4 research outputs found
Portuguese propolis: A potential source of environmentally friendly biofungicides
[Excerpt] The need to increase food production to feed an increasingly growing world population has led to an intensive use of pesticides. Globally, 4.6 million tons of chemical pesticides are sprayed into the environment every year1 . Out of the total
consumption of pesticides, 17.5% are in the form of fungicides. However, pesticides
have undesirable characteristics, such as the development of pathogen resistance and
long degradation periods, and negative impacts on the environment, like soil and water
pollution, bioaccumulation in the food chain, toxicity to non-target organisms and
public health problems2
. Therefore, new environmentally friendly natural products,
which are effective, safe, biodegradable and leave no harmful residues are needed. [...]The need to increase food production to feed an increasingly growing world
population has led to an intensive use of pesticides. Globally, 4.6 million tons of
chemical pesticides are sprayed into the environment every year1
. Out of the total
consumption of pesticides, 17.5% are in the form of fungicides. However, pesticides
have undesirable characteristics, such as the development of pathogen resistance and
long degradation periods, and negative impacts on the environment, like soil and water
pollution, bioaccumulation in the food chain, toxicity to non-target organisms and
public health problems2
. Therefore, new environmentally friendly natural products,
which are effective, safe, biodegradable and leave no harmful residues are needed.
Propolis is a natural resinous mixture made by honeybees (particularly Apis
mellifera L.) from various plant sources and processed with salivary secretions. More
than 300 different compounds have been identified so far in propolis, including several
bioactive compounds such as flavonoids and phenolic acids and derivatives, which are
characteristic of plant secondary metabolism and are related with diverse biological
properties like antimicrobial and antioxidant activities3
. In this work we evaluated the
antifungal activity of ethanolic extracts (EE) from Portuguese propolis samples against
phytopathogenic fungi species responsible for considerable damage in several
economically important crops. Results showed that different propolis samples have
different fungitoxic efficiencies but also that different species exhibit different
susceptibilities. Globally, these findings suggest that propolis EE can be explored as
source of biofungicides for application in a more sustainable agriculture management.
In order to evaluate this propolis application, its phytotoxicity will be studied using in
vitro flax plants (Linum usitatissimum L.)
Potential of Portuguese propolis as source of biofungicides
Agriculture provides livelihoods for 40% of worldwide population1
. Due to the
rapid human population growth, it is estimated that global food production will need to
increase by 60% to feed over 9.8 billion people by 20502
. The use of pesticides contributes
to high crop yields and effective farm management3
. Globally, 4.6 million tons of
chemical pesticides are sprayed into the environment every year4,5. Out of the total
consumption of pesticides, 17.5% are in the form of fungicides5
. Although efficient, these
chemical controls have undesirable characteristics, such as the development of pathogen
resistance, environmental pollution, long degradation periods, bioaccumulation in the
food chain and toxicity to non-target organisms6
. Therefore, alternative paths to the
intensive use of crop protection chemicals are needed, such as the use of natural products
which are effective, biodegradable and leave no harmful residues.
Propolis is a natural resinous mixture made by honeybees (particularly Apis
mellifera L.) from various plant sources and bee wax. Hundreds of different compounds
have been identified so far in propolis, including several bioactive compounds such as
flavonoids and phenolic acids and terpene derivatives, generally associated to its
antibacterial, antifungal, antiviral and antioxidant activities, among others7
.
Previous work showed that propolis ethanol extracts (EEs) can be explored as
source of biofungicides for application in a sustainable agriculture management 8. In this
study we evaluated the antifungal activity of EEs from Portuguese propolis samples
against a range of phytopathogenic fungal species that affect economically important
crops in Portugal. Interestingly, results showed that different propolis samples have
distinct fungitoxic activities but also that different fungi species exhibit distinct
susceptibilitiesFEDER/COMPETE/POCI– Operational
Competitiveness and Internationalization Programme, under Project POCI-01-0145-FEDER-006958 and
National Funds by FCT - Portuguese Foundation for Science and Technology, under the project
UID/AGR/04033/201
Mechanistic studies of cytotoxicity induced by a Portuguese propolis extract, using Saccharomyces cerevisiae as eukaryotic cell model
Propolis is a natural complex mixture produced by honey bees (particularly Apis mellifera
L.) by collecting exudates from various plant sources. Characterized by a plethora of
chemicals, propolis is generally rich in flavonoids, phenolic acids and terpene derivatives,
bioactive compounds associated to it’s antimicrobial, anti-inflammatory, antimutagenic
and antioxidant activities1
. Previous work had shown that the ethanol extract of a sample
from the Portuguese region of Beira Alta exhibited unique dual genotoxic and
antigenotoxic effects using the yeast S. cerevisiae eukaryotic model2
. In this work we
prepared two ethanol extracts (EE) of propolis samples from Pereiro (P) - Beira Alta -
collected in 2010 (P10.EE) and 2017 (P17.EE) to investigate the mechanisms of
cytotoxicity and genotoxicity using specific S. cerevisiae mutants. While P17.EE didn’t
show any toxic effect, yeast cells exposed to P10.EE showed a considerable decreased
viability along time, assessed by colony-forming units. Interestingly, the oxidative stress
response-defective mutant yap1 was more resistant than the wild type, suggesting that
this cytotoxic effect was not mediated by oxidative stress. P.EE’s genotoxicity was also
analysed by the nucleus-cytosolic translocation of NHP6A protein, considered a marker
of necrosis. P10.EE induced NHP6A protein translocation to the cytoplasm, observed by
fluorescence microscopy, suggesting that cytotoxicity of this extract was indeed mediated
by necrosis. Although P17.EE didn’t seem to induce necrotic cell death, both extracts
induced plasma membrane integrity loss, assessed by flow cytometry, using propidium
iodide as marker. As recently observed for erythroleukemic cells with Brazilian propolis3
,
here we present the first evidence that also Portuguese propolis have necrotic-mediated
cytotoxicity in yeast cellsEDER/COMPETE/POCI–
Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145-
FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and
Technology, under the project UID/AGR/04033/201
Portuguese propolis: a source of valuable bioactivities
To FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization
Programme, under Project POCI-01-0145-FEDER-006958 and FCT - Portuguese Foundation for Science and
Technology, under the project UID/AGR/04033/2013