Antihyperalgesic activity of Filipendula ulmaria (L.) Maxim. and Filipendula vulgaris Moench in a rat model of inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Meadowsweet (Filipendula ulmaria (L.) Maxim.), and dropwort (Filipendula vulgaris Moench) flowers are traditionally used to treat various ailments, including inflammatory conditions. The aim of the present study was to validate the aforementioned ethnomedicinal claim by assessing antihyperalgesic and antiedematous activities and toxicity of orally administered lyophilized flower infusions (LFIs) of F. ulmaria and F. vulgaris in experimental animals.

MATERIALS AND METHODS: The phytochemical analysis of LFIs was performed by HPLC-DAD. Antihyperalgesic and antiedematous activities were estimated in a rat model of inflammation induced by intraplantar injection of carrageenan using Von Frey anesthesiometer and plethysmometer, respectively. Moreover, acute oral toxicity of LFIs in mice was evaluated by observing changes in animal behavior and mortality for a period of 14 days following the treatment.

RESULTS: HPLC-DAD analysis revealed the presence of phenolic acids and flavonoids in LFIs, among which spiraeoside was identified as the principal component (56.27±1.03 and 55.67±1.82mg/g of LFI in F. ulmaria and F. vulgaris, respectively). The LFIs of F. ulmaria and F. vulgaris (100-300mg/kg; p.o.) produced significant and dose-dependent antihyperalgesic effects: ED50±SEM values were 164.8±15.4mg/kg (110.3-246.3mg/kg) and 172.2±6.2mg/kg (147.4-201.3mg/kg) for F. ulmaria and F. vulgaris, respectively. On the other hand, LFIs of both species (100-300mg/kg; p.o.) did not significantly reduce edema. Good safety profiles were evidenced in the toxicological study. The median lethal dose (LD50) of the tested extracts is likely to be greater than 2000mg/kg.

CONCLUSION: The results of the present study support the use of F. ulmaria and F. vulgaris flowers in folk medicine for relieving pain in diseases with an inflammatory component.