Flavonoid found in citrus slows lung cancer cell growth in lab tests

Quercetin, a flavonoid found in citrus fruits, onions, and buckwheat, has been found to inhibit the growth of lung cancer cells in laboratory experiments. Researchers at Universitätsklinikum Erlangen at Friedrich-Alexander Universität Erlangen-Nürnberg (FAU) investigated the compound's potential use in treating lung cancer. In the lab, quercetin slowed lung cancer cell division and significantly reduced their migration, especially at higher doses.

The plant compound also decreased oxidative stress in lung cancer cells and decreased levels of two proteins, EGFR and PD-L1, which are involved in tumor growth and immune evasion. Quercetin increased the production of interferon-alpha-2, a substance that boosts the immune system's ability to fight tumors. In mouse studies, the compound resulted in fewer tumor foci, though further research is needed to confirm these findings.

The mouse studies also indicated that quercetin may alter the gut microbiome, which can produce short-chain fatty acids that inhibit lung cancer growth. However, the effect of quercetin on human lung cancer remains unclear. Researchers suggest that a quercetin-rich diet may support lung cancer treatment and may have preventive effects, but further studies are required to determine this.