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Two compounds were isolated from 95% ethanol extract of the gum resin of Boswellia carterii by silica gel column chromatography (CC) and high-performance liquid chromatography (HPLC). Their structures were identified with IR, UV, NMR and HR-ESI-MS spectroscopic data as 7α-hydroxy-3,11-dioxo- tirucalla-8,24-dien-21-oic acid (1) and 21β-hydroxy-3-acetyl-11-keto-β-boswellic acid (2). In addition, their absolute configurations were also identified by ECD calculations. Among them, compound 1 is a new compound and the absolute configuration of compound 2 is confirmed by ECD calculation for the first time.
RESUMO
Objective To explore the relationship between plasticity ofhippocampus neuronal morphology and pathogenesis of epilepsy by observing the changes of mossy fiber sprouting (MFS) and P-glycoprotein (P-gp) expression in the hippoeampus of rat models of amygdala-kindling epilepsy.Methods Ninety male Wistar rats were randomly divided into epilepsy model group (n=40),drug treatment group (n=40) and sham-operated group (n=10).Models of chronic epilepsy were established by stimulating the amygdale; rats in the drug treatment group were perfused antiepileptic drug levetiracetam into stomach [100 mg/(kg·d),twice daily].At different observation time points (1,2,4 and 8 weeks after the treatment),Timm staining was employed to observe the changes of MFS; immunohistochemical method was used to detect the dynamic changes of P-gp.Results (1) After the success of model making,abnormal MFS levels in the hippocampal CA3 transparent layer were noted; lowest MFS scores were noted in S1 subgroup,which showed no significant difference as compared with those in sham-operated group (P＞0.05); the MFS scores in S2,S4 and S8 subgroups increased gradually with a peak level at 8 weeks after inducement,which showed significant difference as compared with those in sham-operated group (P＜0.05).No significant differences on MFS grading scores were noted in the drug treatment group between each two time points (P＞0.05).(2) The P-gp expression in the epilepsy model group showed significant difference at different time points (P＜0.05); highest expression level was noted at one week after the surgery,and returned to normal at four weeks.However,the P-gp expression showed no significant difference in the drug treatment group between each two time points (P＞0.05),except for 1 week after treatment.Conclusion MFS is the important mechanism of chronic epilepsy,and P-gp is the product of epilepsy,which is the main reason of epilepsy drug resistance.