Impaired hippocampal neurogenesis and neuroinflammation are involved in the pathogenesis of radiation-induced brain injury. Kukoamine A (KuA) was demonstrated to have neuroprotective effects through inhibiting oxidative stress and apoptosis after whole-brain irradiation (WBI) in rats. The aim of this study was to investigate whether administration of KuA would prevent radiation-induced neuroinflammation and the detrimental effect on hippocampal neurogenesis. For this study, male Wistar rats received either sham irradiation or WBI (30 Gy single dose of X-rays) followed by the immediate injection of either KuA or vehicle intravenously. The dose of KuA was 5, 10, and 20 mg/kg, respectively. The levels of pro-inflammatory cytokines were assayed by ELISA kits. The newborn neurons were detected by 5-bromo-2-deoxyuridine (BrdU)/neuronal nuclei (NeuN) double immunofluorescence. Microglial activation was measured by Iba-1 immunofluorescence. The expression of Cox-2 and the activation of nuclear factor κB (NF-κB), activating protein 1(AP-1), and PPARδ were evaluated by western blot. WBI led to a significant increase in the level of TNF-α, IL-1β, and Cox-2, and it was alleviated by KuA administration. KuA attenuated microglial activation in rat hippocampus after WBI. Neurogenesis impairment induced by WBI was ameliorated by KuA. Additionally, KuA alleviated the increased translocation of NF-κB p65 subunit and phosphorylation of c-jun induced by WBI and elevated the expression of PPARδ. These data indicate that KuA could ameliorate the neuroinflammatory response and protect neurogenesis after WBI, partially through regulating the activation of NF-κB, AP-1, and PPARδ.
Xin Li,Xiao-wen Jiang,Hai-xiao Chu,Qing-chun Zhao,Huai-wei Ding,Chao-hong Cai
Objective Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in substantia nigra (SN). Our previous study demonstrated kukoamine A (KuA) to exhibit strong neuroprotective effects through antioxidative stress, and autophagy in MPTP/MPP + -induced PD models in vivo and in vitro . It is necessary to evaluate the efficacy of the anti-PD effects under various models. Methods In the present study, total chemical synthesis was used to obtain KuA, which performed low content in Lycii Cortex . Then, 6-OHDA-induced PD model of PC12 cells was used to investigate the effects of KuA on PD. Results Our results demonstrated that KuA ameliorated cell loss and mitochondrial membrane potential (MMP) loss, and inhibited Bax/Bcl-2 ratio increase that were induced by 6-OHDA. Iron accumulation in SN is thought to participate in neuronal death in PD, which subsequently resulted in oxidative stress and overexpression of α-synuclein caused by iron metabolism protein disorder. In our study, KuA could chelate cellular iron content and decrease iron influx. Moreover, KuA could upregulate the expression of ferroportin1 and Hephaestin, downregulate the expression of DMT1, TfR, and Ferritin to maintain cellular iron homeostasis avoiding neuronal death from cellular iron deposition. Moreover, KuA could decrease the expression of a-synuclein in cells. All the results indicated that KuA protected against neurotoxin-induced PD due to the apoptosis inhibition and iron homeostasis maintaining. Conclusion KuA treatment might represent a neuroprotective treatment for PD.