1.THE EXTRACT FROM HIPPOCAMPUS TRIMACULATUS (EHT): ITS EFFECT OF ANTITHROMBOSIS IN RATS AND INGREDIENTS ANALYSIS
Chinese Journal of Marine Drugs 1994;0(01):-
The experiments show that extract from Hippocampus trimaculatus Leach (EHT) can inhibit experimental common carotid artery and cerebral thrombosis in rats, and its effective ingredients are unsaturated fatty acids.
3.Protective effects of xanthones on ischemia/reperfusion injury exaggerated by activation of Na~+/H~+ exchange system
Quanhua HE ; Shibo XU ; Qinying DENG ;
Chinese Pharmacological Bulletin 1986;0(06):-
AIM To study the protective effects of xanthones: 1,8 dihydroxy 3,5 dimethoxyxanthone(Xan Ⅰ); 1 hydroxy 3,5 dimethoxyxanthone(Xan Ⅱ);1 hydroxy 3,7,8 trithoxyxanthone(Xan Ⅲ) from Canscora lucidissima on ischemia reperfusion injury exaggerated by activation of Na +/H + exchange system. METHODS The perfused isovolumic contracting rat hearts were subjected to 20 mmol?L -1 NH 4Cl loading for promoting the Na +/H + exchange in the model of ischemic reperfusion injury and the protective effects being pretreated with Xans on the injury were examed. RESULTS Xans could relieve the effects: activation of Na +/H + exchange inhibited the recovery of ventricular function significantly, and exacerbated the myocardial injury as evidenced by increase in release of LDH, associated with the accumulation of intracellular Na +,Ca 2+ and the loss of intracelullar K +. CONCLUSION Xans has the protective effects on ischemic reperfusion injury exacerbated by activation of Na +/H + exchange system.
4.UV-spectrophotometric screening of 5α-reductase inhibitors for benign prostatic hyperplasia treatment
Donghui XU ; Zhaohe WANG ; Lihong WANG ; Xueting MEI ; Shibo XU
Chinese Journal of Pathophysiology 2007;23(4):828-832
AIM: Tranditional methods of screening drugs for benign prostatic hyperplasia(BPH)requires senile male animals such as dogs or rats.It consumes a long time to get the results. Over-expression of type Ⅱ5α-reductase in prastate induces BPH.A fast and efficient screening model of type Ⅱ5α-reductase inhibitors for BPH was set up in this paper.METHODS:Microsomes were extracted from male Sprague-Dawley rat livers by gradient centrifugation.Type Ⅱ5α-reductase enzyme-catalyzed reaction was assayed by UV-spectrophotometry using testosterone as a substrate and NADPH as hydrogen donor.The change of enzymatic activity was recorded with a NADPH wavelength of 340 nm by subtracted descending velocity of the control(without 5α-reductase).Effects at different conditions(temperatures,pH,enzyme and testosterone concentrations)on 5α-reductase were assayed.RESULTS:The suitable condition of type Ⅱ5α-reductase reaction Was defined as concentration of 109.05 mg protein/L enzyme(pH 6.00)with 2 μmol/L testosterone at 37℃.Michaelis'constant of type Ⅱ5α-reductase was 0.6μmol/L.Finasteride,a new drug for BPH,significantly inhibited activity of type Ⅱ 5α-reductase.IC50 of finasteride Was 64.1 nmol/L.As solvent of drugs,concentration of ethanol below 1.1% did not inhibite enzymatic activity(P>0.05).Concentration of ethanol above 1.6%could obviouslv suppress enzymatic activity(P<0.01).Daytime difference within five days had no significant difference(P>0.05).CONCLUSION:A handy and fast screening method for type Ⅱ 5α-reductase inhibitors has been set up using UV-spectrophotometry.It may be used to screening drugs for BPH treatment.
5.Study on antibacterial effects of crocodilian plasma in vitro
Donghui XU ; Haiping MA ; Xueting MEI ; Shibo XU
Chinese Journal of Marine Drugs 1994;0(01):-
Objective To investigate the effects of crocodilian plasma on 12 bacteria(including G+ bacteria and G-bacteria) lines in vitro.Methods The bacteria CFUs on nutrient broth agar plates were determined after bacteria and crocodilian plasma incubated together for 1h.Then effects of the samples on the survival rate of various concentrations of bacteria were calculated.To evaluate the antibacterial spectrum of crocodilian plasma,the zones of bacterial inhibition were measured through agar disk method.Results and Conclusion Crocodilian plasma had superior bactericidal effects on Escherichia coli M421C1,O111B4,E240-3 LT,Micrococcus catarrhalis,Shiga's bacillus,Pseudomonas aeruginosa and Diplococcus pneumoniae.The results indicated why wound of crocodilian by tearing each other was not susceptible,and crocodilian plasma could be developed a natural antibacterials.
6.UV-spectrophotometric screening of 5?-reductase inhibitors for benign prostatic hyperplasia treatment
Donghui XU ; Zhaohe WANG ; Lihong WANG ; Xueting MEI ; Shibo XU
Chinese Journal of Pathophysiology 1986;0(04):-
0.05).Concentration of ethanol above 1.6 % could obviously suppress enzymatic activity(P0.05).CONCLUSION: A handy and fast screening method for type Ⅱ5?-reductase inhibitors has been set up using UV-spectrophotometry.It may be used to screening drugs for BPH treatment.
10.ANTITUMOR EFFECT OF SOME COMPOUNDS WITH UNSATURATED LACTONE FROM MARINE NATURAL PRODUCTS
Shibo XU ; Hui XIANG ; Jingyu SU ; Yongli ZHONG ;
Chinese Journal of Marine Drugs 1994;0(01):-
The compounds (8R23, 9R221 , 9R6222, 10R221 , H1105) extracted from the soft coral, with unsaturated lactone, showed antitumor effect on EAT, IC50 was 18. 6,85. 8,67. 8,3d. 9, 3.05umol. L-1, respectively; IC50 on S180 was 10. 7,44. 4,30. 9,9. 95,2. 4umol. L-1, respectively. 8R23, 10R221 obviously increased the level of cAMP in the EAT cell. 8R23, 10R221 , III 105 also inhibited DNA synthesis of the EAT cell.These results indicated that these compounds might have antitumor effect, but the mechanism was unknown.