Comparative Analysis of In-Vitro Biological Activities of Methyl Eugenol Rich Cymbopogon khasianus Hack., Leaf Essential Oil with Pure Methyl Eugenol Compound.

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 ß-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.

Study of Anti-oxidant, Anti-inflammatory, Genotoxicity, and Antimicrobial Activities and Analysis of Different Constituents found in Rhizome Essential Oil of Curcuma caesia Roxb., Collected from North East India.

BACKGROUND: This investigation was designed to evaluate the chemical composition, antioxidant, anti-inflammatory, genotoxicity, and antimicrobial activities of Curcuma caesia Roxb rhizome essential oil. METHODS: Gas Chromatography/Mass Spectroscopy (GC/MS) analysis was performed to determine the chemical composition, standard antioxidative test DPPH assay, reducing power assay, in vitro antiinflammatory activity (egg albumin denaturation, protease inhibitory assay) by using standard methods. Similarly, antimicrobial activity was tested using the disc diffusion method, minimum inhibitory concentration ability (MIC); while to test genotoxicity, Allium cepa assay was used. RESULTS: GC/MS analysis revealed eucalyptol (28.55%), epicurzerenone (19.62%), and camphor (21.73%) as the major components of C. caesia rhizome essential oil. Potent antioxidant (IC50= 48.08±0.003 µg/mL), anti-inflammatory (IC50= 121.7±0.0013 µg/mL), and antimicrobial activities of the essential oil were recorded better than the standard drugs Fluconazole for fungus and Ciprofloxacin for bacteria. The essential oil also possessed a strong antibacterial effect against two tested bacterial strains B. subtilis and B. cereus with 7.5 µg/mL MIC value, while for fungal strains the essential oil was most effective against S. cereviaceae with an MIC value of 2.5 µg/mL. All the data were recorded in triplicates. Allium cepa assay revealed minor genotoxicity with mitotic index, MI= 27.70%; chromosome aberration, A= 1.1% of C. caesia rhizome essential oil. CONCLUSION: C. caesia rhizome essential oil possesses potent antioxidant, anti-inflammatory, and antimicrobial properties with negligible genotoxicity. Hence, the present study is highly significant for the utilization of rhizome of C. caesia, a high-value ethnopharmacological plant for advanced R & D and commercial application.