Changes in Antioxidant and Antibacterial Activity and in Phenolic Compounds Levels Due to the Pesticide Residues
Abstract
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Propolis has many
known pharmacological properties. However, acaricides insecticides and
herbicides are contaminants that can be found in propolis. This residues
derive from contamination generated by agricultural practices and the
application of pesticides in the hive. As far as we know, there are not works
that study if the presence of these contaminants could modify the biological
properties of the propolis. Thus, this was the main objective of this
research. To do that, 44 samples of propolis from Chile (Biobio region n=10)
and Spain (Galicia n=12 and Castilla y León n=22). were analysed. The
pesticides were quantified using Gas Chromatography-Mass Spectrometry
(GC-MS). Phenolic acid and derivatives were analysed by HPLC and
antibacterial activity by Five-Plate tests. Total polyphenols were quantified
by Folin-Ciocalteaus method and total flavones and flavonols using AlCl3
colorimetric reaction. Antixidant capacity were determined by ABTS, DPPH and
inhibiting activity of the linoleic acid/-caroten radical methods. Results
show that 70% of samples contained triadimefon (0.4 a 42.2 mg/Kg) and 7.5%
showed residues of dicofol, dichlofluanid, folpet, propham and metazachlor. The phenolic contents and
antioxidant and biocide activities of samples with pesticide residues were
compared with those free of contaminants. Results show that samples with
pesticide residues have lower antioxidant capacity estimated by any of the
assayed methods. The biocide properties similar to antibiotics was also lower
in samples contaminated with pesticides. A significant decrease of phenolic
acids such as cafeic, isoferulic and DMC acids were observed together with a
slight decrease of total polyphenols and flavonoids. |
Keywords
Phenolic Compounds,Antibacterial Activity,Antioxidant activity
References
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