In silico Molecular Docking Approach to Identify Potential Antihypertensive Compounds from Ajuga integrifolia Buch.-Ham. Ex D. Don (Armagusa).

Background: Ajuga integrifolia (Armagusa) is used as a decoction to treat high blood pressure and diabetes, widely in Ethiopia. Specific compounds for anti-hypertension activity were not identified so far. This study aims to provide a scientific basis for the therapeutic use of A. integrifolia as an antihypertension agent.

Methods: In silico studies were used to evaluate the antihypertensive components of A. integrifolia. Flavonoids identified using HPLC analysis and iridoid glycosides isolated from A. integrifolia in this study and those isolated from synonyms (A. remota and A. bractosa) were considered in the molecular docking study. Interactions were studied by using Autodock vina (1.2) on PyRx 0.8 and visualizing in 2D and 3D using ligPlot+ and Discovery studio software. Activities like vasoprotection and druglikeness properties were predicted using online servers.

Results: Flavonoids such as quercetin, myricetin, and rutin were identified and quantified by HPLC analysis from different extracts of A. integrifolia. Reptoside and 8-O-acetylharpgide isolated from the aerial part of A. integrifolia. The binding energies of all 17 candidates considered in this study range from -10.2 kcal/mol to -7.5 kcal/mol and are lower than enalapril (reference drug: -5.9 kcal/mol). The binding energies, in most case, constitute hydrogen bonding. Biological activity predicted using PASS test also showed that the flavonoids have more probability of activity than the iridoid glycosides. Druglikeness properties of the candidate molecules showed that most follow the Lipinski rule of five with few violations.

Conclusion: Lower binding energies involving hydrogen bonding and predicted activities concerning hypertension confirm the traditional use of the aerial part of the medicinal plant concerned. Flavonoids: rutin, myricetin, quercetin, and kaempferol take the leading role in the antihypertensive activity of the aerial part of A. integrifolia. The iridoid glycosides studied are almost similar in their effect on their antihypertensive activity and still better than the reference drug.