Ganoderma tsugae prevents cognitive impairment and attenuates oxidative damage in d-galactose-induced aging in the rat brain.

Lingzhi has long been regarded as having life-prolonging effects. Research in recent years has also reported that Lingzhi possesses anti-tumor, anti-inflammatory, immunomodulatory, hepatoprotective, and anti-lipogenic effects. The D-galactose (D-gal, 100 mg/kg/day)-induced aging Long-Evans rats were simultaneously orally administered a DMSO extract of Ganoderma tsugae (GTDE, 200 µg/kg/day) for 25 weeks to investigate the effects of GTDE on oxidative stress and memory deficits in the D-galactose-induced aging rats. We found that GTDE significantly improved the locomotion and spatial memory and learning in the aging rats. GTDE alleviated the aging-induced reduction of dendritic branching in neurons of the hippocampus and cerebral cortex. Immunoblotting revealed a significant increase in the protein expression levels of the superoxide dismutase-1 (SOD-1) and catalase, and the brain-derived neurotrophic factor (BDNF) in rats that received GTDE. D-gal-induced increase in the lipid peroxidation product 4-hydroxynonenal (4-HNE) was significantly attenuated after the administration of GTDE, and pyrin domain-containing 3 protein (NLRP3) revealed a significant decrease in NLRP3 expression after GTDE administration. Lastly, GTDE significantly reduced the advanced glycosylation end products (AGEs). In conclusion, GTDE increases antioxidant capacity and BDNF expression of the brain, protects the dendritic structure of neurons, and reduces aging-induced neuronal damage, thereby attenuating cognitive impairment caused by aging.

In Vitro and In Vivo Analysis of the Effects of 3,5-DMA and Its Metabolites in Neural Oxidative Stress and Neurodevelopmental Toxicity.

3,5-Dimethylaniline (3,5-DMA), a monocyclic aromatic amine, is widely present in a spectrum of sources including tobacco, dyes, combustion products, and suspended particulates. 3,5-DMA and its metabolites form superoxides, resulting in apoptosis or oncogenesis. Data of a direct effect of 3,5-DMA on the nervous system, especially the developing brain, are lacking. Therefore, we investigated the effects of 3,5-DMA and its metabolites on fetal neurite growth and brain development using in vitro cell cultures of primary cortical neurons to observe whether these compounds caused neuronal cytotoxicity and affected neurite structural development. With increasing concentrations of 3,5-DMA (10, 50, 100, 500, 1000 µM) and its major metabolite 5-dimethylaminophenol (3,5-DMAP) (10, 50, 100, 500, 1000 µM), reactive oxygen species (ROS), cytotoxicity, and DNA damage increased significantly in the cells and dendritic arborization decreased. The addition of 5 mM N-acetylcysteine, an ROS scavenger, reduced ROS in the cells and alleviated the neuronal damage. In vivo studies in Sprague Dawley pregnant rats suggested that exposure to 3,5-DMA (10, 30, 60, 100 mg/kg/day) subcutaneously from GD15 to GD17 led to fetal cerebral cortex thinning. BrdU labeling showed that 3,5-DMA reduced the number and generation of cortical cells. To detect the laminar position of newly generated neurons, cortex layer markers such as Satb2, Ctip2, and Tbr1 were used. 3,5-DMA perturbed the cortical layer distribution in developing fetal rats. In summary, this is the first study to provide evidence for 3,5-DMA and its metabolites causing anomalies of the fetal central nervous system development through ROS production.