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Pyrolae herba (PH), a kind of Chinese herb, has been identified to have an anti-inflammatory effect, while the potential for treating cognitive impairment (CI), as well as the underlying mechanisms, is unclear. Currently, the interaction between neuroinflammation and neural function play a critical role in pathophysiology of CI. To elucidate therapeutic effect of PH for CI as well as its underlying mechanisms with LPS-treated mice model. In this study, male C57BL6/J mice received lipopolysaccharide (LPS) injection for 10 days to establish CI model and were administrated with PH for 14 days. We used piracetam as a positive control. Memory and spatial function was tested by Morris water maze (MWM). The level of inflammation-related cytokines (TNF-α, IL-1β, IL-10, IL-6) were determined by enzyme-linked immunosorbent assay (ELISA) in serum and western blot in hippocampus. Immunofluorescence (IF) was used to measure the levels of ionized calcium binding linker molecule 1 (IBA-1), glial fibrillary acidic protein (GFAP), BrdU, Ki67 and doublecortin (DCX) in hippocampus. The mRNA sequencing was used to screen the potential target of PH with therapeutic CI. Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the gene alteration of triggering receptor expressed on myeloid cells 2 (TREM2) in hippocampus. We used western blot to determine protein expressions of TREM2 and its related signaling, as well as synaptic proteins in hippocampus. The results revealed that LPS contributed to CI, and PH or piracetam treatment significantly ameliorated CI in MWM test. LPS contributed to increasing expressions of TNF-α and IL-1β in serum and hippocampus, which both reversed by PH or piracetam. PH or piracetam could inhibit the activation of glial cells including microglia and astrocyte in the hippocampus in LPS-induced CI model. The mRNA sequencing and RT-PCR results showed that LPS significantly increased the gene expression of TREM2, which was reversed by PH. The alteration of TREM2 expression was the most significant among the 10 genes (TREM2, Slc24a2, Ptch2, Gck, Il1rapl1, Cadps2, Btbd11, Secisbp2l, Tenm3 and Prepl) in hippocampus. Protein results showed that LPS upregulated the expressions of TREM2 and its related proteins including DAP12, spleen tyrosine kinase (SYK) phosphorylation and ADAM 10, which were all reversed by PH or piracetam in hippocampus. Furthermore, LPS was capable of reducing the expression of BrdU and DCX co-labeled positive cells in hippocampal dentate gyrus (DG), which was reversed only by PH. Moreover, PH or piracetam treatment significantly increased the expression of Ki67 and DCX co-labeled positive cells in hippocampal DG. The expression of synapsin1 was obviously decreased by LPS and was significantly reversed by PH or piracetam. PH could alleviate CI by suppressing the secretion of pro-inflammatory cytokines and mitigating astrocyte activity by restraining microglia's activation in hippocampus, further facilitating neurogenesis and proliferation, thereby enhancing pre-synaptic protein. This study highlighted on the clinical application of PH, which might promote the use of phytomedicine in CI patients. [Display omitted] • Pyrolae herba has capable of improving the cognitive impairment in LPS-treated mice. • The effects of Pyrolae herba on improving cognitive impairment by reversing Trem2-related signaling in the hippocampus of LPS-treated mice. • Pyrolae herba enhances neurogenesis, proliferation, and pre-synaptic protein in the hippocampus of LPS-treated mice. • This study shed light on the clinical application of Pyrolae herba, which would promote the use of medicinal herbs in cognitive impairment patients. [ABSTRACT FROM AUTHOR]

Acute pharyngitis is an inflammation of the pharyngeal mucous membrane and submucous lymphoid tissues. Unsatisfactory treatment and repeated occurrences might cause chronic pharyngitis and other complications. Syringa oblata L. (S. oblata) is a traditional Chinese medicine that exhibited a significant therapeutic effect on various inflammatory diseases. Its commercial drug Yan Li Xiao (YLX) capsule is used as a cure for the treatment of inflammatory diseases, such as bacillary dysentery, tonsillitis, bronchitis, and acute gastroenteritis. However, studies about S. oblata relieving acute pharyngitis are rare. In this study, high-performance liquid chromatography (HPLC) was used to analyze the chemical profile of S. oblata, and the bioactive phytoconstituents were isolated and identified by nuclear magnetic resonance (NMR) and mass spectrometry. An ammonia-induced acute pharyngitis rat model was established to estimate the protective effect of S. oblata in vivo for the first time. The severity of pharyngitis was observed by appearance index and HE staining. The cytokines expression was performed by ELISA. Crucial proteins expression associated with TLR4/NF-κB/MAPK and NLRP3 inflammasome signaling pathways were analyzed by western blotting and immunohistochemistry. Furthermore, the anti-inflammatory effect of isolated compounds was evaluated by suppressing lipopolysaccharide- (LPS-) induced NO generation and regulating the cytokines levels in RAW 264.7 cells. The results showed that S. oblata exhibited a protective effect in the ammonia-induced acute pharyngitis rat model, and the compounds exert potential anti-inflammatory properties against LPS-activated RAW 254.7 cells. [ABSTRACT FROM AUTHOR]