Chemical Profiling, Free Radical Scavenging and Anti‑acetylcholinesterase Activities of Essential Oil from Curcuma caesia of Arunachal Pradesh, India

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 IC50s were 103.45 ± 0.58 µg/mL and 190.55 ± 0.75 µg/mL, respectively. The AChE inhibitory IC50 value 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.