Repairing Effects of Ginsenoside Rg1 on Traumatic Brain Injury in Mice

Abstract

Objective To explore the effects of ginsenoside Rg1 on blood-brain barrier, neuroinflammation and behavioral function of traumatic brain injury (TBI) mouse model. MethodsThe experiment was divided into two parts. In the first part, 27 SPF male BALB/c mice were randomly divided into blank group, sham operation group and TBI model group, with 9 mice in each group. TBI model group was made by controlled cortical impact (CCI) after craniotomy, while sham operation group was only performed craniotomy without any treatment, and the blank group was not treated at all. The effect of modeling was evaluated after operation. In the second part, 50 male BALB/c mice were randomly divided into sham operation group, three different drug dosage groups and solvent (DMSO) control group, with 8 mice in each group. The drug treatment groups were injected with ginsenoside Rg1 at the doses of 10, 20 and 40 mg/kg respectively 6 hours after TBI model had been successfully established, while the DMSO control group was given the same amount of 1% DMSO for one week, twice a day. Modified neurological severity scores (mNSS) were performed on the 1st, 3rd, 7th and 14th day after modeling, and the blood-brain barrier leakage was detected by Western blotting on the 3rd day after modeling. On the 14th and 16th day, the elevated cross maze test and water maze test were used to detect the neurobehavioral function. On the 28th day after anesthesia and perfusion, the brains were taken out, and the neuroinflammation such as activation of microglia and astrocytes was observed by immunofluorescence staining. Results The expression level of MMP-9, a marker of blood-brain barrier, decreased in ginsenoside Rg1 treatment group (P<0.01). The number of microglia （Iba-1 positive) and astrocyte (GFAP positive) cells decreased significantly (P<0.05), which indicated that neuroinflammation was inhibited, and the best effect was achieved at the dosage of 20 mg/kg (P<0.01). The mNSS of mice in ginsenoside Rg1 treatment group were significantly lower than those in DMSO control group (P < 0.01), and the proportion of times they entered the open arm was significantly higher than that in DMSO control group (P < 0.05). The time ratio in the quadrant where the water maze experimental platform was located and the times of crossing the platform were significantly higher than those in control group (P < 0.05), and the dosage of 20 mg/kg had the best effect. ConclusionThe TBI mouse model was successfully constructed and applied to the study of ginsenoside Rg1 repair of mouse traumatic brain injury. Ginsenoside Rg1 can significantly improve blood-brain barrier, alleviate neuroinflammation and improve neurobehavioral function in TBI model mice, and the effect is the most significant at the dose of 20 mg/kg.

Keywords

• traumatic brain injury
• ginsenoside rg1
• mice
• nervoinflammation
• ethology