Seeking novel Leishmanicidal natural products from common medicinal plants, the example of Eryngium foetidum L

Leishmaniasis is a human parasitic tropical disease that urgently requires new chemotherapeutic agents. Eryngium foetidum L. (Apiaceae), known as “culantro”, is a popular culinary herb and a medicinal plant used in Latin America for its anti-inflammatory and anti-parasitic properties. A defatted methanolic extract was partitioned with organic solvents and water. The n-hexane fraction inhibited the Leishmania growth by 41.4% at 20µg/ml. Bioassay-guided fractionation of the n-hexane fraction yielded two compounds: (1) lasidiol p-methoxybenzoate, a daucane sesquiterpene and (2) a terpene aldehyde ester. Compound 1 showed an IC₅₀ of 5.34µg/ml in the Leishmania assay and no cytotoxicity in L6 cells (IC₅₀ >20µg/ml), while compound 2 was inactive in the Leishmania assay (IC₅₀ >20µg/ml). These compounds were previously isolated from the medicinal plants Xanthium catharticum Kunth (1) and Ferula hispanica Rouy (2). However, this is the first report of their Leishmanicidal activity, cytotoxicity, and their isolation from a Eryngium species. In conclusion, there is potential to find new Leishmanicidal natural products from common medicinal plants.

Fig.1: lasidiol p-methoxybenzoate (MW=372.50)

Fig.2: terpene aldehyde ester (MW=306.35)