Abstract
Myrtus communis L. (MC) family Myrtaceae, is cultivated in Egypt as an ornamental plant. The essential oil (EO) isolated from different parts of the plant reported for many pharmacological activities. Myrtus black and white (MB &MW) are two varieties of Myrtus diverse from each other in the color of berries; the EO was prepared from the fresh aerial parts of both varieties through hydrodistillation. The EO was screened for its free radicals scavenging activity by five different methods (DPPH, ABTS, NO, SOR, LP) and with Vit. C & BHT as reference standard. It was noticed that the scavenging activity of MB at all used conc. (125 to 1000 µg/mL) was more potent than MW. Screening of the cytotoxic activities of the EO of MB and MW on five cancer cell line (PC3, MCF-7, A549, HepG-2, HCT-116 ) & one normal cell line (Rpel-1) revealed that both EO of the two varieties had activity against PC3& MCF-7 with IC50; 4.7±0.15, 14.2±0.35, 45.2±0.67, 50.5±0.6 compared with Doxrubacin standard 24±0.26, 26.1±0.4, respectively. MB& MW oil are safe on Rpel-1 (normal cell line). The α-amylase enzyme inhibition activity of the oils was investigated using acarbose as reference inhibitor. Both MB& MW have activity more than the standard at 125μg/ml 36.24±0.146; 32.14±.188, 23.16±0.190 and also at the highest conc. (1000 µg/mL) 96.22±0.140, 89.48±.106, 88.81±0.690, respectively. Study of the chemical constituents of the EO by GC/MS analysis resulted in the identification of 25 compounds from both species constituting 99.21% & 99.96% of the total peak area of the identified compound, respectively. The major compounds are α–Pinene (49.33%, 31.10 %); 1,8 Cineole (9.97 %, 19.21 %); Myrtenyl acetate (30.7%, 40.80 %); α –Terpineol (2.18%, 1.73%) and D-Limonene (1.90% , 2.61%) for MB & MW, respectively.