Inhibitory effect of Erigeron breviscapus extract and its flavonoid components on GABA shunt enzymes.

Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter, is metabolized by the successive action of GABA transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH). Inhibition of both enzymes in brain tissues increases the GABA level and may have therapeutic applications in neurological diseases. Erigeron breviscapus ethanol extract was evaluated for their effect on both enzymes. This extract, its ethyl acetate fraction and aqueous fraction, significantly inhibited them at >100 microg/ml. Flavonoid components of E. breviscapus potently and noncompetitively inhibited both enzymes, and the different structure-activity relations were observed with respect to inhibition of both enzymes. Baicalein was the most potent inhibitor for GABA-T with an IC50 value of 12.8+/-1.2 microM, and scutellarein exhibited the best inhibitory effect on SSADH with an IC50 value of 7.20+/-0.9 microM. The present results may imply new pharmacological actions of E. breviscapus and contribute partially to the beneficial effect of the herb and flavonoids on the central nervous system.

[Effect of Panax notoginseng saponins combined isovolumic haemodilution on the retinal microcirculation of patients with retinal vein occlusion].

OBJECTIVE: To study the effect of Panax notoginseng saponins (PNS) or isovolumic haemodilution (IHD) and combination of PNS with IHD on retinal microcirculation of patients with retinal vein occlusion (RVO). METHOD: Seventy three patients with RVO were allocated at random to three groups which were treated with PNS, IHD, or PNS + IHD respectively. The retinal circulation time (RCT) and retinal hemorrhage, edema, leakage of capillary, cystoid macular edema (CME), and nonperfusion area of capillary in retina were observed before and after treatment. RESULT: RCT of patients with RVO was shortened by three treating methods. RCT in the patients who treated by PNS + IHD was the shortest, especially in the patients with nonischemic RVO and branch retinal vein occlusion(BRVO). The retinal hemorrhage, edema, leakage of capillary, and CME in the patients treated by PNS + IHD disappeared quicker than those treated by PNS or IHD. At the same time, the incidence of nonperfusion area in patients whose course of disease was shorter than fourteen days was decreased. The perfusion of capillaries was increased at the edge of nonperfusion area which existed before the treatment. But the effect for nonperfusion area which existed before the treatment in the type of ischemic RVO was not obvious. CONCLUSION: The treatment of PNS + IHD can both shorten RCT of patients with RVO, and promote absorption of retinal hemorrhage, edema, leakage of capillary, and CME. It is possible that PNS + IHD treatment also has an effect to decrease the forming of nonperfusion area in patients whose course of disease is at early stage.