Antiquorum Sensing Activity of Methanolic Seed (Nutmeg) Extract of Myristica Fragrans Against a Gram-Positive Bacterium

Abstract

The increase in multidrug-resistant pathogens has created new anti-pathogenic and anti-virulence compounds. This is because of the behavioural changes bacteria acquire, such as increased antibiotic resistance and virulence capacity. This social behaviour is maintained through a signalling transduction pathway called Quorum sensing. The present study aims to evaluate the inhibition of quorum sensing in Bacillus subtilis with Myristica fragrans seed extract. The seed of M. fragrans is called nutmeg. Methanolic nutmeg extract was used to test the anti-quorum sensing activity of B. subtilis. Total flavonoid and phenolic concentrations of nutmeg were estimated. 10 μg/ml, 30 μg/ml, 50 μg/ml, 70 μg/ml and 90 μg/ml concentrations of nutmeg extract were used to check against bacterial motilities and biofilm formations. Inhibition of biofilm formation was observed under a fluorescence microscope, and inhibition of swimming and swarming motilities were observed on 0.3 % and 0.5 % agar plates, respectively. These observations suggest that the seed of M. fragrans showed anti-quorum sensing activity against B. subtilis. This research work helps to study and isolate natural quorum-sensing inhibitors from medicinal plants. These inhibitors can synthesize novel anti-pathogenic or anti-virulence drugs that combat bacterial infections by interrupting with quorum-sensing controlled phenotypes and decreasing bacterial virulence.