Ranunculus species suppress nitric oxide production in LPS-stimulated RAW 264.7 macrophages.

Aerial parts and roots from three Ranunculus species were extracted with 70% ethanol. The phytochemical composition was investigated using GC-MS and multivariate data analysis. The total phenolic and flavonoid contents were also assessed. The in vitro inhibitory properties were evaluated as nitrite concentration in LPS-stimulated RAW 264.7 macrophage cell line. All the samples induced concentration-dependent inhibitory effects, with R. sceleratus aerial parts extract being the most interesting sample (IC50 = 22.08 ± 1.32 µg/mL), even more active than the reference compound indomethacin. A very good activity was also observed for R. sardous and R. ficaria aerial parts extracts (IC50 = 51.61 ± 3.12 µg/mL and 84.55 ± 3.40 µg/mL). A lesser but noteworthy potential was also demonstrated for the root extracts. The results suggest that Ranunculus hydroalcoholic extracts are able to inhibit nitrite accumulation and may be useful in preventing inflammatory diseases mediated by excessive production of NO.