Lycopene, the tomato-derived antioxidant thought to fight prostate cancer, may also help to inhibit benign tumours of the uterus, which cause painful symptoms for millions of women, say researchers, reports Dominique Patton.
New animal data shows that lycopene reduced the size and incidence of fibroid tumours, also known as leiomyomas or myomas, a team from Turkey and the US reported on Saturday at the annual Experimental Biology meeting underway in the US this week.
Fibroid tumours are growths of uterus muscle cells that occur in around 25 per cent of all women but are even more common in women over the age of 35. Although benign, fibroids can cause heavy bleeding and pain during menstruation, pelvic pain, miscarriage and infertility. Treatments usually involve in the surgical removal of the tumours or, in some cases, hysterectomy.
Human trials have previously demonstrated that lycopene supplements may prevent or slow the progression of certain cancers, particularly prostate cancer. Research presented last week by scientists at DSM, which makes synthetic lycopene, suggests that the carotenoid may reduce the risk of prostate cancer by inhibiting the male hormone's effect on the prostate.
Other researchers say that it could act on the body's oxidative response.
In the new trial, researchers from Firat University in Turkey, the University of Maryland and the Karmanos Cancer Institute at Wayne State University in Detroit supplemented the basic diet of Japanese quails with either 100 mg or 200 mg lycopene per kg of food.
After 10 months, the supplemented quails had fewer leiomyomas compared to a control group fed only the basic diet (10 per cent versus 20 per cent). In addition, the average diameter of the tumours was significantly smaller in the supplemented groups.
The size of the tumours in the group supplemented with 200 mg lycopene was also significantly smaller than those in the group supplemented with 100 mg, indicating a dose response effect of lycopene on the size of the tumours.
Japanese quails are thought to be an excellent model for studying fibroid tumours since, as in humans, the tumours occur spontaneously in the birds' oviduct, an organ similar to the human uterus. Most other animal studies require introduction of the tumours into the species.
Lycopene supplementation also appeared to have a positive effect on the birds' serum concentrations of vitamins C, E and A, homocysteine and malondialdehyde (MDA). Previous studies have shown that serum levels of these vitamins decrease in patients with uterine cervical cancers and that biomarkers of oxidative stress, such as homocysteine in the blood and MDA in the blood and liver, increase.
After lycopene supplementation, however, the vitamin levels of the supplemented birds increased and the levels of homocysteine and MDA decreased.
The researchers also measured tissue concentrations of the bcl-2 and bax, two proteins that are associated with the cell proliferation and cell destruction of tumours. There were no significant differences in levels of these proteins among the study groups.