Histological and Endocrine Effects of Chronic Exposure to MP2.5 Derived from Wood Smoke in the Uterus of Nulliparous Adult Rats

SUMMARY: The study explores the relationship between chronic exposure to fine particulate matter (PM2.5), sourced from wood smoke, and the histological structure and endocrine function of the uterus in nulliparous adult rats. It assesses potential structural changes in the uterus that could impact reproductive health, viewing PM2.5 exposure as a possible risk factor. A controlled experiment was conducted in a city known for high air pollution levels, exposing rats to filtered and unfiltered air conditions, thus mimicking human PM2.5 exposure. Histological findings indicated a significant increase in collagen density and uterine wall thickness in PM2.5 exposed subjects, suggesting a reproductive function risk. However, no significant differences were observed in progesterone and estradiol hormone levels, pointing to the complex relationship between PM2.5 exposure and its endocrine impact, and emphasizing the need for further studies for a deeper understanding. This work highlights the importance of thoroughly investigating the long-term effects of PM2.5 pollution on reproductive health, underlining the significance of considering environmental exposure as a critical factor in reproductive health research.

El estudio explora la relación entre la exposición crónica a partículas finas (PM2,5), procedentes del humo de leña, y la estructura histológica y la función endocrina del útero en ratas adultas nulíparas. Evalúa posibles cambios estructurales en el útero que podrían afectar la salud reproductiva, considerando la exposición a PM2,5 como un posible factor de riesgo. Se llevó a cabo un experimento controlado en una ciudad conocida por sus altos niveles de contaminación del aire, exponiendo ratas a condiciones de aire filtrado y sin filtrar, imitando así la exposición humana a PM2,5. Los hallazgos histológicos indicaron un aumento significativo en la densidad del colágeno y el grosor de la pared uterina en sujetos expuestos a PM2,5, lo que sugiere un riesgo para la función reproductiva. Sin embargo, no se observaron diferencias significativas en los niveles de las hormonas progesterona y estradiol, lo que apunta a la compleja relación entre la exposición a PM2,5 y su impacto endocrino, y enfatiza la necesidad de realizar más estudios para una comprensión más profunda. Este trabajo destaca la importancia de investigar a fondo los efectos a largo plazo de la contaminación por PM2,5 en la salud reproductiva, subrayando la importancia de considerar la exposición ambiental como un factor crítico en la investigación de la salud reproductiva.

Effect of Qingfei Jiangmai Decoction on Content of PM2.5-related Metabolites Mercapturic Acids in Urine / 中国实验方剂学杂志

ObjectiveTo explore the effect of Qingfei Jiangmai decoction （QJD） on the content of mercapturic acids in urine in healthy people amid PM2.5 （particles 2.5 microns or less in size） pollution. MethodA total of 84 healthy students of 18-30 years old in Beijing were recruited and they were randomized into the test group （42 in total， with 1 dropout） and control group （42 in total， with 3 dropouts）. During the pollution， the test group and the control group respectively took QJD granules and placebo for 7 days （1 bag/time， 2 times/day）， and another 7-day intervention with the same drugs was performed at an interval of 4 weeks. The time-activity patterns were recorded during the intervention. On-line solid phase extraction-liquid chromatography/tandem mass spectrometry （SPE-LC-MS/MS） was performed to detect the content of PM2.5-related metabolites S-phenylmercapturic acid （SPMA）， 3-hydroxypropylmercapturic acid （3-HPMA）， 3-hydroxy-1-methylpropylmercapturic acid （HMPMA）， N-acetyl-S-（2-nitrile ethyl）-L-cysteine （CEMA）， and N-acetyl-S-（2-hydroxy ethyl）-L-cysteine （HEMA） in urine before and after intervention. Statistical analysis was followed. ResultThe content of CEMA， HEMA， 3-HPMA， and HMPMA in the test group was all higher after the intervention than before the intervention， with the significant difference in HEMA （P<0.05）. After intervention， content of HEMA and SPMA was significantly higher in the test group than in the control group （P<0.05）， and the difference in HEMA （Z=-3.614， P<0.01） and HMPMA （Z=-1.988， P<0.05） before and after invention in the test group was significantly larger than that in the control group. After the intervention， HEMA in the test group was significantly higher than that in the control group （F=7.597， P<0.01）. ConclusionDuring PM2.5 pollution， QJD can increase the excretion of HEMA， a metabolite of ethylene oxide， in the urine of healthy people in Beijing， and enhance the detoxification process of toxic components in PM2.5， which is of great value in preventing and treating haze-related illnesses.

Comparative study of PM2.5 - and PM10 - induced oxidative stress in rat lung epithelial cells

Accurate estimation of the exposure-response relationship between ambient urban particulate matters (PM) and public health is important for regulatory perspective of ambient urban particulate matters (PM). Ambient PM contains various transition metals and organic compounds. PM10 (aerodynamic diameter less than 10 microgram) is known to induce diverse diseases such as chronic cough, bronchitis, chest illness, etc. However, recent evaluation of PM2.5 (aerodynamic diameter less than 2.5 microgram) against health outcomes has suggested that the fine particles may be more closely associated with adverse respiratory health effects than particles of larger size. This study was performed to evaluate PM2.5-induced oxidative stress in rat lung epithelial cell in order to provide basic data for the risk assessment of PM2.5. PM2.5 showed higher cytotoxicity than PM10. Also, PM 2.5 induced more malondialdehyde (MDA) formation than PM10. In Hoechst 33258 dye staining and DNA fragmentation assay, apopotic changes were clearly detected in PM2.5 treated cells in compared to PM10. Expression of catalase mRNA was increased by PM2.5 rather than PM10. PM2.5 induced higher Mth1 mRNA than PM10. In pBR322 DNA treated with PM2.5, production of single strand breakage of DNA was higher than that of PM10. In Western blot analysis, PM2.5 induced more Nrf-2 protein, associated with diverse transcriptional and anti-oxidative stress enzymes, compared to PM10. Our data suggest that PM2.5 rather than PM10 may be responsible for PM-induced toxicity. Additional efforts are needed to establish the environmental standard of PM2.5.