In vitro antileishmanial activity of a black morel, Morchella importuna (Ascomycetes)

We studied the anti-Leishmania activity of a fractionated extract from the mushroom Morchella importuna in an in vitro system. Leishmaniasis is an important infectious disease caused by a range of Leishmania species, which are multihost protozoa parasites transmitted to humans by the sand fly and infecting macrophages. Leishmaniasis is an increasing worldwide health problem, including in the Mediterranean basin. Current chemotherapy treatments are limited by their toxic effects, the need for long-term treatment, and the increasing development of resistance by the parasite cells. Thus, alternative therapies are being considered, including herbal and mushroom products. We studied the effect of extracts from M. importuna on L. tropica promastigote cell proliferation and survival, and on their toxicity against human macrophages. The aqueous mushroom extract was compared with 3 successive extracted fractions: an 80% ethanol fraction, a water-soluble polysaccharide fraction, and a polyphenolic fraction. All 4 extracts showed anti-Leishmania activity; the aqueous extract was most active. The inhibition activity was dose dependent in killing Leishmania. No cell recovery was recorded after exposure to the mushroom extract. Microscopic observation showed morphological changes and the loss of flagella on the parasites. No cytotoxic activity was recorded against human macrophages at the same extract concentrations. The findings suggest the potential use of extracts of an edible Morchella mushroom against the Leishmania parasite in humans.