In vitro hypoglycaemic and ACE inhibitory activities of Marrubium radiatum Devile ex Benth and Salvia acetabulosa L.: two traditional medicinal plants from Lebanon

M. Rosa Loizzo; R. Tundis; F. Menichini; V. Piccolo; M. Bonesi; F. Conforti; M. Marrelli; G. A. Statti; A. M. Saab; M. Nicoletti; P. J. Houghton

doi:10.1055/s-2007-987246

In vitro hypoglycaemic and ACE inhibitory activities of Marrubium radiatum Devile ex Benth and Salvia acetabulosa L.: two traditional medicinal plants from Lebanon

M Rosa Loizzo ¹, R Tundis ¹, F Menichini ¹, V Piccolo ¹, M Bonesi ¹, F Conforti ¹, M Marrelli ¹, GA Statti ¹, AM Saab ², M Nicoletti ³, PJ Houghton ⁴, F Menichini ¹

¹Department of Pharmaceutical Science, Faculty of Pharmacy and Nutrition and Health Sciences, University of Calabria, I-87030 Rende (CS) Italy
²Chemistry Department, Faculty of Sciences II, Lebanese University, P.O. Box:90656 Fanar, Beirut, Lebanon
³Department of Plant Biology, Faculty of Pharmacy, University „La Sapienza“, P.le Aldo Moro, 5, 00185 Rome, Italy
⁴Pharmaceutical Sciences Division, King's College London, 150 Stamford Street, London SE1 9NH, UK

Abstract

Marrubium radiatum Devile ex Benth and Salvia acetabulosa L. (Lamiaceae) were used for treatment of hypertension and diabetes in Lebanon traditional medicine. In order to find a scientific validation of their traditional use, in vitro assays for α-amylase and α-glucosidase inhibition were performed while the antihypertensive action was analysed by the inhibition of Angiotensin Converting Enzyme (ACE) [1–3]. Plant material was extracted using methanol or n-hexane as solvent [4]. The ACE inhibitory activity was measured through the cleavage of the chromophore-fluorophore labelled substrate dansyltriglycine by ACE preparation from rabbit lung (EC 3.4.15.1) into dansylglycine, which is quantitatively measured by HPLC. M. radiatum showed a IC₅₀of 72.79 and 75.42µg/mL while S. acetabulosa exhibited a IC₅₀of 52.71 and 105.22µg/mL for MeOH and n-hexane, respectively. The glucose absorption, from the intestine to the blood is elated to the α-amylase and α-glucosidase activity. Both M. radiatum and S. acetabulosa are able to inhibit α-amylase. In particular the MeOH extract exert highest activity with a IC₅₀of 61.12 and 91.16µg/mL. The ability of M. radiatum and S. acetabulosa MeOH extract to inhibit α-glucosidase was weak (IC₅₀ of 365.95 and 315.89µg/mL). In conclusion, this study supports the traditional use of these species and further work is necessary in order to identify active principles responsible for the found activities.

References: [1] Conforti, F. et al. Biol. Pharm. Bull.(2005) 28: 1098. [2] Anonymous, Sigma Tech. Bull No. 510 6/76 (1978). [3] Elbl, G. & Wagner, H. Planta Med. (1991) 57: 137. [4] Choi, H.K. et al. Phytochem. (2004) 65: 857.