The inhibitory effect of Filipendula ulmaria (L.) Maxim. on colorectal carcinogenesis induced in rats by methylnitrosourea

Ethnopharmacological relevance: Meadowsweet (Filipendula ulmaria (L.) Maxim.) is a medicinal plant with a variety of therapeutic properties, traditionally used in various diseases including treatment and prevention of tumors. The aim of this study was to present an ethnomedicinal justification that a meadowsweet decoction is able to inhibit colorectal carcinogenesis induced by the methylnitrosourea (MNU) in rats. Materials and methods: The chemical composition of meadowsweet extracts was studied by traditional methods. In animal experiments adult outbred female rats received four intrarectal instillations of MNU, one per week, at dose 4 mg in 0.5 ml saline (the total dose of MNU during the 4-week exposure was 16 mg/rat). After carcinogenic exposure one group (MNU) of rats continued to receive standard feed and tap water throughout life. In another group (MNU + meadowsweet), rats were given daily a decoction of the meadowsweet instead of drinking water and standard feed. Results: Meadowsweet extracts showed a sufficiently high content of fiavonoids and tannins and also some individual phenolic compounds and salicylic acid. In rats after administration of MNU the overall incidence of tumors was 91% with tumor multiplicity of 3.5. The majority of rats (86%) developed multiple tumors of large intestine (most often adenocarcinomas:88 from 107; index of multiplicity 2.0). In rats from the group MNU + meadowsweet there was a statistically significant decrease of the overall tumor incidence and multiplicity by 1.4 and 2.9 times, respectively, and the incidence and multiplicity of colon tumors - by 2.0 and 2.8 times, respectively; the incidence and multiplicity of malignant tumors of other localizations was also reduced by 2.2 and 3.0 times, respectively. Conclusions: Meadowsweet extract is an effective inhibitor of colorectal carcinogenesis in experiment, that provides support for the traditional use of this plant in the oncology.