Pharmacological perspectives from Brazilian Salvia of ﬁ cinalis (Lamiaceae): antioxidant, and antitumor in mammalian cells

Salvia of ﬁ cinalis (Lamiaceae) has been used in south of Brazil as a diary homemade, in food condiment and tea-beverage used for the treatment of several disorders. The objective of this study was to characterize chemical compounds in the hydroalcoholic (ExtHS) and aqueous (ExtAS) extract from Salvia of ﬁ cinalis (L.) by gas chromatography-mass spectrometry (GC-MS) and by high-resolution electrospray ionization mass spectrometry (ESI-QTOF MS/MS), evaluate in vitro ability to scavenge the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH • ) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS •+ ), catalase (CAT-like ) and superoxide dismutase (SOD-like ) activity, moreover cytotoxic by MTT assay, alterations on cell morphology by giemsa and apoptotic-induced mechanism for annexin V/propidium iodide. Chemical identi ﬁ cation sage extracts revealed the presence of acids and phenolic compounds. In vitro antioxidant analysis for both extracts indicated promising activities. The cytotoxic assays using tumor (Hep-2, HeLa, A-549, HT-29 and A-375) and in non-tumor (HEK-293 and MRC-5), showed selectivity for tumor cell lines. Immunocytochemistry presenting a majority of tumor cells at late stages of the apoptotic process and necrosis. Given the results presented here, Brazilian Salvia of ﬁ cinalis (L.) used as condiment and tea, may protect the body against some disease, in particularly those where oxidative stress is involved, like neurodegenerative disorders, in ﬂ ammation and cancer.


INTRODUCTION
The importance of plants traditionally used by the population can lead us to search for new active compounds with application in chemoprevention or anticancer therapy.In Brazil, the use of plants to treat numerous diseases is part of the local culture (Ceolin et al. 2014).
Originally found in the East Mediterranean region, Salvia officinalis (Linneu, 1753), is a perennial shrubby herb belonging to the Lamiaceae, that is being extensively researched, plants of this family commonly used as a diary condiment in food, hydroalcoholic tincture and tea is the most consumed beverages used for the treatment of several disorders in traditional and folk medicine (Berdowska et al. 2013).Currently, many reports are using S. officinalis (L.) to analyze its pharmacological activity and studies have shown its potential as anti-inflammatory (Rodrigues et al. 2012), antimicrobial (Garcia et al. 2012), hypoglycemiant (Shafiee-Nick et al. 2012), anti-diabetic (Christensen et al. 2010), antioxidant (Generalic et al. 2012), to prevent neurodegenerative disease (Takano et al. 2011) and antitumor activity (Al-Barazanjy et al. 2013, Akaberi et al. 2015).
Drug development derived from natural products became a highly promising strategy for identifi cation of new antitumor agents.Tumor cells exposed to sage extracts may reduce cell viability by mechanisms not elucidated, but it is believed that this plant exerts its antitumor effect by changing the redox equilibrium, inducing apoptosis pathways and cell cycle arrest (Zare Shahneh et al. 2013, Vasko et al. 2014).
Given sage extract promising biological activities, the aim of this study is to investigate the major compounds presented in the hydroalcoholic and aqueous sage extract, its antioxidant activity and cytotoxic effect against well-known tumor cell lines: human laryngeal carcinoma (Hep-2), human cervix adenocarcinoma (HeLa), human lung carcinoma (A-549), human colorectal adenocarcinoma (HT-29) and human melanoma (A-375).Cytotoxic effects were also tested in normal cell lines: non-malignant human embryonic kidney (Hek-293) and human lung fibroblast .Moreover, this study also evaluated the morphological alterations and induction of apoptosis and necrosis after exposure to hydroalcoholic and aqueous sage extract.

Salvia offi cinalis (L.) SAMPLE
Salvia offi cinalis (L.) was collected in September in Farroupilha city, district of Rio Grande do Sul, Brazil (Lat.-29º13'30"S by Lon.-51º20'52"W) and deposited at the UCS Herbarium (HUCS -37944), University of Caxias do Sul (UCS).The leaves were dried in a circulating air oven (Fabbe) at 40-45±1 °C for seven days.The dried material was ground in a knife mill (Wiley) and stored in amber bottles for further tests.

Salvia offi cinalis (L.) EXTRACTS
The hydroalcoholic extract of Salvia offi cinalis (L.) (ExtHS) was obtained from a dried ground sample (1 g) with 80% (v/v) EtOH-H 2 O mixture (10 mL) through maceration process at room temperature for seven days in an amber bottle, under controlled shaking conditions.The extract was fi ltered and the solution evaporated to dryness, yielding a darkgreen fi ne powder.The powder was resuspended in 70% (v/v) EtOH-H 2 O at different concentrations (5-625 μg mL -1 ) and aliquots were ultrafiltered through a 0.22 μm polyethersulfone membrane (TPP, Techno Plastic Products, Switzerland).
The aqueous extract of S. officinalis (L.) (ExtAS) was obtained from a dried ground sample (1 g) with infusion, using distilled water at 100 °C for 10 minutes (10 mL).The extract was fi ltered with reduced pressure and lyophilized, producing a darkbrown fi ne powder.The powder was resuspended in distilled water, at different concentrations (5-5000 μg mL -1 ), and further ultrafi ltered through a 0.22 μm polyethersulfone membrane (TPP, Techno Plastic Products, Switzerland).

CHEMICAL CHARACTERIZATION
The major chemical constituents of dried S. officinalis hydroalcoholic and aqueous extracts were evaluated by high-resolution electrospray ionization mass spectrometry (ESI-QTOF MS/MS) on a Bruker Daltonics micrOTOF-Q II instrument in negative mode.The samples were solubilized in HPLC-grade methanol containing formic acid, 99.9/0.1 (v/v), and injected into the ESI source by means of a syringe pump at a fl ow rate of 5.0 μL min -1 .Diagnostic ions were identifi ed by the comparison of their ESI(-)-MS/MS dissociation patterns with previous studies.GC-MS analyses were performed with an Agilant 6890 chromatograph equipped with an electron impact detector at 70 eV and a DB-5 fused-silica capillary column (30 m x 0.25 mm i.d., 0.25 μm) using helium as carrier gas with a constant fl ow rate of 1.0 mL min -1 (split = 1:20).Identifi cation of the constituents was carried out comparing the obtained mass spectra with NIST 2005 library spectra.
TOTAL PHENOLIC CONTENT ANALYSIS ExtHS and ExtAS total phenolic content (10 μg μL -1 ) was measured using the Folin-Ciocalteu colorimetric method as described by Singleton and Rossi (1965).The absorbance was measured at 765 nm (Shimadzu UV-1700 spectrophotometer, Kyoto, Japan) after 30 min of reaction.Gallic acid was used as standard to produce the linear regression curve (r 2 =0.998).Total phenolic content was expressed in μg of gallic acid equivalents (GAE) μL -1 of extract.
The capacity of the extracts to reduce radical cation 2,2'-azino-bis(3-ethylbenzothiazoline-6sulfonic acid) (ABTS •+ ) was determined following a previously published method (Re et al. 1999).ABTS •+ radical scavenging ability was calculated as percentage of inhibition (% I) = (A734 of blank -A734 of sample)/A734 of blank 100%.The blank solution was previously prepared with ABTS •+ and ethanol only for ExtHS and ABTS •+ and distilled water only for ExtAS.The results are expressed in IC 50 (amount of extract needed to reduce 50% of the ABTS •+ radical cation), obtained by linear regression of the % I values.Gallic acid was used as positive control.
To evaluate enzyme-like activities, ExtHS and ExtAS were prepared in a concentration of 10 μg mL -1 .The superoxide dismutase (Sod)like assay was measured as the inhibition of the self-catalytic adrenochrome formation rate at 480 nm in a reaction medium containing 1 mmol L -1 adrenaline (pH 2.0) and 50 mmol L -1 glycine (pH 10.2) (Bannister and Calabrese 1987).This reaction was performed at 30 °C for 3 min.The results are expressed as superoxide dismutase units (USOD).Catalase-like assay was measured according to the method described by Aebi (1984).The assay determines the rate of H 2 O 2 decomposition at 240 nm.The reaction was conducted at 30 °C for 1 min.The results are expressed as catalase units (UCAT).Gallic acid was used as positive control (0.05 μg μL -1 ).

CYTOTOXIC ACTIVITY
Cell viability was measured using the MTT assay, which is based on the conversion of MTT to formazan crystals by mitochondrial dehydrogenases (Mosmann 1983, Alley et al. 1988).Briefly, tumor (Hep-2, HeLa, HT-29, A-549, A-375) and non-tumor (HEK-293 and MRC-5) cells were seeded at a density of 8x10 4 cells mL -1 in 100 μL of supplemented culture media.After 24 h, cells were treated with different concentrations (5-625 μg mL -1 ) of ExtHS and different concentrations (5-5000 μg mL -1 ) of ExtAS.Negative controls were treated with the same amounts of hydroalcoholic (residual amount ethanol = 3% on cells) and aqueous solution without extract, incubated at 37 ºC in 5% CO 2 for 24 h.The medium was removed and 1 mg mL -1 MTT dye in serum-free medium was added to the wells.Plates were incubated at 37 ºC for 2 h in humidifi ed 5% CO 2 atmosphere.Subsequently, the MTT solution was dissolved in 100 μL DMSO.Absorbance was measured using a microplate reader at 570 nm (Spectra Max190, Molecular Devices, USA).The readings were compared with the control, which represented 100% viability.All the cells used in the study were acquired commercially from Banco de Células do Rio de Janeiro.

MORPHOLOGICAL EXAMINATION AND INDUCTION OF APOPTOSIS IN DIFFERENT CELL LINES
Cell morphology of Hep-2, HeLa, HT-29, A-549, A-375, HEK-293 and MRC-5 lines was monitored using an inverted microscope under a conventional Giemsa staining protocol (Nersesyan et al. 2006).Changes in the cellular morphology were observed and documented after 24 h ExtHS and ExtAS treatment exposure at its IC 50 , The negative control group was treated with EtOH-H2O 70% (v/v), respecting the residual amount ethanol of 3% for ExtHS and destilate water for ExtAS for the same period of time.
For apoptosis analysis, all cell lines were seeded on coverslips into 24-well plates at a density of 8x10 4 cells mL -1 in 500 μL of supplemented culture media (DMEM).After 24 hours, cells were treated with different concentrations of ExtHS and ExtAS at its IC 50 , followed by extract incubation at 37 ºC in 5% CO 2 for 24 hours.Next, treatment with sage extract was removed, washed with phosphate buffered saline, followed by primary antibody incubation using 2.5 μg mL -1 of Annexin V (Abcam® -ab14196) at 37 ºC, in 5% CO 2 atmosphere, for 1 hour.Samples were washed with ligation buffer solution and incubate with secondary antibody, 2.5 μg mL -1 Dylight® 488 (Abcam® -ab115637) at 37 ºC, in 5% CO 2, atmosphere for 30 minutes.Next, cells were stained with 0.5 μg mL -1 propidium iodate (PI) (Sigma-Aldrich®-P4170) for 30 minutes, washed with ligation buffer and fi xed with formaldehyde 4% at room temperature, for 15 minutes.The percentage of cells undergoing early apoptosis (annexin V positive), late apoptosis (annexin V positive and PI positive) and/or necrosis (PI positive) was estimated by counting four fi elds for each condition using a fl uorescence microscope (BX43, Olympus).To confi rm cell apoptosis, we used the technique of staining with dye acridine orange (100 μg mL -1 ) and ethidium bromide (100 μg mL -1 ), data not shown.

STATISTICAL ANALYSIS
All biological measurements were conducted on the basis of three independent experiments.Statistical signifi cance was evaluated using t-test and oneway analysis of variance (ANOVA) with post hoc multiple comparisons test (Tukey) to assess statistical differences in case of normal distribution.Signifi cance was accepted at p lower than 0.05 using the Statistical Package for Social Sciences (SPSS, version 19.0) for Windows.

CHEMICAL CHARACTERIZATION
The GC-MS analysis showed major essential oil components present in the S. officinalis hydroalcoholic extract (Table I).Identified molecules include monoterpene eucalyptol, α-thujone, β-thujone, camphor; sesquiterpenes β-caryophyllene, α-caryophyllenen, viridiflorol and diterpenemannol.These compounds were commonly found in the essential oil of S. offi cinalis, however, with different concentrations depending on plant geographic origin and harvest season.
The highest intense peaks shown in the ESI-QTOF analysis (negative ionization mode) from the hydroalcoholic extract (Table II, entries 1-4) were the deprotonated molecules [M-H] -at m/z 345.2086 and m/z 455.3773, which correspond to a nominal mass of 346 u and 456 u, respectively.
According to literature data, compounds isolated from Salvia genus, such as rosmanol and its isomers, methyl carnosate, and 12-methoxycarnosinic acid possess nominal mass of 346 u.Rosmanol and its isomers were discarded due to high difference between the accurate mass and the exact mass of these compounds.A tandem MS/MS analysis of the peak at m/z 345.2086 shows a major fragment at m/z 301, which represents a loss of neutral CO 2 molecule (MW = 44).
This fragmentation behavior identified the 12-methoxycarnosinic acid it is compared the fragment pathway between 12-methoxycarnosinic acid and methyl carnosate.The deprotonated molecules [M-H] -with m/z 455.3573 (entry 4) was attributed to the ursolic acid [M-H] -; 455.3531 that is present in different Salvia species.This assignment was confirmed by comparison with HRMS analysis of commercially available ursolic acid (Sigma-Aldrich -USA).The rosmarinic acid that is frequently found in sage extracts and considered a potent antioxidant molecule was also present in both hydroalcoholic and aqueous extracts (Table II, entries 3 and 10).This compound was identified due to the accurate m/z of 359.0783 (entry 3) and 359.0785 (entry 10).The MS 2 analyses revealed the major fragments at m/z 197, 179 and 161.The compounds were identifi ed on GC-MS (gas chromatograph coupled with mass spectrometry) and listed according to their elution.RT = retention time.

Entry
Observed

TOTAL POLYPHENOL CONTENT AND ANTIOXIDANT ACTIVITY
The total phenolic content were analyzed through Folin-Ciocalteu assay and showed polyphenols in the ExtHS that presents 1.88±0.01mgGAE mL -1 and ExtAS shows 1.61±0.95mgGAE mL -1 .The ExtHS and ExtAS were able to donate electrons to the stable radicals DPPH • and ABTS •+ and showed promissing SOD-like and CAT-like activities, being the CAT-like activity of ExtHS and ExtAS higher to that presented by gallic acid, a standard antioxidant (Table III).

CYTOTOXIC ACTIVITY
Cytotoxic activity after 24 hours treatment with ExtHS showed 50% inhibitory concentration that varied according to each tumor cell line investigated, ranging from 45 to 235 μg mL -1 .The Hep-2 revealed the lowest IC 50 (45±1 μg mL -1 ) whereas A-549 presented the highest level for IC 50 (235±1 μg mL -1 ).Non-tumor lines IC 50 values were above 335.00μg mL -1 .The ExtAS treatment showed less promising 50% inhibitory concentration, which varied also according to the tumor cell line, from 1500 to 5000 μg mL -1 .Tumor-cells A-549 revealed the lowest fi fty percent inhibitory concentration (1500±1 μg mL -1 ), whereas A-375 presented the highest level for IC 50 (above 5000 μg mL -1 ).Nontumor cells Hek-293 and MRC-5 IC 50 values were again above the ones found in the tumor lines, 5000 μg mL -1 .Both non-tumor cells treated with ExtHS an ExtAS showed higher IC 50 compared to the tumor lines, indicating a selective cytotoxic activity (Table IV).Results presented as mean ± SD. a Amount (mg mL -1 ) of the S. offi cinalis extracts required to scavenge 50% of the DPPH • and ABTS •+ radical.b Amount (μg mL -1 ) of the gallic acid required to scavenge 50% of the DPPH • and ABTS •+ radical.USOD = One unit of Sod is defi ned as the amount of extract (uL) that inhibits the rate of adrenochrome formation by 50%.UCAT= One unit of Cat is defi ned as the amount of extract (uL) that decomposes 1 mmol of H 2 O 2 in 1 min at pH 7.4.* Values obtained for the extracts were statistically different the Gallic acid using t-test for independent samples (p≤0.05).

TABLE IV IC 50 values -50% inhibitory concentration obtained in the MTT assay for tumor and non-tumor cell after S.
offi cinalis exposure 24h treatment.

Morphological cells alterations after ExtHS and
ExtAS treatment with IC 50 compared to the untreated groups were monitored under a light microscope (Olympus BX43).Modifi cations in morphology after Giemsa staining could be observed after 24 h extract treatment.Changes include cell shrinkage and apoptotic body formation, suggesting the induction of apoptosis as a consequence of extracts exposure.Negative controls here treated exclusively with distilled water and hydroalcoholic solvent 70 % (v/v) and presented no alterations on cell morphology.However, modifications in morphology were more expressive in tumor cells when compared a non-tumor cells.
The apoptotic potential was assessed by indirect immunofl uorescence with annexin V/FITC -PI and confi rmed with acridine orange/ethidium bromide staining (data not shown).Tumor and non-tumor cells were treated with ExtHS and ExtAS at IC 50 for 24 h.Signaling for cell death was observed in the majority of the cell treated with ExtHS compared to the untreated control group, similar patterns were observed for ExtAS but in lesser proportions (Table IV).Percent of cells immunostained in late apoptosis (Annexin Vpositive/PI positive) and/or necrosis (PI positive) are represented in Figure 1.Signifi cantly lower percentages of late apoptosis/ necrosis events were observed for the two extracts of non-tumor cells Hek-293 and MRC-5 compared to the tumor lines Hep-2, HeLa, HT-29, A-549 and A-375.

DISCUSSION
Some of the compounds herein identified, such as tartaric acid, malic acid and citric acid, exhibit antimicrobial activity and are widely used in the food industry to control the oxidative instability, acting as antioxidant by sequestering free radicals.Similarly, we found these compounds in aqueous extract of S. offi cinalis (L.), indicating that sage actually presents molecules with promissing antioxidant activity.These organic acids may be Another interesting molecule found in the aqueous extract (ExtAS) was the succinic acid, an intermediate of the citric acid cycle that may participate on the immune system regulation.It has been attributed that dicarboxylic acids increases mitochondrial calcium levels, forming pores in the mitochondrial membrane and releasing cytochrome c into the cytosol, activating caspases (Rubic et al. 2008).The 12-methoxycarnosinic acid which was found in the hydroalcoholic extract (ExtHS), previously was reported to interact with the nuclear peroxisome proliferator-activated receptor (PPARs) in mouse embryonic fibroblasts, and plays an important role in anti-diabetic responses, once they regulate glucose homeostasis, lipid metabolism and infl ammation (Christensen et al. 2010).
Other compounds herein identifi ed participate in apoptosis induction mechanisms.The eucalyptol (50 mM) was able to regulate activity of p38 and caspase-3, inducing apoptosis and suppressing proliferation in the colorectal humam cancer (Murata et al. 2013).Camphor has been atributed to present cytotoxic activity in human squamous cell carcinoma (HSC-2) (Cherneva et al. 2012).Ursolic acid was able to induce apoptosis in ovarian cancer cells via activation of caspase and reduction of glycogen and protein synthesis by phosphorylation of the enzyme of glycogen synthase kinase -3 β (GSK-3β) (Song et al. 2012).This molecule was able to up-regulate Bax and down-regulate Bcl-2 levels, releasing cytochrome c to the cytosol and decreasing mitochondrial membrane potential, thereby activating extrinsic and intrinsic apoptosis pathway in human breast cancer cell line (Kim et al. 2011, Akaberi et al. 2015).
Furthermore, rosmarinic acid, also found in the hydroalcoholic (ExtHS) and aqueous (ExtAS) extracts, was suggested to inhibit proliferation and induce apoptosis in tumor cells Caco-2 and HSC T6, by down-regulating Bcl-2 and decreasing the expression of CyclinD1, inhibiting phosphorylation of STAT3, responsible for the progression and invasion of cancer (Zhang et al. 2012).Other compound found in both extracts was the caffeic acid.Previous studies using A-549 cell model reported that this compound may cause apoptosis on S/G2 cell cycle arrest, up-regulating Bax and down-regulating Bcl2 proteins (Ulasli et al. 2013).
The ExtHS and ExtAS obtained from sage leaves were rich in polyphenols compounds with in vitro ability to scavenge the free radicals DPPH • and ABTS •+ , furthermore, cytotoxic activity in tumor cells.Polyphenol compounds are commonly found in sage, however, crude extracts will present different concentrations of polyphenols depending on several conditions like extraction method, plant geographic origin and harvest season (Russo et al. 2013).
It is known that superoxide dismutase and catalase enzymes have an important role in maintaining the physiologic redox equilibrium.The two extracts used in this study presented important in vitro SOD-like and CAT-like activities compared with the standard gallic acid.This study verifi ed the antioxidant properties of hydroalcoholic and waterbased extracts, which are widely used in Brazil as plant tincture and tea, and may have an important role in maintaining the redox equilibrium, decreasing oxidative stress.These properties could contribute to play a key role to various diseases, such neurodegenerative disorders, infl ammation and cancer.
Cytotoxicity analysis with MTT showed that non-tumor cell lines presented a higher IC 50 compared to the tumor lines at the same extract exposure time , indicating less cytotoxicity.Also to be considered, the ExtAS treatment showed less promising 50% inhibitory concentrations in tumor cell lines.Non-tumor cell lines presented, as observed to the ExtHA, a higher IC 50 after incubation with ExtAS , indicating increase resistance when exposed to the aqueous extract and selective cytotoxic activity.
Moreover, the cytotoxicity assays of plant extracts presented effect in a dose-dependent manner.Kozics et al. (2013) determined the viability of HepG2 cells with 24-h treatment using various concentrations of hidroalcoholic sage extract.Cells were immediately rescued from culture and MTT analysis was performed showing a IC 50 of 5.7 mg mL -1 , similar to the ExtAS in this study.Whereas, Zare Shahneh et al. (2013) tested on six cancer cell lines; non-Hodgkin's B-cell lymphoma (Raji), human leukemic monocyte lymphoma (U937), human acute myelocytic leukemia (KG-1A), human breast carcinoma (MCF-7 cells), human prostate cancer (PC3) and mouse fibrosarcoma (WEHI-164) and reported a range of IC 50 39.95-166.89μg mL -1 , similar for the hidroalcoholic samples tested in this study.In addition, non-tumor cell human umbilical vein endothelial (HUVEC) presented lower cytotoxicity (IC 50 > 600 μg mL -1 ), that is in accordance with our fi ndings.
Here, the antioxidant activity was evaluated using chemical assays, while the cytotoxic potential was performed in mammalian cells.It is already know that the mechanisms of the biological effects of the polyphenols are different in cells than that of chemical assays.So, it is possible than a compound that showed antioxidant activity in DPPH • and ABTS •+ assays could act as pro-oxidant in tumor cells.The pro-oxidant effect demonstrated in our work (mammalian cells) was dose-dependent, however, we showed only the IC 50 of the both extracts for the seven cell lines studied.
The colorimetric technique gives a good highcontrast polychromatic stain and shows morphology alterations compatible with apoptosis.Here, negative control cells were shown as rounded-like structures, with abundant and intact cytoplasm.The cells treated with ExtHS and ExtAS at its inhibitory 50% concentration presented several modifi cations in morphology and reduced number of cells.
Death response mechanisms after extracts exposure was also investigated, indicating that most cells died in late stages of apoptosis or necrosis.Cells in late apoptosis or necrosis demonstrate similar patterns, once both annexin V and PI crosses the cell membrane after permeabilization, thus cannot be distinguished.Overlapping of annexin V and PI was considered to be a late apoptosis and/ or necrosis event and signaling for cell death was observed in the majority of the cell treated with ExtHS compared to the untreated control group.Late apoptosis and/or necrosis were observed after ExtAS incubation and presented similar ExtHS induction pathway, but in less proportion, fi ndings that were confirmed using acridine orange and ethidium bromide staining (data not shown).
In summary, the results here presented demonstrate that the cytotoxic potential was more promising in cells after ExtHS incubation, however, changes in extraction methodology may potentiate its activity in tumor cells.In addition, all compounds are of pharmaceutical importance and the presence or not of synergistic, antagonistic or additive combinations of bioactive molecules should be investigated for better comprehension of the effects of natural products in cell metabolism.These fi ndings evoke additional studies to clarify the relationship of compounds here identifi ed and the molecular mechanisms involved in its biological activity.Brazilian Salvia offi cinalis (L.) extracts presented favorable cytotoxic response, generating morphological changes and induction of apoptosis, and also showing selectivity for tumor cells.Its compounds may lead to new drug discovery with reduction of toxic side effects in cancer patients.

Figure 1 -
Figure 1 -Percent of cells immunostained in late apoptosis (Annexin V positive/PI positive) and/ or necrosis (PI positive).Results were obtained from three independent experiments.Each bar represents the average percentage of late apoptosis/necrosis ± SD relative to control, which was normalized to 100%.Letters correspond to statistically signifi cant differences using ANOVA-Tukey test (p ≤ 0.05).