Curcumin targets vascular endothelial growth factor viaactivating the PI3K/Akt signaling pathway and improves brainhypoxic-ischemic injury in neonatal rats

ABSTRACT

This study aimed to evaluate the effect of curcumin on brain hypoxicischemic(HI) damage in neonatal rats and whether the phosphoinositide 3-kinase(PI3K)/Akt/vascular endothelial growth factor (VEGF) signaling pathway is involved.Brain HI damage models were established in neonatal rats, which received the followingtreatments curcumin by intraperitoneal injection before injury, insulin-likegrowth factor 1 (IGF-1) by subcutaneous injection after injury, and VEGF by intracerebroventricularinjection after injury. This was followed by neurological evaluation,hemodynamic measurements, histopathological assessment, TUNEL assay,flow cytometry, and western blotting to assess the expression of p-PI3K, PI3K, p-Akt,Akt, and VEGF. Compared with rats that underwent sham operation, rats with brainHI damage showed remarkably increased neurological deficits, reduced right bloodflow volume, elevated blood viscosity and haematocrit, and aggravated cell damageand apoptosis; these injuries were significantly improved by curcumin pretreatment.Meanwhile, brain HI damage induced the overexpression of p-PI3K, p-Akt, and VEGF,while curcumin pretreatment inhibited the expression of these proteins. In addition,IGF-1 treatment rescued the curcumin-induced down-regulated expression of p-PI3K, p-Akt, and VEGF, and VEGF overexpression counteracted the inhibitory effectof curcumin on brain HI damage. Overall, pretreatment with curcumin protectedagainst brain HI damage by targeting VEGF via the PI3K/Akt signaling pathway inneonatal rats.