ANTIOXIDANT ACTIVITY IN EXTRACTS FROM PLEUROCHAETE SQUARROSA (BRYOPHYTA) STRESSED BY HEAVY METALS, HEAT SHOCK AND SALINITY

摘要

Several cell components can be damaged by free radicals formed under biotic and abiotic stresses such as heavy metal pollution, salinity, pathogenic infections, heat shock etc. Plants have developed mechanisms to remove these free radicals (e.g., via enzymatic and non-enzymatic antioxidative systems such as glutathione, vitamins C and E, and hydroquinones) and it is known that levels of total glutathione and glutathione reductase activities increase with increasing metal uptake or other environmental stresses. Only scarce data are available on antioxidant activity in extracts from Bryophyta. Here we studied the antioxidant activity of the moss Pleurochaete squarrosa (Pottiaceae) a species which chiefly grows on the sandy soil of Mediterranean "macchia" and pine-wood vegetation and is resistant to many environmental stresses. The effects of heat shock, salinity and two heavy metals, lead and cadmium, on antioxidant activity of the moss was studied and discussed in relation to its resistance capacity to different stresses. For this study, the acetonic extracts of the moss Pleurochaete squarrosa were tested for antioxidant activity, on human whole blood leukocytes, as well as on isolated neutrophils, by a chemiluminescence (CL) assay.