Benzo[b]fluoranthene induces male reproductive toxicity and apoptosis via Akt-Mdm2-p53 signaling axis in mouse Leydig cells: Integrating computational toxicology and experimental approaches.

This study aims to explore the male reproductive toxicity of Benzo[b]fluoranthene (BbF) and related mechanisms. The results of computational toxicology analysis indicated male reproductive toxicity of BbF was related to apoptosis of Leydig cells and that Akt/p53 pathway might play a key role. In experiments, BbF induced testosterone decline, decreased concentration and motility of sperm and aggravated testicular pathological injury in mice. Besides, BbF led to apoptosis in Leydig cells, and decreased expressions of p-Akt and Bcl2, while improving the expressions of p53, Bax and Cleaved Caspase-3 in vivo and in vitro. Further, compared with BbF group, Akt activator SC79 significantly reduced cell apoptosis rate, improved cell viability, promoted the expressions of p-Akt and p-Mdm2, and reversed the above molecular expressions. Similarly, p53 inhibitor Pifithrin-α also significantly enhanced the cell vitality, alleviated the apoptosis of TM3 cells induced by BbF, and decreased the expressions of Bax and Cleaved Caspase-3, with the up-regulation of Bcl2. To sum up, by inhibiting Akt-Mdm2 signaling, BbF activated the p53-mediated mitochondrial apoptosis pathway, further inducing the apoptosis of Leydig cells, therefore resulting in testosterone decline and male reproductive damage. Besides, this study provided a valid mode integrating computational toxicology and experimental approaches in toxicity testing.

[Chemical constituents from rhizome of Menispermum dauricum and their anti-hypoxic activities].

To study the chemical constituents from the rhizome of Menispermum dauricum,fifteen compounds,N-methylcorydaldine( 1),thalifoline( 2),stepholidine( 3),acutumine( 4),daurisoline( 5),acutumidine( 6),dauricicoline( 7),bianfugecine( 8),6-O-demethylmenisporphine( 9),bianfugedine( 10),dauricoside( 11),eleutheroside D( 12),aristolactone( 13),aristoloterpenateⅠ( 14) and aristolochic acid( 15) were isolated from 75% ethanol extract of Menispermi Rhizoma by using thin layer chromatography and column chromatography methods. Their structures were identified based on their physicochemical properties and spectral data. Among them,compounds 12-15 were obtained from the genus Menispermum for the first time. Six alkaloids with higher contents were subjected to evaluate the anti-hypoxic activities by using MTT method. As a result,six alkaloids exhibited significant anti-hypoxia activities.

The Role of HINT1 in Methamphetamine-Induced Conditioned Place Preference.

Drug addiction is a chronically relapsing disorder in humans; yet, the underlying mechanism remained unclear. Recent studies suggested that the histidine triad nucleotide binding protein 1 (HINT1) may play significant roles in diverse neuropsychiatric diseases including drug addiction. In our present study, we used different batches of mice to establish the different stages of methamphetamine (METH)-induced conditioned place preference (CPP) to explore the dynamic changes throughout the process of addiction in different brain regions, including prefrontal cortex (PFC), nucleus accumbens (NAc), corpus striatum (CPu), and hippocampus (Hip). We found that in NAc of the METH group mice, the HINT1 expression level initially increased after acquisition phases, and then dropped to the normal level after extinction phase, and again increased after reinstatement phase. However, there was no statistical difference in the HINT1 expression level in other three encephalic regions (PFC, CPu, and Hip). Therefore, the HINT1 protein, particularly in the NAc, plays a vital role in the METH-induced CPP. However, the precise mechanisms will require further investigation.