Essential oil of Acorus tatarinowii Schott inhibits neuroinflammation by suppressing NLRP3 inflammasome activation in 3 × Tg-AD transgenic mice

Shi chang pu (Acorus tatarinowii Schott) is a herbal used in the treatment of Alzheimer's disease (AD) in China. The essential oil of Shi chang pu (SCP-oil) is the main active component. However, its effects on the neuroinflammation of AD have not been well studied.Neuroinflammation mediated by the NLRP3 inflammasome plays a crucial role in AD. This study was designed to evaluate the effect of SCP-oil on cognitive impairment of AppSwe/PSEN1M146V/MAPTP301L triple transgenic (3 × Tg-AD) mice model and investigate the mechanism underlying its anti-inflammation effects.Thirty-two 3 × Tg-AD mice at 12 months and 8 wild-type B6 mice were used for this experiment. The 3 × Tg-AD mice were administered with SCP-oil or donepezil hydrochloride for 8 weeks. Morris water maze test and step-down test were used to evaluate the cognitive ability of mice. The pathological changes, neuroinflammation, and the NLRP3 inflammasome related-protein of AD mice were detected by histomorphological examination, TUNEL staining, immunofluorescence, immunohistochemistry, qRT-PCR, Elisa, and western blot assays.SCP-oil treatment attenuated cognitive dysfunction of 3 × Tg-AD mice. Moreover, SCP-oil also ameliorated characteristics pathological of AD, such as pathological changes damage, deposition of Aβ, phosphorylation of Tau, and neuronal loss. Additionally, SCP-oil treatment alleviated the neuroinflammation and inhibited phosphorylation of IKKβ, NF-κB, and NLRP3 inflammasome related-protein NLRP3, ASC, Caspase-1, cleaved-Caspase-1, and GSDMD-N in the hippocampus of 3 × Tg-AD mice.Overall, SCP-oil contributed to neuroprotection in 3 × Tg-AD mice by reduced activation of NLRP3 inflammasome by inhibiting the NF-κB signaling pathway.