Comparative Study on the Chemical Composition and Biological Activities of the Essential Oils of <i>Lavandula angustifolia</i> and <i>Lavandula x intermedia</i> Cultivated in Lebanon

Abstract

The phytochemical profile of essential oils is influenced by genetic and paragenetic factors. In this research, we studied the essential oils of <i>Lavandula angustifolia</i> and <i>Lavandula x intermedia</i> cultivated in Lebanon. The latter is a cross hybrid between <i>Lavandula angustifolia</i> and <i>Lavandula latifolia</i> and is also known as lavandin and <i>Lavandula hybrida</i>. Specifically, the chemical composition and biological activities (antibacterial, antioxidant, anticancer, and hemolytic) of the essential oils were assessed. GC-MS results showed marked differences in the chemical compositions of the oils. For example, linalool was more abundant in <i>L. x intermedia</i> (44.15%) than in <i>L. angustifolia</i> (32%), while an opposite trend was observed for the percentages of 1,8-cineole (8.6% in <i>L. angustifolia</i> and 4.0% in <i>L. x intermedia</i>). FTIR analysis confirmed the richness of both oils in monoterpenes and sesquiterpenes. In terms of antioxidant activity, <i>L. angustifolia</i> essential oil demonstrated significantly better activity (IC₅₀= 5.24 ± 1.20 mg/mL) compared to <i>L. x intermedia</i> oil in the DPPH radical scavenging assay. MTT cell viability assays revealed that <i>L. angustifolia</i> essential oil was a slightly more potent antiproliferative agent than <i>L. x intermedia</i> oil on human colorectal (HCT-116) and human breast (MCF-7) cancer cells. The antibacterial activity of the essential oils was tested against <i>Staphylococcus aureus</i>, <i>Staphylococcus epidermidis</i>, <i>Enterococcus faecalis</i>, <i>Escherichia coli</i>, and <i>Serratia marcescens</i>. Both oils showed good antibacterial activities with MIC values of 0.174 and 0.169 mg/mL for <i>L. angustifolia</i> and <i>L. x intermedia</i> oils, respectively. MBC determinations revealed that the antibacterial activity was bactericidal against all bacteria, except <i>Staphylococcus aureus</i>. Furthermore, both essential oils did not exhibit notable hemolytic activity on red blood cells. Overall, Lebanese <i>L. angustifolia</i> and <i>L. x intermedia</i> essential oils have promising industrial and medicinal values.