Volatile and Non-Volatile Chemical Compounds and Biological Power of the genus Lavandula: Case of two Moroccan Lavenders Lavandula angustifolia Mill. (Cultivated Lavender) and Lavandula pedunculata (Mill.) Cav. (Spontaneous Lavender)

This work consists of the comparison of the chemical composition, the antioxidant activity, and the antimicrobial effect of two species of the genus Lavandula essential oils (EOs) and extracts (hydroethanolic, aqueous and decocted), that were collected from the region of Ifrane in Morocco "Lavandula angustifolia and Lavandula pedunculata". Gas chromatographic analyzes coupled with mass spectrometry of the studied EOs showed that L. angustifolia contains camphor and linalool as majority compounds with 20,17% and 12,41% respectively, while camphor (41,15%) and fenchone (15,70%) are the major compounds of L. pedunculata. The dosage of hydroethanolic, aqueous and decocted extracts showed that the content of polyphenols and flavonoids is higher in the hydroethanolic extracts of L. pedunculata, while L. angustifolia contains the highest content of tannins. The determination of the antioxidant activity was carried out using FRAP and DPPH methods, the last method revealed that the EO of L. angustifolia is less effective (IC50=7,98 mg/ml) than that of L. pedunculata (EC50=7,47 mg/ ml) while, there was no great divergence concerning the IC50 values of the hydroethanolic and decocted extracts of the two species. As for the aqueous extract, the value recorded by L. pedunculata was slightly higher than that of L. angustifolia. Finally, tests of the antimicrobial activity of EOs and extracts of the two species were carried out on six bacteria and five fungal strains whose antimicrobial power was remarkable. As a conclusion, the two Lavenders' extracts can be considered as alternative sources of powerful natural antioxidants, antifungals and antibiotics.