FUKUOKA – Erectile dysfunction drugs and a phenol found in green tea may be effective in fighting cancer when administered together, according to research on mice conducted by a Kyushu University academic.

In the study published Friday in the Journal of Clinical Investigation, professor Hirofumi Tachibana said the treatment’s clinical trials on humans are scheduled to begin in the United States later this year. But he cautioned the public against trying the concoctions at home due to possible side effects.

In 2004, Tachibana found that the EGCG type of catechin found in green tea suppressed cancer cell activity, although some researchers doubted its potency. He then suspected that the human enzyme PDE5 might be weakening its effectiveness.

Since Viagra and other erectile dysfunction drugs block PDE5, Tachibana tried injecting them into a mouse suffering blood cancer together with EGCG and found that the cancer cells stopped growing.

Malignant cells also disappeared when he tried the treatment on a mouse that was implanted with human breast cancer cells.

In-vitro experiments conducted on other types of cancer, including pancreatic, stomach and prostate tumors, have proven Tachibana’s treatment to be more effective than existing treatments, according to the study.