TNF and brain edema: In order to validate the therapeutic effects of mannitol (MA), hypertonic saline (HS), and saline on LPS-induced cerebral edema, the brain water content (BWC) and the concentrations of multiple inflammatory factors including IL-1β, TNF-α, IgG and AQP-4 in different groups were analyzed as shown in Fig. 1 (ANOVA test, BWC: F = 19.634, IgG: F = 19.964, IL-1β: F = 19.096, TNF-α: F = 45.120, AQP-4: F = 48.541).