Oestrogenic activity using a recombinant yeast screen assay (RCBA) in South African laboratory water sources

Abstract

Many chemicals released into the environment are believed to disrupt normal endocrine functions in humans and animals. These endocrine disrupting chemicals (EDCs) affect reproductive health and development. A major group of EDCs that could be responsible for reproductive effects are those that mimic natural oestrogens, known as xeno-oestrogens. A number of in vivo and in vitro screening strategies are being developed to identify and classify xeno-oestrogens, in order to determine whether they pose a health risk to humans and animals. It is also important to be able to apply the assays to environmental samples for monitoring purposes. In South Africa information on the levels of EDCs in water is limited. While establishing the recombinant yeast screen bioassay (RCBA) using the yeast strain Sacchyromyces cerivisiae for oestrogenic activity, problems were experienced with contamination. Four South African laboratory water sources were assessed. From the results it was clear that the water used in the preparation of the medium for the assay was the source of oestrogenic contamination. Care should be taken to eliminate all possible sources of contamination in the test procedures to eliminate the reporting of false positive results. The fact that South African laboratory and surface waters tested positive for estrogenic activity has far reaching implications regarding reproductive and general health.

Transformation of Oxidation Products and Reduction of Estrogenic Activity of 17β-Estradiol by a Heterogeneous Photo-Fenton Reaction

“…Most endocrine disrupting compounds (EDCs) are synthetic organic chemicals introduced into the environment by anthropogenic input, but they can also be naturally generated estrogenic hormones (e.g., estrone, 17β-estradiol) and therefore are ubiquitous in aquatic environments – . EDCs may mimic hormonal activity and disturb the biological equilibrium of aquatic ecosystems and be harmful to the general health of the population , . In surface waters, estrogens are present at a level from picograms per liter to nanograms per liter , .…”

Urban effluent discharges as causes of public and environmental health concerns in South Africa’s aquatic milieu

“…This points to the need for further studies to determine the effects of EDCs on various populations based on socio-economic conditions and, probably, geographic location as well. No studies could be found on the health effects of EDCs on humans in South Africa except on monitoring of these in aquatic environments (Aneck-Hahn et al 2005;Slabbert et al 2008;Bornman et al 2009;Olujimi et al 2010;Manickum and John 2014). Antibiotics also, especially those belonging to the quinolone group (including fluoroquinolones), have been fingered in potential inhibition of DNA gyrase (a key enzyme in DNA replication) (Bryan et al 1989) while Jolibois et al (2003) attribute the genotoxicity of hospital wastewater effluents to compounds such as anti-cancer drugs and antibiotics such as ciprofloxacin.…”

The role of science in deepening democracy: the case for water in post-Apartheid South Africa

“…The loss of dilution capacity in our national rivers, combined with failing sewage treatment works pose a specific chemical-related risk in the form of oestrogen, which disrupts the endocrine system and unleashes a process of androgyny. Work in this regard has been done by Aneck-Hahn et al, (2002) Barnhoorn et al, (2004), Bornman et al, (2007) and Slabbert et al, (2007a;2007b). Considerable effort has been made to develop a coherent national research response to this form of contamination (Offringa et al, 2007).…”