Chemical profiling, free radical scavenging and anti-acetylcholinesterase activities of essential oil from curcuma caesia of Arunachal Pradesh, India

Abstract

Background and Aim: The rhizomes of Curcuma caesia have traditional applications for pain healing and are an imperiled species of India. A study on investigation of in vitro anti-oxidant and acetylcholinesterase (AChE) inhibitory efficacy of essential oil from the rhizome part was carried out through extraction by hydrodistillation. Materials and Methods: The phyto components present in this volatile oil were identified by gas chromatography-mass spectrometric analysis and based on Spearman's correlation, the cooccurrence network of the 21 compounds were analyzed. In vitro anti-oxidant, anti-AChE activities were assessed with different concentrations of essential oil by spectrophotometric analysis, following the standard protocols. Results: The studies revealed that major compounds identified were Androsta-1,4-dien-3-one,17-(acetyloxy)-, (17.beta.)-Santanol acetate (16.11%), Eucalyptol (12.98%), Cycloprop[e]indene-1a,2(1H)-dicarboxaldehyde,3a,4,5,6,6a,6b-hexahydro-5,5,6b-trimethyl, (1a. alpha., 3a. beta., 6a. beta., 6b. alpha) (8.96%), methyl 7,12-octadecadienoate (6.75%), and (+)-2-Bornanone (6.60%). The major interactions of terpenoidal compounds with other compounds give a picture that terpenoids have a very significant role as anti-oxidants and cholinesterase inhibitors. The essential oil showed the total phenolic content of 26.72 ± 0.38 mg/g of gallic acid equivalent and total flavonoid content of 18.92 ± 0.27 mg/g of quercetin equivalent (QE). 2, 2-diphenyl-1-picrylhydrazyl and 2, 2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid radical scavenging 50% inhibitory concentration (IC50) values of the oil were 186.33 ± 0.46 μg/mL and 109.41 ± 0.43 μg/mL. The hydrogen peroxide and nitric oxide radical scavenging IC50swere 103.45 ± 0.58 μg/mL and 190.55 ± 0.75 μg/mL, respectively. The AChE inhibitory IC50value was 156.33 ± 0.44 μg/mL. Conclusion: The study demonstrated on essential oil extracted from rhizomes of C. caesia indigenous to Arunachal Pradesh, India, has moderate anti-oxidant property and would be a valuable non-toxic source for managing neurodegenerative diseases.