Study on chemical composition and biological activities of essential oil and extracts from Stevia rebaudiana Bertoni leaves

Essential oil (EO), water extract (WE), and methanol-water (MWE) (50/50 v:v) were prepared from Stevia rebaudiana Bertoni leaves. Their chemicals compounds, antioxidant, anti-inflammation and antimicrobial activities were evaluated. The EO was analyzed by gas chromatography/mass spectrometry. The WE, and MWE compounds were identified by RP-HPLC. In EO, carvacrol, caryophyllene, caryophyllene oxide, spathulenol, cardinol, α-pinene, limonene, isopinocarveol and ibuprofen were identified as major compounds. Furthermore, in the WE and MWE, the major compounds were, quercetin dihydrate, protocatechuic acid and quercetin glucosyl. These results show that S. rebaudiana EO and extracts possess high antioxidant, anti-inflammation and antimicrobial properties. The antimicrobial and antifungal activities of the extracts (EO, WE, MWE) were tested on Staphylococcus aureus; Bacillus subtillis; Escherichia coli; Pseudomonas aeruginosa; Aspergillus niger and Candida albicans, the lowest activity was founded on the EO extract.