No abstract

Licochalcone A, 3-a,a-dimethylallyl-4,4'-dihydroxy-6-methoxychalcone, from the root of Glycyrrhiza inflata Beta (Leguminosae) (Xin-jiang liquorice) showed anti-inflammatory action towards mouse ear edema induced by arachidonic acid (AA) and 12-O-tetradecanoylphorbol 13-acetate (TPA) by topical application. Anti-tumour promoting action of licochalcone A was also observed in vivo for mouse skin papilloma initiated by dimethylbenz[a]anthracene (DMBA) and promoted by TPA. It inhibited in vitro 32Pi-incorporation to phospholipids in HeLa cells promoted by TPA. A competitive interaction of licochalcone A with the TPA-receptors in the cell membrane has been suggested.

In this study, approaches to improve chiral resolutions in simultaneous enantioseparation of beta-agonists by CE via a CD inclusion complexation modified with ionic liquids (ILs) are described. Different types of ILs, including tetraalkylammonium-based ILs, alkylimidazolium-based ILs and alkylpyridinium-based ILs, were examined and compared for controlling the EOF in order to improve resolutions of beta-agonists enantiomers. In this regard, tetraalkylammonium-based ILs were more effective because they could be used at much higher concentrations than other types of ILs. N-octylpyridinium hexafluorophosphate gave poor resolutions of beta-agonists enantiomers. In addition, when different ILs were mixed to use, they would present particular properties of their own. Moreover, the presence of ILs was essential in the chiral separations of (+/-) salbutamol, (+/-) cimaterol and (+/-) formoterol, which were reportedly not enantioseparated by using the buffer electrolytes containing only beta-CD as a chiral selector.

Paeoniflorin (PF) is an active ingredient of Radix Paeoniae, which is known to exert neuroprotective effects. However, the mechanims behind the neuroprotective effects of PF are not yet fully understood. The apoptosis of neurons plays an important role in the cerebral ischemia-induced cascade response. This study aimed to investigate neuroprotective effects of PF against glutamate-induced PC12 cellular cytotoxicity and to determine whether these effects are mediated via the inhibition of apoptosis in vitro and the activity of mitochondrial apoptosis-associated proteins in PC12 cells. Exposure of the PC12 cells to glutamate induced cell morphological changes, significantly decreased cell viability and induced apoptosis, with similar results being observed from the Hoechst 33342 staining and Annexin V/PI staining experiments. Glutamate also increased the lactate dehydrogenase release by the PC12 cells. However, treatment with PF prevented these effects. Furthermore, PF inhibited Bax and Bad expression and increased Bcl-2 and Bcl-xL expression; it also decreased the levels of downstream protein (caspase-3 and caspase-9). Collectively, our results indicate that PF protects PC12 cells against glutamate-induced neurotoxicity possibly through the inhibition of the expression of mitochondrial apoptosis-associated proteins.

A capillary electrophoresis method using carboxymethyl-beta-cyclodextrin as the chiral selector and mixture of methanol and ethanol as the organic additive was successfully developed for the simultaneous enantioseparation and determination of six beta-blockers, namely, carteolol, atenolol, sotalol, metoprolol, esmolol and propranolol in this paper. The most suitable running buffer for enantioseparation was found to be the solution of 20 mmol/L NaH(2)PO(4)-Na(2)HOP(4) (pH 5.5) containing 1.5% w/v carboxymethyl-beta-cyclodextrin, 5% v/v methanol and 5% v/v ethanol. Furthermore, field-amplified sample injection as an on-line sample stacking method was developed in order to increase the detection sensitivity. The experimental conditions for both simultaneous enantioseparation and the field-amplified sample injection method had been investigated in detail. Under the optimum conditions, the detection limits (defined as S/N=3) of this method were 0.01, 0.05, 0.05, 0.05, 0.05 and 0.5 microg /mL for (+/-) carteolol, (+/-) atenolol, (+/-) sotalol, (+/-) metoprolol, (+/-) esmolol and (+/-) propranolol, respectively, which were much lower than those of the conventional methods. The enhancement factors were greatly improved by 25-fold for the enantiomers of the beta-blockers except five-fold for (+/-) propranolol. Eventually, the proposed method has been applied for the analysis of human serum sample.