Isoamericanin A ameliorates neuronal damage and alleviates vascular cognitive impairments by inhibiting oxidative stress through activation of the Nrf2 pathway.
Yanqiu Yang, Libin Xu, Xiaohu Yao, Yingjie Wang, Mingxia Fang, Di Zhou, Ning Li, Yue Hou
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引用次数: 0
Abstract
Oxidative stress is critically involved in the cognitive dysfunction and neuronal progressive degeneration in the vascular cognitive impairment (VCI). The natural lignan molecular isoamericanin A (ISOA) containing multiple hydroxyl groups has great potential for suppressing oxidative stress in VCI. The primary objective of this study was to delve into the pharmacological properties of ISOA against VCI, as well as to elucidate the mechanisms driving this effect from the perspective of antioxidative stress. Transient bilateral common carotid arteries occlusion (tBCCAO) mice model and hydrogen peroxide (H2O2) treated N2a cells were employed in vivo and in vitro, respectively. Behavioral tests showed that ISOA (5, 10 mg/kg) treatment alleviated learning, memorizing, and recognition in tBCCAO model mice. ISOA alleviated the neuronal damages by increasing the number of NeuN-positive cells, decreasing the TUNEL-positive cells density, up-regulating MAP-2 expression, lighting the damage of neuronal nucleus and synapse. Mechanistically, we found that ISOA reduced the oxidative stress in neurons, which manifested by reduction on the expressions of superoxide, H2O2, intercellular reactive oxygen species (ROS) and malondialdehyde (MDA) level, and up-regulations on the expressions of anti-oxidant enzymes superoxide dismutase, heme oxygenase-1, glutathione peroxidase 4, glutathione, and NAD(P)H: quinone oxidoreductase 1. Further investigation showed that ISOA activated nuclear factor erythroid 2-related factor 2 (Nrf2) pathway by downregulating the expression of kelch-like ECH-associated protein 1, upregulating the nuclear translocation and expression of Nrf2, and augmenting antioxidant response elements (ARE) promotor activity. The ISOA-mediated promotion on ARE promotor activity and anti-oxidant enzymes expressions, and suppression on superoxide and ROS expressions and MDA levels were weakened by pharmacological inhibition or genetic knockdown of Nrf2. These effects were enhanced after knockdown Keap1 in H2O2-treated cells. Our study demonstrates that ISOA alleviates the cognitive impairments and neuronal loss in VCI by attenuating oxidative stress through promoting the activation of Nrf2 pathway.
期刊介绍:
International Immunopharmacology is the primary vehicle for the publication of original research papers pertinent to the overlapping areas of immunology, pharmacology, cytokine biology, immunotherapy, immunopathology and immunotoxicology. Review articles that encompass these subjects are also welcome.
The subject material appropriate for submission includes:
• Clinical studies employing immunotherapy of any type including the use of: bacterial and chemical agents; thymic hormones, interferon, lymphokines, etc., in transplantation and diseases such as cancer, immunodeficiency, chronic infection and allergic, inflammatory or autoimmune disorders.
• Studies on the mechanisms of action of these agents for specific parameters of immune competence as well as the overall clinical state.
• Pre-clinical animal studies and in vitro studies on mechanisms of action with immunopotentiators, immunomodulators, immunoadjuvants and other pharmacological agents active on cells participating in immune or allergic responses.
• Pharmacological compounds, microbial products and toxicological agents that affect the lymphoid system, and their mechanisms of action.
• Agents that activate genes or modify transcription and translation within the immune response.
• Substances activated, generated, or released through immunologic or related pathways that are pharmacologically active.
• Production, function and regulation of cytokines and their receptors.
• Classical pharmacological studies on the effects of chemokines and bioactive factors released during immunological reactions.