Author(s):
Dias, Maria Inês 
; Calhelha, Ricardo C. ; Barreira, João C.M. ; Queiroz, Maria João R.P. ; Oliveira, M.B.P.P. ; Soković, Marina ; Ferreira, Isabel C.F.R.
Date: 2013
Persistent ID: http://hdl.handle.net/10198/9403
Origin: Biblioteca Digital do IPB
Subject(s): Antimicrobial; Antitumorals; Laurus nobilis L.; PCA; Phenolic compounds
Description
Laurus nobilis L. (Laureaceae), commonly known as laurel, is a native plant from the Mediterranean region. Most
widely used as culinary spice, it is also consumed as infusion to treat some gastrointestinal problems (Dall’Acqua
et al., 2009) and has been reported as a rich source of bioactive compounds namely, essential oils and phenolic
compounds (Dadalioğlu et al., 2004; Dias et al., 2013).
In the present work, methanolic and aqueous extracts of wild and cultivated L. nobilis were studied for their in
vitro antitumor (against five different human tumor cell lines) and antimicrobial (antibacterial and antifungal)
activities. Furthermore, a two-dimensional principal component analysis (PCA) was used to understand how each
extract act differentially towards specific bacterial and fungal species, and also selected human tumor cell lines.
Both assayed factors, origin (wild or cultivated) and extract type (methanolic or aqueous) act in a differentiated
manner; i.e., the same evaluated parameter gave sometimes statistically significant differences regarding laurel
origin, but no effect at all from extract type, or vice versa. Nevertheless, the extract type induced the most marked
changes in bioactivity of laurel samples. From the PCA biplot, it became clear that wild samples were more
effective to inhibit tumor cell lines growth, especially HeLa, MCF7, NCI-H460 and HCT15. It was also observed
that methanolic extracts tended to have higher antimicrobial activity, except for Aspergillus niger, Aspergillus.
fumigatus and Penicillium verrucosum. The differences in bioactivity might be related to the higher phenolic
compounds content (flavonols, flavones and even, total phenolic compounds) presented by methanolic extracts,.
The most interesting finding in this work was the bioactive specificity of each laurel extract, considering its wild or
cultivated origin. Moreover, from the PCA biplot obtained is possible to choose the combination extract type/origin
with potentially highest effect against determined bacteria, fungi or tumor cell line, depending on the objective of
the study.
