Chemical constituents from stems of Hedyotis hedyotidea and their immunosuppressive activity / 中国中药杂志

Hedyotis hedyotidea has been traditionally used for the treatment of arthritis, cold, cough, gastro-enteritis, headstroke, etc. But few studies have screened the active compounds from extracts of H. hedyotidea. In this study, the structure of the chemical constituents from stems of H. hedyotidea were determined and the immunosuppressive activity of the compounds was evaluated. The compounds were separated and purified with silica gel, gel column chromatographies and preparative HPLC, and their structures were identified by spectral methods such as MS and NMR. Eleven compounds were obtained and identified as(6S,9S) -vomifoliol (1), betulonic acid (2), betulinic acid (3), betulin(4), 3-epi-betulinic acid (5), ursolic acid (6), β-sitosterol (7), stigmast-4-en-3-one (8), 7β-hydroxysitosterol (9), (3β,7β) -7-methoxystigmast-5-en-3-ol (10) and morindacin (11). This is the first report of compounds 1, 2, 4, 8, 9, 10 and 11 from H. hedyotidea. Compounds 1, 2 and 8-11 were firstly isolated from the genus Hedyotis, and compounds 9 and 10 were isolated from the family Rubiaceae for the first time. The immunosuppressive activity of these compounds was tested using the lymphocyte transsormationtest. Compounds 4, 6 and 9 showed significant immunosuppressive activity.

Highly expressed N1-acetylpolyamine oxidase detoxifies polyamine analogue N1-cyclopropylmethyl-N11-ethylnorspermine in human lung cancer cell line A549 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The critical roles of polyamines in cell growth and differentiation have made polyamine metabolic pathway a promising target for antitumor therapy. Recent studies have demonstrated in vitro that some antitumor polyamine analogues could be used as substrates and oxidized by purified recombinant human N(1)-acetylpolyamine oxidase (APAO, an enzyme that catabolizes natural polyamines), indicating a potential role of APAO in determining the sensitivity of cancer cells to specific antitumor analogues. This study evaluated, in vivo, the effect of APAO on cytotoxicity of antitumor polyamine analogue, N(1)-cyclopropylmethyl-N(11)-ethylnorspermine (CPENS) and its mechanism when highly expressed in human lung cancer line A549.</p><p><b>METHODS</b>A clone with high expression of APAO was obtained by transfecting A549 lung cancer cell line with pcDNA3.1/APAO plasmid and selecting with quantitative realtime PCR and APAO activity assay. Cell proliferation was determined by MTT method and apoptosis related events were evaluated by DNA fragmentation, sub-G1/flow cytometric assay, western blotting (for cytochrome C and Bax) and colorimetric assay (for casapse-3 activity).</p><p><b>RESULTS</b>A clone highly expressing APAO was obtained. High expression of APAO in A549 cells inhibited accumulation of CPENS, decreased their sensitivity to the toxicity of CPENS and prevented CPENS induced apoptosis.</p><p><b>CONCLUSION</b>These results indicate a new drug resisting, mechanism in the tumor cells. High expression of APAO can greatly decrease the sensitivity of tumor cells to the specific polyamine analogues by detoxifying those analogues and prevent analogue induced apoptosis.</p>

Establishment of experimental subarachnoid hemorrhage model with endo-cerebrovascular perforation / 中华急诊医学杂志

Objective To establish an experimental subarachnoid hemorrhage(SAH)model with endo- cerebrovascular peroration.Method The right external carotid artery of SD rats were isolated,leaving a stump of approximately 3 to 4 mm.A-3-O monofilament nylon suture was inserted up through the stump of external carotid artery to the internal carotid artery for about 18～19 mm.A small resistance was usually felt,and the suture was then advanced 2 mm further and the suture was immediately withdrawn.Two hours or two days after SAH induction,SAH extension was observed.Two days after SAH induction,the diameter of the basilar artery was measured.Results SAH extends from the ipsilateral artery to the eontralateral artery after SAH induction.The diameters of basilar arteries in SAH animals were smaller than those of control rats,indicating the present of cerebrovascular spasm in SAH animals.Conclusions The endo-cerebrovascular perforation technique for establishing a non-craniotomy SAH model is reliable.