Chemical constituents from the rhizome of Acorus tatarinowii Schott and their anti-inflammatory activities in LPS induced PC12 cells

Abstract

IntroductionAcorus tatarinowii Schott is a traditional Chinese medicine that aromatizes dampness, opens the body and pacifies the mind, and is used medicinally as the dried rhizome of Acorus tatarinowii, family Tenaxaceae. Research has confirmed that it has a strong anti-inflammatory activity, however, its mechanism of anti-inflammatory is still unclear, and we continue to investigate its chemical composition and anti-inflammatory mechanism. MethodsThe separation and purification of the EtOH extract was carried out by preparative thin layer chromatography and column chromatography. The structures of the isolated compounds were identified by NMR spectroscopy and comparing their spectral data with those previously reported in literature. CCK-8 method was used to evaluate the anti-inflammatory activity of all compounds. The MDA, NO, SOD, IL-10, IL-1β, IL-6 and TNF-α levels were analyzed using ELISA kits. TNF-α and Beclin-1 expression were examined by western blot and immunofluorescence. ResultsTen compounds, named cinnamic acid(1), sinapic acid(2), isoferulic acid(3), α-asarone(4), ferulic acid(5), arbutin (6), caffeic acid (7), 3-(3-hydroxyl phenyl)propanol(8), ethyl caffeate(9) and β-asarone(10) were isolated from the rhizome of Acorus tatarinowii Schott. Their structures were elucidated on the basis of extensive spectroscopic analyses, as well as by comparison with literature data. The anti-inflammatory effects of the all compounds were evaluated in lipopolysaccharide(LPS)-induced PC12 cell models in our study. The results of activity test showed that compounds 3 and 6 had good inhibitory effects on 5 μg·mL−1 LPS-induced PC12 cells. The IC50 of compounds 3 and 6 against PC12 cells were 27.41 ± 0.09 µmol·L−1 and 30.19 ± 0.10 µmol·L−1, respectively. Moreover, compounds 3 and 6 showed a significant protective effect on inflammation by increasing the IL-10 and SOD levels, and reducing the TNF-α, IL-6, IL-1β, MDA and NO levels. The most important point is that their anti-inflammatory effect is related to the autophagy factor Beclin-1. ConclusionThese findings imply that compounds 3 and 6 exerts anti-inflammatory effects by regulating TNF-α/Beclin-1 pathway, which provide a new basis for the anti-inflammatory activity of Acorus tatarinowii Schott.