger activity

The new complex [VO(chrysin)(2)EtOH](2) (VOchrys) has been synthesized and thoroughly characterized. Fourier transform IR, UV-vis, diffuse reflectance, and EPR spectroscopies as well as elemental analysis and thermal measurements were performed. In solution, different species could be detected by EPR spectroscopy as a function of the ligand-to-metal ratio. The stoichiometry of the chelate complex formed at pH 5 was also determined by spectrophotometric titrations. Since flavonoids are natural antioxidant compounds, the antioxidant capacity of chrysin and its vanadyl(IV) complex was investigated using different radicals. Chrysin and its complex were not able to diminish the level of superoxide and 1,1-diphenyl-2-picrylhydrazyl radicals to a great extent. In contrast, they were strong scavengers for 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt radical cations and OH. radicals with a greater potency for VOchrys. Taking into account their selective antioxidant properties, we investigated the bioactivity of these compounds in two osteoblast-like cells in culture. Chrysin and VOchrys caused an inhibition of cell proliferation in MC3T3E1 normal osteoblasts and UMR106 tumor cells in a dose-response manner, with a greater effect in the latter cell line. The generation of reactive oxygen species (ROS) was evaluated in both cell lines and a correlation could be established between the antiproliferative effects of chrysin and the increase in the ROS levels. The complex did not generate types of ROS that can be detected by the dihydrorhodamine 123 technique so the antiproliferative effect may be attributed to the formation of other radicals such as superoxide, which is not detected by this probe. The morphological alterations were in agreement with these changes.

Relationship between seawater pollution and qualitative changes in the extracted proteins from mussels Mytilus galloprovincialis

The aim of this study was to find a reliable biomarker of seawater pollution. For this purpose the contents of Zn and Cu, proteins and antioxidant activity in mussels Mytilus galloprovincialis collected from polluted and non-polluted sites of the Bulgarian Black Sea coast were compared. To determine the above-mentioned indices atomic spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy, fluorescence, differential scanning calorimetry (DSC), and two antioxidant tests were used. It was found that the amounts of Zn and Cu were significantly higher in the mussel proteins from the polluted than from the non-polluted sites (P<0.05). FT-IR spectroscopy and fluorescence revealed specific qualitative changes in secondary and tertiary structures in mussel proteins in the samples from polluted sites. The thermodynamic properties of proteins and the changes upon denaturation were correlated with the secondary structure of proteins and disappearance of alpha-helix. Purified protein scavenging activity against 2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS(*+)) was significantly higher in mussel samples from polluted than from non-polluted sites. Therefore, the changes in Zn and Cu concentration, in protein's secondary and tertiary structures and antioxidant activity in mussels M. galloprovincialis from polluted sites can be a reliable biomarker of the level of the seawater pollution.

Molecular biomarkers of oxidative stress in aquatic organisms in relation to toxic environmental pollutants

The potential of oxygen free radicals and other reactive oxygen species (ROS) to damage tissues and cellular components, called oxidative stress, in biological systems has become a topic of significant interest for environmental toxicology studies. The balance between prooxidant endogenous and exogenous factors (i.e., environmental pollutants) and antioxidant defenses (enzymatic and nonenzymatic) in biological systems can be used to assess toxic effects under stressful environmental conditions, especially oxidative damage induced by different classes of chemical pollutants. The role of these antioxidant systems and their sensitivity can be of great importance in environmental toxicology studies. In the past decade, numerous studies on the effects of oxidative stress caused by some environmental pollutants in terrestrial and aquatic species were published. Increased numbers of agricultural and industrial chemicals are entering the aquatic environment and being taken up into tissues of aquatic organisms. Transition metals, polycyclic aromatic hydrocarbons, organochlorine and organophosphate pesticides, polychlorinated biphenyls, dioxins, and other xenobiotics play important roles in the mechanistic aspects of oxidative damage. Such a diverse array of pollutants stimulate a variety of toxicity mechanisms, such as oxidative damage to membrane lipids, DNA, and proteins and changes to antioxidant enzymes. Although there are considerable gaps in our knowledge of cellular damage, response mechanisms, repair processes, and disease etiology in biological systems, free radical reactions and the production of toxic ROS are known to be responsible for a variety of oxidative damages leading to adverse health effects and diseases. In the past decade, mammalian species were used as models for the study of molecular biomarkers of oxidative stress caused by environmental pollutants to elucidate the mechanisms underlying cellular oxidative damage and to study the adverse effects of some environmental pollutants with oxidative potential in chronic exposure and/or sublethal concentrations. This review summarizes current knowledge and advances in the understanding of such oxidative processes in biological systems. This knowledge is extended to specific applications in aquatic organisms because of their sensitivity to oxidative pollutants, their filtration capacity, and their potential for environmental toxicology studies.

Changes in mussel Mytilus galloprovincialis protein profile as a reaction of water pollution

In the present report the changes in mussels Mytilus galloprovincialis protein profile, as a reaction of water pollution, is presented. The antioxidant capacity was determined by the efficacy to scavenge the derived radical in mussel samples using the Trolox Equivalent Antioxidant Capacity (TEAC) assay. The highest percentage of inhibition was estimated in protein mussels from the dirty area (DM) in comparison with the clean samples (CM). The amounts of both zinc and copper determined by atomic spectroscopy were significantly higher in the protein mussels from the dirty than from the clean areas (P<0.05). Fourier Transform Infrared (FT-IR) spectroscopy and fluorescence revealed specific qualitative changes in secondary and tertiary structures of mussel proteins from the dirty area by the shift in the amides I and II positions and fluorescence intensity. Estimated temperature and enthalpy of denaturation in the protein mussels well correlated with fluorescence and spectroscopic measurements and showed the changes influenced by water pollution.

Partial characterization of proteins from mussel Mytilus galloprovincialis as a biomarker of contamination

Preservation of a healthy environment is a very important task, especially in the time of the total industrial revolution. Therefore, attempts to find new additional biomarkers of contamination are welcomed. For this aim, the functional and antioxidant properties of mussel Mytilus galloprovincialis proteins and the heavy metals Cd and Pb were explored. Mussels were collected in contaminated and noncontaminated sites in the Varna area of the Bulgarian Black Sea coast. Proteins were extracted from mussel entire soft tissue and analyzed using instrumental (Fourier transform infrared [FT-IR] spectroscopy, fluorescence, atomic absorption spectrophotometry), and biochemical (2,2'-azinobis 3-ethylbenzothiazoline-6-sulfonate) radical cation [ABTS(.+)]) methods. It was found that mussel proteins from the contaminated sites had specific qualitative changes: partial unfolding of the alpha-helix, slight shift in amide I bands, increased hydrophobicity, and fluorescent intensity in native and denatured samples. In the same mussel samples, an increased radical-scavenging capacity and increased contents of Cd and Pb in entire soft tissue were registered. Therefore, the above-mentioned indices could be used as additional biomarkers of sea water contamination.