Ginsenoside Rb1 attenuates lipopolysaccharide-induced neural damage in the brain of mice via regulating the dysfunction of microglia and astrocytes

The purpose of our research was to evaluate whether ginsenoside Rb1 has neuroprotective effects against lipopolysaccharide (LPS)-induced brain injury. ICR mice were intraperitoneally (i.p.) injected with 20 or 40 mg/kg Rb1 or saline for 7 consecutive days. On the 7th day, 30 minutes after Rb1 or saline administration, a single dose of LPS (LPS group, Rb1+LPS group) or saline (control group) was injected i.p. into the mice. Results demonstrated that Rb1 treatment could significantly improve the behavior performance of LPS mice in both the open field test and the beam walking test. Rb1 can also markedly attenuate the neuronal lesion in both hippocampus and somatosensory cortex in the brain of LPS mice. In addition, Rb1 treatment also significantly inhibits the LPS-induced neuroinflammation in the brain, indicated by reduced reactive microglia and decreased IL-1 beta production. Both immunostaining and western blot results suggest that Rb1 can further enhance the LPS-induced GLT-1 expression and alleviate LPS-induced GS reduction in the brain. Our findings show that Rb1 has a protective effect on LPS-induced neuronal damage in the CA1 of the hippocampus and in the somatosensory area of the cerebral cortex in mice, which is likely to be the basis for its improvement of locomotor and motor coordination. Rb1 regulating the function of astrocytes and microglia through GLT-1 and GS in astrocytes may be involved in its neuroprotective effects.