Transformation kinetics of trenbolone acetate metabolites and estrogens in urine and feces of implanted steers

Environmental fate and toxicity of androgens: A critical review

Androgens are released by humans and livestock into the environment and which cause potent endocrine disruptions even at nanogram per liter levels. In this article, we reviewed updated research results on the structure, source, distribution characteristics and the fate of androgens in ecological systems; and emphasized the potential risk of androgens in aquatic organism. Androgens have moderately solubility in water (23.6-58.4 mg/L) and moderately hydrophobic (log Kow 2.75-4.40). The concentration of androgens in surface waters were mostly in ng/L ranges. The removal efficiencies of main wastewater treatment processes were about 70-100%, except oxidation ditch and stabilization ponds. Sludge adsorption and microbial degradation play important role in the androgens remove. The conjugated androgens were transformed into free androgens in environmental matrices. Global efforts to provide more toxicity data and establish standard monitoring methods need a revisit. Of the day available, there is an urgent need for comprehensive consideration of the impact of androgens on the environment and ecology.

Fungal laccase-triggered 17β-estradiol humification kinetics and mechanisms in the presence of humic precursors

Naturally-occurring phenolic acids (PAs) act as humic precursors that participate in the conversion behaviors and coupling pathways of steroidal estrogens (SEs) during laccase-triggered humification processes (L-THPs). Herein, the influences and mechanisms of PAs on Trametes versicolor laccase-evoked 17β-estradiol (E2) conversion kinetics and humification routes were explored. Fungal laccase was fleet in converting > 99% of E2, and the calculated pseudo-first-order velocity constant and half-time values were respectively 0.039 min^-1 and 17.906 min. PAs containing an O-dihydroxy moiety such as gallic acid and caffeic acid evidently hampered E2 humification owning to the yielded highly reactive O-quinones reversed E2 radicals by hydrogen transfer mechanism, implying that the inhibition effect was enormously dependent upon the number and position of the phenolic -OH present in humic precursors. Oligomers and polymers with carbon-carbon/oxygen links were tentatively found as E2 main humified species resulting from laccase-evoked successive oxidative-coupling. Note that PAs participating in the humification also encountered oxydehydrogenation, self-polymerization, and cross-binding to E2. Interestingly, the -COOH and -OCH₃ groups of PAs could be deprived in radical-caused self/co-polymerization. The generation of humified products not only circumvented the environmental risks of parent compounds but accelerated global carbon sequestration. To our knowledge, this is the first in-depth revelation of the humification pathways and related mechanisms of SEs with humic precursors in aquatic ecosystems by L-THPs.

Can Serum be a Match for Urine in the Regulatory Analysis of Boldenone in Cattle? A Systematic Comparison Between Detection Window, Stability, and Enzymatic Hydrolysis

This work involved a systematic comparison between serum and urine for the monitoring of anabolic androgenic steroids in livestock. Incurred samples were collected over 120 days from crossbred steers treated with intramuscular injections containing boldenone undecylenate. Independent high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) methods were used for the assessment of the respective detection windows, which were larger for serum samples. Both matrices presented adequate performance in terms of long-term stability, assessed using an isochronous approach during 196 days at -20 °C and for five freeze-thaw cycles. The effectiveness of the enzymatic hydrolysis reaction using Helix pomatia juice was also compared. The calculated concentrations in serum samples were not statistically influenced by the deconjugation reaction. On the other hand, urine hydrolysis conditions were studied using a 3³ Box-Behnken Design, in which a central point condition led to a satisfactory deconjugation performance. It could be observed that serum exhibited equivalent or better performance than urine for most of the evaluated criteria; thus, its inclusion in the regulatory analysis of boldenone in cattle is supported.

Occurrence, sorption, and transformation of free and conjugated natural steroid estrogens in the environment

Natural steroid estrogens (NSEs), including free estrogens (FEs) and conjugated estrogens (CEs), are of emerging concern globally among public and scientific community due to their recognized adverse effects on human and wildlife endocrine systems in recent years. In this review, the properties, occurrence, sorption process, and transformation pathways of NSEs are clarified in the environment. The work comprehensively summarizes the occurrence of both free and conjugated estrogens in different natural and built environments (e.g., river, WWTPs, CAFOs, soil, and sediment). The sorption process of NSEs can be impacted by organic compounds, colloids, composition of clay minerals, specific surface area (SSA), cation exchange capacity (CEC), and pH value. The degradation and transformation of free and conjugated estrogens in the environment primarily involves oxidation, reduction, deconjugation, and esterification reactions. Elaboration about the major, subordinate, and minor transformation pathways of both biotic and abiotic processes among NSEs is highlighted. The moiety types and binding sites also would affect deconjugation degree and preferential transformation pathways of CEs. Notably, some intermediate products of NSEs still remain estrogenic potency during transformation process; the elimination of total estrogenic activity needs to be addressed in further studies. The in-depth researches regarding the behavior of both free and conjugated estrogens are further required to tackle their contamination problem in the ecosystem. Graphical abstract ᅟ.

Occurrence, fate and risk assessment of androgens in ten wastewater treatment plants and receiving rivers of South China

Androgens are one class of steroids that could cause endocrine disrupting effects in aquatic organisms. However, little information is available about androgens in wastewater treatment plants (WWTPs) with different treatment technologies. Here we investigated the occurrence, removal, and fate of fourteen natural and synthetic androgens in ten WWTPs of Guangdong province, south China. The results showed detection of ten androgens in the influents of the ten WWTPs, with concentrations up to 4650 ng/L (androsta-1,4-diene-3,17-dione). But only three androgens androsta-1,4-diene-3,17-dione, 4-androstene-3,17-dione and 17β-boldenone were detected in the final effluents of the ten WWTPs, while six androgens androsta-1,4-diene-3,17-dione (N.D. to 43.0 ng/g), 4-androstene-3,17-dione (2.06-42.7 ng/g), epi-androsterone (N.D. to 506 ng/g), testosterone (0.29-4.24 ng/g), 17β-boldenone (N.D. to 2.05 ng/g) and methyl testosterone (N.D. to 0.70 ng/g) were found in activated sludge. The aqueous phase removal rates for most androgens in the WWTPs exceeded 95% except for 4-androstene-3,17-dione with its removal rates varying between 79.5% and 100%. The removal of androgens in the WWTPs could be attributed mainly to biodegradation while removal by precipitation, volatilization, sludge absorption and oxidation was very limited. Eight androgens were also found in five receiving rivers. The risk quotients of some androgens (androsta-1,4-diene-3,17-dione, 4-androstene-3,17-dione, methyl testosterone, 17α-trenbolone) exceeded 1 in the receiving rivers, showing high risks to aquatic organisms. Further studies are needed to understand the origin of these high risk androgens and ecological effects.

Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields

Runoff generated from livestock manure amended row crop fields is one of the major pathways of hormone transport to the aquatic environment. The study determined the effects of manure handling, tillage methods, and rainfall timing on the occurrence and transport of steroid hormones in runoff from the row crop field. Stockpiled and composted manure from hormone treated and untreated animals were applied to test plots and subjected to two rainfall simulation events 30days apart. During the two rainfall simulation events, detection of any steroid hormone or metabolites was identified in 8-86% of runoff samples from any tillage and manure treatment. The most commonly detected hormones were 17β-estradiol, estrone, estriol, testosterone, and α-zearalenol at concentrations ranging up to 100-200ngL^-1. Considering the maximum detected concentrations in runoff, no more than 10% of the applied hormone can be transported through the dissolved phase of runoff. Results from the study indicate that hormones can persist in soils receiving livestock manure over an extended period of time and the dissolved phase of hormone in runoff is not the preferred pathway of transport from the manure applied fields irrespective of tillage treatments and timing of rainfall.

Urinary Concentrations of Steroids in Bulls under Anabolic Treatment by Revalor-XS® Implant

Despite the European ban of using anabolics in food-producing animals, growth promoters might still be illegally used in the European Union. To control the food chain and guarantee consumers' health, there is a need of highly sensitive analytical methods for the identification of marker residues of such treatments. In the present study, a group of bulls (n = 16) received trenbolone acetate (200 mg) and estradiol (40 mg) by a commercial ear implant during a time range of 71 days, and a second group (n = 16) was kept for control. The aim of the research was to measure the residual urinary concentrations of the administered drugs (β-trenbolone and β-estradiol), their main metabolites (α-trenbolone and α-estradiol), and possible alterations of the urinary profile of other endogenous hormones metabolically related. The analytical method was based on liquid chromatography-tandem mass spectrometry. Results showed average urinary concentrations of α-trenbolone and α-estradiol during treatment in the range of (0.81 ÷ 2.1) ng mL^-1 and (0.96 ÷ 4.4) ng mL^-1, respectively, whereas β-trenbolone and β-estradiol exhibit urinary concentrations lower than 0.22 ng mL^-1 in both cases. Data obtained from the urinary profiles of endogenous steroids indicate that they could be useful to indirectly detect the ongoing treatment.

Occurrence and Characterization of Steroid Growth Promoters Associated with Particulate Matter Originating from Beef Cattle Feedyards

Studies of steroid growth promoters from beef cattle feedyards have previously focused on effluent or surface runoff as the primary route of transport from animal feeding operations. There is potential for steroid transport via fugitive airborne particulate matter (PM) from cattle feedyards; therefore, the objective of this study was to characterize the occurrence and concentration of steroid growth promoters in PM from feedyards. Air sampling was conducted at commercial feedyards (n = 5) across the Southern Great Plains from 2010 to 2012. Total suspended particulates (TSP), PM10, and PM2.5 were collected for particle size analysis and steroid growth promoter analysis. Particle size distributions were generated from TSP samples only, while steroid analysis was conducted on extracts of PM samples using liquid chromatography mass spectrometry. Of seven targeted steroids, 17α-estradiol and estrone were the most commonly detected, identified in over 94% of samples at median concentrations of 20.6 and 10.8 ng/g, respectively. Melengestrol acetate and 17α-trenbolone were detected in 31% and 39% of all PM samples at median concentrations of 1.3 and 1.9 ng/g, respectively. Results demonstrate PM is a viable route of steroid transportation and may be a significant contributor to environmental steroid hormone loading from cattle feedyards.