Thistle extract shows promise against acute lung injury and stomach cancer, studies find

New research suggests that thistle, long known as a medicinal plant that supports liver health, may also help prevent acute lung injury and suppress the growth of stomach cancer tumors.

One of South Korea's most representative native plants, thistle has been used in traditional herbal medicine for centuries for its liver-protective, hemostatic and anti-inflammatory properties. Researchers are now actively working to develop its bioactive compounds into treatments for inflammatory diseases and cancer.

A research team led by Kim Geun-dong at the Korea Food Research Institute published findings in an international journal showing that thistle extract can suppress excessive inflammatory activity in immune cells and reduce widespread inflammatory responses, making it a potential material for treating lung injury.

Acute respiratory distress syndrome, or ARDS, occurs when a sudden inflammatory reaction in the lungs — triggered by infection, sepsis or trauma — causes respiratory failure, pulmonary edema and alveolar damage. The condition is fatal in 40 to 60 percent of cases worldwide, yet no single approved treatment exists. Care currently relies mainly on supplemental oxygen and mechanical ventilation, driving demand for new therapies that can broadly suppress respiratory inflammation.

The research team induced ARDS in mice by injecting bacterial toxins, then administered thistle extract and observed changes in lung tissue.

Mice that received the thistle extract showed a marked reduction in the major pathological signs of ARDS, including inflammatory cell infiltration in lung tissue, thickening of the alveolar walls and the formation of hyaline membranes.

The effects were also confirmed at the molecular level. The thistle extract suppressed the expression of inflammation-related genes in lung tissue and reduced excessive inflammatory activation in macrophages, a type of immune cell. The findings suggest that thistle can regulate widespread inflammatory responses and potentially alleviate acute lung injury.

A separate component of thistle is drawing attention in stomach cancer research. Scientists at the Korea Institute of Toxicology confirmed that pectolinarigenin, a natural flavonoid found in thistle and other plants, can slow the growth of gastric cancer tumors.

Flavonoids are secondary metabolites widely found in plants and fungi, known to exhibit a range of biological activities including antioxidant and anti-inflammatory effects.

After administering pectolinarigenin to mice implanted with human-derived gastric cancer cells, the researchers observed delayed tumor growth and a reduction in tumor weight. Blood analysis showed no significant systemic toxicity or side effects.

Mass spectrometry analysis of tumor tissue found that pectolinarigenin reduced the expression of six proteins known to be elevated in cancer. The researchers confirmed the result through polymerase chain reaction, or PCR.

The team said it expects the research to serve as foundational data for developing natural-compound-based treatments for stomach cancer that could reduce the side effects of conventional chemotherapy.

Neither study means that thistle itself can treat lung disease or cancer in humans. Both the lung injury and stomach cancer findings were obtained at the animal and cellular level, and further research — including identification of active compounds, confirmation of mechanisms of action, safety verification and human clinical trials — will be needed before any treatment application becomes possible.