Effects of ginsenoside Rb1 on oxidative stress injury in rat spinal cords by regulating the eNOS/Nrf2/HO‑1 signaling pathway
Authors: Ying Zi
Hailong Yu
Yu Wang
Liangbi Xiang
Yanchun Xie
Xinwei Liu
Xiaochuan Gu
Miaomiao Yu
Journal: Experimental and Therapeutic Medicine (2018)
Discipline: CLINICAL MEDICINE
Keywords: antioxidant response element; endothelial nitric oxide synthase; ginsenoside Rb1; nuclear factor E2-related factor 2; oxidative stress
Affiliations: Department of Orthopedics, Rescue Center of Severe Wound and Trauma of the PLA, General Hospital of Shenyang Military Area Command, Shenyang, Liaoning 110016, P.R. China., Department of Orthopedics, Changhai Hospital Αffiliated to The Second Military Medical University, Shanghai 200433, P.R. China., Department of Emergency, Hospital 463 of the PLA, Shenyang, Liaoning 110042, P.R. China.

Abstract:  The present study aimed to investigate whether ginsenoside Rb1 (G-Rb1) attenuates spinal cord injury-associated oxidative stress in rats by regulating the endothelial nitric oxide synthase eNOS/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase (HO)-1 signaling pathway. Sprague Dawley rats were randomly divided into the sham operation group (S group), spinal cord injury group (SCI group), G-Rb1 treatment group (G-Rb1 group) and SCI+G-Rb1+Inhibitor L-name group (L-name group). The posterior limb function was evaluated via the Basso, Beattie and Bresnahan scoring method. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) and glutathione (GSH) in serum were measured by ELISA. The pathological changes in the spinal cord were observed by H&amp;E staining. Reverse transcription-quantitative polymerase chain reaction and western blot analyses were used to detect eNOS, phosphorylated (p)-eNOS, heat shock protein (HSP)90, Nrf2 and NAD(P)H quinone dehydrogenase 1 (Nqo1) at the mRNA and protein level. Immunohistochemistry was used to detect the expression of Nrf2 and p-eNOS. Compared with the S group, the scores of spinal cord function in the SCI group were significantly lower, and the levels of MDA were significantly increased, while the levels of SOD, CAT and GSH protein in spinal cord were significantly decreased (P&lt;0.05). The spinal cord tissue exhibited hemorrhage, neuronal degeneration/necrosis, as well as mononuclear cell and lymphocyte infiltration. The eNOS, HSP90, Nrf2, Nqo1 and HO-1 mRNA levels were decreased (P&lt;0.05). Compared with those in the SCI group, the spinal cord function score in the G-Rb1 group were significantly higher and the serum MDA content was significantly decreased, while the activity of SOD, CAT and GSH was significantly increased (P&lt;0.05). The degeneration/necrosis of spinal cord neurons was attenuated, inflammatory cell infiltration was significantly reduced and the levels of eNOS, HSP90, Nrf2, Nqo1 and HO-1 were significantly upregulated (P&lt;0.05). In the group that was administered the eNOS inhibitor L-name, the levels of eNOS, HSP90, Nrf2, Nqo1 and HO-1 were significantly decreased. In conclusion, G-Rb1 attenuates oxidative stress in injured spinal cords. The mechanism may at least in part involve the eNOS/Nrf2/HO-1 pathway. 

Retracted: No

PubPeer comments:
  Figure 7. Expression of p-eNOS and Nrf2 protein as determined by immunohistochemistry . ![file] I would have expected less overlap between p-eNOS and Nrf2. , 
 At left: Figure 5.  Expression of eNOS, HSP90, Nrf2, Nqo1 and HOu20111 protein determined by western blot analysis. At right: Figure 6.  Effect of L-name on the expression of eNOS, HSP90, Nrf2, Nqo1 and HO-1 in a rat model of SCI. eNOS SCI and eNOS G-Rb1 blobs appear in both figures (red box), which would not be a problem, except that the other results for SCI and G-Rb1 are **not** the same. Two other protein blobs appear in both figures (blue boxes), differently identified and rotated through 180 deg, which **is** a problem calling out for an explanation. ![file] ,