The aim of this work was to evaluate the effect of different olive leaf extracts (OLE) from different leaf growing stages on human carcinoma cell lines. OLE were tested in human carcinoma cell lines in vitro and cells were plated in 96-microtiter culture plates for each OLE concentration. Fresh (F) and freeze-dried (FD) leaves exhibited phenolic compounds in the range of 2.09 ± 0.10 to 8.44 ± 0.64 and 7.72 ± 0.56 to 24.65 ± 1.9 mg gallic acid equivalents/g leaves, respectively. OLE from several Portuguese olive tree cultivars were found to inhibit the growth of human carcinoma cell lines in a range of 2.09-8.44 μg phenolic compound/well (209-844 μg/ml) and 0.07-2.40 μg phenolic compounds/well (7-240 μg/ml) for fresh and freeze-dried leaves, respectively. Young (Y) leaves have revealed the highest cell growth inhibition ranging from about 95% for Cobrançosa, followed by 90% for Cobrançosa, 90% for Arbequina and 75% for Arbequina for cell lines A549, HeLa, A431 and OE21, respectively. The lowest cell growth inhibition (35%) was observed for Galega (Y) leaf extract on cell line A549. However, FD samples exhibited a distinctive pattern since cell growth inhibition was highest at highest extract dilution tested, for A431 (Galega Y) followed by A549 (Cobrançosa Y) with cell inhibition of 75% and 70%, respectively. The data presented in this work strongly suggest that OLEs inhibit the growth of human carcinoma cell lines.

Introduction: Mushroom polysaccharides play an important role in nutraceutical and functional food because they act as biological active modifiers. The aim of the present work involved the production, purification and partial characterization of intracellular (IPS) and extracellular polysaccharides (EPS) from several basidiomycete strains. Such polysaccharides were used to investigate their effect on growth of human carcinoma cell lines.Methods: Mushroom polysaccharides were produced from several basidiomycete strains by submerged and solid state fermentations, assayed for superoxide radical scavenging activity, purified by gel filtration chromatography, analysed by FTIR and their effect on human carcinoma cell line was investigated by MTT method.Results: Mushroom polysaccharides have revealed scavenging activity in the range of 22 -81 % for Po (s) and Pe (2), respectively. FTIR analysis of polysaccharides showed absorption bands characteristics of these biological macromolecules. IPS inhibited cell growth of HeLa in the range of 16.8 -27.01 % for Po (s) and Ga (1), respectively.EPS inhibited cell growth of HeLa, A459, A431 and OE21 in the ranges of 3.08 -92.2 %, 13.8 -97.4 %, 14.7 -93. 8% and 25 -94% for Il (1) and Ga (1), Gc (1) and Ga (1), Il (1) and Ga (1), Le (1) and Ga (1), respectively.Purified preparations of polysaccharides confirmed the growth inhibition of these biomolecules. Conclusion:The present results strongly suggest growth inhibition of human carcinoma cell lines by mushroom polysaccharides and it will require a future research to understand its molecular mechanism of action.