Maternal Triclosan consumption alters the appetite regulatory network on Wistar rat offspring and predispose to metabolic syndrome in the adulthood

Effect of triclosan exposure on ovarian hormones, trace elements and growth in female rats

Triclosan (TCS) is an antibacterial compound used mainly in personal care products. Its widespread use for decades has made it one of the most widely detected compounds in environmental matrices and in biological fluids. Although it has been shown to be an endocrine disruptor in rats and aquatic species, its safe use by humans is unclear. The aim of the present study was to evaluate the effects of exposure to TCS in female rats. To this end, 14 rats were divided into two groups and fed daily as follows: the control group with sesame oil and the TCS group at a dose of 50 mg/kg/day for 28 days. Any signs of toxicity in the rats were observed daily, and the weight and phase of the estrous cycle were recorded. At the end, the rats were decapitated, the serum and ovaries were collected. The levels of testosterone and progesterone in serum were determined by immunoassay and mass spectrometry. Estradiol (in serum) and kisspeptin-10 (in serum and ovary) were measured only by immunoassays. Trace elements were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The weight gain study of the rats showed a significant decrease by exposure to TCS, while the estrous cycle was not significantly affected compared to the control. The optimized methods based on mass spectrometry showed a significant decrease in the levels of progesterone and testosterone due to exposure to TCS. In addition, elements determined by ICP-MS in rat serum showed significant changes in calcium, lithium and aluminum due to TCS treatment. Finally, the kisspeptin-10 levels did not show a negative effect due to the treatment by TCS. The results suggest that medium-term exposure to TCS did not significantly alter estrous cyclicity but caused alterations in growth, sex hormone levels and some elements in the rat serum.

Association between triclosan exposure and obesity measures among 7-year-old children in northern China

BACKGROUND

Triclosan (TCS) is a widely used synthetic antibacterial compound with ubiquitous human exposure. Animal studies have suggested the obesogenic effect of TCS exposure, but knowledge regarding its impacts on childhood obesity was limited.

OBJECTIVE

To investigate the associations of TCS exposure with childhood obesity in northern China.

METHODS

This study included 423 children who participated in the 7-year-old follow-up visits of Laizhou Wan Birth Cohort in Shandong, northern China. Children's TCS exposure were determined in spot urine samples via high performance liquid chromatography-tandem mass. Their height, weight, waist circumference, body fat percentage, body mass index (BMI), and waist-to-height ratio (WHtR) were measured or calculated. BMI z-score ≥ 85th percentile was defined as overweight/obesity, and WHtR ≥ 0.5 was considered to be abdominal obesity. Multivariable linear regressions, generalized linear models (GLMs), and multivariable logistic regressions were performed to examine the associations between TCS exposure and obesity measures in children.

RESULTS

Linear regressions showed that TCS concentrations, when treated as continuous variables, were positively associated with BMI z-score (β = 0.12, 95% CI: 0.01, 0.24) and body fat percentage (β = 0.82, 95% CI: 0.13, 1.52). When TCS concentrations were categorized as a four-level ordinal variable, the results of GLMs were similar those of continuous variables and both of the positive trends were significant (p-trend = 0.049 for BMI z-score; p-trend = 0.023 for body fat percentage). Moreover, the higher TCS levels versus reference group were associated with an approximate 2-3 fold increased risk of abdominal obesity (p-trend = 0.044).

CONCLUSION

Exposure to TCS was positively associated with obesity measures among 7-year-old children in northern, China. Given to the cross-sectional study design, a large prospective study is warranted to confirm our findings.

Maternal intake of alpha-lipoic acid prevents development of symptoms associated with a fructose-rich diet in the male offspring in Wistar rats

The hypothesis was that maternal intake of the antioxidant alpha-lipoid acid (ALA), during the developmental period of the hypothalamic orexigenic neurons, causes a permanent beneficial effect in offspring metabolism. Pregnant Wistar rats were fed with standard diet (food) + ALA (0.4% wt/wt) from day 14 of gestation to day 20 of lactation (n = 4) or food (n = 4). At 3 months of age, male offspring born from ALA-fed rats or controls (CT) were randomly assigned to be fed with food + 10% fructose solution in drinking water (F) or food + tap water (C), resulting in four groups: ALAF, ALAC, CTF, and CTC (n = 5/group). Food intake and body weight (BW) were measured twice a week for 31 days. Metabolites' levels in blood, mRNA expressions of Npy, Agrp (hypothalamus), Fasn, Srebf1, Ppard, and Pparg (liver), and the antioxidant capacity of the liver were determined. Results significance was set at p < 0.05. Average BW gain, daily BW gain, and intraabdominal fat tissue at necropsy were higher in CTF group followed by CTC, ALAF, and ALAC groups. There were no differences between groups in Kcal intake per day. mRNA expressions of hypothalamic and hepatic genes and plasmatic levels of glucose and triglycerides were higher in CTF group followed by ALAF, CTC, and ALAC groups. Fructose intake affected the oxidative capacity of the liver, but this effect was not observed in the ALAF group. In conclusion, maternal ALA intake protected the adult offspring to develop metabolic symptoms associated with high fructose in the drinking water.

Variations, Determinants, and Coexposure Patterns of Personal Care Product Chemicals among Chinese Pregnant Women: A Longitudinal Study

Exposure to mixtures of personal care product chemicals (PCPCs) is commonplace among the Chinese population; yet, limited data are available on the variations, determinants, and coexposure patterns of PCPCs, particularly among pregnant women at multiple time points during gestation. Here, we measured concentrations of 11 most common PCPCs (five parabens, five benzophenones, and triclosan) in 2823 urine samples collected from 941 pregnant women over three trimesters. Based on the quantification results, we calculated the intraclass correlation coefficient (ICC) to assess within-person variability of targeted compounds, applied linear mixed mode models to explore associations between urinary concentrations of PCPCs and exposure-related factors, and used percentile analysis to evaluate exposure to specific or multiple chemicals at one or three trimesters. Seven targeted compounds: methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), 4-hydroxybenzophenone (4-OH-BP), 2,4-dihydroxybenzophenone (BP-1), 2-hydroxy-4-methoxybenzophenone (BP-3), and triclosan (TCS) were detected in over 66% of samples. The median urinary concentrations (ng/mL) of MeP, EtP, PrP, 4-OH-BP, BP-1, BP-3, and TCS were 15.44, 0.49, 0.61, 0.16, 0.25, 0.53, and 0.48, respectively. We observed that benzophenones (ICC: 0.46-0.55) and triclosan (ICC: 0.50) were less variable than parabens (ICC: 0.35-0.40). Urinary levels of parabens were related to physical activity frequency; urinary levels of benzophenones were associated with the refurbishment of homes and household income, and urinary levels of triclosan were contingent upon the personal basic information (prepregnancy body mass index and age). Notably, higher levels of benzophenones and triclosan but lower paraben levels were observed in summer than in winter. Both coexposure to high percentiles of multiple pollutants at one trimester and exposure to one pollutant at high-dose through three trimesters were rare in the study population. Our findings suggest that these exposure-related factors should be taken into consideration, and health risks should be assessed on mixtures of pollutants in future epidemiological studies.

Early-life exposure to endocrine disrupting chemicals associates with childhood obesity

Increasing prevalence of childhood obesity poses threats to the global health burden. Because this rising prevalence cannot be fully explained by traditional risk factors such as unhealthy diet and physical inactivity, early-life exposure to endocrine disrupting chemicals (EDCs) is recognized as emerging novel risk factors for childhood obesity. EDCs can disrupt the hormone-mediated metabolic pathways, affect children's growth and mediate the development of childhood obesity. Many organic pollutants are recently classified to be EDCs. In this review, we summarized the epidemiological and laboratory evidence related to EDCs and childhood obesity, and discussed the possible mechanisms underpinning childhood obesity and early-life exposure to non-persistent organic pollutants (phthalates, bisphenol A, triclosan) and persistent organic pollutants (dichlorodiphenyltrichloroethane, polychlorinated biphenyls, polybrominated diphenyl ethers, per- and polyfluoroalkyl substances). Understanding the relationship between EDCs and childhood obesity helps to raise public awareness and formulate public health policy to protect the youth from exposure to the harmful effects of EDCs.

Exposure of pregnant mice to triclosan causes hyperphagic obesity of offspring via the hypermethylation of proopiomelanocortin promoter

Triclosan (TCS), as a broad spectrum antibacterial agent, is commonly utilized in personal care and household products. Maternal urinary TCS level has been associated with changes in birth weight of infants. We in the present study investigated whether exposure of mice to 8 mg/kg TCS from gestational day (GD) 6 to GD14 alters prenatal and postnatal growth and development, and metabolic phenotypes in male and female offspring (TCS-offspring). Compared with control offspring, body weight in postnatal day (PND) 1 male or female TCS-offspring was reduced, but body weight gain was faster within postnatal 5 days. PND30 and PND60 TCS-offspring showed overweight with increases in visceral fat and adipocyte size. PND60 TCS-offspring displayed delayed glucose clearance and insulin resistance. PND30 TCS-offspring showed an increase in food intake without the changes in the oxygen consumption and respiratory exchange ratio (RER). The expression levels of proopiomelanocortin (POMC), α-melanocyte-stimulating hormone (α-MSH) and single-minded 1 (SIM1) in hypothalamus arcuate nucleus (ARC) and paraventricular nucleus (PVN), respectively, were significantly reduced in PND30 TCS-offspring compared to controls. The hypermethylation of CpG sites at the POMC promoter was observed in PND30 TCS-offspring, while the concentration of serum leptin was elevated and the level of STAT3 phosphorylation in ARC had no significant difference from control. This study demonstrates that TCS exposure during early/mid-gestation through the hypermethylation of the POMC promoter reduces the expression of anorexigenic neuropeptides to cause the postnatal hyperphagic obesity, leading to metabolic syndrome in adulthood.

Maternal urinary triclosan level, gestational diabetes mellitus and birth weight in Chinese women

Triclosan (TCS) is an antibacterial chemical widely used in personal-care products and an endocrine disruptor. While TCS exposure is associated with insulin resistance and metabolic disorders in animals, few studies have assessed its effect on the risk of gestational diabetes mellitus (GDM) in humans. This study aimed to explore whether maternal urinary TCS level is associated with the risk of GDM and infant birthweight. We examined 620 pregnant women from Shanghai, China in 2012-2013. Urinary TCS level was measured with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and categorized into high, medium and low in tertiles. GDM was defined based on recommendation of International Association of Diabetes and Pregnancy Study Groups (IADPSG). The GDM rate was 12.7%. TCS was detectable (≥0.1 ng/mL) in 97.9% women (median 2.7 ng/mL). There was a positive, but statistically non-significant association between urinary TCS levels and GDM (adjusted odds ratio 1.17; 95%CI: 0.99, 1.39, with each unit increase of log (TCS) ng/mL) with adjustment for urinary creatinine, maternal age, education, passive smoking, parity and prepregnancy BMI categories. 48.1% of infants were females. Birthweight was 122.8 g higher (95% CI: 13.9, 231.6 g) for female infants of women in high TCS (median 13.3 ng/mL) versus low TCS (median 0.77 ng/mL), with adjustment for urinary creatinine, prepregnancy BMI, GDM and other confounders. No association was found between maternal TCS and birthweight in male infants. These results suggested the potential for TCS to be associated with increased risk of GDM and a gender-specific association with higher birthweight among female infants in a population with widespread but moderate exposure to TCS.