Baocai Li

Medicinal compounds with antiepileptic/anticonvulsant activities

Epilepsy is a serious neural disease that affects around 50 million people all over the world. Although for the majority patients with epilepsy, seizures are well controlled by currently available antiepileptic drugs (AEDs), there are still >30% of patients suffered from medically refractory epilepsy and approximately 30–40% of all epileptic patients affected by numerous side effects and seizure resistance to the current AEDs. Therefore, many researchers try to develop novel approaches to treat epilepsy, for example, to discover new antiepileptic constituents from herbal medicines. Although there are already several reviews on phytotherapy in epilepsy, most of them placed emphasis on the plant crude extracts or their isolated fractions, not pure active compounds derived from herbal medicines. This article aims to review components in herbal medicines that have shown antiepileptic or anticonvulsant properties.

Cytotoxicity of pregnane glycosides of Cynanchum otophyllum.

Fourteen new pregnane glycosides, including nine caudatin glycosides (1-9), three qinyangshengenin glycosides (10-12), one kidjoranin glycosides (13) and one gagaminin glycosides (14), along with twelve known analogs (15-26) were isolated from roots of Cynanchum otophyllum Schneid. Their structures were deduced by detailed analysis of 1D and 2D NMR spectra, as well as HRESIMS. In this study, all pregnane glycosides obtained (1-26) were evaluated for their cytotoxic activities using three cancer cell lines (HepG2, Hela, U251). As results, except 6 and 10, other twenty-four pregnane glycosides showed cytotoxicities at different degrees against three cell lines.

Antiepileptic C21 steroids from the roots of Cynanchum otophyllum

In order to discover more natural products possessing potentially antiepileptic activities, three C21 steroids, including a new one, characterized as caudatin-3-O-β-d-cymaropyranosyl-(1 → 4)-β-d-cymaropyranosyl-(1 → 4)-β-d-cymaropyranoside (1), and two known analogs, otophylloside B (2) and caudatin-3-O-β-d-oleandropyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-cymaropyranosyl-(1 → 4)-β-d-cymaropyranoside (3), were isolated from the chloroform extract of the roots of Cynanchum otophyllum and evaluated for their antiepileptic activities by pentylenetrazole (PTZ)-induced zebrafish larval locomotor assay. The results showed that all of them had marked activities of suppressing PTZ-induced seizure behaviors in larval zebrafish at the dose of 10 μg/ml.

C21 steroidal glycosides from the roots of Cynanchum saccatum.

Eight new C21 steroidal glycosides, named cynsaccatols A-H (1-8), along with two known analogs (9-10), were isolated from the roots of Cynanchum saccatum. Their structures were determined on the basis of detailed spectroscopic analysis, as well as HRESIMS. All compounds (1-10) were tested for their cytotoxicity in vitro using three human cancer cell lines (HepG2, Hela and U251), and compounds 1, 4, 5, 9, 10 showed weak inhibitory activities against different cell lines, respectively.

Optimization of Micellar Electrokinetic Chromatography Method for the Simultaneous Determination of Seven Hydrophilic and Four Lipophilic Bioactive Components in Three Salvia Species

A micellar electrokinetic chromatography (MEKC) method was developed for the simultaneous determination of seven hydrophilic phenolic acids and four lipophilic tanshinones in three Salvia species. In normal MEKC mode using SDS as surfactant, the investigated 11 compounds could not be well separated. Therefore, several buffer modifiers including β-cyclodextrins (β-CD), ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) and organic solvents have been added to the buffer solution to improve the separation selectivity. Under the optimized conditions (BGE, 15 mM sodium tetraborate with 10 mM SDS, 5 mM β-CD, 10 mM [bmim]BF4 and 15% ACN (v/v) as additives; buffer pH, 9.8; voltage, 20 kV; temperature, 25 °C), the 11 investigated analytes could achieve baseline separation in 34 min. The proposed MEKC was additionally validated by evaluating the linearity (R2 ≥ 0.9965), LODs (0.27–1.39 μg·mL−1), and recovery (94.26%–105.17%), demonstrating this method was reproducible, accurate and reliable. Moreover, the contents of the 11 compounds in three Salvia species, including S. miltiorrhiza, S. przewalskii and S. castanea were analyzed. The result showed that the established MEKC method was simple and practical for the simultaneous determination of the hydrophilic and lipophilic bioactive components in Salvia species, which could be used to effectively evaluate the quality of these valued medicinal plants.

Determination of Radical Scavengers from Salvia Plants by HPLC

Salvia yunnanensis, S.przewalskii var. przewalskii, and S.castanea are three species of the Salvia plants in China. In order to discover the biologically active compounds, their free radical scavengers were screened based on an off-line and on-line HPLC-2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) assay coupled with a diode array detector and tandem mass spectrometry. In the off-line assay, the roots and rhizomes (the underground part) of S. przewalskii displayed the strongest antioxidant properties, while the leaves and stems (the aerial part) of S. yunnanensis displayed the weakest activities. In the on-line assay, all of the underground parts and the aerial parts of the three plants were tested by HPLC and the underground parts of S. yunnanensis and S. przewalskii, as well as the aerial part of S.przewalskii were analyzed by LC-ESI MSn. Among the seventeen antioxidants screened, tanshinone I, salvianolic acid B, and tanshinone IIA were confirmed by authentic standards; and another five compounds were tentatively identified based on the tandem mass spectroscopy. 7,20-Epoxyroyleanone, tanshinone I, and 1-oxoferruginol were reported as antioxidants for the first time. Using the on-line method, the order of antioxidant activities was found to be salvianolic acid B > vitamin C > tanshinone I > tanshinone IIA. Furthermore, it was observed that the regression curve between negative peak areas and sample concentrations could be inflected at high concentrations.

Protective Effects of Otophylloside N on Pentylenetetrazol-Induced Neuronal Injury In vitro and In vivo

Approximately 30% of epileptic patients worldwide are medically unable to control their seizures. In addition, repeated epileptic seizures generally lead to neural damage. Pentylenetetrazol (PTZ) is a clinical circulatory and respiratory stimulant that is experimentally used to mimic epileptic convulsion in epilepsy research. Here, we systematically explore the neuroprotective effects of a pure compound isolated from Cynanchum otophyllum Schneid (Qingyangshen), Otophylloside N (OtoN), against PTZ-induced neuronal injury. We used three models: in vitro primary cortical neurons, in vivo mice, and in vivo zebrafish. Our results revealed that OtoN treatment may attenuate PTZ-induced morphology changes, cell death, LDH efflux in embryonic neuronal cells of C57BL/6J mice, and convulsive behavior in zebrafish. Additionally, our Western blot and RT-PCR results demonstrated that OtoN may attenuate PTZ-induced apoptosis and neuronal activation in neuronal cells, mice, and zebrafish. OtoN may reduce PTZ-induced cleavage of poly ADP-ribose polymerase and upregulation of the Bax/Bcl-2 ratio and decrease the expression level of c-Fos. This study is the first investigation of the neuroprotective effects of OtoN, which might be developed as a novel antiepileptic drug.

Separation and Determination of Four Tanshinones in Danshen and Related Medicinal Plants by Micellar Electrokinetic Chromatography Using Ionic Liquids as Modifier

A simple and fast micellar electrokinetic chromatography (MEKC) method using ionic liquids as modifier was established for simultaneous determination of four hydrophobic tanshinones, including dihydrotanshinone I ( 1: ), cryptotanshinone ( 2: ), tanshinone I ( 3: ) and tanshinone IIA ( 4: ), in Danshen and related medicinal plants. In normal MEKC using sodium dodecyl sulfate (SDS) as surfactant and organic solvents as additives, the four tanshinones, especially cryptotanshinone and tanshinone I, could not be well separated. Fortunately, further addition of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) resulted in a baseline separation of these four analytes. After an optimization study, 10 mM borax-10 mM SDS-10 mM [bmim]BF4 containing 15% acetonitrile (v/v) at pH 9.6 was adopted as the running buffer to complete the separation within 16 min at the voltage of 25 kV, temperature of 25°C and detection wavelength of 254 nm. The relative standard deviations of migration time and peak area were in the range of 0.62-2.21 and 1.33-3.90%, respectively, indicating the good repeatability of the developed method. This method was extensively validated by evaluating the linearity (R(2) ≥ 0.9992), limits of detection (0.75-1.11 μg mL(-1)), limits of quantification (2.26-3.32 μg mL(-1)) and recovery (96.11-103.74%). Under the optimum conditions, samples of Danshen and related medicinal plants were well analyzed with high separation efficiency.

A New Method of Testing and Evaluating the Quality of Refined Montan Wax: Digital Color and GC Fingerprint

To establish a new method of testing and evaluating the quality of refined montan wax (RMW), digital color and GC fingerprint technology were introduced and applied. CIE Lab color mode was used to digitize the exterior colors of RMW, and the score obtained through a fitting function was also used to reflect its quality. It is shown that they were in complete accord with the human visual perception trend. The GC fingerprint was used to characterize the internal chemical information of RMW, and the composition of its internal features was reflected through the relative retention time (RRT) and relative peak area (RPA) values. It is shown that there was a high degree of similarity between the fingerprints, while certain differences also existed. This can be used to implement effective application of RMW to aspects such as quality control, adulteration identification, and origin attributions.

Neuroprotective effects of extracts from the radix Curcuma aromatic on H2O2-induced damage in PC12 cells.

Aim & Objectives: Curcuminoids are characteristic constituents in Curcuma, displaying obviously neuroprotective activities against oxidative stress. As one of the Traditional Chinese Medicines from Curcuma, the radix of Curcuma aromatica is also rich in those chemicals, but its neuroprotective activity and mechanism remain unknown. The aim of the current study is to evaluate the neuroprotective effects of extracts from the radix of C. aromatica (ECAs) on H2O2-damaged PC12 cells. MATERIAL AND METHODS The model of oxidative stress damage was established by treatment of 400 µM H2O2 on PC12 to induce cell damage. After the treatment of ECWs for 24 h, the cell viability, LDH, SOD, CAT and GSH were measured to evaluate the neuroprotection of ECAs on that model. The potential action mechanism was studied by measurement of level of ROS, cell apoptosis rate, mitochondrial membrane potential (MMP), morphologic change, the intracellular Ca2+ content (F340/F380) and the expressions of Bcl-2, Bax and Caspase-3. Additionally, the constituents from tested extracts were analyzed by HPLC-DAD-Q-TOF-MS method. RESULTS Compared with a positive control, Vitamin E, 10 µg/ml of 95% EtOH extract (HCECA) and 75% EtOH extract (MCECA) can markedly increase the rate of cell survival and enhance the antioxidant enzyme activities of SOD, CAT, increase the levels of GSH, decrease LDH release and the level of ROS, attenuate the intracellular Ca2+ overloading, reduce the cell apoptotic rate and stabilize MMP, down-regulate Bcl-2 expression, up-regulate Bax and caspase-3 expression, and improve the change of cell morphology. The chemical analysis showed that diarylheptanoids and sesquiterpenoids are the major chemicals in tested extracts and the former were richer in HCECA and MCECA than others. CONCLUSIONS These findings indicated that the effects of HCECA and MCECA on inhibiting the cells damage induced by H2O2 in PC12 are better than other extracts from the radix of C. aromatica, and the active constituents with neuroprotective effects consisting in those two active extracts are diarylheptanoids.