EFEK VASODILATASI DAN INHIBISI ANGIOTENSIN CONVERTING ENZYME DARI EKSTRAK ETANOL DAN FRAKSI DAUN BINAHONG (ANREDERA CORDIFOLIA (TEN). V. STEENIS) - Afrillia Nuryanti Garmana; Elin Yulinah Sukandar; Irda Fidrianny (Acta Pharmaceutica Indonesia, 2017)
ABSTRAKEfek antihipertensi binahong pada model hewan hipertensi yang diinduksi dengan adrenalin dan deksametason telah dibuktikan pada penelitian sebelumnya. Pada penelitian ini, dikaji mekanisme kerja lebih lanjut dari efek antihipertensi ekstrak etanol daun binahong dan fraksinya. Pengujian secara ex vivo dilakukan dengan menggunakan aorta kelinci yang diinduksi dengan norepinefrin, metilen biru- norepinefrin, dan kalium klorida. Efek pemberian ekstrak etanol daun binahong (EEDB), fraksi n-heksana (FH), fraksi etil asetat (FE), dan fraksi air (FA) diamati pada kimograf lalu dihitung persen relaksasi dan waktu relaksasi. Pengujian secara in vitro dilakukan dengan menggunakan Hip-His-Leu sebagai substrat dan mengukur produk yang terbentuk secara spektrofotometri UV-sinar tampak pada panjang gelombang 228 nm. Dari data absorbansi, dihitung persen inhibisi angiotensin converting enzyme (ACE) dan ditentukan nilai IC50. Pada kontraksi yang diinduksi norepinefrin, EEDB, FH, FE, dan FA menunjukkan persen relaksasi berturut-turut sebesar 60,9; 39,2; 48,2; dan 52,5%. Waktu relaksasi pada semua kelompok uji menurun secara signifikan terhadap kelompok yang diinduksi norepinefrin (p<0,05). Pada kontraksi yang diinduksi norepinefrin dengan pretreatmen metilen biru, persen relaksasi yang terjadi akibat pemberian EEDB, FH, FE, dan FA berturut-turut sebesar 21,4; 30,7; 21,6; dan 23,8% serta tidak terjadi penurunan waktu relaksasi. Pada kontraksi yang diinduksi KCl, persen relaksasi yang terjadi akibat pemberian EEDB, FH, FE, dan FA berturut-turut sebesar 42,2; 20,4; 49,1; dan 35,8%, akan tetapi tidak terjadi penurunan waktu relaksasi. Nilai IC50 pada pemberian EEDB, FH, FE, dan FA berturut-turut sebesar 22,63; 242,60; 115,77; dan 97,53 Î¼g/mL. Ekstrak etanol daun binahong memiliki efek vasodilatasi melalui jalur NO, inhibisi kanal kalsium (lemah), dan inhibisi ACE (sedang). Fraksi n-heksana tidak menunjukkan efek inhibisi kanal kalsium dan inhibisi ACE, tetapi menunjukkan efek vasodilatasi melalui jalur NO. Fraksi etil asetat menunjukkan efek vasodilatasi melalui jalur NO, inhibisi kanal kalsium (lemah), serta inhibisi ACE (lemah). Fraksi air menunjukkan efek vasodilatasi melalui jalur NO serta inhibisi ACE (lemah), tetapi tidak menunjukkan efek inhibisi kanal kalsium.Kata kunci: Anredera cordifolia, binahong, vasodilatasi, nitrit oksida, inhibisi kanal kalsium, inhibisi angiotensin converting enzymeVASODILATATION AND ANGIOTENSIN CONVERTING ENZYME INHIBITION EFFECT OF ETHANOL EXTRACT AND FRACTION FROM MADEIRA VINE (ANREDERA CORDIFOLIA (TEN). V. STEENIS) LEAFABSTRACTThe antihypertensive effects of Anredera cordifolia (madeira vine) on adrenaline-induced and dexamethasone-induced hypertensive rat have been demonstrated in previous studies. In this study, mechanism of antihypertensive effect of ethanol extract of madeira vine leaves and its fraction studied further. Ex vivo experiment was performed using rabbit aortic rings induced with norepinephrine, methylene blue-norepinephrine, and potassium chloride. The respond of aortic rings to ethanol extract of madeira vine (EEMV), n-hexane fraction (HF), ethyl acetate fraction (EF), and water fraction (WF) were observed in the kymograph, then percentage of relaxation and relaxation time were calculated from the graph obtained. Angiotensin converting enzyme (ACE) inhibitor activity test was performed in vitro using Hip-His-Leu as the substrate. The product of enzymatic reaction measured using UV-visible spectrophotometry at wavelength 228 nm. From the absorbance data, percentage of enzyme inhibition was calculated and IC50 value was determined. In norepinephrine-induced contraction, EEMV, HF, EF, and WF showed percentage of relaxation 60.9; 39.2; 48.2; and 52.5%, respectively. Relaxation time of all groups were significantly decrease compared to norepinephrine group (p<0.05). In norepinephrine-induced contraction with methylene blue pretreatment, the percent of relaxation were 21.4; 30.7; 21.6; and 23.8%, respectively for EEMV, HF, EF, and WF, and there was no reduction in relaxation time. In KCl-induced contraction, the percentage of relaxation of EEMV, HF, EF, and WF were 42.2; 20.4; 49.1; and 35.8%, respectively, but no reduction in relaxation time. IC50 of EEMV, HF, EF, and WF were 20.76, 198.13, 115.77, and 88.41 Î¼g/mL, respectively. The ethanol extract of madeira vine leaves showed vasodilator effect through the endothelium-dependent pathway, inhibition of calcium channel (weak), and ACE inhibition (moderate). The n-hexane fraction showed no inhibitory effect of calcium channel and ACE, but showed vasodilation effect via endothelium-dependent pathway. Vasodilation effect of ethyl acetate fraction occurred through the endothelium-dependent pathway, inhibition of calcium channel (weak), and ACE inhibition (weak). The water fraction showed vasodilation effect through endothelium-dependent pathway and inhibition of ACE (weak), but did not show calcium channel inhibition effect.Keywords: Anredera cordifolia, madeira vine, vasodilatation, nitric oxide, calcium channel blocker, angiotensin converting enzyme inhibition