Metabolomics Provide Sensitive Insights into the Impacts of Low Level Environmental Contamination on Fish Health—A Pilot Study

This exploratory study aims to investigate the health of sand flathead (Platycephalus bassensis) sampled from five sites in Port Phillip Bay, Australia using gas chromatography-mass spectrometry (GC-MS) metabolomics approaches. Three of the sites were the recipients of industrial, agricultural, and urban run-off and were considered urban sites, while the remaining two sites were remote from contaminant inputs, and hence classed as rural sites. Morphological parameters as well as polar and free fatty acid metabolites were used to investigate inter-site differences in fish health. Significant differences in liver somatic index (LSI) and metabolite abundance were observed between the urban and rural sites. Differences included higher LSI, an increased abundance of amino acids and energy metabolites, and reduced abundance of free fatty acids at the urban sites compared to the rural sites. These differences might be related to the additional energy requirements needed to cope with low-level contaminant exposure through energy demanding processes such as detoxification and antioxidant responses as well as differences in diet between the sites. In this study, we demonstrate that metabolomics approaches can offer a greater level of sensitivity compared to traditional parameters such as physiological parameters or biochemical markers of fish health, most of which showed no or little inter-site differences in the present study. Moreover, the metabolite responses are more informative than traditional biomarkers in terms of biological significance as disturbances in specific metabolic pathways can be identified.

Protective Effects of Phytoextract Blend Against Ethanol-induced Chronic Liver Injury in Mice (P06-083-19)

Objectives Ethanol consumption is associated with a spectrum of diseases in the liver ranging from steatosis, alcoholic hepatitis to cirrhosis and hepatocellular carcinoma. We established an alcoholic liver disease model in mice to investigate the protective effects of the phytoextract blend (PB) including schisandra, grape seed and tart cherry. Methods A total of 100 mice were randomly divided into 5 groups. The groups were: a) control group, b) ethanol group and c) three experimental groups. Animals in the control and ethanol groups were orally gavaged with distilled water, while the other groups were given varying concentrations of PB for 30 days. The ethanol group and the treatment groups were then given ethanol for 15 days. The liver/somatic index, levels of ALT, AST, TBIL and TG in serum, and the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured. The liver tissues were stained with hematoxylineosin (H&E) for evaluation of histopathological changes. Results The liver/somatic index was increased in the ethanol group while it was decreased nearly to the normal value in treated groups. ALT increased significantly in ethanol group. PB reduced serum ALT concentrations in a dose-dependent manner. Ethanol elevated AST in the ethanol group. Although PB low dose group showed increased AST levels, AST was decreased by medium and high doses of PB compared with the ethanol group. Ethanol slightly though not significantly downregulated TBIL level in the ethanol group, while low and medium doses of PB increased TBIL. Ethanol-induced TG upregulation was completely reversed by PB treatment. The expression of hepatic IL-6 and TNF-α mRNA were elevated after ethanol consumption, whereas these inflammatory cytokines were reduced after treatment. Ethanol induced necrosis and substantial small fat droplets in the liver section. However, livers of mice in all treated groups showed noticeable recovery with fewer small fat droplets and hepatocyte necrosis. Conclusions This study showed the PB containing schisandra, grape seed and tart cherry could protect liver by reducing hepatic steatosis and hepatocyte necrosis and alleviating inflammation. The PB used in this study may provide insights into the prevention and treatment of ethanol-induced liver injury. Funding Sources Nu Skin Research Funding. Supporting Tables, Images and/or Graphs

Reproduction De Heterotis Niloticus (Cuvier, 1829) De La Riviere Agneby (Cote d’Ivoire)

The reproductive biology of Heterotis niloticus has been studied from monthly samples taken from artisanal fishing on the Agneby river during the period june 2013 to May 2015. The whole sample consisted of 498 specimens of which 269 females and 229 males were examined. Sex-ratio observed was in favour of females (1: 1.17; X2 = 3.21; p > 0.05). The monthly evolution of the gonado-somatic index (GSI), the liver-somatic index (LSI), the condition factor (K) and maturation stages suggests that this fish has two periods of reproduction. The two periods were respectively from june to august and from november to december. The standard length at first sexual maturity was 490.6 mm for females and 436.3 mm for males. The absolute fecundity was ranged from 5424 to 25591 oocytes in females of 595 mm to 780 mm standard length. The relative fecundity was 3752± 1491 oocytes/kg of female.

Biologie De La Reproduction Du Sciaenidae Pseudotolithus Elongatus Dans La Lagune Ebrie (Cote d’Ivoire)

The study of reproduction of Pseudotolithus elongatus in the Ebrie lagoon was investigated between July 2013 and June 2015 on a whole of individuals of 550 specimens. the total length ranges from 14.5 to 42.7 cm. The monthly evolution of the gonado-somatic index (GSI), the liver-somatic index (LSI), the condition factor (K), the Sex-ratio, the fecundity, the diameter of eggs revealed that this species spawns throughout the year but the main breeding period was in raining season. Sex-ratio observed was in favour of females (1: 1. 14; X2 = 2.26; p > 0.05). The percentage of mature specimens by sexes was calculated for each size class. Total length at first maturity was 21.06 cm for females and 20.21cm for males. The ripe ovaries contained 39883-814757 eggs. The relative fecundity was 216-1979 eggs per g of body weight of females. And the mean diameter of eggs is 336 ±138 microns.

Population structure and somatic indexes of Hypostomus cf. ancistroides (Siluriformes, Loricariidae) collected from the Bonito river, Ivaí river basin, Turvo, Paraná

This study aimed to provide information about the population structure and somatic index of Hypostomus cf. ancistroides collected from the Bonito river, located in the Ivaí river basin. The length-weight relationship was isometric for both the sexes. The length structure analysis showed that the larger individuals (from 18.1cm to 27.0cm in length) predominated, and the lowest abundances occurred at the size extremes (9.1-12cm and 27.1-30.0cm). The reproduction period occured between October and January for the females and between November and January for the males. The liver somatic index cannot be used as an indicator of the reproduction period in either of the sexes, due to no correlation between the liver somatic index and the gonad somatic index. The gonad weight exerted no influence on the monthly mean condition factor and the correlation between the condition factor and gonad somatic index was high. The condition factor could be an indicator of the reproduction period of this species.

Interaction of cadmium and oestradiol-17β on metallothionein and vitellogenin synthesis in rainbow trout (Oncorhynchus mykiss)

The induction of metallothionein and vitellogenin synthesis in rainbow trout liver was studied after injection of oestradiol-17 beta alone or in combination with cadmium or zinc. Intraperitoneal injection of oestradiol-17 beta increased the liver somatic index, with subsequent induction of vitellogenin synthesis. Oestradiol-17 beta did not induce metallothionein synthesis. Injection of cadmium induced the synthesis of metallothionein mRNA and metallothionein. Injection of oestradiol-17 beta in combination with cadmium resulted in inhibition of transcription and translation of both vitellogenin and metallothionein. Chromatography of liver cytosols revealed that cadmium, when co-injected with oestradiol-17 beta, did not bind to metallothionein but would initially bind to high-molecular-mass (HMr) cytosolic proteins. In fish injected with cadmium in combination with oestradiol-17 beta, cadmium was gradually redistributed from HMr proteins to metallothionein. This resulted in induction of metallothionein synthesis and in binding of most of the cadmium to metallothionein. Induction of vitellogenin mRNA was observed 15 days after injection, as cadmium was being redistributed to newly synthesized metallothionein. These findings indicate that cadmium inhibits the transcription of vitellogenin. The binding of cadmium to these non-metallothionein proteins represses the induction of metallothionein and results in increased toxicity of the metal. Preinduction of metallothionein by zinc injections resulted in decreased cadmium sensitivity of the fish and a decrease in the repression of vitellogenin mRNA. Furthermore, a role for metallothionein in the detoxification of cadmium is indicated by the induction of vitellogenin synthesis that occurs once metallothionein has begun sequestering cadmium.