Browsing by Author "El-Shiekh, Riham A"

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Lepidium meyenii (Maca) Roots: UPLC-HRMS, Molecular Docking, and Molecular Dynamics
(American Chemical Society, 13/05/2022) Ibrahim, Rana M; Elmasry, Ghada F; Refaey, Rana H; El-Shiekh, Riham A
Lepidium meyenii or Maca is widely cultivated as a health care food supplement due to its nutritional and medicinal properties. Although there are a few in-depth studies evaluating Maca antihypertensive effects, the correlations between the chemical constituents and bioactivity of the plant have not been studied before. Thus, the roots were extracted using different solvents (aqueous, methanol, 50% methanol, and methylene chloride) and investigated for their antihypertensive and antioxidant activities through several in vitro assays. The methanolic extract exhibited the best renin and angiotensin converting enzyme (ACE) inhibitory activities with IC50 values of 24.79 ± 1.3 ng/mL and 22.02 ± 1.1 ng/mL, respectively, along with the highest antioxidant activity. In total, 120 metabolites from different classes, e.g., alkylamides, alkaloids, glucosinolates, organic acids, and hydantoin derivatives, were identified in the methanolic extract using ultrahigh-performance liquid chromatography/high-resolution mass spectrometry (UPLC/HRMS). Molecular docking simulations were used to investigate the potential binding modes and the intermolecular interactions of the identified compounds with ACE and renin active sites. Glucotropaeolin, β-carboline alkaloids, succinic acid, and 2,4-dihydroxy-3,5- cyclopentyl dienoic acid showed the highest affinity to target the ACE with high docking scores (S ranging from −35.32 to −22.51 kcal mol−1 ) compared to lisinopril (S = −36.64 kcal mol−1 ). Interestingly, macamides displayed the greatest binding affinity to the active site of renin with docking scores (S ranging from −22.47 to −28.25 kcal mol−1 ). Further, β-carbolines achieved docking scores comparable to that of the native ligand (S ranging from −13.50 to −20.06 kcal mol−1 ). Molecular dynamics simulations and MMPBSA were also carried out and confirmed the docking results. Additionally, the computational ADMET study predicted that the compounds attaining promising docking results had proper pharmacokinetics, drug-likeness characteristics, and safe toxicological profiles. Ultimately, our findings revealed that Maca roots could be considered a promising candidate as an antihypertensive drug.
Metabolomics driven analysis of Nigella sativa seeds identifies the impact of roasting on the chemical composition and immunomodulatory activity
(Elsevier Ltd., 2022-08-07) Salem, Mohamed A; El-Shiekh, Riham A; Aborehab, Nora M; Al‐Karmalawy, Ahmed A; Ezzat, Shahira M; Alseekh, Saleh; Fernie, Alisdair R
Nigella sativa L. seeds (NS) are known as one of the most traditional immunomodulatory and nutritive food additives. NS can, furthermore, be roasted to give curries, breads, and other dishes a smoky, nutty flavor. This study evaluated the effect of roasting NS on the metabolic profile and immunomodulatory activity. Non-targeted metabolomics analysis was conducted using several analytical platforms, including GC-MS and UPLC-MS. A total of 197 metabolites were identified, belonging to different classes such as saponins, alkaloids, flavonoids, and lipids. In vitro immunomodulatory activity on the differentiated monocytic cell line THP-1 was assessed, revealing that the roasted seeds showed significantly-decreased immunomodulatory activity. Furthermore, a molecular docking study, which was carried out against immunomodulation- related pathway protein (iNOS), revealed that compounds which showed the best binding scores were severely decreased by roasting. Conclusively, our results demonstrate that the roasting of NS results in severe losses in their bioactive metabolites and immunomodulatory activity.