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Friday, 14 December 2018

Phenolic-rich extracts of Eurycoma longifolia and Cylicodiscus gabunensis inhibit enzymes responsible for the development of erectile dysfunction and are antioxidants.

J Basic Clin Physiol Pharmacol. 2018 Nov 27;29(6):689-696. doi: 10.1515/jbcpp-2017-0160. Oboh G1, Adebayo AA2, Ademosun AO2. Author information 1 Functional Foods and Nutraceutical Research Unit, Department of Biochemistry, Federal University of Technology, P.M.B. 704, Akure, Nigeria, Phone: +2347031388644. 2 Functional Foods and Nutraceutical Research Unit, Department of Biochemistry, Federal University of Technology, Akure, Nigeria. Abstract BACKGROUND: Herbs have been used from ages to manage male sexual dysfunction. Hence, this study sought to investigate the effects of Eurycoma longifolia (EL) and Cylicodiscus gabunensis (CG) stem bark extracts on some enzymes implicated in erectile dysfunction in vitro. METHODS: The extracts were prepared, and their effects on phosphodiesterase-5 (PDE-5), arginase, and angiotensin-1-converting enzyme (ACE) as well as pro-oxidant-induced lipid peroxidation were assessed. Furthermore, phenolic contents were determined, and their components were characterized and quantified using high-performance liquid chromatography with diode array detector (HPLC-DAD). RESULTS: The results revealed that the extracts inhibited PDE-5, arginase, and ACE in a concentration-dependent manner. However, IC50 values revealed that CG had higher inhibitory potential on PDE-5 (IC50=204.4 μg/mL), arginase (IC50=39.01 μg/mL), and ACE (IC50=48.81 μg/mL) than EL. In addition, the extracts inhibited pro-oxidant-induced lipid peroxidation in penile tissue homogenate. HPLC-DAD analysis showed that CG is richer in phenolic compounds than EL, and this could be responsible for higher biological activities observed in CG than EL. CONCLUSIONS: Hence, the observed antioxidant property and inhibitory action of CG and EL on enzymes relevant to erectile dysfunction in vitro could be part of possible mechanisms underlying their involvement in traditional medicine for the management of male sexual dysfunction. KEYWORDS: Cylicodiscus gabunensis; Eurycoma longifolia; PDE-5; arginase; erectile dysfunction PMID: 29777610 DOI: 10.1515/jbcpp-2017-0160