Aim of the study: In recent years the use of medicinal plants has been growing worldwide and this is particularly true in Lebanon. In the present investigation we report the inhibitory activity against digestive enzymes related to diabetes and angiotensin converting enzyme (ACE) of extracts of nine plant species collected in Lebanon, where they have a traditional use against diabetes.
Materials and methods: In order to evaluate if the extraction procedure could influence the activity we decided to perform different extractions with methanol, n-hexane and chloroform of Calamintha origanifolia, Satureja thymbra, Prangos asperula, Sideritis perfoliata, Asperula glomerata, Hyssopus officinalis, Erythraea centaurium, Marrubium radiatum and Salvia acetabulosa and test each of them.
Results and conclusions: Marrubium radiatum and Salvia acetabulosa methanol extracts exerted the highest activity against alpha-amylase (IC(50) 61.1 and 91.2 microg/ml, respectively) and alpha-glucosidase (IC(50) 68.8 and 76.9 microg/ml, respectively). The same extracts exhibited a strong inhibitory activity against ACE with IC(50) of 72.7 and 52.7 microg/ml, respectively. The results support the traditional use of some the species examined.