Chemical profiling, antioxidant, antimicrobial and antibiofilm activities of Vitex pinnata leaf essential oil: a rare species

Vitex pinnata (Lamiaceae), is used to treat jaundice, malaria, epilepsy, stomach ache, fever, hypertension, bone fractures, etc worldwide. Very few records are available on chemical profiling along the with biological roles of leaf essential oil. The current study focuses on determining the chemical constituents of V. pinnata leaf essential oil (VPLEO) with antioxidant, antimicrobial, and biofilm inhibition activities. V. pinnata leaves were hydrodistilled for oil extraction and chemical constituents were identified through GC-MS analysis. allo-aromadendrene (15.44%) and γ-amorphene (14.15%) were found to be the major constituents. This VPLEO exhibited antioxidant potency in both ABTS and DPPH assays with IC50 values of 1.1 mg/ml, and 5 mg/mL, respectively. Significant bactericidal action was found against both the tested multidrug-resistant strains with a strong antimicrobial action against Stephylococcus aureus having minimum inhibitory concentration (MIC) value of 12.5 µL/mL than Kebsiella pneumoniae with 25 µL/mL MIC value. At the 1/2MIC concentration of essential oil (12.5 µL/mL), K. pneumoniae biofilm development was efficiently reduced by 84.85% which was further confirmed by scanning electron microscope (SEM) analysis. The findings demonstrated that VPLEO may be considered as an important alternative against biofilms formed by pathogenic bacteria and yeasts, as well as a potential bioresource for pharmaceutical industries.