Wild thyme (Thymus serpyllum L.) of family Laminaceae is an unexplored perennial medicinal shrub. Aerial part of this plant is traditionally used for the treatment of respiratory and gastrointestinal problems. The current study was designed to evaluate the GC-MS, antimicrobial and synergistic potential of T. serpyllum essential oil (TEO). Chemical characterization of TEO showed the presence of thymol (15.79%), Phenol, 2-(1,1-dimethylethyl) (11.55%), o-Cymene (10.96%) as major phytocompounds. Antimicrobial activity of TEO in terms zone of inhibition (ZOI) varied from 13.66 ± 0.58 mm to 33.66 ± 1.52 mm, while, thymol (10%, v/v) showed ZOI ranged from 15.5 ± 0.5 mm to 26.33 ± 2.08 mm against tested bacterial and fungal species. MIC of TEO was 0.039% to 0.078% against tested bacterial and fungal species, whereas, thymol showed 1.25% to 2.5% MIC against tested bacterial and fungal species. Different combinations of TEO (2MIC to ½MIC) and thymol (2MIC to ½MIC) with antibacterial and antifungal antibiotics (2MIC to ½MIC) were found to increase the efficacy of antibiotics by 4-130 folds against bacterial and fungal pathogens. Molecular docking showed the good binding of thymol with both bacterial and fungal targets. Whereas MD simulation showed the stability of thymol complexed with target proteins over 100 ns time scale. Thymol also fulfills the Lipinski rule and showed characteristics similar to that of drugs. Therefore, it can be concluded from the present study that TEO and its major phytocompound, thymol can act as a bioactivity enhancer of antibacterial and antifungal antibiotics and could be used as a potential candidate to fight against antimicrobial drug resistance.Communicated by Ramaswamy H. Sarma.
Keywords: Antimicrobial; MD simulations; Molecular docking; Synergistic; Thymus serpyllum.