Antimicrobial flavonoids isolated from Indian medicinal plant Scutellaria oblonga inhibit biofilms formed by common food pathogens

Abstract

Scutellaria oblonga Benth., a hitherto phytochemically unexplored Indian medicinal folklore plant was extracted with acetone and subjected to chromatography to yield nine flavonoids, for the first time from this plant. Antimicrobial assays were performed against 11 foodborne pathogens, and three molecules (Techtochrysin, Negletein and Quercitin-3-glucoside) depicted significant activity. These molecules were assessed for their rate of antibacterial action using time–kill curves which depicted complete inhibition of most of the bacteria within 12–16 h. The significant biofilm-reducing capability exhibited by these three molecules formed a significant finding of the current study. In most of the experiments, a 90–95% reduction in biofilms was observed. Thus, flavonoids as natural molecules from S. oblonga could be further researched to be used as potent antimicrobial and antibiofilm agents.

Keywords:

• Scutellaria oblonga
• food pathogens
• flavonoids
• biofilm inhibition

Acknowledgement

The authors would like to thank the Management, Sastra University, for providing the necessary facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The financial support of Department of Science and Technology, Government of India, under fast track scheme (SR/FT/CS-10/2011) is earnestly acknowledged.