PDF(Pubmed)
Abstract：
OBJECTIVE: To investigate the effect of near-infrared (NIR) light therapy on depression-induced intestinal dysfunction in rats and explore the possible mechanism.
METHODS: Thirty-two male SD rats were randomly divided into control group, model group, low-dose NIR light group and high-dose NIR light group. All the rats except for those in the control group were subjected to chronic restrained stress (CRS) for 4 weeks, and NIR light therapy of the head was administered in the two NIR light groups. The depression- like behaviors, intestinal functions, fecal water content and number of fecal pellets of the rats were evaluated. HE staining was used for detecting histopathological changes in the hippocampus and colon, and hippocampal expressions of BDNF, Nrf2 and PGC-1α were detected with Western blotting.
RESULTS: The rats in the CRS model group showed significantly increased immobility time and visceral sensitivity in the behavioral tests, decreased fecal pellets and fecal water content, and lowered expressions of BDNF, Nrf2, and PGC-1α in the hippocampus (P<0.05). Histopathological examination of the CRS rats revealed loosely arranged hippocampal pyramidal cells, obvious neuronal damages, and obvious inflammatory cell infiltration in the colon with irregularly arranged mucosal glands and a high pathological score. High-dose NIR light therapy significantly lowered the immobility time and visceral sensitivity, increased the number of fecal pellets and fecal water content (P<0.05), and enhanced hippocampal expressions of BDNF, Nrf2, and PGC-1α (P<0.05) of the depressive rats. The rats receiving high-dose NIR light therapy also exhibited close arrangement of the hippocampal pyramidal cells with significantly reduced neuronal damage and colonic inflammatory cell infiltration, neatly arranged mucosal glands, and lowered pathological score.
CONCLUSIONS: NIR light therapy can significantly improve depression-like behavior and intestinal function in rats possibly by ameliorating oxidative stress via the PGC-1α/Nrf2 signaling pathway and increasing BDNF level in the hippocampus.
METHODS: Thirty-two male SD rats were randomly divided into control group, model group, low-dose NIR light group and high-dose NIR light group. All the rats except for those in the control group were subjected to chronic restrained stress (CRS) for 4 weeks, and NIR light therapy of the head was administered in the two NIR light groups. The depression- like behaviors, intestinal functions, fecal water content and number of fecal pellets of the rats were evaluated. HE staining was used for detecting histopathological changes in the hippocampus and colon, and hippocampal expressions of BDNF, Nrf2 and PGC-1α were detected with Western blotting.
RESULTS: The rats in the CRS model group showed significantly increased immobility time and visceral sensitivity in the behavioral tests, decreased fecal pellets and fecal water content, and lowered expressions of BDNF, Nrf2, and PGC-1α in the hippocampus (P<0.05). Histopathological examination of the CRS rats revealed loosely arranged hippocampal pyramidal cells, obvious neuronal damages, and obvious inflammatory cell infiltration in the colon with irregularly arranged mucosal glands and a high pathological score. High-dose NIR light therapy significantly lowered the immobility time and visceral sensitivity, increased the number of fecal pellets and fecal water content (P<0.05), and enhanced hippocampal expressions of BDNF, Nrf2, and PGC-1α (P<0.05) of the depressive rats. The rats receiving high-dose NIR light therapy also exhibited close arrangement of the hippocampal pyramidal cells with significantly reduced neuronal damage and colonic inflammatory cell infiltration, neatly arranged mucosal glands, and lowered pathological score.
CONCLUSIONS: NIR light therapy can significantly improve depression-like behavior and intestinal function in rats possibly by ameliorating oxidative stress via the PGC-1α/Nrf2 signaling pathway and increasing BDNF level in the hippocampus.
摘要：
目的：观察近红外(NIR)光疗对抑郁症大鼠肠功能障碍的影响并探讨其可能的作用机制。
方法:32只雄性SD大鼠随机分为对照组,模型组,低剂量NIR光组和高剂量NIR光组。除对照组外，所有大鼠均接受慢性约束应激（CRS）4周，在两个NIR光组中进行头部的NIR光疗法。类似抑郁的行为，肠道功能,评估大鼠的粪便含水量和粪便颗粒数量。HE染色用于检测海马和结肠的组织病理学改变，和海马BDNF的表达，用蛋白质印迹法检测Nrf2和PGC-1α。
结果：CRS模型组大鼠在行为测试中表现出明显的不动时间和内脏敏感性增加，减少粪便颗粒和粪便含水量，并降低BDNF的表达，Nrf2和PGC-1α在海马中的表达(P<0.05)。CRS大鼠的组织病理学检查显示海马锥体细胞排列松散，明显的神经元损伤，结肠有明显的炎性细胞浸润，粘膜腺体排列不规则，病理评分高。大剂量NIR光疗显著降低了不动时间和内脏敏感性,增加粪便颗粒数量和粪便含水量(P<0.05)，海马BDNF表达增强，抑郁大鼠的Nrf2和PGC-1α(P<0.05)。接受大剂量NIR光治疗的大鼠海马锥体细胞排列紧密，神经元损伤和结肠炎症细胞浸润明显减少，整齐排列的粘膜腺体，降低了病理评分。
结论：NIR光治疗可显著改善大鼠抑郁样行为和肠道功能，其机制可能是通过PGC-1α/Nrf2信号通路改善氧化应激，提高海马BDNF水平。
方法:32只雄性SD大鼠随机分为对照组,模型组,低剂量NIR光组和高剂量NIR光组。除对照组外，所有大鼠均接受慢性约束应激（CRS）4周，在两个NIR光组中进行头部的NIR光疗法。类似抑郁的行为，肠道功能,评估大鼠的粪便含水量和粪便颗粒数量。HE染色用于检测海马和结肠的组织病理学改变，和海马BDNF的表达，用蛋白质印迹法检测Nrf2和PGC-1α。
结果：CRS模型组大鼠在行为测试中表现出明显的不动时间和内脏敏感性增加，减少粪便颗粒和粪便含水量，并降低BDNF的表达，Nrf2和PGC-1α在海马中的表达(P<0.05)。CRS大鼠的组织病理学检查显示海马锥体细胞排列松散，明显的神经元损伤，结肠有明显的炎性细胞浸润，粘膜腺体排列不规则，病理评分高。大剂量NIR光疗显著降低了不动时间和内脏敏感性,增加粪便颗粒数量和粪便含水量(P<0.05)，海马BDNF表达增强，抑郁大鼠的Nrf2和PGC-1α(P<0.05)。接受大剂量NIR光治疗的大鼠海马锥体细胞排列紧密，神经元损伤和结肠炎症细胞浸润明显减少，整齐排列的粘膜腺体，降低了病理评分。
结论：NIR光治疗可显著改善大鼠抑郁样行为和肠道功能，其机制可能是通过PGC-1α/Nrf2信号通路改善氧化应激，提高海马BDNF水平。
