Highlights:
- Strawberry
extract can inhibit the spread of laboratory-grown breast cancer cells to
healthy tissue in mice.
- The extract
decreased cell viability, blocked the cycle leading to cell division and
inhibited migration.
- Scientists do
point out that the results from animal testing do not apply to humans
until tested.
Berries, especially strawberries, have numerous bioactive compounds that
help deal with diseases and promote overall health. Strawberries are also
called superfoods because of their antioxidant value.
A recent study done in mice shows that polyphenol-rich strawberry
extract (PRSE), obtained from the "Alba" variety, reduces the highly
aggressive and invasive basal-like breast cancer cell line A17.
‘Strawberry extract inhibits the spread of breast cancer cells in female mice, even when they are inoculated to induce tumors.’
Strawberry Effect
Strawberries
are a rich source of
folate, vitamin C and several phytochemicals. The high levels of antioxidant
compounds, most of which are phenolic compounds such as anthocyanins,
flavonols, flavanols, condensed tannins, hydroxybenzoic and hydroxycinnamic
acid derivatives, have the ability to lower the severity of diseases.
'Alba',
a variety of strawberry was extracted and presents high levels of Vitamin C
(0.57 mg/g) and phytochemical compounds.
Bioactive
compounds in strawberries prevents cancer progression but involves different
mechanisms, which have not yet been fully elucidated.
"We have shown for the
first time that strawberry extract, rich in phenolic compounds, inhibits the
proliferation of breast cancer cells in in vitro and in vivo models," said
Maurizio Battino, co-author of the paper and a principal investigator at the
Marche Polytechnic University (Italy) and the European University of the
Atlantic in Santander (Spain).
Tumor
growth, recurrence and metastasis formation are dependent on certain cells
called cancer initiating cells (CICs) or cancer stem cells (CSCs). They are
self-renewing cells. A17 cells are a highly tumorigenic and display properties
of CICs and basal-like breast cancer.
For the
study, the in vitro model used A17 tumour cell line.
These were treated with different concentrations (between 0.5 and 5 mg/ml) of
extract of the Alba variety of strawberry, for periods of 24, 48 and 72 hours.
Previous investigations have
shown that the intake of 500 g of strawberries (between 10 and 15 strawberries)
per day offers antioxidant and anti-inflammatory benefits and reduces blood
cholesterol levels. But the group of phytochemicals responsible for cancer
prevention was unknown.
The results of the study
demonstrated that
strawberry extract reduced the expression of several genes
involved in the processes of invasion and metastasis, such as Csf1, Mcam,
Nr4a3 and Set.
Htatip2, a gene that is
thought to suppress metastasis to the lymphatic ganglion in breast cancer
patients was stimulated after the ingestion of the
extract.
Testing the Extract
The effect of Alba strawberry
extract was tested in female laboratory mice. They were divided into two
groups: one was given a standard diet, while the other group was given a diet;
15% of which was strawberry extract. Breast cancer was induced in the mice
after a month using A17 breast cancer cells.
The tumors were monitored twice
weekly and after 5 weeks, the tumors were extracted and analysed to evaluate
their weight and volume.
The study found that
supplementing
the daily diet with strawberry extract stopped the propagation of cancer cells
to adjacent the healthy tissue. "We also saw a significant reduction
in the weight and volume of the tumor," Battino stresses.
"The majority of diseases,
including cancer, are complex, and involve complex interactions between
cellular and molecular systems that determine the development of the disease."
The authors also added, "these
results are without a doubt valid for understanding potential effects of
strawberries on breast cancer and the molecular mechanisms involved, but they
must be complemented with clinical and epidemiological studies to verify
whether humans experience the same positive effects as we have observed in
mice."
The
effect of the extract is significantly higher in breast cancer A17cell lines,
suggesting a therapeutic window for PRSE
in vivo.
The concentration of phenolic
compounds can vary greatly between varieties of strawberry. Apart from
strawberries, a balanced diet with fruits and vegetables, and a healthy active
lifestyle also have the potential to protect against cancer.
References :- Polyphenol-rich strawberry extract (PRSE) shows in
vitro and in vivo biological activity against invasive breast cancer
cells - (https://www.ncbi.nlm.nih.gov/pubmed/27498973)
Source: Medindia
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