Chemical composition and pharmacological screening of Micromeria fruticosa serpyllifolia volatile oils collected from West Bank-Palestine
سلامه, نهاية محمد يوسف
An-Najah National University
Background and Objectives Micromeria fruticosa subspecies serpyllifolia (M. Bieb.) is one of the Medicinal Aromatic Plants (MAP) which are dominated in the eastern Mediterranean regions including Palestine, has pleasant minty fragrance, in hot summer provide sensation of coolness. The objective of the current work was to screen and compare the chemical constituents and potential pharmacological properties of Micromeria fruticosa serpyllifolia volatile oils collected from three different regions in the West Bank -Palestine. Methods The volatile oils of three samples of Micromeria fruticosa serpyllifolia were extracted using Microwave - ultrasonic apparatus method. The volatile oils samples were analyzed for chemical constituents using GC-MS. The antioxidant activity of the volatile oils of the three samples were screened by the inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. The antilipase activity was evaluated using porcine pancreatic lipase (PL) and p-nitrophenyl butyrate (PNPB). The anti amylase activity was assessed using porcine pancreatic α- amylase, starch and 3,5-dinitrosalicylic (DNSA). The antimicrobial activity was examined using broth microdiltution method separate for antibacterial and then for antifungal and agar dilution method for fungal assessment. Nine bacterial strains were used four Gram-positive: Staphylococcus aureus, Staphylococcal enterotoxin B (SEB), Enterococcus faecium, "methicillin"-resistant Staphylococcus aureus (MRSA), and five Gram-negative strains; Proteus mirabilis, Pseudomonas aeruginosa, Escherichia coli, Shigella sonnie, Klebsilla pneumoniae and one fungus Epidermophyton floccosum and one yeast Candida albicans. Results Plant extracts yield range was (0.67 to 0.99%) (w/w%). GC-MS analysis showed the high percentages of oxygenetated components with the range of (86.1-89.88%), non oxygenated components in the range of (4.38-4.71%), the total identified compounds range was (90.48-94.44%). Seven components were observed, pulegone was the most abundant components in the three samples in the range of (74.43-86.04%), isomenthone was the second abundant components with the range of (3.16-14.41%).The sample from Ramallah (middle region) showed the potent antioxidant agent with IC50 0.45 µg/mL, the sample from Hebron (southern region) was the potent antilipase agent with IC50 85.00 µg/mL. The sample from Nablus (northern region) was the potent antiamylase agent with IC50 3.00 µg/mL. The three samples exhibited broad antimicrobial activity; the three samples showed potent antifungal activity at minimum inhibitory concentration (MIC) with the range of (0.206 to 0.781 mg/mL). The sample from Hebron (southern region) showed the highest potency against Shigella sonnie with lowest reported MIC value (1.56 mg/mL), the sample of Nablus (northern region) demonstrated the least potency against Staphylococcal enterotoxin B (SEB) and 'methicillin" resistance Staphylococcus Aureus (MRSA) with highest MIC value (6.250 mg/mL). However, the three samples showed broadspectrum antibactreial activity with MIC value (3.125 mg/mL). Conclusion The study showed that Micromeria fruticosa serpyllifolia volatile oils samples from different regions in Palestine contained different proportions of phytochemicals which provided different potential biological activities such as: antioxidant, antiobesity, antidiabetes and antimicrobial activities that were in line with traditional uses of the plant extracts. The plant extracts showed higher antioxidant, antilipase and antiamylase potency higher than that of the relative references and there were significant differences in these activities compared to each other. Further in vivo studies are required to evaluate the potential pharmacological activities, safety and toxicity of plant extract. Also further studies are needed to isolate, identify and characterize the main components responsible for potential pharmacological activities..