A New Exopolysaccharide from a Wood-Decaying Fungus Spongipellis borealis for a Wide Range of Biotechnological Applications.

Fungi are a unique natural resource rich in polysaccharides, proteins, and other components. Polysaccharides are considered one of the most important bioactive components in fungi. Increasing numbers of studies have confirmed that fungal polysaccharides have various biological activities. Given these facts, the main aim of this investigation was to carry out isolation, identification, and structural characterisation of a new polysaccharide (EPS) derived from laboratory-cultured vegetative mycelium of a new Spongipellis borealis strain isolated from the environment. The examination of monosaccharides in the EPS demonstrated that the isolated biopolymer was composed mainly of glucose, galactose, and mannose monomers. The analysis of the methylation of the studied polymer indicated that it contained mainly terminal, →3)-linked, →4)-linked, and →2,4)-linked hexoses. The effect of fungal polysaccharides on S. borealis proteolytic enzymes (pepsin, trypsin, and pycnoporopepsin) and laccase activity was determined for the first time. Incubation of the enzyme preparation and EPS showed an influence of EPS on the stability of these enzymes, compared to the control values (without EPS).

Working towards arabinogalactan proteins (AGPs) from fruit: carbohydrate composition and impact on fungal growth.

BACKGROUND: Arabinogalactan proteins (AGPs) are extracellular matrix constituents involved in plant response to fungal infection. The aim of the current study was to investigate the antifungal effect of AGPs ex situ and to determine the structural features of AGPs that may have an influence on this activity. The features of AGPs isolated from fruit were investigated with molecular tools based on specific monoclonal antibodies recognizing carbohydrate AGP epitopes. The Antifungal (well-diffusion) Susceptibility Test and the Agar Invasion Test were used to assess the impact of AGPs on Penicillium notatum culture. RESULTS: The results definitely ruled out the influence of AGPs on fungal growth. The immunochemical analyses revealed that AGPs consist mainly of carbohydrate chains composed of ß-linked glucuronosyl residues recognized by LM2 and GlcA-ß(1 → 3)-GalA-α(1 → 2) Rha recognized by JIM13, which do not have the same functional properties outside the plant cell in in vitro experimental conditions. CONCLUSIONS: The action of a single cell wall component does not elicit any influence ex situ. The extensive accumulation of glycan chains of AGPs in infected tissue as a result of a complex mechanism occurring in the cell wall emphasizes the importance of dependencies between particular components of the extracellular matrix in response to fungal attack.

Medical Use of Polycatecholamines + Oxidoreductases-Modified Curdlan Hydrogels-Perspectives.

Curdlan (ß-1,3-glucan), as a biodegradable polymer, is still an underestimated but potentially attractive matrix for the production of dressing materials. However, due to its lack of susceptibility to functionalization, its use is limited. The proposed curdlan modification, using a functional polycatecholamine layer, enables the immobilization of selected oxidoreductases (laccase and peroxidase) on curdlan hydrogel. The following significant changes of biological and mechanical properties of polycatecholamines + oxidoreductases-modified matrices were observed: reduced response of human monocytes in contact with the hydrogels, modulated reaction of human blood, in terms of hemolysis and clot formation, and changed mechanical properties. The lack of toxicity towards human fibroblasts and the suppression of cytokines released by human monocytes in comparison to pristine curdlan hydrogel, seems to make the application of such modifications attractive for biomedical purposes. The obtained results could also be useful for construction of a wide range of biomaterials based on other polymer hydrogels.

Low-Molecular-Weight Secondary Metabolites from Fungi: Cerrena unicolor as a New Proposal of an Effective Preparation against Rhabditis Nematodes.

Plants and fungi are known as a valuable source of natural medicines used in the treatment of various diseases. Many of them are used to treat human and animal gastrointestinal diseases caused by parasites. The aim of this study was to investigate for the first time the antinematode properties of extracellular low-molecular subfractions (ex-LMS) obtained from the liquid growth medium of idiophasic Cerrena unicolor cultures. The fungal fractions were isolated according to a procedure previously described by Jaszek et al. The in vitro tests were performed using nematodes of the Rhabditis genus. As demonstrated by the results, the total fraction with a molecular weight < 10 kDa (CU-A) and the 0.02−1.5 kDa fraction (CU-B) had nematicidal activity. It was found that the analyzed substances induced movement disturbances caused by the paralysis of the back part of the nematode's body. The degree of body paralysis was proportional to the increase in the concentration of the tested fractions. Summarizing the obtained results in the context of the available literature data, it seems that C. unicolor may be a good new candidate for research on nematode infections.

Electric Cell-Substrate Impedance Sensing (ECIS) as a Convenient Tool to Assess the Potential of Low Molecular Fraction Derived from Medicinal Fungus Cerrena unicolor in Action on L929 and CT-26 Cell Lines.

The increase in the incidence of cancer has contributed to the search for new therapeutic methods. In recent years, the use of preparations of natural origin from medical fungi has increased. One such active substance is the extracellular, low molecular active fraction obtained from the medicinal fungus Cerrena unicolor. This study aimed to monitor the pharmacokinetics of different concentrations of substances isolated from the medicinal fungus Cerrena unicolor (ex-LMS) using the ECIS technique. In the study, mouse L929 fibroblasts and colon cancer CT26 cell lines were treated with different concentrations of the active fractions obtained from Cerrena unicolor: C1 = 2.285 (µg/mL); C2 = 22.85 (µg/mL); and C3 = 228.5 (µg/mL). This study demonstrated that the tested preparation from Cerrena unicolor had no considerable effect on the resistance, capacitance, and impedance of L929 fibroblast cells, which was an indicator of no significant effect on its physiological processes. At the same time, those parameters exhibited a decrease in colon cancer cell viability. Following our previous and current studies on Cerrena unicolor, ex-LMS extracts can be safely used in anticancer therapy or chemoprevention with no significant harmful effects on normal cells.

Lasius fuliginosus Nest Carton as a Source of New Promising Bioactive Extracts with Chemopreventive Potential.

Six new water extracts (E1-E6) were obtained from nest carton produced by jet black ants Lasius fuliginosus and tested for their biochemical and bioactive properties, including antioxidative and anticancer effects. The present study demonstrated significant qualitative and quantitative differences in the content of individual biochemical constituents, as well as bioactive properties between the investigated samples. All tested extracts demonstrated antioxidant properties (determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods), and the highest antioxidative potential was recorded in extracts E1 and E2 (188.96 and 313.67 µg/mL of ascorbic acid equivalent for ABTS and 176.42 and 202.66 µg/mL for DPPH reagent). Furthermore the six extracts exhibited strong inhibitory activity towards human melanoma cells of the A-375 CRL-1619 line in a dose-dependent manner. The most interesting chemopreventive activity was exhibited by extract E2, which inhibited the proliferation of A-375 cells to the greatest extent, while having a minimal effect on Vero cells. The effect on cancer cells has been confirmed using the Electric Cell-substrate Impedance Sensing (ECIS) technique. Significant impedance changes have been detected in A-375 and Vero cells following the administration of extract E2. The obtained results are really promising and constitute the basis for further research on the nest carton of jet black ant.

Combined Effect of Light and Nutrients on the Micromorphology of the White rot Fungus Cerrena Unicolor.

Light influences developmental pathways in fungi. Recent transcriptomic and biochemical analyses have demonstrated that light influences the metabolism of a white-rot basidiomycete Cerrena unicolor. However, the expression profile of genes involved in the growth and development, or micromorphological observations of the mycelium in response to variable lighting and culturing media, have not performed. We aim to reveal the effect of light and nutrients on C. unicolor growth and a potential relationship between the culture medium and lighting conditions on fungus micromorphological structures. Confocal laser scanning microscopy and scanning electron microscopy were employed for morphological observations of C. unicolor mycelium cultivated in red, blue, green, and white light and darkness on mineral and sawdust media. A comprehensive analysis of C. unicolor differentially expressed genes (DEGs) was employed to find global changes in the expression profiles of genes putatively involved in light-dependent morphogenesis. Both light and nutrients influenced C. unicolor growth and development. Considerable differences in the micromorphology of the mycelia were found, which were partially reflected in the functional groups of DEGs observed in the fungus transcriptomes. A complex cross-interaction of nutritional and environmental signals on C. unicolor growth and morphology was suggested. The results are a promising starting point for further investigations of fungus photobiology.

A Mutation in the Mesorhizobium loti oatB Gene Alters the Physicochemical Properties of the Bacterial Cell Wall and Reduces Survival inside Acanthamoeba castellanii.

In our previous report, we had shown that the free-living amoeba Acanthamoeba castellanii influenced the abundance, competiveness, and virulence of Mesorhizobium loti NZP2213, the microsymbiont of agriculturally important plants of the genus Lotus. The molecular basis of this phenomenon; however, had not been explored. In the present study, we demonstrated that oatB, the O-acetyltransferase encoding gene located in the lipopolysaccharide (LPS) synthesis cluster of M. loti, was responsible for maintaining the protective capacity of the bacterial cell envelope, necessary for the bacteria to fight environmental stress and survive inside amoeba cells. Using co-culture assays combined with fluorescence and electron microscopy, we showed that an oatB mutant, unlike the parental strain, was efficiently destroyed after rapid internalization by amoebae. Sensitivity and permeability studies of the oatB mutant, together with topography and nanomechanical investigations with the use of atomic force microscopy (AFM), indicated that the incomplete substitution of lipid A-core moieties with O-polysaccharide (O-PS) residues rendered the mutant more sensitive to hydrophobic compounds. Likewise, the truncated LPS moieties, rather than the lack of O-acetyl groups, made the oatB mutant susceptible to the bactericidal mechanisms (nitrosative stress and the action of lytic enzymes) of A. castellanii.

New alkaline lipase from Rhizomucor variabilis: Biochemical properties and stability in the presence of microbial EPS.

A new strain of Rhizomucor variabilis producing an active extracellular lipase was identified and characterized in the present studies. The culture conditions were optimized and the highest lipase production amounting to 136 U/mL was achieved after 4 days of cultivation. The optimum pH (5.5) and temperature (28 °C) were determined as the best conditions for R. variabilis lipase production. The isolated enzyme preparation exhibited maximum activity at 40 °C and pH 8.0. Lipase from R. variabilis was stable up to 50 °C during 2 H retaining 80% of its initial activity. The enzyme was highly stable in the pH range of 7.0-9.0. Moreover, the addition of naturally obtained exopolysaccharides (EPS) significantly enhanced lipase activity. The presence of EPS derived from Ganoderma applanatum and Rhizobium leguminosarum enhanced the lipase activity, which was 22% and 31%, respectively, higher than that in the control experiments. Simultaneously, the pH activity profiles remained unchanged. The Michaelis-Menten constant and the turnover number of the enzyme for p-nitrophenyl palmitate in the standard assay conditions were estimated at a level of 0.631 mM and 0.674 Sec(-1) . In conclusion, the results obtained in this work present a newly isolated lipase preparation stabilized with EPS or without modification as a very effective tool for industrial application.

Complex Biochemical Analysis of Fruiting Bodies from Newly Isolated Polish Flammulina velutipes Strains.

The present study examined Polish strains of Flamulina velutipes as a potential source of nutraceuticals and found that their nutritional value is dependent on the fruiting bodies gathering time. To prove the above hypothesis protein, carbohydrate and phenolic substances concentration were determined. Moreover, catalase, superoxide dismutase, cellobiose dehydrogenase activities were assayed. In order to prove the healing properties of Enoki fruiting bodies the obtained extracts were tested for antioxidant and bacteriostatic abilities. We have proved that Polish F. velutipes fruiting bodies may be a rich source of antioxidants and that they are capable of inhibiting Staphylococcus aureus growth.

Pro-Health and Anti-Cancer Activity of Fungal Fractions Isolated from Milk-Supplemented Cultures of Lentinus (Pleurotus) Sajor-caju.

The present study aimed to demonstrate Lentinus (formerly Pleurotus) sajor-caju (PSC) as a good source of pro-health substances. It has also shown that supplementation of its culture medium with cow milk may further improve its beneficial properties. Intracellular fractions from fungi grown on a medium supplemented with cow milk were analyzed using various biochemical methods for determination of the nutrient composition. Furthermore, anti-cancer properties of selected extracts were investigated on colorectal cancer cell lines (HT-29, LS 180, and SW948) in vitro. Biochemical analysis showed enrichment in health-enhancing compounds, such as proteins or polysaccharides (about 3.5- and 4.5-fold increase in concentration of proteins and carbohydratesin extracts of mycelia cultured on whole milk (PSC2-I), respectively), with a decrease in the level of free radicals (10-fold decrease in extract grown on milk and medium mixture (1:1) (PSC3-II)), which was related to increased catalase and superoxide dismutase activity (7.5-fold increase in catalase activity and 5-fold in SOD activity in PSC3-II compared to the control). Moreover, the viability of the cancer cells was diminished (to 60.0 ± 6.8% and 40.0 ± 8.6% of the control, on HT-29 and SW948 cells, respectively), along with pro-apoptotic (to 18.8 ± 11.8 and 14.7 ± 8.0% towards LS 180 and SW948 cells, respectively) and NO-secreting effects (about 2-fold increase) of the extracts. This study suggests that PSC has multiple nutritional and anti-cancer properties and can be used as a source of healthy biomolecules in modern medicine or functional foods.

Thromboelastometric Analysis of Anticancer Cerrena unicolor Subfractions Reveal Their Potential as Fibrin Glue Drug Carrier Enhancers.

In this study, the influence of two subfractions (with previously proven anti-cancer properties) isolated from wood rot fungus Cerrena unicolor on the formation of a fibrin clot was investigated in the context of potential use as fibrin glue and sealant enhancers and potential wound healing agents. With the use of ROTEM thromboelastometry, we demonstrated that, in the presence of fibrinogen and thrombin, the S6 fraction accelerated the formation of a fibrin clot, had a positive effect on its elasticity modulus, and enhanced the degree of fibrin cross-linking. The S5 fraction alone showed no influence on the fibrin coagulation process; however, in the presence of fibrin, it exhibited a decrease in anti-proliferative properties against the HT-29 line, while it increased the proliferation of cells in general at a concentration of 100 µg/mL. Both fractions retained their proapoptotic properties to a lesser degree. In combination with the S6 fraction in the ratio of 1:1 and 1:3, the fractions contributed to increased inhibition of the activity of matrix metalloproteinases (MMPs). This may suggest anti-metastatic activity of the combined fractions. In conclusion, the potential of the fractions isolated from the C. unicolor secretome to be used as a means of improving the wound healing process was presented. The potential for delivering agents with cytostatic properties introduced far from the site of action or exerting a pro-proliferative effect at the wound site with the aid of a fibrin sealant was demonstrated.

Epidermal Growth Factor Receptor and its Oncogenic EGFRvIII Variant in Benign and Malignant Brain Tumors.

BACKGROUND/AIM: Tumorigenesis and cancer progression might be driven by abnormal activation of growth factor receptors. Importantly, molecular changes in EGFR-dependent signaling is one of the most common characteristics of brain tumors. PATIENTS AND METHODS: HER1 and EGFRvIII variants in meningiomas and glioblastomas were evaluated at the RNA level. RESULTS: EGFRvIII was found in 18.6% of glioblastomas (GBM), whereas 25% of EGFRvIII positive tumors express wild-type EGFR as well. HER1 was over-expressed in benign meningiomas compared to glioblastomas, whereas HER1 expression in meningiomas differed significantly between sub-types of meningiomas. EGFRvIII and HER1 where positively correlated in glioblastomas. Yet, the patient overall survival did not differ between high- and low-HER1 expressing glioblastomas or between EGFRvIII positive and negative GBMs. CONCLUSION: HER1 may be considered as an independent factor for classification of benign meningiomas. The mRNA levels of HER1 or EGFRvIII should not be used as independent prognostic factors for patients with gliomas.

Medicinal potential of mycelium and fruiting bodies of an arboreal mushroom Fomitopsis officinalis in therapy of lifestyle diseases.

Fomitopsis officinalis is a medicinal mushroom used in traditional European eighteenth and nineteenth century folk medicine. Fruiting bodies of F. officinalis were collected from the natural environment of Swietokrzyskie Province with the consent of the General Director for Environmental Protection in Warsaw. Mycelial cultures were obtained from fragments of F. officinalis fruiting bodies. The taxonomic position of the mushroom mycelium was confirmed using the PCR method. The presence of organic compounds was determined by HPLC-DAD analysis. Bioelements were determined by AF-AAS. The biochemical composition of the tested mushroom material was confirmed with the FTIR method. Antioxidant properties were determined using the DPPH method, and the antiproliferative activity was assessed with the use of the MTT test. The presence of indole compounds (L-tryptophan, 6-methyl-D,L-tryptophan, melatonin, 5-hydroxy-L-tryptophan), phenolic compounds (p-hydroxybenzoic acid, gallic acid, catechin, phenylalanine), and sterols (ergosterol, ergosterol peroxide) as well as trace elements was confirmed in the mycelium and fruiting bodies of F. officinalis. Importantly, a high level of 5-hydroxy-L-tryptophan in in vitro mycelium cultures (517.99 mg/100 g d.w) was recorded for the first time. The tested mushroom extracts also showed antioxidant and antiproliferative effects on the A549 lung cancer cell line, the DU145 prostate cancer cell line, and the A375 melanoma cell line.

Antitumor potential of new low molecular weight antioxidative preparations from the white rot fungus Cerrena unicolor against human colon cancer cells.

The aim of this study was to investigate the anticancer and antioxidant activities of low molecular weight subfractions isolated from secondary metabolites produced by the wood degrading fungus Cerrena unicolor. Human colon cancer cells (stage I) HT-29 and human normal colon epithelial cells CCD 841 CoTr were used in the research. The present study demonstrated that the low molecular weight subfractions exhibited inhibitory activity towards human colon cancer cells HT-29 at a concentration range of 25-200 µg/mL. All 6 subfractions inhibited proliferation of cells down to 47.5-9.2% at the highest concentrations in a dose-dependent manner. The most desired activity was exhibited by subfractions S, 3, 4, and 5, as the proliferation of HT-29 cells was inhibited to the greatest extent (16.5, 47.5, 42.7, and 26.1% of the control, respectively), while the effect on CCD 841 CoTr cells was the mildest (inhibition to 54.4, 71.4, 79.4, and 53.4%, compared to the control, respectively). The microscopic observation revealed that all extracts induced programmed cell death, i.e. apoptosis (up to 44.4% (subfraction 6) towards HT-29 and less than 20% (most fractions) towards CCD 841 CoTr), with no or a significantly low level of necrosis in both cell lines at the same time.

The Influence of Adhesive Compounds Biochemical Modification on the Mechanical Properties of Adhesive Joints.

The main purpose of this paper was to determine the effect of biochemical modification of epoxy adhesive compounds on the mechanical properties of hot-dip galvanized steel sheet DX51+Z275 adhesive joints. The epoxy adhesives (resin and curing agent) were biochemically modified by lyophilized fungal metabolites (in the form of lyophilized fungal fractions or materials preparation containing low molecular weight secondary metabolites of lignocellulose-degrading white rot fungi (WRF) Pycnoporus sanguineus (L.) Murrill and prepared by two methods). The epoxy adhesives (epoxy resin Epidian 53 and poliaminoamide curing agent PAC) were biochemical modified by lyophilized fungal metabolites and prepared by two methods. In the first method (Method I), the epoxy resin and the curing agent were mixed with the fungal material in the desired concentration. In the second method (Method II), the resin was mixed with mortar-grounded lyophilized post-culture liquid of the desired concentration and after following thorough mixing, a suitable amount of the poliaminoamide curing agent was added. The single-lap adhesive joints were prepared by modified epoxy adhesive compounds and were cured in various climatic factors. The specimens of adhesive joints were cured at single stage at the same temperature and humidity as during adhesive bonding (Variant A and Variant B). At the second stage, Method I adhesive joints were seasoned for two months at the temperature of 50 °C and 50% humidity in a climate test chamber (Variant C). The shear strength tests of the single-lap adhesive joints were performed using a Zwick/Roell Z150 testing machine in accordance with the DIN EN 1465 standard. The analysis of results revealed that the addition of the biological modifier can lead to reduced adhesive joint strength in ambient conditions, yet at elevated temperature and the higher humidity it results in a significant increase in adhesive joint strength.

Anticancer, antioxidant, and antibacterial activities of low molecular weight bioactive subfractions isolated from cultures of wood degrading fungus Cerrena unicolor.

The aim of this study is to investigate in vitro the anticancer, antioxidant, and antibacterial activities of three low molecular weight subfractions I, II and III isolated from secondary metabolites produced by the wood degrading fungus Cerrena unicolor. The present study demonstrated that the low molecular weight subfractions III exhibited the strongest inhibitory activity towards breast carcinoma cells MDA-MB-231, prostatic carcinoma cells PC3, and breast cancer cells MCF7 with the half-maximal inhibitory concentration (IC50) value of 52,25 µg/mL, 60,66 µg/mL, and 54,92 µg/mL, respectively. The highest percentage of inhibition was noted at a concentration of 300 µg/mL in all the examined tumor lines. A significant percentage (59.08%) of ex-LMSIII inhibition of the MDA-MB-231 tumor line was reached at a concentration of 15 µg/ml, while the concentration applied did not affect normal human fibroblast cells. The low molecular weight subfraction III was the most effective and additionally showed the highest free radical 1,1-diphenyl-2-picryl-hydrazyl scavenging activity (IC50 20.39 µg/mL) followed by the low molecular weight subfraction I (IC50 64.14 µg/mL) and II (IC50 49.22 µg/mL). The antibacterial activity of the tested preparations was evaluated against three microorganisms: Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The MIC minimal inhibitory concentration (MIC) values for the low molecular weight subfraction I, II, and III showed a stronger inhibition effect on S. aureus than on B. subtilis and E. coli cells. The MIC values for the low molecular weight subfraction II against S. aureus, B. subtilis, and E. coli were 6.25, 12.5, and 100 mg/mL, respectively.

Antimelanomic Effects of High- and Low-Molecular Weight Bioactive Subfractions Isolated from the Mossy Maze Mushroom, Cerrena unicolor (Agaricomycetes).

Three bioactive fractions isolated from Cerrena unicolor cultures-crude endopolysaccharide (c-EPS), laccase, and a subfraction of low-molecular weight secondary metabolites-were used to determine potential cytotoxic effects on the mouse melanoma B16-F10 cell line (American Type Culture Collection CRL-6475). The results obtained prove that all examined fractions exhibited activity against the investigated tumor cells. In addition, an evident immunomodulatory effect of the c-EPS fraction was observed. Our results show that the levels of 2 cytokines (tumor necrosis factor-a and chemokine ligand 2) in mouse inner medullary collecting duct mIMCD-3 cells (American Type Culture Collection CRL-2123) stimulated by c-EPS were significantly higher. A lipopolysaccharide model was used at the same concentration (10 µg/mL) as a positive control.

Effective and complex stimulation of the biodegradation system of fungus Cerrena unicolor by rapeseed meal fermentation.

The effect of supplementation of medium with rapeseed meal (RM) on production of biotechnologically important enzymes was investigated in submerged cultures of the white rot fungus Cerrena unicolor. The addition of RM (3.5% w/v) distinctly stimulated the activities of laccase, chitinase, and ß-glucosidase. As compared to the control, the activities of chitinase, ß-glucosidase, and laccase in the RM supplemented cultures were up to 4.1, 8.4, and 3.9 times higher, respectively. The results of the spectrophotometric and spectrofluorometric measurements were additionally confirmed by zymographic analysis of the samples. The level of sugars and phenolic compounds as well as the antioxidative ability of fungal preparations were also determined. The results obtained indicate that the submerged liquid fermentation of rapeseed meal can be proposed as an inexpensive and very effective method for biotechnological production of chitinase, ß-glucosidase, and laccase by C. unicolor.

Laccase purified from Cerrena unicolor exerts antitumor activity against leukemic cells.

Chronic lymphocytic leukemia (CLL) is the most commonly observed adult hematological malignancy in Western countries. Despite the fact that recent improvements in CLL treatment have led to an increased percentage of complete remissions, CLL remains an incurable disease. Cerrena unicolor is a novel fungal source of highly active extracellular laccase (ex-LAC) that is currently used in industry. However, to the best of our knowledge, no reports regarding its anti-leukemic activity have been published thus far. In the present study, it was hypothesized that C. unicolor ex-LAC may possess cytotoxic activity against leukemic cell lines and CLL primary cells. C. unicolor ex-LAC was separated using anion exchange chromatography on diethylaminoethyl cellulose-Sepharose and Sephadex G-50 columns. The cytotoxic effects of ex-LAC upon 24- and 48-h treatment on HL-60, Jurkat, RPMI 8226 and K562 cell lines, as well as CLL primary cells of nine patients with CLL, were evaluated using 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay. Annexin V/propidium iodide staining of Jurkat cells treated with ex-LAC was used to investigate apoptosis via flow cytometry. Ex-LAC induced changes in Jurkat and RPMI 8226 cells, as visualized by fluorescence and scanning electron microscopy (SEM). The XTT assay revealed high cytotoxic rates following treatment with various concentrations of ex-LAC on all the cell lines and CLL primary cells analyzed, with a half maximal inhibitory concentration ranging from 0.4 to 1.1 µg/ml. Fluorescence microscopy and SEM observations additionally revealed apoptotic changes in Jurkat and RPMI 8226 cells treated with ex-LAC, compared with control cells. These results were in agreement with the apoptosis analysis of Jurkat cells on flow cytometry. In conclusion, C. unicolor ex-LAC was able to significantly induce cell apoptosis, and may represent a novel therapeutic agent for the treatment of various hematological neoplasms.