The inhibitory effect of meadowsweet (Filipendula ulmaria) on radiation-induced carcinogenesis in rats.

To examine the ability of the meadowsweet preparation to inhibit carcinogenesis induced by ionizing radiation in female rats.

The chemical composition of meadowsweet (Filipendula ulmaria) raw material (ethanol and aqueous extracts of meadowsweet flowers) has been studied for the presence of flavonoids, tannins and catechins. Adult female LIO strain rats were subjected to a single whole body γ-irradiation at a dose of 4 Gy in animal experiments. One group of irradiated rats served as control while the other group, starting from the 10th day after irradiation and until the end of the experiment, was given meadowsweet as a decoction of the flowers instead of drinking water. The average daily intake of meadowsweet (dry raw material) was 1 g/kg body weight. Rats were observed for 16 months.

The analyzed meadowsweet extracts showed a sufficiently high content of flavonoids and tannins. In irradiated rats after 16 months the overall incidence of tumors was 79.6% (in 82 of 103 rats), the incidence of malignant tumors was 43.7% and the overall tumor multiplicity was 1.48. Most tumors were localized in the mammary gland - 57.3%. In rats that received meadowsweet, the incidence of all malignant tumors and overall multiplicity of tumors were significantly decreased by 1.5 and 1.3 times, respectively. The greatest reduction of many parameters has been identified for breast tumors: the overall incidence was decreased by 1.5 (p = 0.0174) and the overall multiplicity and multiplicity of malignant tumors - by 1.6 (p = 0.0002) and 2.2 (p = 0.0383) times, respectively.

Meadowsweet preparation showed inhibiting activity on radiation carcinogenesis.