Background:
The essential oil of methyl eugenol rich Cymbopogon khasianus Hack. was
evaluated and its bioactivities were compared with pure methyl eugenol. So far, methyl eugenol rich
essential oil of lemongrass was not studied for any biological activities; hence, the present study was
conducted.
Objective:
This study examined the chemical composition of essential oil of methyl eugenol rich
Cymbopogon khasianus Hack., and evaluated its antioxidant, anti-inflammatory, antimicrobial, and
herbicidal properties and genotoxicity, which were compared with pure compound, methyl eugenol.
Material and Methods:
Methyl eugenol rich variety of Cymbopogon khasianus Hack., with registration
no. INGR18037 (c.v. Jor Lab L-9) was collected from experimental farm CSIR-NEIST, Jorhat,
Assam (26.7378°N, 94.1570°E). The essential oil wasobtained by hydro-distillation using a Clevenger
apparatus. The chemical composition of the essential oil was evaluated using GC/MS analysis and its
antioxidant (DPPH assay, reducing power assay), anti-inflammatory (Egg albumin denaturation assay),
and antimicrobial (Disc diffusion assay, MIC) properties, seed germination effect and genotoxicity
(Allium cepa assay) were studied and compared with pure Methyl Eugenol compound (ME).
Results:
Major components detected in the Essential Oil (EO) through Gas chromatography/mass
spectroscopy analysis were methyl eugenol (73.17%) and β-myrcene (8.58%). A total of
35components were detected with a total identified area percentage of 98.34%. DPPH assay revealed
considerable antioxidant activity of methyl eugenol rich lemongrass essential oil (IC50= 2.263 μg/mL),
which is lower than standard ascorbic acid (IC50 2.58 μg/mL), and higher than standard Methyl Eugenol
(ME) (IC50 2.253 μg/mL). Methyl eugenol rich lemongrass EO showed IC50 38.00 μg/mL, ME
36.44 μg/mL, and sodium diclofenac 22.76 μg/mL, in in-vitro anti-inflammatory test. Moderate antimicrobial
activity towards the 8 tested microbes was shown by methyl eugenol rich lemongrass essential
oil whose effectiveness against the microbes was less as compared to pure ME standard. Seed germination
assay further revealed the herbicidal properties of methyl eugenol rich essential oil. Moreover,
Allium cepa assay revealed moderate genotoxicity of the essential oil.
Conclusion:
This paper compared the antioxidant, anti-inflammatory, antimicrobial, genotoxicity and
herbicidal activities of methyl eugenol rich lemongrass with pure methyl eugenol. This methyl eugenol
rich lemongrass variety can be used as an alternative of methyl eugenol pure compound. Hence, the essential
oil of this variety has the potential of developing cost-effective, easily available antioxidative/
antimicrobial drugs but its use should be under the safety range of methyl eugenol and needs further
clinical trials.
Chemical Composition, Allelopathic, Antioxidant, and Anti-Inflammatory Activities of Sesquiterpenes Rich Essential Oil of Cleome amblyocarpa Barratte & Murb.