Evaluation of Antioxidant and Anti-Inflammatory Activity of Acorus calamus Essential Oil Using in Silico and in Vitro Methods

Abstract

Background: Acorus calamus is a perennial herbaceous plant indigenous to wetlands in Asia and Europe. It is also known by the common names Sweet Flag and Calamus. Traditional medicine and perfumery have long utilized its unusual sword-shaped leaves and scented rhizomes. In addition to being treasured for its possible therapeutic benefits, it is a cultural emblem in many communities. The current study investigates the composition of phytoconstituents of Acorus calamus essential oil (ACEO), assesses its drug-likeness properties, performs molecular docking studies with interleukin (IL)-1β, and evaluates its antioxidant and anti-inflammatory activities. Methods: Gas Chromatography-Mass Spectrometry (GC-MS) was used for the analysis of phytoconstituents present in the ACEO. In silico studies were carried out to determine the pharmacokinetics, toxicity, drug-likeliness and interaction of ACEO phytoconstituents with IL-1β. In vitro assays, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and protein denaturation inhibition, were done to investigate the potential antioxidant and anti-inflammatory activities of the bioactive molecules present in ACEO, respectively. Results: GC-MS analysis revealed the presence of 20 secondary metabolites with (Z)-Asarone as the major component (91.44%). In silico analysis showed the drug-likeness of (Z)-Asarone, isoshyobunone, and γ-Asarone. Molecular docking revealed strong binding affinities of these compounds with IL-1β. In vitro experiments demonstrated ACEOs significant (p < 0.01) antioxidant activity at the concentrations 6 and 12 μg/mL with an IC₅₀ value of 6.68 μg/mL, comparable to the standard (ascorbic acid, IC₅₀ = 3.69 μg/mL). ACEO also exhibited significant (p < 0.05) protein denaturation inhibition compared to diclofenac sodium (IC₅₀ = 365.43 μg/mL vs. 446.20 μg/mL). Conclusion: Acorus calamus essential oil primarily composed of (Z)-Asarone, possesses potential antioxidant and anti-inflammatory properties. These findings suggest its therapeutic potential in addressing oxidative stress-related conditions and inflammation-associated diseases, warranting further investigation and development as a natural remedy.