Evaluation of Bioactive Compounds from Paeonia emodi of Uttarakhand through Molecular Docking: Antimicrobial and Antioxidant Potential

Abstract

In the present study, the essential oil of Paeonia emodi Wall. ex-Royle was investigated for its chemical composition and antimicrobial and antioxidant potential, which was also complemented with molecular docking studies. Paeonia emodi, locally known as Chandra, belongs to the family Paeoniaceae, is an important medicinal plant of the Himalayan region, growing from Kashmir to the Garhwal–Kumaon Himalaya of Uttarakhand, India, between 1800 and 2800 m above sea level (ASL). The essential oil was obtained by hydrodistillation of 500 g of plant matter, and the amount of essential oil obtained was 0.05% (v/w), or approximately 250 μl of essential oil, and its volatile components were identified by GC–MS. The main components found were 2-propenal (84.70%), bicyclo[3.1.1]heptane-2-carboxaldehyde (6.27%), and (1R)-(-)-myrtenal (3.15%). The essential oil showed antibacterial activity against six pathogenic bacteria, with the maximum inhibition zone at 100 µL/mL of the essential oil against S. pneumoniae (21.45 ± 0.21 mm), followed by K. pneumoniae (18.65 ± 0.35 mm) and E. coli (16.80 ± 0.14 mm). The MIC and MBC values ranged from 0.094–3.125 mg/ml and 0.188–6.250 mg/ml, respectively. The oil also exhibited antifungal activity against Candida albicans with an inhibition zone of 16.70 ± 0.28 mm, while the oil's antioxidant activity was shown by both the DPPH and ABTS assays with IC50 values of 14.56 µg/mL and 75.46 µg/mL, respectively. On molecular docking analysis, propenal shows a binding affinity range of −4.6 to −5.3 kcal/mol, while bicycloheptane shows a binding affinity range of −5.1 to −6.1 kcal/mol, with the best binding affinity for bicycloheptane with 8JTP (−6.1 kcal/mol). The results show that the essential oil of P. emodi is a valuable source of bioactive compounds showing antimicrobial and antioxidant activity and can be further explored for natural therapeutic applications.