Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Apr 19;18(4):4651-68.
doi: 10.3390/molecules18044651.

Evaluation of biological value and appraisal of polyphenols and glucosinolates from organic baby-leaf salads as antioxidants and antimicrobials against important human pathogenic bacteria

Alfredo Aires  1 , Esperança Marques, Rosa Carvalho, Eduardo A S Rosa, Maria J Saavedra
Affiliations

Evaluation of biological value and appraisal of polyphenols and glucosinolates from organic baby-leaf salads as antioxidants and antimicrobials against important human pathogenic bacteria

Alfredo Aires et al. Molecules. .

Abstract

The present investigation has been carried out to investigate the biological role of four different types of baby-leaf salads and to study their potential as natural sources of antioxidants and antimicrobials against several isolates from important human pathogenic bacteria. Four single types of salads (green lettuce, red lettuce, rucola and watercress) and two mixtures [(1) red lettuce+green lettuce; (2) green lettuce + red lettuce + watercress + rucola] were assayed. The HPLC analysis revealed interesting levels of polyphenols and glucosinolates. The results showed a significant variation (p < 0.05) of polyphenols and glucosinolates with plant material. Nine different types of polyphenols grouped in three major classes were found: gallic acid, chlorogenic acid, caffeic acid and dicaffeoyltartaric acid (phenolic acids); quercitin-3-O-rutinoside, quercitin-3-O-rhamnoside, luteolin-7-O-glucoside and isorhamnetin (flavonoids); and cyanidin-3-glucoside (anthocyanins). Only three different glucosinolates were found: glucoraphanin; gluconasturtiin and 4-methoxy-glucobrassicin. A positive correlation was detected between polyphenol contents and antioxidant activity. Red lettuce and mixture 1 were the baby-leaf salads with the highest antioxidant potential. As for the antimicrobial activity, the results showed a selective effect of chemicals against Gram-positive and Gram-negative bacteria and Enterococcus faecalis and Staphylococcus aureus were the bacteria most affected by the phytochemicals. Based on the results achieved baby-leaf salads represent an important source of natural antioxidants and antimicrobial substances.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Example of a HPLC chromatogram of polyphenols detected in a red lettuce baby-leaf extract recorded at 370 nm.
Figure 2
Figure 2
HPLC chromatogram of glucosinolates detected in a watercress (A) and rucola (B) baby-leaf extract recorded at 229 nm.
Figure 3
Figure 3
Multivariable analysis results: (1) gallic acid (2) chlorogenic acid; (3) caffeic acid; (4) cyanidin-3-glucoside; (5) quercetin-3-O-rutinoside; (6) Luteolin-4-O-glucoside; (7) caffeic derivatives; (8) quercetin-3-O-rhamnoside; (9) Isorhamnetin.
See this image and copyright information in PMC

References

    1. Cushnie T.P.T., Lamb A.J. Antimicrobial activity of flavonoids. Int. J. Antimicrob. Ag. 2005;26:343–356. doi: 10.1016/j.ijantimicag.2005.09.002. - DOI - PMC - PubMed
    1. Zhang Y., Seeram N.P., Lee R., Feng L., Heber D. Isolation and identification of strawberry phenolics with antioxidant and human cancer cell antiproliferative properties. J. Agric. Food Chem. 2008;56:670–675. doi: 10.1021/jf071989c. - DOI - PubMed
    1. Talalay P., Fahey J.W. Phytochemicals from cruciferous plants protect against cancer by modulating carcinogen metabolism. J. Nutr. 2001;131 (Suppl. 11):S3027–S3033. - PubMed
    1. Kunyanga C.N., Imungi J.K., Okoth M.W., Biesalski H.K., Vadivel V. Flavonoid content in ethanolic extracts of selected raw and traditionally processed indigenous foods consumed by vulnerable groups of Kenya: antioxidant and type II diabetes-related functional properties. Int. J. Food Sci. Nutr. 2011;62:465–473. - PubMed
    1. Shahidi F., Liyana-Pathirana C.M., Wall D.S. Antioxidant activity of white and black sesame seeds and their hull fractions. Food Chem. 2006;99:478–483. doi: 10.1016/j.foodchem.2005.08.009. - DOI

Publication types

MeSH terms