Chemical Composition and Enzymatic Screening of Volatile Oils Collected from Three Different Regions of West Bank, Palestine.

Introduction: Volatile oils (VOs) have been commonly used in cosmetics and food as fragrances, flavoring, and preservative agents or in alternative medicine for their therapeutic effects. This necessitates investigating those plants and their VOs. This study was conducted to investigate the chemical compositions of the VOs of growing widely in three regions in Palestine (i.e., Hebron, Ramallah, and Nablus districts representing south, middle, and north of West Bank). Afterwards, VOs were subjected to screening and their enzymatic properties were compared.

Methods: The analysis of chemical components of VOs was performed by gas chromatography coupled with mass spectrometry (GC-MS). The antilipase activity was evaluated using porcine pancreatic lipase and -nitrophenyl butyrate. The antiamylase activity was assessed using porcine pancreatic -amylase, starch, and 3,5-dinitrosalicylic.

Results: Plant extracts yield range was 0.67 to 0.99 w/w%. GC-MS analysis showed the high percentages of oxygenated components in the range of 86.1-89.88% and nonoxygenated components in the range of 4.38-4.71%. Seven components were observed, pulegone was the most abundant component in the three samples in the range of 74.43-86.04%, and isomenthone was the second most abundant component with the range of 3.16-14.41%. The sample collected from Nablus showed the most potent antilipase and antiamylase activity with IC50 values of 39.81 g/mL and 3.31 g/mL, respectively.

Conclusions: The study showed that volatile oils samples from different regions in Palestine contained different proportions of phytochemicals which provided different potential biological activities such as antiobesity and antidiabetes activities that were in line with traditional uses of the plant extracts. The plant extracts showed higher antilipase and antiamylase potency than that of the relative references and there were significant differences in these activities compared to each other.