• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.361-366
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• 2014

In this study, Glycyrrhiza uralensis and Glycyrrhiza glabra extracts, with their countries of origin as Korea (Jecheon), Uzbekistan and China, were prepared under various extraction conditions. There were 8 extraction conditions which the licorice were subjected to, and all conditions had different extraction solvents, temperatures and times. Antimicrobial activity on skin flora was evaluated comparatively by a disc diffusion assay, broth macrodilution assay, and kill time curve assay. Based on the antimicrobial activity of their extract confirmed by disc diffusion assay, we established optimal extraction conditions. The Korean licorice extract (85% ethanol, $40^{\circ}C$, 12 h) showed the best activity amongst the samples examined. In particular, its antimicrobial activity against Propionibacterium acnes was the highest. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the licorice extracts revealed that the Korean licorice ($156{\mu}g/ml$ and $1,250{\mu}g/ml$) had better antimicrobial activity than that of the Uzbekistani licorice ($625{\mu}g/ml$ and $2,500{\mu}g/ml$) and the Chinese licorice ($625{\mu}g/ml$ and $5,000{\mu}g/ml$). Taken together, it was shown that Korean licorice extracted in group F (85% ethanol, $40^{\circ}C$, 12 h) had the highest antimicrobial activity amongst the licorices from the other countries of origin. These results also suggest that the optimal extraction conditions are 85% ethanol, $40^{\circ}C$, 12 h, and that licorice has a potential application as a natural preservative in cosmetics products, thereby replacing synthetic preservatives.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.250-260
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• 2012

In the present study, the antioxidative and antibacterial activities of Artemisia princeps Pampanini (A. princeps Pamp.) extract were investigated. The ethyl acetate fraction of A. princeps Pamp. showed the most prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}=12.27{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of A. princeps Pamp. extract on $Fe^{3+}-EDTA/H_2O_2$ systems were investigated using a luminol-dependent chemiluminescence assay. The ethyl acetate fraction of the extract ($OSC_{50}=0.33{\mu}g/mL$) had a 5 times greater ROS scavenging activity than L-ascorbic acid ($1.50{\mu}g/mL$), known as a water soluble antioxidant. The cellular protective effects of fractions of A. princeps Pamp. on the rose-bengal sensitized photohemolysis of human erythrocytes were examined. The aglycone fraction of extracts suppressed photohemolysis in a concentration dependent manner. The inhibitory effects of A. princeps Pamp. extract on tyrosinase were investigated to assess their whitening efficiency. The ethyl acetate fraction demonstrated a 7 times higher tyrosinase inhibitory effect ($IC_{50}=29.20{\mu}g/mL$) than albutin, known as a whitening agent. The antibacterial activity of ethyl acetate fractions against various normal skin flora were measured. The results showed that the antibacterial activity of the fraction was the highest on Staphylococcus aureus, Bacillus subtilis, and Propionibacterium acnes. Antioxidant substances were isolated and purified from the ethyl acetate fractions. Eupatilin and jaceosidin were identified. These results indicate that the extract/fractions of A. princeps Pamp. can function as antioxidant and/or antibacterial agents for the skin.