Mechanistic Studies of the Vascular and Cardiac Effects of the Aqueous Calyx Extract of Hibiscus sabdariffa

Cooperating countries: Namibia, Nigeria and Austria

Coordinating institution: Medical University of Graz, Goswami Nandu, nandu.goswami@medunigraz.at

Partner institutions: University of Namibia, Usmanu Danfodiyo University

Project duration: 1 June 2023 - 31 May 2025

Abstract:

Aims and objectives: The purpose of this ethnopharmacological-and vascular biology- project is to carry out mechanistic studies of the vascular and cardiac effects of the aqueous calyx extract of Hibiscus sabdariffa. This study is designed to carry out the following on the Namibian and Nigerian varieties of HS:
1.    Does chronic ingestion of HS calyx extract by the DSS rat modify the response of peripheral vascular resistance (PVR) to alpha-adrenegic agonists (AAA) like phenylephrine?
2.    What happens to the cardiac functions (systolic and diatrolic), including tissue Doppler imaging (TDI), using echocardiographic parameters, after chronic ingestion of HS aq calyx extract?

Methodology: The extract of HS will be purified in Namibia and Nigeria. it will be tested in Austria. In Austria, innovative (cardio-)vascular measurements will be carried out in rats fed HS and then subsequently on the aortic rings isolated from the euthanized animals. Specific measurements that will be carried out include vascular biology (contractile/relaxant responses to agonists in aortic rings and the underlying mechanisms).

Impact: The study is expected to generate new knowledge on vascular and cardiac effects of the aqueous calyx extract of Hibiscus sabdariffa and the underlying mechanisms.  In addition to skills transfer from Austrian to Namibian and Nigerian researchers during this project, strengthening of interdisciplinary and trans disciplinary research cooperation between Austria, Namibia and Nigeria will lay a strong foundation for future collaborative research, development of research capacities and empower young African scientists, especially females. Finally, this project is in concordance with several of UN’s SDGs.