Azithromycin exposure during pregnancy disturbs the fetal development and its characteristic of multi-organ toxicity

Emerging antibiotic pollution and its remedy by waste based biochar adsorbents: a review

One of the pollutants of emerging concern, antibiotics, have been reported in soil, water, sediment, animal manure, food, and even drinking water. Their partially metabolized forms reach wastewater treatment plants (WWTPs) and natural waters wherein the development of antibiotic resistant bacteria (ARB) and dissemination of antibiotic resistance genes (ARGs) have been reported to occur. Antimicrobial resistance (AMR) is projected to cause 10 million deaths annually across the world by 2050 in case stringent measures are not taken. In this study, various methods of adsorptive removal of antibiotics with their critical analysis and emphasis on the application of biochar (BC) and modified biochar derived from waste biomass have been comprehensively reviewed. Also, the antibiotic toxicity, preparation of biomass waste-derived BC adsorbents from cost-effective precursors to ensure sustainability, the adsorption kinetics, isotherm models and thermodynamic parameters have been discussed. It was inferred that biochars are quite efficient in terms of antibiotic removal in water owing to their large surface area, excellent surface characteristics and functionality, facile synthesis and the potential to be regenerated, while being cost-effective and sustainable in nature. This review aims to guide the expansion of research in the aforementioned area of interest and to provide a progressive push towards the development of a circular economy.

Disturbance of Fetal Growth by Azithromycin Through Induction of ER Stress in the Placenta

Aim: Azithromycin (AZM) is widely used to treat mycoplasma infection in pregnancy. However, there is no adequate evaluation of its side effect on the placenta. In this study, using human placental syncytiotrophoblasts and a mouse model, we investigated whether AZM use in pregnancy might adversely affect placental function and pregnancy outcome. Results: Transcriptomic analysis of AZM-treated human placental syncytiotrophoblasts showed increased expression of endoplasmic reticulum (ER) stress-related genes and decreased expression of genes for hormone production and growth factor processing. Verification studies showed that AZM increased the abundance of ER stress mediators (phosphorylated eIF2α, activating transcription factor 4 [ATF4], and C/EBP Homologous Protein [CHOP]) and decreased the abundance of enzymes involved in progesterone and estradiol synthesis (STS, CYP11A1, and CYP19A1) and insulin-like growth factor binding protein (IGFBP) cleavage (PAPPA and ADAM12) in human placental syncytiotrophoblasts. Inhibition of ER stress blocked AZM-induced decreases in the expression of CYP19A1, CYP11A1, PAPPA, and ADAM12, suggesting that the inhibition of AZM on those genes' expression was secondary to AZM-induced ER stress. Further mechanism study showed that increased ATF4 in ER stress might repressively interact with C/EBPα to suppress the expression of those genes, including CEBPA itself. Mouse studies showed that AZM administration decreased fetal weights along with increased ER stress mediators and decreased levels of insulin-like growth factor, estrogen, and progesterone in the maternal blood, which could be alleviated by inhibition of ER stress. Innovation and Conclusion: These findings first support the fact that AZM, often used during pregnancy, may affect fetal growth by inhibiting crucial enzymes for estrogen and progesterone synthesis and disrupting crucial proteases for IGFBP cleavage via inducing ER stress in placental syncytiotrophoblasts. Antioxid. Redox Signal. 42, 16-35.

Association between pyrrolizidine alkaloids exposure and risk of abnormal serum indices-Insights from a descriptive cross-sectional study in Yunnan Province

The hazard of pyrrolizidine alkaloids (PAs) has been widely reported in animal studies but rarely in population-based research, especially reports about daily exposure. A single-centre descriptive cross-sectional study was conducted on 552 Lahu Autonomous County residents recruited in 2021. Blood PAs exposure biomarker (pyrrole- protein adduct, PPA) and serum biochemical indices were measured. The prevalence of abnormal serum indices and PAs exposure in this region were elucidated using descriptive analyses. 75 % of Lahu Autonomous County participants were exposed to PAs. PAs exposure risk in males was lower than in females (OR=0.357, 95 % CI: 0.222-0.574), and varied with the ethnicity of Lahu Autonomous County. PPA concentration was positively correlated with serum alanine transaminase (ALT) activity (r=0.6263, P < 0.01) and triglyceride level (r=0.2327, P < 0.01); PAs exposure was positively associated with anbormal serum ALT activity (x2=99.629, P < 0.001; OR=1.428, 95 % CI: 1.293-2.319) and hypertriglyceridemia (x2=15.376, P < 0.001; OR=1.629, 95 % CI: 1.229-2.251). These results suggest that PAs exposure might be a risk factor for serum ALT abnormality and hypertriglyceridemia in the local population. This study conducted the first epidemiological study on PAs exposure in China and established the etiological hypotheses for health issues in Lahu Autonomous County.

Developmental exposure of antibiotics shortens life span and induces teratogenicity in Drosophila melanogaster

Antibiotics are the major therapeutic arsenal against bacterial infections. Yet, beneath this medical triumph lies an under investigated challenge of the potential teratological and toxicological impacts associated with the use of antibiotics. In the present study, we have explored the teratogenic potential of five commonly used antibiotics (streptomycin, metronidazole, tigecycline, doxycycline and norfloxacin) on Drosophila melanogaster Oregon-R strain. Except norfloxacin, all other tested antibiotics significantly delayed the onset of pupariation. Consistently, metronidazole, doxycycline and tigecycline resulted in statistically significant drops in egg-to-adult viability and adversely affected egg-to-pupa transition. In comparison, embryonic exposure of streptomycin impeded pupa-to-fly transition. All tested antibiotics induced morphological defects in antenna, wings, proboscis, eye, head, thorax, haltere and abdomen. Interestingly, developmental exposure of antibiotics resulted in statistically significant decrease in the lifespan of both male and female flies. This suggests an increased incidence of teratogenic faults at the systemic level, which are otherwise not manifested morphologically, due to the exposure of tested antibiotics during development. Taken together, our data show that developmental exposure of antibiotics may induce varying degrees of teratogenicity in D. melanogaster. Given the genomic homology and conservation of major molecular pathways that underpin development in humans and D. melanogaster, the findings do hold translational potential.

The characterization of developmental toxicity in fetal offspring induced by acetaminophen exposure during pregnancy

OBJECTIVE

Acetaminophen (APAP), an antipyretic and analgesic commonly used during pregnancy, has been recognized as a novel environmental contaminant. Preliminary evidence suggests that prenatal acetaminophen exposure (PAcE) could adversely affect offspring's gonadal and neurologic development, but there is no systematic investigation on the characteristics of APAP's fetal developmental toxicity.

METHODS

Pregnant mice were treated with 100 or 400 mg/kg∙d APAP in the second-trimester, or 400 mg/kg∙d APAP in the second- or third-trimester, or different courses (single or multiple) of APAP, based on clinical regimen. The effects of PAcE on pregnancy outcomes, maternal/fetal blood phenotypes, and multi-organ morphological and functional development of fetal mice were analyzed.

RESULTS

PAcE increased the incidence of adverse pregnancy outcomes and altered blood phenotypes including aminotransferases, lipids, and sex hormones in dams and fetuses. The expression of key functional genes in fetal organs indicated that PAcE inhibited hippocampal synaptic development, sex hormone synthesis, and osteogenic and chondrogenic development, but enhanced hepatic lipid synthesis and uptake, renal inflammatory hyperplasia, and adrenal steroid hormone synthesis. PAcE also induced marked pathological alterations in the fetal hippocampus, bone, kidney, and cartilage. The sensitivity rankings of fetal organs to PAcE might be hippocampus/bone > kidney > cartilage > liver > gonad > adrenal gland. Notably, PAcE-induced multi-organ developmental toxicity was more considerable under high-dose, second-trimester, and multi-course exposure and in male fetuses.

CONCLUSION

This study confirmed PAcE-induced alterations in multi-organ development and function in fetal mice and elucidated its characteristics, which deepens the comprehensive understanding of APAP's developmental toxicity.

Decrypting the skeletal toxicity of vertebrates caused by environmental pollutants from an evolutionary perspective: From fish to mammals

The rapid development of modern society has led to an increasing severity in the generation of new pollutants and the significant emission of old pollutants, exerting considerable pressure on the ecological environment and posing a serious threat to both biological survival and human health. The skeletal system, as a vital supportive structure and functional unit in organisms, is pivotal in maintaining body shape, safeguarding internal organs, storing minerals, and facilitating blood cell production. Although previous studies have uncovered the toxic effects of pollutants on vertebrate skeletal systems, there is a lack of comprehensive literature reviews in this field. Hence, this paper systematically summarizes the toxic effects and mechanisms of environmental pollutants on the skeletons of vertebrates based on the evolutionary context from fish to mammals. Our findings reveal that current research mainly focuses on fish and mammals, and the identified impact mechanisms mainly involve the regulation of bone signaling pathways, oxidative stress response, endocrine system disorders, and immune system dysfunction. This study aims to provide a comprehensive and systematic understanding of research on skeletal toxicity, while also promoting further research and development in related fields.

PeRinatal, neOnatal, and Maternal OuTcomEs with azithromycin prophylaxis in pregnancy and labour (PROMOTE-PROPHYLAXIS): systematic review and meta-analysis

Background

Initial randomised controlled trials (RCTs) showed that prophylactic azithromycin in pregnant women improved maternal and neonatal outcomes; however, the recent evidence did not show any benefit to neonatal survival. There is conflicting evidence over the role of azithromycin prophylaxis in antenatal and intrapartum periods. We explored whether azithromycin prophylaxis in pregnant women improves maternal and neonatal outcomes.

Methods

For this systematic review and meta-analysis registered on PROSPERO [CRD42023411093], we searched seven databases (PubMed, Scopus, Embase, Cochrane Library, EBSCOHost, ProQuest, and Web of Science) and clinical trial registries until 04/23/2024, for RCTs evaluating antenatal/intrapartum azithromycin prophylaxis against placebo/routine care in pregnant women. The primary outcome was neonatal mortality. Intrapartum and antenatal administration were assessed separately. We used random-effects meta-analysis. The risk of bias was assessed using the Cochrane RoB 2 tool. The GRADE approach was used to evaluate the certainty of the evidence.

Findings

Screening 2161 records retrieved 20 RCTs (56,381 participants). Intrapartum azithromycin may make little or no difference to neonatal mortality [5 RCTs, 44,436 participants; Risk Ratio (RR): 1.02, 95% CI 0.86-1.20, I 2  = 0%, very low certainty], and maternal mortality [3 RCTs, 44,131 participants, RR: 1.26, 0.65-2.42, I 2  = 0%, low certainty]. Similarly, antenatal azithromycin may have little or no effect on neonatal mortality [3 RCTs; 5304 participants; RR: 0.74, 0.35-1.56, I 2  = 43%, very-low certainty] and maternal mortality [3 RCTs; 8167 participants RR: 1.62, 0.67-3.91, I 2  = 0%, low certainty]. There is no data on long-term adverse outcomes and antimicrobial resistance.

Interpretation

Low to very low certainty evidence suggests that intrapartum or antenatal azithromycin prophylaxis in pregnant women might not reduce maternal or neonatal mortality.

Funding

None.

Prenatal prednisone exposure impacts liver development and function in fetal mice and its characteristics

Prednisone, a widely used glucocorticoid drug in human and veterinary medicine, has been reported to cause developmental toxicity. However, systematic studies about the effect of prednisone on fetal liver development are still unclear. We investigated the potential effects of maternal exposure to clinically equivalent doses of prednisone during different gestational stages on cell proliferation and apoptosis, cell differentiation, glucose and lipid metabolism, and hematopoiesis in the liver of fetal mice, and explored the potential mechanisms. Results showed that prenatal prednisone exposure (PPE) could suppress cell proliferation, inhibit hepatocyte differentiation, and promote cholangiocyte differentiation in the fetal liver. Meanwhile, PPE could result in the enhancement of glyconeogenesis and bile acid synthesis and the inhibition of fatty acid β-oxidation and hematopoiesis in the fetal liver. Further analysis found that PPE-induced alterations in liver development had obvious stage and sex differences. Overall, the alteration in fetal liver development and function induced by PPE was most pronounced during the whole pregnancy (GD0-18), and the males were relatively more affected than the females. Additionally, fetal hepatic insulin-like growth factor 1 (IGF1) signaling pathway was inhibited by PPE. In conclusion, PPE could impact fetal liver development and multiple functions, and these alterations might be partially related to the inhibition of IGF1 signaling pathway.

Effects of azithromycin exposure during pregnancy at different stages, doses and courses on testicular development in fetal mice

Azithromycin is a commonly used antibiotic during pregnancy, but some studies have suggested its potential developmental toxicity. Currently, the effects and mechanisms of prenatal azithromycin exposure (PAzE) on fetal testicular development are still unclear. The effects of prenatal exposure to the same drug on fetal testicular development could vary depending on different stages, doses, and courses. Hence, in this study, based on clinical medication characteristics, Kunming mice was administered intragastrically with azithromycin at different stages (mid-/late-pregnancy), doses (50, 100, 200 mg/kg·d), and courses (single-/multi-course). Fetal blood and testicular samples were collected on GD18 for relevant assessments. The results indicated that PAzE led to changes in fetal testicular morphology, reduced cell proliferation, increased apoptosis, and decreased expression of markers related to Leydig cells (Star), Sertoli cells (Wt1), and spermatogonia (Plzf). Further investigation revealed that the effects of PAzE on fetal testicular development were characterized by mid-pregnancy, high dose (clinical dose), and single course having more pronounced effects. Additionally, the TGFβ/Smad and Nrf2 signaling pathways may be involved in the changes in fetal testicular development induced by PAzE. In summary, this study confirmed that PAzE influences fetal testicular morphological development and multicellular function. It provided theoretical and experimental evidence for guiding the rational use of azithromycin during pregnancy and further exploring the mechanisms underlying its developmental toxicity on fetal testicles.