Ezzat, Shahira MOkba M.M.Ezzat M.I.Aborehab N.M.Mohamed S.O.Pharmacognosy DepartmentFaculty of PharmacyCairo UniversityKasr El-Ainy StreetCairo11562Egypt; Pharmacognosy DepartmentFaculty of PharmacyOctober University for Modern Sciences and Arts (MSA)October12566Egypt; Biochemistry DepartmentFaculty of PharmacyOctober University for Modern Sciences and Arts (MSA)6th October12566Egypt; School of Pharmaceutical SciencesUniversiti Sains MalaysiaMalaysia2020-01-092020-01-0920191741427Xhttps://doi.org/10.1155/2019/4341592PubMed ID :https://t.ly/geyw8ScopusMSA Google ScholarBackground. Eurycoma longifolia Jack (Fam.: Simaroubaceae), known as Tongkat Ali (TA), has been known as a symbol of virility and sexual power. The aim of the study was to screen E. longifolia aqueous extract (AE) and isolates for ROCK-II inhibition. Results. The AE (1-10 ?g/ml) showed a significant inhibition for ROCK-II activity (62.8-81%) at P < 0.001 with an IC50 (651.1 � 32.9 ng/ml) compared to Y-27632 ([(+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide dihydrochloride]) (68.15-89.9 %) at same concentrations with an IC50 (192 � 8.37 ng/ml). Chromatographic purification of the aqueous extract (AE) allowed the isolation of eight compounds; stigmasterol T1, trans-coniferyl aldehyde T2, scopoletin T3, eurycomalactone T4, 6?- hydroxyeurycomalactone T5, eurycomanone T6, eurycomanol T7, and eurycomanol-2-O-?-D-glucopyranoside T8. This is the first report for the isolation of T1 and T3 from E. longifolia and for the isolation of T2 from genus Eurycoma. The isolates (at 10 ?g/ml) exhibited maximum inhibition % of ROCK-II 82.1 � 0.63 (T2), 78.3 � 0.38 (T6), 77.1 � 0.11 (T3), 76.2 � 3.53 (T4), 74.5 � 1.27 (T5), 74.1 � 2.97 (T7), 71.4 � 2.54 (T8), and 60.3 � 0.14 (T1), where the newly isolated compound trans-coniferyl aldehyde T2 showed the highest inhibitory activity among the tested isolated compounds and even higher than the total extract AE. The standard Y-27632 (10 ?g/ml) showed 89.9 � 0.42 % inhibition for ROCK-II activity when compared to control at P < 0.0001. Conclusion. The traditional use of E. longifolia as aphrodisiac and for male sexual disorders might be in part due to the ROCK-II inhibitory potential. � 2019 Shahira M. Ezzat et al.EnglishOctober University for Modern Sciences and Artsجامعة أكتوبر للعلوم الحديثة والآدابUniversity of Modern Sciences and ArtsMSA University4 (1 aminoethyl) n (4 pyridyl)cyclohexanecarboxamide6alpha hydroxyeurycomalactonealdehydeaphrodisiac agentEurycoma longifolia extracteurycomalactoneeurycomanoleurycomanol 2 o beta d glucopyranosideeurycomanoneglucopyranosideRho kinaserho kinase iiscopoletinstigmasteroltrans coniferyl aldehydeunclassified drugArticlechemical compositioncontrolled studydrug isolationenzyme inhibitionerectile dysfunctiongenusnonhumanpurificationstandardArticlehttps://doi.org/10.1155/2019/4341592PubMed ID :