Toxicokinetics and distribution in female rats after chronic nonylphenol exposure

Nonylphenol induces anxiety-like behavior in rats by regulating BDNF/TrkB/CREB signal network

This study aimed to verify whether chronic exposure to nonylphenol (NP) induces anxiety behavior in rats and explored NP's regulatory effect on the BDNF/TrkB/CREB signal network in vitro. Anxiety-like behavior was assessed by elevated plus-maze and light-dark box tests. The residence time in the closed arm increased with NP dose (4, 40 mg/kg) and exposure time (3 and 6 months) (P < 0.05). The hippocampal neurons in the medium dose (M-NP, 4 mg/kg) and high dose (H-NP, 40 mg/kg) groups showed disorderly arrangement, cell swelling, and nuclear pyknosis/necrosis. The protein/mRNA expressions of BDNF/TrkB/CREB in the H-NP group decreased, and the decrease was more significant at 6 months (P < 0.05). Both, NP exposure and BDNF knockdown, increase the number of apoptotic cells (P ＜0.001). NP downregulated the proteins/mRNA expressions of BDNF/TrkB/CREB, and the trend was consistent with the BDNF silence group. Chronic exposure to NP could induce anxiety-like behavior in rats and reduce the expression of key proteins/genes in the BDNF/TrkB/CREB signaling network.

Developmental immunotoxicity and its potential gender differences of perinatal exposure to 4-nonylphenol on offspring rats: JAK-STAT signaling pathway involved

The aim of our study was to explore the developmental immunotoxicity (DIT) and its potential gender differences of perinatal exposure to 4-nonylphenol (4-NP), which was significant for the risk assessment of 4-NP exposure to fetuses and infants. Wistar pregnant rats were given the National Institution of Health (NIH)- 31 modified feed containing 0, 10, 100 and 500 mg/kg 4-NP from the gestation day (GD) 6 to the postnatal day (PND) 21. At PND21, the offspring rats were randomly selected to detect developmental immunotoxicity related indicators. Results suggested that high-dose 4-NP perinatal exposure caused growth retardation in infancy of male offspring rats, which was not obvious in female offspring rats. Also, 4-NP perinatal exposure induced DIT (mainly manifested as immunosuppression) with potential gender differences, including decreased weight of immune organs, suppressed immune function, decreased ratio of transforming growth factor (TGF)-β/interleukin (IL)- 17A, increased ratio of T helper (Th) 17/regulatory T (Treg) cells et al. In addition, exploration of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway showed that JAK-STAT pathway mediated the leftward of Th17/Treg cells balance. Furthermore, the DIT to female offspring rats was more sensitive than to the males, which may be related to the differences of biological processes involved and needed to be further explored.

Baseline and time-updated factors in preclinical development of anionic dendrimers as successful anti-HIV-1 vaginal microbicides

Although a wide variety of topical microbicides provide promising in vitro and in vivo efficacy, most of them failed to prevent sexual transmission of human immunodeficiency virus type 1 (HIV‐1) in human clinical trials. In vitro, ex vivo, and in vivo models must be optimized, considering the knowledge acquired from unsuccessful and successful clinical trials to improve the current gaps and the preclinical development protocols. To date, dendrimers are the only nanotool that has advanced to human clinical trials as topical microbicides to prevent HIV‐1 transmission. This fact demonstrates the importance and the potential of these molecules as microbicides. Polyanionic dendrimers are highly branched nanocompounds with potent activity against HIV‐1 that disturb HIV‐1 entry. Herein, the most significant advancements in topical microbicide development, trying to mimic the real‐life conditions as closely as possible, are discussed. This review also provides the preclinical assays that anionic dendrimers have passed as microbicides because they can improve current antiviral treatments' efficacy.

This article is categorized under:

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease

Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine