Pomelo Peel Volatile Oil Alleviates Neuroinflammation on Focal Cerebral Ischemia Reperfusion Injury Rats via Inhibiting TLR4/NF-κB Signaling Pathway

• Published in: Current pharmaceutical biotechnology
• Main Authors: Tian, Xin-Yue, Xie, Lu, Wang, Wen-Yan, Zou, Xin-Sen, Zhao, Gao-Yang, Chen, Meng-Hua
• Format: Journal Article
• Language: English
• Published: Netherlands 06.10.2021
• Subjects: TLR4; NF-κB; stroke; inflammation; cerebral ischemia reperfusion injury; pomelo peel volatile oil
• ISSN: 1873-4316
• DOI: 10.2174/1389201022666201231114403

Restoration of blood flow during ischemic stroke leads to cerebral ischemia reperfusion injury (CIRI) by activating neuroinflammatory cascades. Pomelo peel volatile oil (PPVO) extracted from Citrus maxima (Burm.) from the genus Rutaceae, comprises some anti-inflammatory ingredients, such as limonene and β-myrcene. The present study aimed to investigate the potential effect of PPVO on alleviating CIRI related to the Toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) pathway. Transient middle cerebral artery occlusion/reperfusion (tMCAO/R) rats were performed in 65 rats which were then distributed into five groups (n = 13/group) depending on the intervention they received : normal saline (NS) group, normal glycerin (GL) group, low-dose PPVO (LP, 10mg/kg) group, high-dose PPVO (HP, 30 mg/kg) group, and shamoperated (SH) group. Neurological deficit scores (NDSs) and histological changes were evaluated. Infarct volumes were measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining. The expression of TLR4 and neutrophil infiltration were detected by immunofluorescence (IF) staining. Moreover, the downstream molecules of the TLR4/NF-κB signaling pathway, such as IL-6, IL-1β, TNF-α, p-IκB/IκB, and p-NF-κB p65/NF-κB p65 were analyzed by western blot (WB). The results showed that PPVO (30 mg/kg) significantly decreased infarct volumes, improved neurological deficits and pathologic changes, inhibited TLR4/NF-κB signaling pathway, and suppressed neutrophil infiltration and pro-inflammatory cytokine release. It can be concluded that PPVO may alleviate neuroinflammation and protect against CIRI via inhibiting the TLR4/NF-κB signaling pathway.