Fathead minnow response to broad-range exposure of β-sitosterol concentrations during life-cycle testing

Detection and accumulation of environmentally-relevant glyphosate concentrations delivered via pulse- or continuous-delivery on passive samplers

Glyphosate is the most commonly used herbicide globally, which has contributed to its ubiquitous presence in the environment. Glyphosate application rates and delivery to surface water vary with land use. Streams in urban and agricultural catchments can experience continuous delivery of low concentrations of glyphosate and aminomethylphosphonic acid (AMPA), while their presence in forest streams occurs as an episodic pulse following silvicultural application. We assessed whether trace concentrations of glyphosate delivered as a 1-day pulse (mimic silvicultural applications) followed by flushing with deionized water would affect the detection of glyphosate or AMPA on novel passive samplers, Polar Organic Chemical Integrative Sampler with Molecular Imprinted Polymer (POCIS-MIP), compared with continuous delivery (mimic agricultural or urban applications). Within each delivery type, POCIS-MIP were exposed to seven treatment concentrations of Rodeo (equivalent to 0.0 to 1.84 μg glyphosate L-1). Experimental results demonstrate POCIS-MIP can detect differences in relative glyphosate concentrations above 0.115 μg L-1 (pulse-delivery) or 0.23 μg L-1 (continuous-delivery), but were unable to distinguish trace concentrations (i.e., < 0.115 or 0.23 μg L-1). Our results suggest POCIS-MIP may better retain glyphosate when delivered as a pulse than when delivered continuously, but both underestimated actual treatment concentrations by 46 to 56%. There is a need to demonstrate the field applicability of passive sampling methods to improve environmental monitoring of silvicultural herbicides, and our results demonstrate passive samplers were unable to distinguish lower concentrations, suggesting a limited utility for determining trace concentration levels such as those experienced during or immediately after silvicultural application.

Super-critical fluid extract of Bryonopsis laciniosa (Shivlingi) seeds restores fertility in zebrafish models through revival of cytological and anatomical features

Background

The Ayurvedic system of medicine mentions the use of seeds of Bryonopsis laciniosa (L.) Naud. (also known as Shivlingi due to their unique structure resembling a ‘Shivling’) for treating sexual dysfunction, impaired fertility, and as a general virility-booster in both males and females. To investigate the scientific basis for such claims, the current study was designed for the chemical characterization of the super critical fluid extracted Shivlingi seed oil (SLSO), and subsequent evaluation of its reproductive fecundity in the zebrafish model of N-ethyl-N-nitrosourea induced infertility.

Results

Linoleic and linolenic acids were the major fatty acids in the SLSO, with trace amounts of β-sitosterol and stigmasterol. Both male and female zebrafish, when fed orally with the SLSO infused pallets, showed a dose-dependent increase in fertility and fecundity rates. Microscopic observations revealed recovery in the gross ovarian anatomy and consequential improvement in egg production in infertile female zebrafish. Similarly, cytological studies exhibited increased sperm counts and motility in male zebrafish. SLSO exhibited effects similar to the human equivalent dose of Letrozole.

Conclusion

Taken together, these observations demonstrated the fertility-boosting potentials of SLSO comparable to the widely used infertility drugs. As a whole, this research work has provided scientific evidence for the rationale behind the use of Shivlingi seeds in Ayurvedic treatment for infertility in humans. Finally, but importantly, this study warrants further scientific investigations into different aspects of SLSO on human reproductive health.

Interpretation of fish biomarker data for identification, classification, risk assessment and testing of endocrine disrupting chemicals

Chemical induced changes in fish biomarkers vitellogenin (VTG), secondary sex characteristics (SSC), and sex ratio indicate modes/mechanisms of action (MOAs) of EAS (estrogen, androgen and steroidogenesis) pathways. These biomarkers could be used for defining MOAs and the causal link between MOAs and adverse effects in fish for the identification of endocrine disrupting chemicals (EDCs). This paper compiled data sets of 150 chemicals for VTG, 57 chemicals for SSC and 38 chemicals for sex ratio in fathead minnow, medaka and zebrafish. It showed 1) changes in fish biomarkers can indicate the MOAs as anticipated; 2) in addition to EAS pathways, chemicals with non-EAS pathways induced changes in fish biomarkers; 3) responses of fish biomarkers did not always follow the anticipated patterns of EAS pathways. These responses may result from the interaction of chemical-induced multiple MOAs and confounding factors like fish diet, infection, culture conditions, general toxicity and stress response. The complex response of fish biomarkers to a chemical of interest requires EDC testing at multiple biological levels. Interpretation of fish biomarker data should be combined with relevant information at different biological levels, which is critical for defining chemical specific MOAs. The utility of fish biomarker data for identification, classification, PBT assessment, risk assessment, and testing of EDCs in the regulatory context was discussed. This paper emphasizes the importance of fish biomarker data in the regulatory context, a weight of evidence approach for the interpretation of fish biomarker data and the need for defining levels of evidence for the identification of EDCs.