Anti-inflammation Research Of Terpenoids And Their Derivatives In Scrophularia Dentata And Eriobotrya Japonica

OBJECTIVE:Inflammation is a series of physiological reactions caused by persistent infection or dysregulation of immune responses in healthy tissues.It is involved in the pathological processes of many diseases.Natural plants,especially traditional Chinese medicines,play an important role in the clinical treatment of inflammation-related diseases.It is important to clarify the anti-inflammatory active ingredients in TCM.Previous studies have found that medicinal plants have abundant terpenoids,which are important material basis for anti-inflammatory activities of these plants.It is also an important source of anti-inflammatory new drug development derived from Chinese herbal medicine.This article is based on the importance of the anti-inflammatory activity of terpenoids in traditional Chinese medicine.Screening the anti-inflammatory activity of terpenoids accumulated in the previous study by our group（including the iridoid glycosides and their derivatives,diterpenoids derived from Scrophularia dentata with triterpenoids derived from loquat leaves）.In order to explore their anti-inflammatory activity and structure-activity relationship and preliminary mechanism of action.METHODS:LPS stimulation of THP-1 cell inflammation model was used to study the anti-inflammatory activity of iridoid glycosides and their derivatives and diterpenoids derived from Scrophularia dentata as follows:One hour after sample pretreatment,LPS stimulated THP-1 cells to detect inhibition of IL-1βm RNA expression for 4 or 6hours.The expression of IL-1βm RNA was detected by LPS stimulation at different time.The expression of inflammatory factors IL-6,TNF-αand IL-8 was detected by ELISA.The effect of the compound on the activity of NF-κB was examined by a reporter gene method.The Western Blotting method was used to find anti-inflammatory protein targets for compounds.The effect of compounds on NF-κB activity was examined by reporter gene assay in 293T cells.The effects of triterpenoids derived from loquat leaves on lung inflammation are as follows:Establish a model of acute lung injury in mice with tracheal instillation of LPS.The in vivo anti-inflammatory effects of the leaves extract were verified by pathological damage of lung tissue and various indicators in BALF.The differences in the effects of extracts with different content triterpenoids on BALF in mice were compared.RESULTS:From 60 terpenoids in Scrophularia dentata,we screened ZH121117,ZH121120,ZH121123 and ZH12167 four compounds with good anti-inflammatory activity.ZH121117,ZH12112 and ZH121123 significantly inhibited the production of IL-6,with IC₅₀of 16.98μM,8.118μM,2.168μM,respectively.These three compounds also have strong inhibitory activity against TNF-α,IC₅₀is 6.892μM,8.9μM,38.13μM,respectively.The inhibition rate of IL-1βm RNA expression by best-acting compound ZH12167 was as high as 93.0%.The expression of IL-1βand IL-6 was inhibited in a dose-dependent manner with IC₅₀of 21.13μM and 10.45μM,respectively.A mechanism study of ZH12167 revealed that it can inhibit the phosphorylation of JNK and STAT3 phosphorylation in THP-1 cells.In the study of the constituents of Triterpenoids,it was found that the extract of Triterpenoids can effectively inhibit the lung inflammation of ALI mice,reduce mononuclear inflammatory cell infiltration and alveolar septal thickening,and the effect of the mixture is better than that of single triterpenic acid,such as ursolic acid.Conclusion:Through the study of this paper,we have screened three sterol derivatives with anti-inflammatory effects.The structure-activity relationship analysis found that catalposide and Picroside II introduced a non-polar group through the 6-position phenolic hydroxyl increased their anti-inflammatory activity.The diterpene compound ZH12167 is anti-inflammatory active ingredient in Scrophularia dentata.Them inhibit inflammation through the JNK/STAT3 pathway.The total triterpenoids in the loquat leaves can effectively inhibit the lung inflammation in ALI mice.Increasing the content of triterpenoids in loquat leaves is beneficial to its anti-inflammatory effect.Our result provides a new idea for clinical treatment of acute lung injury patients.Screening for the activity of terpenoids in Scrophularia dentata and Loquat leaves is useful for the development of anti-inflammatory terpenes.These compounds can be used as lead structure or to screen out new drugs that are biologically active and have little toxic side effects.