Investigation of some biological activities 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 used in traditional medicine as tonic, expectorant, stomachic, diuretic and for the treatment of diarrhoea, dyspepsia, nephritis, bronchitis and diabetes. 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 Rosa species 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 Rosa 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 (BuChE) and angiotensin converting enzyme (ACE) in order to evaluate the potential role of these plants as sources for the development of new therapeutic agents of Alzheimer disease and hypertension.The results showed that the extracts show potent inhibitory activity against AChE, BuChE and ACE, contain high amount of phenolic compounds and possess significant antioxidant activity wich 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 enzymes in noncompetitive manner. The results showed that the leaves of Rosa species under study have a high potential for the development of new drugs with different pharmaceutical uses. Keywords: Rosa species, leaves, phenolic compounds, antioxidant, anticholinergic activity, angiotensin converting enzyme inhibition