Curcumin is widely used to convey the color and taste of food, but scientists have found that this yellow powder derives from the roots of turmeric (Curcuma longa) can also help prevent or fight stomach cancer.
The study by researchers at the Federal University of São Paulo (UNIFESP) and the Federal University of Courage (UFPA) in Brazil identified the possible therapeutic effects of this pigment and other bioactive ingredients found in food for stomach cancer, the third and fifth most common type of cancer in Brazilian men and women, respectively.
The study was part of a thematic project supported by the FoSESP Research Foundation in Sao Paulo. Her findings are published in the journal Epigenicemia.
"We made a huge overview of the scientific literature on all nutrients and bioactive compounds with the potential to prevent or treat stomach cancer and found that curcumin is one of them," said Daniel Ciroz Calgano, a professor at UFPA and the first author of the study for.
According to Kalkano, who conducted a post-doctoral study of UNIFESP with a FAPESP scholarship, compounds such as cholecalciferol (a form of vitamin D), resveratrol (polyphenol) and quercetin can prevent or fight gastric cancer because they are natural histone regulators activity.
Histons are proteins in cellular nuclei that organize the double helix of DNA in structural units called nucleosomes. Each nucleus is made of DNA bent as a coupling around eight histone proteins (histone octamer) to compile DNA so it fits into the cell where it is packaged in chromatin.
Posttranslational chemical modification of the amino acid chain in these proteins, such as acetylation (acetyl group introduction) or methylation (addition of methyl group), can affect the compression of chromatin, and hence the gene expression.
"If histones are acetylated, for example, chromatin will be less condensed, and the gene in the region of the DNA DNA segment will be available to express it. Conversely, if the histones are not acetylated, the chromatin will be more condensed and the gene will not be expressed, "explained Calgano.
A survey conducted in recent years suggests that post-transplant histone modification causes changes in gene expression without affecting the DNA sequence. These epigenetic variations affect the development of different types of cancer.
To determine if this hypothesis was applied to stomach cancer, several groups of researchers coordinated by Maria de Arruda, Cardozo Smith, a UNIFESP professor, studied histone acidic patterns in stomach-like samples from healthy individuals and cancer patients diagnosed with on the stomach.
The researchers found that cells from patients with stomach cancer showed changes in the expression of histone acetyltransferase (HATs) and histone deacetylases (HDACs). These changes are epigenic and affect the structure and integrity of the genome in many tumors, including stomach cancer.
As recent studies have also shown that nutrients and bioactive compounds can regulate the activity of HATs and HDACs, UNIFESP and UFPA scientists are trying to identify which could affect histone acetylation and thereby help prevent cancer stomach or even to treat diseases.
In addition to kerumin, other compounds that are found to play a key role in modulating the activity of histone were cholecalciferol, resveratrol (present mainly in grape seeds and red wine), quercetin (abundant with apples, broccoli and onions), garcinol (isolated from the bark of tree coconut, Garcinia indica) and sodium butyrate (produced from intestinal bacteria through the fermentation of dietary fiber).
"These compounds can support the activation or repression of genes involved in the development of stomach cancer by promoting or inhibiting histone acetylation," said Calgiano.
Curcumin, for example, affects the histone modification primarily by inhibition of HATs and HDACs to suppress the proliferation of cancer cells and cause apoptosis (programmed cell death). Garcinol, whose chemical structure is similar to that of curcumin, inhibits HATs and helps prevent stomach cancer by neutralizing free radicals.
"We are now planning to clarify the anticancer and epigenetic effects of bioactive compounds derived from plants in the Amazon, such as açaí [Euterpe oleracea] and a ninja or gall [Byrsonima crassifolia], given their future use in the prevention and treatment of stomach cancer, "said Calgiano.