Apocynin preserves glutamatergic neurons in the basolateral amygdala in mice with neonatal sevoflurane exposure

Apocynin exerts neuroprotective effects in fumonisin b1-induced neurotoxicity via attenuation of oxidative stress and apoptosis in an animal model

The Fusarium verticillioides produces a mycotoxin, that is, fumonisin b1 (Fb1), which commonly infects corn and agricultural commodities. The Fb1 showed hepatotoxicity, neurotoxicity, and carcinogenicity in animals. Hence, the present investigation aimed to evaluate the effect of apocynin (AP) on Fb1-induced neurotoxic effects and its mechanism in the mice model and cell line. The male Balb/c mice, with the 6.75 mg/kg bwt of Fb1 were injected subcutaneously for 5 days to induce neurotoxicity. A significant elevation of serotonin (5-HT) was observed in mice treated with Fb1 in the whole brain showing biogenic amines may reflect Fb1 neurotoxicity, but the negatively regulated mechanisms were attenuated by the pretreatment of AP. In addition, AP pretreatment normalized apoptotic changes in histology and immunohistochemistry studies. In Western blotting studies, apoptotic genes were upregulated and oxidative stress genes were downregulated due to Fb1 treatment; while treating with AP, these gene expressions were rectified. Further cell cytotoxicity was investigated by MTT and lactate dehydrogenase (LDH) assays in SH-SY5Y cell line. MTT and LDH assays indicated the IC50 value to be 150 µM of Fb1, which was protected by 100 µg of AP. The electron microscopy evaluated the Fb1-induced apoptotic conditions and its cell morphology recovery by AP. These results suggest that nicotinamide adenine dinucleotide phosphate hydrogen oxidase-mediated reactive oxygen species is the primary upstream signal leading to increased Fb1-mediated neurotoxicity in mice. The use of the antioxidant AP reversed the toxin-induced oxidative stress and apoptosis by its antioxidant potency.

Apocynin alleviates weight gain and obesity-induced adipose tissue inflammation in high-fat diet-fed C57BL/6 mice

Obesity involves chronic low-grade inflammation within adipose tissue. Apocynin (APO) is a therapeutic agent for the treatment of inflammatory diseases. Therefore, the present study aimed to investigate whether APO can reduce weight gain and obesity-induced adipose tissue inflammation. C57BL/6 mice were administered APO or orlistat (Orli) as a positive control with a high-fat diet (HFD) for 12 weeks. Lipopolysaccharide-stimulated 3T3-L1 adipocytes were used for the in vitro study. Our results showed a significantly lower white adipose tissue (WAT) mass index in 10 mg/kg APO-treated mice than in 20 mg/kg Orli-treated mice. Moreover, the protein expression of adipose triglyceride lipase, fatty acid synthase, sterol regulatory element-binding transcription factor 1, and peroxisome proliferator-activated receptor γ was reversed in the WAT of 10 mg/kg APO-treated mice. Furthermore, APO reduced the expression of the macrophage marker F4/80, decreased the mRNA levels of tumor necrosis factor-α and monocyte chemoattractant protein-1, and increased the mRNA levels of interleukin-10 in WAT. APO decreased the phosphorylation of c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p65 in vivo and in vitro. Notably, APO had a stronger effect on the amelioration of adipose tissue inflammation than Orli did. Our findings lay the foundation for research on the use of APO as an agent to ameliorate weight gain and obesity-induced inflammatory diseases.

Sevoflurane Induces Neurotoxicity in the Animal Model with Alzheimer's Disease Neuropathology via Modulating Glutamate Transporter and Neuronal Apoptosis

Perioperative neurocognitive disorders are frequently observed in postoperative patients and previous reports have shown that pre-existing mild cognitive impairment with accumulated neuropathology may be a risk factor. Sevoflurane is a general anesthetic agent which is commonly used in clinical practice. However, the effects of sevoflurane in postoperative subjects are still controversial, as both neurotoxic or neuroprotective effects were reported. The purpose of this study is to investigate the effects of sevoflurane in 3 × Tg mice, a specific animal model with pre-existing Alzheimer’s disease neuropathology. 3 × Tg mice and wild-type mice were exposed to 2 h of sevoflurane respectively. Cognitive function, glutamate transporter expression, MAPK kinase pathways, and neuronal apoptosis were accessed on day 7 post-exposure. Our findings indicate that sevoflurane-induced cognitive deterioration in 3 × Tg mice, which was accompanied with the modulation of glutamate transporter, MAPK signaling, and neuronal apoptosis in the cortical and hippocampal regions. Meanwhile, no significant impact was observed in wild-type mice. Our results demonstrated that prolonged inhaled sevoflurane results in the exacerbation of neuronal and cognitive dysfunction which depends on the neuropathology background.

TLR4/NF-κB Signaling Pathway Participates in the Protective Effects of Apocynin on Gestational Diabetes Mellitus Induced Placental Oxidative Stress and Inflammation

Gestational diabetes mellitus (GDM) is a temporary form of diabetes during pregnancy which influences the health of both mother and child. Both inflammation and oxidative stress have been implicated in the pathophysiology of GDM. Apocynin, acetophenone with anti-oxidative and anti-inflammation activities, has been shown to protect against insulin resistance. In the current study, the effects of apocynin on GDM symptoms, productive outcomes, oxidative stress, and inflammation were evaluated and the underlying mechanisms were explored. We administrated apocynin to GDM mice and monitored the GDM symptoms including body weight, serum levels of glucose, insulin, lipid profile, and the fetal outcomes in GDM mice. We also evaluated the effects of apocynin on placental oxidative stress, inflammation, and activation of TLR4/NF-κB signaling pathway in GDM mice. Here, we reported that apocynin treatment significantly reduced serum levels of glucose, cholesterol, triglyceride, and low-density lipoprotein in GDM mice, while significantly increased serum level of insulin and high-density lipoprotein. Apocynin improved fetal outcomes in GDM mice. Apocynin ameliorated placental oxidative stress and inflammation and inhibited TLR4/NF-κB signaling pathway activation in GDM mice. We concluded that apocynin suppressed oxidative stress and inflammation in GDM by inhibiting the TLR4/NF-κB signaling pathway.