Biological activities of methanolic extracts from leaves of Rosa micrantha, Rosa pisiformis, Rosa phoenicia and Rosa pulverulenta species growing in Turkey

The genus Rosa L. is represented by 26 species in Turkey and some of them are long been used in the folk medicine due to their potential curative activities. Some of these traditional and folk usages such as antioxidant and antihypertensive agent were evaluated in this study, showing the potential medicinal use of the rose leaves. In our previous studies it was reported that one of the beneficial effects of Rosa agrestis, Rosa sempervirens and Rosa horrida leaves extracts is the antioxidant and free radical scavenging activity of the phenolic and flavonoid contents. Phytochemical analysis of rose leaves extracts indicated the presence of major phytocompounds, including flavonoids like rutin, kaempherol, quercetin and ellagic acid. In order to complement our previous studies on rose species, the methanolic extracts prepared from leaves of Rosa micrantha, Rosa pisiformis, Rosa phoenicia and Rosa pulverulenta were tested in vitro for their polyphenolic contents, antioxidant and inhibitory activities against acetylcholinesterase (AChE), buthylcholinesterase (BChE) and angiotensin converting enzyme (ACE) in order to exploit the possible role of these plants as a source of the alternative agents for the prevention and treatment of neurodegenerative disease and hypertension. The results showed that the extracts have potent inhibitory activities against AChE, BChE and ACE, contain high amount of phenolic compounds and possess significant antioxidant activity which may be attributed to a strong reducing power, DPPH• , ABTS•+ and superoxide radicals scavenging and lipid peroxidation inhibitory activities. The enzyme kinetic studies revealed that ellagic acid, kaempherol and quercetin inhibit reversibly both the AChE and BChE enzymes in non-competitive manner. The results showed that the leaves of rose species under study could provide new therapeutical applications.