Chemical composition, antimicrobial and antioxidant activities of the essential oil of Tibetan herbal medicineDracocephalum heterophyllumBenth

Abstract

The essential oil of Tibetan medicine Dracocephalum heterophyllum Benth was obtained by hydrodistillation with a 0.7% (v/w) yield. The chemical composition of the essential oil was analyzed by gas chromatography-mass spectral (GC-MS). Eighty-three compounds, constituting about 89.83% of the total oil, were identified. The main compound in the oil were Cineole (14.89%), trans-nerolido (7.10%), 1-m-ethyl-2-(1-methylethyl)-benzene (4.42%), Germacrene-D (4.84%), Decahydro-1,1,4,7-tetramethyl-4aH-cycloprop[e]azulen-4a-ol (4.94%), p-menth-1-en-4-ol,acetate (4.34%), 4-methyl-1-(1-methylethyl)-3-cyclohexen-1-ol (4.10%). The antimicrobial activity of the oil was evaluated against nine bacterial, one yeast, and three fungi. The antimicrobial test result showed that the essential oil strongly inhibited the growth of test microorganisms studied. The maximal inhibition zones and MIC values for bacterial, yeast and fungi strain were in the range of 18-25 mm and 0.039-0.156 mg mL(-1); *20 mm, and 0.156 mg mL(-1); 8-24 mm and 0.313-2.5 mg mL(-1); respectively. The antioxidant activity of the oil was determined by the malonyldialdehyde (MDA) test, measuring the MDA concentration in mouse liver cell microsomal after induced lipid peroxidation using FeSO(4) and ascorbic acid, The inhibition of lipid peroxidation was 59.3% with a concentration of 0.5 mg mL(-1). Result presented here may suggest that the essential oil of D. heterophyllum posses antimicrobial and antioxidant properties, and therefore, they can be one of new medicinal resources for antimicrobial agent and/or used as a natural preservative ingredient in food and cosmetics and pharmaceuticals industry.

Comparative Analysis of Chemical Compositions and Antimicrobial Activities of Essential Oils from Abies holophylla and Abies koreana

“…However, the MIC values (5.5-21.8 mg/ml) of the essential oils were comparatively higher than those of other essential oils. For example, essential oil from the Tibetan medicinal herb Dracocephalum heterophyllum Benth is reported to have MIC values of 0.039-0.156 mg/ml against various Gram-positive and Gram-negative bacteria [26]. This difference can be attributed to the bacterial strains and assay conditions, especially media used for cultivating bacteria, as well as the composition of the essential oils used in each particular study.…”

Chemical Composition and Biological Activity of Essential Oils of Dracocephalum heterophyllum and Hyssopus officinalis from Western Himalaya

“…Further moderate antimicrobial activity was found for the essential oil of H. officinalis var decumbens from plants collected in France against three Candida strains (MICs between 1500-3000 μg/mL), as well as Gram-positive and Gram-negative bacteria (MICs ≥ μg/mL) [22]. [18]. Since 1,8-cineole is known to exhibit low antimicrobial activity [20] the above reported antimicrobial effect might rather be due to secondary compounds or components that have not been detected by GC-MS. Additionally, unpredictable synergistic and antagonistic effects of monoterpenecombinations play an important role in essential oil properties [26].…”

Essential oil of <i>Thymus vulgaris</i> L. and <i>Rosmarinus officinalis</i> L.: Gas chromatography-mass spectrometry analysis, cytotoxicity and antioxidant properties and antibacterial activities against foodborne pathogens

“…The essential oils are considered among the most important antimicrobial agents present in the plants, and may also have cytotoxic and antioxidant activities [2]. They are a rich source of biologically active compounds mainly monoterpenes, sesquiterpenes, and their oxygenated derivatives such as alcohols, aldehydes, esters, ethers, ketones, and phenols which may be involved in its physiological and biological activities [15,16].…”