The key facts

  • Quercetin from citrus fruits, onions and buckwheat slowed the growth and movement of lung cancer cells in the laboratory
  • In mice, EGFR and PD-L1 levels decreased, interferon alpha-2 increased, and gut microbiota changed
  • The effect in humans has not been studied; further research is needed

A natural compound against tumor cells

Scientists at the University of Erlangen–Nuremberg have established that quercetin — a natural compound found in citrus fruits, onions and buckwheat — can slow the growth and spread of lung cancer cells. The results of the work were published in the journal Cell Death Discovery.

What the experiments showed

The researchers studied the effect of the substance on lung cancer cells, lung tissue of mice and living animals. In laboratory conditions, quercetin slowed the division of tumor cells and suppressed their motility, which plays an important role in the spread of cancer and the formation of metastases. The effect increased with rising concentration: at the maximum dose, cell movement practically ceased. According to the study, quercetin also reduced the levels of the proteins EGFR and PD-L1, which are associated with tumor growth and the ability of cancer cells to evade the immune response, and in the lung tissue of mice the content of interferon alpha-2, involved in protecting the body, increased.

Microbiota changes and limitations of the work

The animals showed changes in gut microbiota: the number of bacteria capable of producing substances that suppress the growth of tumor cells increased. There were also signs of a reduction in the number of tumor foci, but this result, the authors note, requires additional verification. The scientists believe that quercetin could be used as an additional agent in the treatment of lung cancer, but so far its effectiveness has been studied only in the laboratory and in animals. Further research is needed to establish whether the substance acts in the same way in humans.