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

Bioaccumulation of polystyrene microplastics and changes in antioxidant and AChE pattern in a freshwater snail (Filopaludina bengalensis) from river Ganga

Microplastic pollution is a leading global problem affecting terrestrial and marine aquatic ecosystems. Due to the stagnant nature of microplastics, the toxic effect of microplastics is more pronounced to benthic organisms than the surface feeder. Hence, the present study effort was to study the microplastic bioaccumulation pattern and changes in the enzymatic and nonenzymatic antioxidant and AChE pattern of freshwater snail Filopaludina bengalensis, which were subjected to 0.5 ppm to 5 ppm levels of polystyrene microsphere (∼ 30 µm) for 27 days. The study showed that microplastics were easily accumulated in the test organism in a dose and time-dependent manner, amounting to 82 ± 6.02 particles /individuals at a 5 ppm dose on the 27th day. However, no mortality was observed at the test microplastic dosages. The enzymatic antioxidant profile (SOD and catalase) showed limited variability and remained stable with increased duration and microplastic dose. However, the nonenzymatic antioxidant profile showed distinct variability with the complete seizing of the DPPH activity on the 27th day at 5 ppm microplastic dose and a gradual decrease of ABTS and FRAP activity at all the dose ranges. Even the AChE activity decreased with higher exposure concentrations. The present study for the first time shows the direct impact of microplastics on a freshwater snail widely available in the Indian subcontinent, indicating the role of microplastic pollution will create havoc in the Ganga river eco-biosystem in the long run.

Baseline levels of antioxidant activities in Mytilus galloprovincialis along the coast of Cape Town, South Africa

Antioxidant activities in Mytilus galloprovincialis were determined from samples collected at Scarborough, Hout Bay, Green Point, Milnerton and Bloubergstrand in Cape Town, South Africa. Antioxidant enzyme activity was determined by measuring CAT, SOD and GSH. The total antioxidant capacity was measured using FRAP and ORAC, while the content and lipid peroxidation marker levels of CDs and TBARS. Antioxidant activities and responses in mussels varied between sites with significant correlations for 85% and 71% of all antioxidant measurements made for Fe and Zn, respectively. The oxidative stress results reported here are novel for the region and indicated that mussels in Cape Town do not have (relatively) high levels of antioxidant activities as a result of exposure to metals. The research undertaken suggests that antioxidant responses was an appropriate biomarker of exposure to metals but more environmental parameters should be considered when interpreting antioxidant responses in the natural environment.

Characterization of Rapana thomasiana as an indicator of environmental quality of the Black Sea coast of Bulgaria

The aim of this investigation was to determine the contents of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), minerals, trace elements and bioactivity in the gastropod Rapana thomasiana, which can be used as an environmental bioindicator organism. The chemical differences between Rapana thomasiana from polluted (RapaPol) and non-polluted (RapaNPol) sites of the Black Sea coast in Bulgarian were investigated. Chromatography and high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) were used for evaluation of PAHs, PCBs, minerals and trace elements. Methanol extracts from RapaPol and RapaNPol (to a lesser degree) contained relatively high amounts of free phenolics (2.50 +/- 0.3 and 1.57 +/- 0.18 mg GAE/g DW, respectively) and exhibited the following respective levels of antioxidant activities determined by two radical-scavenging assays (microMTE/g DW): 1.8 +/- 0.2 and 0.98 +/- 0.08 by 1-diphenyl-2-picrylhydrazyl method (DPPH); 1.74 +/- 0.17 and 1.04 +/- 0.12 by cupric reducing antioxidant capacity (CUPRAC). The total amounts of elements, PAHs and PCBs were higher in RapaPol than in RapaNPol. The obtained indices of Rapana thomasiana can serve as a bioindicator of the environmental ecological quality.

Concentration of bioactive compounds in mussels Mytilus galloprovincialis as an indicator of pollution

The polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organotins were analyzed in mussels Mytilus galloprovincialis from polluted and unpolluted sites from Mokpo Bay, Korea. The total PAH's concentrations (10(-3)mgkg(-1)) measured by GC-MS were in the range from 31+/-23 to 1+/-1. Among the eight PAHs the predominant ones were fluoranthene, phenanthrene and pyrene and accounted approximately 63% of the total PAHs. Among the four detected PCBs the highest content was of PCB 153, which accounted about 47% of the total PCBs. The main organotin compounds were dibutyltindichloride (DBT) and tributyltinchloride (TBT) and their composition was approximately 33% and 24%. PAHs, PCBs and organotins were found only in the mussels from polluted site. The antioxidant activity by ABTS [2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)] test was higher in mussels from polluted than from unpolluted sites (P<0.05). It was found a correlation between the determined compounds (PAHs, PCBs and organotins) and the antioxidant activity of the mussel tissue from polluted site and the correlation coefficients were 0.96, 0.92 and 0.80, respectively. Such correlation can be explained by the properties of mussels. Since the mussel cell wall and tissues are hydrophobic, they can concentrate a number of hydrophobic pollutants like PAHs and PCBs from the marine environment by solubility rules. On the other hand, proteins are lipophilic compounds having antioxidant properties. Certain amino acid residues and thiol (-SH) groups, contained in proteins, respond to the ABTS antioxidant activity assay. Thus there may be a correlation between the total antioxidant activity of the organism and the PAH-PCB pollutants which were concentrated from its environment. The studied properties of mussels from polluted site can be used as an additional indicator of pollution.