To investigate the role of hesperitin in regulating inflammatory response in early brain injury after subarachnoid hemorrhage (SAH).

A total of 96 adult male SD rats were divided into sham-operated group, SAH group, solvent group and intervention group (n=24) by random number table method. The SAH rat models in the latter three groups were prepared by carotid artery puncture method; the rats in the intervention group were given oral administration of hesperidin solution, which was dissolved in 5% dimethyl sulfolide (DMSO), with a concentration of 1 mg/100 μL and a dosage of 40 mg/kg within 30 min after operation; rats in the solvent group were given oral administration of an equal volume of 5% DMSO solution. Modified Garcia behavioral scale was used to evaluate the neurobehavior of rats, and the wet/dry weight method was used to measure the water content in the brain tissues of the left and right hemispheres of the rats 24 h after SAH. Immunofluorescence staining was used to detect the microglia activation, Fluoro-dyed Jade C staining was used to assess the brain neuron degeneration, enzyme-linked immunosorbent assay (ELISA) was employed to detect the inflammatory factors interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) content in the brain tissues, and Western blotting was used to detect the nuclear factor-κB (NF-κB) and phosphorylated (p)-NF-κB protein expressions.

As compared with the solvent group, intervention group had significantly increased improved modified Garcia behavioral scale scores(10.08±1.73 vs. 13.83±1.70), and significantly decreased water content of brain tissues in the left and right hemispheres ([81.44±1.05]% vs. ([79.14±0.82]%; [80.55±1.55]% vs. [78.79±1.02]%), significantly smaller number of CD68⁺ and Iba1⁺ microglias (30.17±1.04 vs. 10.67±0.75; 29.33±1.16 vs. 12.00±0.41), significantly smaller number of degenerate neurons (53.21±0.94 vs. 31.33±0.28), significantly reduced levels of inflammatory cytokines IL-1β, IL-6 and TNF-α ([429.88±106.32] pg/mL vs. [221.50±48.80] pg/mL; [1015.50±221.80] pg/mL vs. [448.11±93.40] pg/mL; [1021.75±149.17] pg/mL vs. [595.71±190.81] pg/mL), and significantly lower p-NF-κB/NF-κB ratio (1.13±0.07 vs. 0.71±0.02, P<0.05).

Hesperitin may reduce the inflammatory response mediated by microglia after subarachnoid hemorrhage by inhibiting NF-κB pathway, thereby improving the neurological dysfunction of rats.

Hesperitin; Subarachnoid hemorrhage; Early brain injury; Inflammatory response