Fish bioaccumulation and biomarkers in environmental risk assessment: a review

http://aerg.canberra.edu.au/library/sex_general/2002_Devlin_Nagahama_sex_determination_in_fish_review.pdf

Sex determination and sex differentiation in fish: an overview of genetic, physiological, and environmental influences

The phytochemical resveratrol, which is found in grapes and wine, has been reported to have a variety of anti-inflammatory, anti-platelet, and anti-carcinogenic effects. Based on its structural similarity to diethylstilbestrol, a synthetic estrogen, we examined whether resveratrol might be a phytoestrogen. At concentrations (≈3–10 μM) comparable to those required for its other biological effects, resveratrol inhibited the binding of labeled estradiol to the estrogen receptor and it activated transcription of estrogen-responsive reporter genes transfected into human breast cancer cells. This transcriptional activation was estrogen receptor-dependent, required an estrogen response element in the reporter gene, and was inhibited by specific estrogen antagonists. In some cell types (e.g., MCF-7 cells), resveratrol functioned as a superagonist (i.e., produced a greater maximal transcriptional response than estradiol) whereas in others it produced activation equal to or less than that of estradiol. Resveratrol also increased the expression of native estrogen-regulated genes, and it stimulated the proliferation of estrogen-dependent T47D breast cancer cells. We conclude that resveratrol is a phytoestrogen and that it exhibits variable degrees of estrogen receptor agonism in different test systems. The estrogenic actions of resveratrol broaden the spectrum of its biological actions and may be relevant to the reported cardiovascular benefits of drinking wine.

https://www.pnas.org/content/pnas/94/25/14138.full.pdf

Resveratrol, a polyphenolic compound found in grapes and wine, is an agonist for the estrogen receptor

Foods with plant stanol or sterol esters lower serum cholesterol levels. We summarize the deliberations of 32 experts on the efficacy and safety of sterols and stanols. A meta-analysis of 41 trials showed that intake of 2 g/d of stanols or sterols reduced low-density lipoprotein (LDL) by 10%; higher intakes added little. Efficacy is similar for sterols and stanols, but the food form may substantially affect LDL reduction. Effects are additive with diet or drug interventions: eating foods low in saturated fat and cholesterol and high in stanols or sterols can reduce LDL by 20%; adding sterols or stanols to statin medication is more effective than doubling the statin dose. A meta-analysis of 10 to 15 trials per vitamin showed that plasma levels of vitamins A and D are not affected by stanols or sterols. Alpha carotene, lycopene, and vitamin E levels remained stable relative to their carrier molecule, LDL. Beta carotene levels declined, but adverse health outcomes were not expected. Sterol-enriched foods increased plasma sterol levels, and workshop participants discussed whether this would increase risk, in view of the marked increase of atherosclerosis in patients with homozygous phytosterolemia. This risk is believed to be largely hypothetical, and any increase due to the small increase in plasma plant sterols may be more than offset by the decrease in plasma LDL. There are insufficient data to suggest that plant stanols or sterols either prevent or promote colon carcinogenesis. Safety of sterols and stanols is being monitored by follow-up of samples from the general population; however, the power of such studies to pick up infrequent increases in common diseases, if any exist, is limited. A trial with clinical outcomes probably would not answer remaining questions about infrequent adverse effects. Trials with surrogate end points such as intima-media thickness might corroborate the expected efficacy in reducing atherosclerosis. However, present evidence is sufficient to promote use of sterols and stanols for lowering LDL cholesterol levels in persons at increased risk for coronary heart disease.

Efficacy and Safety of Plant Stanols and Sterols in the Management of Blood Cholesterol Levels

The paper outlines a 2-tier approach for wide-scale biomonitoring programmes. To obtain a high level of standardization, we suggest the use of caged organisms (mussels or fish). An "early warning", highly sensitive, low-cost biomarker is employed in tier 1 (i.e. lysosomal membrane stability (LMS) and survival rate, a marker for highly polluted sites). Tier 2 is used only for animals sampled at sites in which LMS changes are evident and there is no mortality, with a complete battery of biomarkers assessing the levels of pollutant-induced stress syndrome. Possible approaches for integrating biomarker data in a synthetic index are discussed, along with our proposal to use a recently developed Expert System. The latter system allows a correct selection of biomarkers at different levels of biological organisation (molecular/cellular/tissue/organism) taking into account trends in pollutant-induced biomarker changes (increasing, decreasing, bell-shape). A selection of biomarkers of stress, genotoxicity and exposure usually employed in biomonitoring programmes is presented, together with a brief overview of new biomolecular approaches.

The use of biomarkers in biomonitoring: a 2-tier approach assessing the level of pollutant-induced stress syndrome in sentinel organisms.

Wood-derived estrogens: studies in vitro with breast cancer cell lines and in vivo in trout.

Expression of the vitellogenin gene in the liver of juvenile whitefish (Coregonus lavaretus L. s.l.) exposed to effluents from pulp and paper mills.

Samples of perch (Perca fluviatilis L) and roach (Rutilus rutilus L) populations were collected in Lake Saimaa in September-October, after the onset of vitellogenesis and deposition of yolk in the eggs The study area received elemental chlorine-free (ECF)-bleached kraft mill effluent (BKME) The pulp and paper mill studied used chlorine dioxide for bleaching and its effluents were treated in a modern activated sludge plant The amounts of chlorophenolics in the bile of perch and roach at the mill site, 1 km from the discharge point, were two to four times higher than in fish from the upstream reference site In the roach population near the mill liver the 7-ethoxyresorufin 0-deethylase (EROD) activity was four times that measured in the reference areas However, the EROD activity in the perch remained unchanged The liver 7-pentoxyresorufin 0-dealkylase (PROD) activity was induced to twice the amount only in male roach near the mill, whereas the relative liver size (LSI) was increased in female and male roach and female perch The plasma concentrations of oestradiol-17β were decreased in female perch and female roach, but increased in male roach at the mill site Near the mill, vitellogenin gene expression was also reduced in female perch In addition, the plasma testosterone concentrations were reduced in female and male perch near the mill No differences were noted in the plasma immunoglobulin concentrations in roach and in the relative gonad size (GSI) in the perch and roach populations The condition factor was significantly lower only in female roach near the mill

Pirkko Mellanen

Papers

Wood-derived estrogens: studies in vitro with breast cancer cell lines and in vivo in trout.

Expression of the vitellogenin gene in the liver of juvenile whitefish (Coregonus lavaretus L. s.l.) exposed to effluents from pulp and paper mills.

Effects of ECF-Bleached Kraft Mill Effluent on Reproductive Steroids and Liver MFO Activity in Populations of Perch and Roach