ผลของสารสกัดจากสีเสียดเหนือต่อหลอดเลือดดำที่แยกจากสายสะดือมนุษย์ / พินธัส ปราบโรค = Effect of the extract from acacia catechu on isolated human umbilical vein / Pintus Parbrok
Thin layer chromatogram (TLC fingerprint) characterizing the pattern of constituents in the ethanol extract of Acacia cathechu (AC) was performed to assure the identity and quality of the extract studied. To assess the vasodilating effect and mode of action of AC extract, isolated human umbilical vein (HUV) obtained from full term normal newborn and healthy mother was used. The strips of isolated HUV with or without endothelium was induced to contract with 0.5-20 mM KCl or 10[superscript -5]M histamine with or without the presence of AC. The results showed that AC in a dose-dependent manner inhibited the KCl induced contraction of isolated HUV with intact endothelial cells. At the concentration of 0.3 mg/ml, AC showed maximum inhibitory response. On the contrary AC could not significantly inhibit the histamine induced contraction of isolated HUV with intact endothelial cells. Nitric oxide synthase (NOS) inhibitor, cyclo-oxygenase (COX) inhibitor, bradykinin receptor antagonist and potassium channel blocking agent were used in elucidating the role of mediators in producing vasodilating effect of ACE. The results showed inhibitory effect of ACE on KCl-induced contraction of the endothelium-intact segment of isolated HUV. The responses were mediated by at least three different pathways involving release of endothelium-derived relaxing factors (EDRF). One of the alternative pathway involved the production of prostacyclin. The second pathway involved production of nitric oxide. The last pathway possibly involved endothelium-derived hyperpolarizing factor (EDHF). Whereas bradykinin was unlikely to involve in mediating the vasodilatory effect of AC.
