Posted: Wednesday, April 14, 2021
Cristiane Okuda Torello, PhD, of the University of Campinas, São Paulo, Brazil, and colleagues evaluated the effect of green tea extract on the immune response of elderly patients with acute myeloid leukemia (AML). The researchers concluded that treatment with green tea is not only safe, but it may even improve the immune system for individuals with myelodysplasia-related changes. Their findings were published in Integrative Cancer Therapies.
This phase II study focused on 10 patients with myelodysplasia-related AML who were older than age 60; they could not undergo aggressive chemotherapy or bone marrow transplants. Each patient was administered two 500-mg capsules of green tea extract once a day for 6 months or until disease progression. Participants also received subcutaneous low-dose cytarabine every 12 hours for 14 days based on fragility.
The median age of patients was 77, and 60% had an intermediate-risk or worse disease. Hospitalization rates were lower in the green tea group than the control group (12 vs. 19 days), though they were not statistically significant. Grade 1 nausea and grade 2 alkaline aminotransferase elevation were observed in four and one patient, respectively.
An improvement in cytotoxic response occurred in those given green tea, demonstrated by an increase in various T cells and reduced mRNA expression of immunosuppressive molecules. After 30 days of treatment, a significant increase in bone marrow (P = .0313) and peripheral blood (P = .0140) monocytes was observed, especially in classical monocytes.
There was a significant decrease of reactive oxygen species levels in bone marrow CD34-positive cells, suggesting that green tea may collect oxygen-free radicals to protect tissues and cells from oxidative damage. Green tea treatment for 30 days also reduced NRF2 and HIF-1α in the bone marrow. After 180 days, the improvement in cytotoxic response remained for all patients.
Disclosure: The study authors reported no conflicts of interest.