Immunomodulatory activity of bioproducts obtained from edible mushroom Pleurotus sp.

Date: 27 May 2016

Venue: University of Oriente, Santiago de Cuba, Cuba

PhD candidate: Gabriel Llauradó Maury

Principal investigator: Paul Cos

Short description: PhD defence Gabriel Llauradó Maury - Department Pharmaceutical Sciences


Title PhD thesis: Immunomodulatory activity of bioproducts obtained from edible mushroom Pleurotus sp.

Edible and medicinal mushrooms constitute a significant and still untapped source of bioactive substances. In the last decades, the genus Pleurotus has gained a lot of popularity and it is now considered as a natural 'bio-factory' of several mycochemicals with immunomodulatory and antitumoral properties. However, little is known about the potential use of mushroom-derived food components for modulating metabolic and immunological disorders associated with malnutrition. Protein-energy malnutrition represents a major public health problem and is a common complication in patients with cancer and AIDS and in undernourished elderly people. It has a negative impact on the body weight, immune status and the digestive function.

The aim of this PhD study was to evaluate in in vitro and in vivo models the immunomodulatory activities of bioproducts obtained from the edible mushroom Pleurotus sp. Crude extracts and/or partially refined fractions from fruiting bodies or mycelia were produced and characterized. None of the Pleurotus-derived bioproducts showed significant cytotoxicity on peritoneal murine macrophages and RAW 264.7 macrophages. Pleurotus hot crude fractions extracted from the mycelium stimulated strongly the oxygen and non-oxygen dependent mechanisms in peritoneal murine macrophages. The hot water extract also showed a more potent effect on the nitric oxide production of RAW 264.7 macrophages compared to the cold crude extract from Pleurotus fruiting bodies. The Pleurotus mycelial extract activated in vitro both the alternative and the classical complement pathways.

The Pleurotus mycelial extract and fruiting bodies powder exerted radio- and chemo-protective effects in immunosuppressed Balb/c mice, as shown by the stimulation of haemopoiesis and phagocytic functions of peritoneal, splenic and Kupffer macrophages. Pleurotus fruiting bodies powder also increased the cell-mediated immune response on mice treated with cyclophosphamide. The oral administration of the cold crude extract from Pleurotus fruiting bodies to malnourished mice, reestablished the haemopoiesis and the normal functions of liver and intestinal tract. The cold water extract also stimulated the innate and humoral immune response.

This work has highlighted the widespread nutritional and curative potential of Pleurotus sp. mushrooms and its use as complementary medicine in some immunopathologies. Moreover, the prophylactic use of these bioproducts can contribute to the maintenance of healthy conditions reducing thereby the oxidative stress and the risk to acquire opportunistic infections.