Antimicrobial Activity of Scutellaria Baicalensis Extract with Different Solvents against Escherichia coli

Abstract

Background: Huang Qin (Scutellaria baicalensis, S. baicalensis) has been used to treat various diseases such as fever, diarrhea, and dysentery. Escherichia coli (E. coli) is a standard part of intestinal microbiota and the common cause of several diseases that come with diarrhea, stomach cramps, and fever.

Objectives: This paper aimed to determine the antimicrobial activity of S. baicalensis extract with different solvents (water, ethanol, and ethyl acetate) against E. coli.

Materials and Method: S. baicalensis is ground into powder and macerated in solvents until exhausted and extracted via evaporation under vacuum. The water extract S. baicalensis (WHQ), ethanol extract S. baicalensis (EtOHHQ), and Ethyl Acetate extract S. baicalensis (EtOAcHQ) dissolved in dimethyl sulfoxide (DMSO). The agar wall diffusion method was used to test antimicrobial activity. The microdilution method determined the minimum inhibitory concentration (MIC) of the extractions. The extractions' minimum bactericidal concentration (MBC) was evaluated from the agar plate, and no microbial growth area was observed.

Results: The average inhibition zone in MIC of EtOHHQ was 7.33 ± 0.58 mm, EtOAcHQ was 7.67 ± 0.58 mm, Baicalein was 7.67 ± 0.58 mm, while Gentamicin showed 16.33 ± 0.58 mm. MIC of EtOHHQ, EtOAcHQ, and Baicalein were > 2,000 μg/ml, while MIC of Gentamicin was 6.25 μg/ml. MBC of EtOHHQ, EtOAcHQ, and Baicalein were > 2,000 μg/ml, while MBC of Gentamicin was 6.25 μg/ml. WHQ and Baicalin did not show antimicrobial activity against E. coli.