Background: Reliable intraoperative tools for donor liver assessment are needed, particularly in the context of steatotic and extended-criteria grafts. While histology remains the reference standard, it is limited by sampling variability and logistical constraints. Preservation fluid may provide a complementary, whole-organ source of biochemical information. Methods: In this single-center prospective exploratory pilot study, liver tissue and preservation fluid were collected from 30 donation-after-brain-death grafts during the back-table procedure. Biochemical parameters, including arginase activity, β-hydroxybutyrate (βHB), acetoacetate, and total protein, were measured using standard assays. Associations with histological steatosis on wedge biopsy were assessed using nonparametric correlation analyses, and paired preservation fluid samples were compared. Results: Most grafts demonstrated absent or mild steatosis; only two exhibited moderate steatosis, and none were severely steatotic. No preservation fluid biomarker showed a statistically significant association with histological steatosis. Weak, non-significant positive correlations were observed for βHB and arginase activity (Spearman r ≈ 0.33-0.35). Protein concentration and arginase activity decreased between start and end samples, whereas ketone body levels remained relatively stable. Conclusions: Preservation fluid biomarker measurement during routine graft preparation is feasible. Although no significant associations with histological steatosis were identified, the observed weak correlations suggest possible associations requiring validation in larger studies. Larger, adequately powered studies, including a broader spectrum of steatosis and clinically relevant outcomes, are required to determine potential clinical applicability.

Liver transplantation is a critical and evolving field in modern medicine, offering life-saving treatment for patients with end-stage liver disease and other hepatic conditions. Despite its transformative potential, transplantation faces persistent challenges, including a global organ shortage, increasing liver disease prevalence, and significant waitlist mortality rates. Current donor evaluation practices often discard potentially viable livers, underscoring the need for refined graft assessment tools. This review explores advancements in graft evaluation and utilization aimed at expanding the donor pool and optimizing outcomes. Emerging technologies, such as imaging techniques, dynamic functional tests, and biomarkers, are increasingly critical for donor assessment, especially for marginal grafts. Machine learning and artificial intelligence, exemplified by tools like LiverColor, promise to revolutionize donor-recipient matching and liver viability predictions, while bioengineered liver grafts offer a future solution to the organ shortage. Advances in perfusion techniques are improving graft preservation and function, particularly for donation after circulatory death (DCD) grafts. While challenges remain—such as graft rejection, ischemia-reperfusion injury, and recurrence of liver disease—technological and procedural advancements are driving significant improvements in graft allocation, preservation, and post-transplant outcomes. This review highlights the transformative potential of integrating modern technologies and multidisciplinary approaches to expand the donor pool and improve equity and survival rates in liver transplantation.

Enoxacin (ENX), a fluoroquinolone antibiotic, was modified with various fatty acids to explore dual anticancer and antimicrobial activity. Several conjugates-especially those with polyunsaturated fatty acids like linoleic and docosahexaenoic acid (DHA)-showed potent cytotoxicity (IC50 < 10 μM) against prostate (PC3) and colon (SW620) cancer cells, while sparing normal cells. Mechanistic studies revealed apoptosis induction, ROS generation, and cell cycle arrest, with the DHA conjugate achieving up to 99 % cancer cell death. Notably, some derivatives also reduced inflammatory IL-6 secretion and retained antibacterial potency, suggesting these ENX-fatty acid hybrids as promising multifunctional therapeutic candidates.

We designed and synthesized a series of pyrazole-tagged alkanoyl (1-15) and oxoalkyl (16-31) derivatives of ciprofloxacin (CP) by modifying the nitrogen atom of the C-7 piperazinyl ring. Next, we evaluated their antibacterial activity, bactericidal kinetic, cytotoxicity, antibiofilm properties, and molecular interactions with bacterial topoisomerases. These compounds showed strong antibacterial activity against standard and clinical Gram-positive and Gram-negative pathogens, with several derivatives (5, 8, 19, 22, 23) with MIC values of 0.4-0.5 µg/mL being as effective as CP, and compounds 12 and 22 proving even more potent against S. aureus strains (MICs values of 0.25-0.4 µg/mL). Cytotoxicity tests on human HaCaT cells confirmed their low toxicity (IC50 ranged from 25 to >100 µM). Analogs 12 and 22 demonstrated both bactericidal activity and strong biofilm-inhibitory effects in most studies. They inhibited the formation of biofilms by the most susceptible S. aureus, S. epidermidis and S. pasteuri isolates at concentrations corresponding to the MIC or MBC. Notably, compound 12 was significantly more potent than CP at eradicating mature S. aureus biofilms, reducing biofilm mass two to three times more effectively than CP, and achieving biofilm survival rates of 18-57 %. Molecular docking studies confirmed that both derivatives bind to bacterial topoisomerases in a similar manner to CP, with differences in substituent orientation influencing their interactions. Overall, conjugate 12 emerges as a promising lead due to its strong antibacterial and antibiofilm properties, making it a potential candidate for further development.

The distinct chemical structure of thiourea derivatives provides them with an advantage in selectively targeting cancer cells. In our previous study, we selected the most potent compounds, 2 and 8, with 3,4-dichloro- and 3-trifluoromethylphenyl substituents, respectively, across colorectal (SW480 and SW620), prostate (PC3), and leukemia (K-562) cancer cell lines, as well as non-tumor HaCaT cells. Our research has demonstrated their anticancer potential by targeting key molecular pathways involved in cancer progression, including caspase 3/7 activation, NF-κB (Nuclear Factor Kappa-light-chain-enhancer of activated B cells) activation decrease, VEGF (Vascular Endothelial Growth Factor) secretion, ROS (Reactive Oxygen Species) production, and metabolite profile alterations. Notably, these processes exhibited no significant alterations in HaCaT cells. The effectiveness of the studied compounds was also tested on spheroids (3D culture). Both derivatives 2 and 8 increased caspase activity, decreased ROS production and NF-κB activation, and suppressed the release of VEGF in cancer cells. Metabolomic analysis revealed intriguing shifts in cancer cell metabolic profiles, particularly in lipids and pyrimidines metabolism. Assessment of cell viability in 3D spheroids showed that SW620 cells exhibited better sensitivity to compound 2 than 8. In summary, structural modifications of the thiourea terminal components, particularly dihalogenophenyl derivative 2 and para-substituted analog 8, demonstrate their potential as anticancer agents while preserving safety for normal cells.

We report the design, synthesis, and antimicrobial evaluation of a series of ciprofloxacin (CP) conjugates coupled with nitrogen-containing heterocycles. In vitro screening of these new hybrid compounds (1-13) against a panel of planktonic bacterial strains highlighted thiazolyl homologs 6 and 7 as the most promising candidates for further investigation. These derivatives demonstrated potent growth-inhibitory activity against various standard and clinical isolates, with minimum inhibitory concentrations (MICs) ranging from 0.05 to 0.4 mu g/ml, which are higher or comparable to the reference fluoroquinolone. Both compounds effectively inhibited biofilm formation by selected staphylococci across all tested concentrations (1-8 x MIC), displaying greater efficacy at higher doses compared to CP alone. Notably, conjugate 7 also significantly eradicated existing biofilms formed by S. aureus of various origin. Molecular docking studies revealed that conjugate 7 engages in a broader range of interactions with DNA gyrase and DNA topoisomerase IV than CP, suggesting stronger binding affinity and enhanced flexibility. This may contribute to its potential in overcoming bacterial resistance mechanisms. The above findings indicate compound 7 as a promising candidate for clinical development.

New halogenated thiourea derivatives were synthesized via the reaction of substituted phenylisothiocyanates with aromatic amines. Their cytotoxic activity was examined in in vitro studies against solid tumors (SW480, SW620, PC3), a hematological malignance (K-562), and normal keratinocytes (HaCaT). Most of the compounds were more effective against SW480 (1a, 3a, 3b, 5j), K-562 (2b, 3a, 4a), or PC3 (5d) cells than cisplatin, with favorable selectivity. Their anticancer mechanisms were studied by Annexin V-fluorescein-5-isothiocyanate apoptosis, caspase-3/caspase-7 assessment, cell cycle analysis, interleukin-6 (IL-6) release inhibition, and reactive oxygen species (ROS) generation assay. Thioureas 1a, 2b, 3a, and 4a were the most potent activators of early apoptosis in K-562 cells, and substances 1a, 3b, 5j triggered late-apoptosis or necrosis in SW480 cells. This proapoptotic effect was proved by the significant increase of caspase-3/caspase-7 activation. Cell cycle analysis revealed that derivatives 1a, 3a, 5j increased the number of SW480 and K-562 cells in the sub-G1 and/or G0/G1 phases, and one evoked cycle arrest at the G2 phase. The most potent thioureas inhibited IL-6 cytokine secretion from PC3 cells and both colon cancer cell lines. Apoptosis-inducing compounds also increased ROS production in all tumor cell cultures, which may enhance their anticancer properties.

Copper complexes with 1,3-disubstituted thiourea derivatives, all containing 3-(trifluoromethyl)phenyl tail and 1-alkyl/halogen-phenyl substituent, were synthesized. The experimental spectroscopic studies and theoretical calculation revealed that two ligands coordinate to Cu(II) in a bidentate fashion via thiocarbonyl S and deprotonated N atoms of thiourea moiety. Such monomers are characteristic of alkylphenylthiourea complexes, whereas the formation of a sandwich-type dimer is observed for halogeno derivatives. For the first time, the structural identifications of CuN2S2-based complexes using experimental and theoretical X-ray absorption near edge structure are demonstrated. The dimeric halogeno derivatives showed higher antimicrobial activity in comparison with alkylphenylthiourea complexes. The Cu(II) complex of 1-(4-chloro-3-nitrophenyl)-3-[3-(trifluoromethyl)phenyl]thiourea was active against 19 strains of methicillin-resistant Staphylococci (MIC = 2 µg/mL). This derivative acted as a dual inhibitor of DNA gyrase and topoisomerase IV isolated from Staphylococcus aureus. Additionally, complexes of halogenphenylthiourea strongly inhibited the growth of mycobacteria isolated from tuberculosis patients, even fourfold stronger than the reference isoniazid. The complexes exerted weak to moderate antitumor activity (towards SW480, SW620, and PC3) being non-toxic towards normal HaCaT cells.

The positive and pro-economic trend in the management of cancer treatment is the search for the antineoplastic potential of known, widely used and safe drugs with a different clinical purpose. A good candidate seems to be moxifloxacin with broad-spectrum antibacterial activity, which as the member of the fourth generation fluoroquinolone is known to affect not only bacterial but also eukaryotic DNA topoisomerases, however at high concentration. Due to the fact that the modification of parent drug with lipid component can improve anticancer potential by increasing of bioavailability, selectivity, and cytotoxic efficiency, we evaluated the mechanisms of cytotoxic activity of novel moxifloxacin conjugates with fatty acids and verified metabolic profile in SW480, SW620 and PC3 cell lines. Our study revealed that cytotoxic potential of moxifloxacin conjugates was stronger than free moxifloxacin, moreover, they remained non-toxic to normal HaCaT cells. PC3 were more sensitive to MXF conjugates than colon cancer cells. The most promising cytotoxic activity exhibited conjugate 4m and 16m with oleic and stearic acid reducing viability of PC3 and SW620 cells. Tested conjugates activated caspases 3/7 and induced late-apoptosis, mainly in PC3 and SW620 cells. However, the most pronounced inhibition of NF-κB activation and IL-6 secretion was observed in SW480. Metabolomic analysis indicated influence of the moxifloxacin conjugates on intensity of lipid derivatives with the most successful metabolite profile in PC3. Our findings suggested the cytotoxic potential of moxifloxacin conjugates, especially with oleic and stearic acid can be beneficial in oncological therapy, including their possible anti-inflammatory and known antibacterial effect.

Novel conjugates (CP) of moxifloxacin (MXF) with fatty acids (1m–16m) were synthesized with good yields utilizing amides chemistry. They exhibit a more pronounced cytotoxic potential than the parent drug. They were the most effective for prostate cancer cells with an IC50 below 5 µM for respective conjugates with sorbic (2m), oleic (4m), 6-heptenoic (10m), linoleic (11m), caprylic (15m), and stearic (16m) acids. All derivatives were evaluated against a panel of standard and clinical bacterial strains, as well as towards mycobacteria. The highest activity towards standard isolates was observed for the acetic acid derivative 14m, followed by conjugates of unsaturated crotonic (1m) and sorbic (2m) acids. The activity of conjugates tested against an expanded panel of clinical coagulase-negative staphylococci showed that the compound (14m) was recognized as a leading structure with an MIC of 0.5 μg/mL denoted for all quinolone-susceptible isolates. In the group of CP derivatives, sorbic (2) and geranic (3) acid amides exhibited the highest bactericidal potential against clinical strains. The M. tuberculosis Spec. 210 strain was the most sensitive to sorbic (2m) conjugate and to conjugates with medium- and long-chain polyunsaturated acids. To establish the mechanism of antibacterial action, selected CP and MXF conjugates were examined in both topoisomerase IV decatenation assay and the DNA gyrase supercoiling assay, followed by suitable molecular docking studies.

Purpose: To assess cytotoxic effect of ciprofloxacin conjugates with fatty acids on prostate cancer cells (LNCaP and DU-145) with different hormone sensitivity, based on previous promising results from the PC3 cells. Methods: Cytotoxicity were estimated using MTT and LDH tests, whereas its mechanisms were estimated by apoptosis and IL-6 assays. The intensity of proteins involved in lipid metabolism was determined using ML-CS assay. Results: The hormone insensitive DU-145 cells were more vulnerable than the hormone sensitive LNCaP cells. The IC50 values for oleic (4), elaidic (5) and docosahexaenoic acid (8) conjugates were 20.2 µM, 17.8 µM and 16.5 µM, respectively, in DU-145 cells, whereas in LNCaP cells IC50 exceeded 20 µM. The strong conjugate cytotoxicity was confirmed in the LDH test, the highest (70.8%) for compound (5) and 64.2% for compound (8) in DU-145 cells. This effect was weaker for LNCaP cells (around 60%). The cytotoxic effect of unconjugated ciprofloxacin and fatty acids was weaker. The early apoptosis was predominant in LNCaP while in DU-145 cells both early and late apoptosis was induced. The tested conjugates decreased IL-6 release in both cancer cell lines by almost 50%. Proteomic analysis indicated influence of the ciprofloxacin conjugates on lipid metabolic proteins in prostatic cancer. Conclusion: Our findings suggested the cytotoxic potential of ciprofloxacin conjugates with reduction in proteins involved in prostate cancer progress.

Enoxacin as a second-generation synthetic quinolone is known for its antibacterial action; however, in recent years there have been studies focusing on its anticancer potential. Interestingly, it turns out that compared to other fluoroquinolones, enoxacin exhibits uncommon cytotoxic properties. Besides its influence on apoptosis, the cell cycle and cell growth, it exhibits a regulatory action on microRNA biogenesis. It was revealed that the molecular targets of the enoxacin-mediated inhibition of osteoclastogenesis are vacuolar H+-ATPase subunits and the c-Jun N-terminal kinase signaling pathway, causing a decrease in cell invasiveness. Interestingly, the prooxidative nature of the subjected fluoroquinolone enhanced the cytotoxic effect. Crucial for the anticancer activity were the carboxyl group at the third carbon atom, fluorine at the seventh carbon atom and nitrogen at the eighth position of naphyridine. Modifications of the parent drug improved the induction of oxidative stress, cell cycle arrest and the dysregulation of microRNA. The inhibition of V-ATPase–microfilament binding was also observed. Enoxacin strongly affected various cancer but not normal cells, excluding keratinocytes, which suffered from phototoxicity. It seems to be an underestimated anticancer drug with pleiotropic action. Furthermore, its usage as a safe antibiotic with well-known pharmacokinetics and selectivity will enhance the development of anticancer treatment strategies. This review covers articles published within the years 2000–2021, with a strong focus on the recent years (2016–2021). However, some canonical papers published in twentieth century are also mentioned.

Abstract Introduction Glutaminolysis, beside glycolysis, is a key metabolic pathway of a cancer cell that provides energy and substrates for the synthesis of nucleic acids, proteins, and lipids. The pathway is mediated by both mitochondrial and cytosolic enzymes. Neither expression of glutaminolysis enzymes in colon cancer cells nor the influence of various oxygen concentrations on their expression has been studied so far. Objectives The aim of the study was to determine and compare the mRNA expression of enzymes involved in glutaminolysis at various oxygen levels in human primary (SW480) and metastatic (SW620) colon cancer cells cultured in 1% O2 (hypoxia), 10% O2 (tissue normoxia), 21% O2 (atmospheric normoxia). Methods Cell viability was determined by Trypan Blue exclusion (TB) and Thiazolyl Blue Tetrazolium Bromide (MTT). The expression of HIF1α, GLUT1, GLS1, AST1, AST2, ACL, PC and GC1, GC2 at mRNA levelwas determined by RT-qPCR. Results. Correlation between increasing oxygen concentration and cell count was not observed. In both cell lines the number of viable cells was the lowest at 10% oxygen. The enzyme profile and expression of proteins involved in glutaminolysis varied depending on oxygen pressure and type of cell lines. In summary, our findings suggest differences in metabolic adaptation to oxygen availability in vivo between primary and metastatic colon cancer cells.

Substituted thiourea derivatives possess confirmed cytotoxic activity towards cancer but also normal cells. To develop new selective antitumor agents, a series of 3-(trifluoromethyl)phenylthiourea analogs were synthesized, and their cytotoxicity was evaluated in vitro against the cell line panel. Compounds 1–5, 8, and 9 were highly cytotoxic against human colon (SW480, SW620) and prostate (PC3) cancer cells, and leukemia K-562 cell lines (IC50 ≤ 10 µM), with favorable selectivity over normal HaCaT cells. The derivatives exerted better growth inhibitory profiles towards selected tumor cells than the reference cisplatin. Compounds incorporating 3,4-dichloro- (2) and 4-CF3-phenyl (8) substituents displayed the highest activity (IC50 from 1.5 to 8.9 µM). The mechanisms of cytotoxic action of the most effective thioureas 1–3, 8, and 9 were studied, including the trypan blue exclusion test of cell viability, interleukin-6, and apoptosis assessments. Compounds reduced all cancerous cell numbers (especially SW480 and SW620) by 20–93%. Derivatives 2 and 8 diminished the viability of SW620 cells by 45–58%. Thioureas 1, 2, and 8 exerted strong pro-apoptotic activity. Compound 2 induced late apoptosis in both colon cancer cell lines (95–99%) and in K-562 cells (73%). All derivatives acted as inhibitors of IL-6 levels in both SW480 and SW620 cells, decreasing its secretion by 23–63%.

Currently, over 100 countries are fighting against a common enemy, the severe acute respiratory syndrome coronavirus (SARS-CoV)-2, which causes COVID-19. This has created a demand for a substance whose effectiveness has already been demonstrated in a similar scenario. Glycyrrhizin (GZ) is a promising agent against SARS-CoV-2 as its antiviral activity against SARS-CoV has already been confirmed. It is worthwhile to extrapolate from its proven therapeutic effects as there is a high similarity in the structure and genome of SARS-CoV and SARS-CoV-2. There are many possible mechanisms through which GZ acts against viruses: increasing nitrous oxide production in macrophages, affecting transcription factors and cellular signalling pathways, directly altering the viral lipid-bilayer membrane, and binding to the ACE2 receptor. In this review, we discuss the possible use of GZ in the COVID-19 setting, where topical administration appears to be promising, with the nasal and oral cavity notably being the potent location in terms of viral load. The most recently published papers on the distribution of ACE2 in the human body and documented binding of GZ to this receptor, as well as its antiviral activity, suggest that GZ can be used as a therapeutic for COVID-19 and as a preventive agent against SARS-CoV-2.

A series of eight copper (II) complexes with 3-(4-chloro-3-nitrophenyl)thiourea were designed and synthesized. The cytotoxic activity of all compounds was assessed in three human cancer cell lines (SW480, SW620, PC3) and human normal keratinocytes (HaCaT). The complexes 1, 3, 5, 7 and 8 were cytotoxic to the studied tumor cells in the low micromolar range, without affecting the normal cells. The complexes 1, 3, 7 and 8 induced lactate dehydrogenase (LDH) release in all cancer cell lines, but not in the HaCaT cells. They provoked early apoptosis in pathological cells, especially in SW480 and PC3 cells. The ability of compounds 1, 3, 7 and 8 to diminish interleukin-6 (IL-6) concentration in a cell was established. For the first time, the influence of the most promising Cu (II) complexes on intensities of detoxifying and reactive oxygen species (ROS) scavenging the enzymes of tumor cells was studied. The cytotoxic effect of all copper (II) conjugates against standard and hospital bacterial strains was also proved.

Leflunomide (LFN) is a well-known immunomodulatory and anti-inflammatory prodrug of teriflunomide (TFN). Due to pyrimidine synthesis inhibition TFN also exhibits potent anticancer effect. Because, there is the strict coupling between the pyrimidine synthesis and the mitochondrial respiratory chain, the oxygen level could modify the cytostatic TNF effect. The aim of the study was to evaluate the cytostatic effect of pharmacologically achievable teriflunomide (TFN) concentrations at physiological oxygen levels, i.e. 1% hypoxia and 10% tissue normoxia compared to 21% oxygen level occurred in routine cell culture environment. The TFN effect was evaluated using TB, MTT and FITC Annexin tests for human primary (SW480) and metastatic (SW620) colon cancer cell lines at various oxygen levels. We demonstrated significant differences between proliferation, survival and apoptosis at 1, 10 and 21% oxygen in primary and metastatic colon cancer cell lines (SW480, SW620) under TFN treatment. The cytostatic TFN effect was more pronounced at hypoxia compared to tissue and atmospheric normoxia in both cancer cell lines, however metastatic cells were more resistant to antiproliferative and proapoptotic TFN action. The early apoptosis was predominant in physiological oxygen tension while in atmospheric normoxia the late apoptosis was induced. Our findings showed that anticancer TFN effect is more strong in physiological oxygen compared to atmospheric normoxia. It suggests that results obtained from in vitro studies could be underestimated. Thus, it gives assumption for future comprehensive studies at real oxygen environment involving TNF use in combination with other antitumor agents affecting oxygen-dependent pyrimidine synthesis.

A series of nine copper complexes were synthesized by reacting 1,3-disubstituted thioureas with copper(II) chloride. The new compounds were characterized by elemental analysis, infrared, ultraviolet-visible and X-ray absorption spectroscopies as well as molecular modelling. The molecular structure of complexes in the solid state consists of two thiourea ligands chelated to the Cu(II) ion through the S and deprotonated N atoms (CuN2S2). The coordination polyhedron of metal cation in powdered samples exhibits two different geometries. Pseudo-tetrahedral structure is observed for noncentrosymmetric complexes with cis-N2S2 arrangement around Cu(II). A distorted square planar geometry is characteristic for centrosymmetric compounds with trans arrangements of chelating atoms around the central ion. All complexes after dissolving in dimethyl sulfoxide adopt a centrosymmetric coordination, while after diluting this solution with water, the reorganization of atoms around the metal cation is observed, leading to the formation of a tetrahedral compounds. Initial ligands and Cu(II) complexes were evaluated for their cytotoxicity. Two complexes with 4- and 3-bromophenyl attached to the (1,7,8,9,10-pentamethyl-3,5-dioxo-4-azatricyclo[5.2.1.02,6]dec-8-en-4-yl)thiourea moiety (Cu1, Cu3) are cytotoxic against SW480 and PC3 cells (IC50 4-19 μm), and non-cytotoxic against HaCaT cells (IC50 ≥ 84 μm), being more selective than doxorubicin and cisplatin used as references. The compounds induced apoptosis in cancer cells, however, Cu3 was estimated to be highly active inducer of late apoptosis in SW480 and PC3 cells at lower toxicity against normal cells. The likely mechanism of action of complexes is correlated with decreasing release of IL-6 in cancer cell lines.

Currently, over 100 countries are fighting against a common enemy, the severe acute respiratory syndrome coronavirus (SARS‐CoV)‐2, which causes COVID‐19. This has created a demand for a substance whose effectiveness has already been demonstrated in a similar scenario. Glycyrrhizin (GZ) is a promising agent against SARS‐CoV‐2 as its antiviral activity against SARS‐CoV has already been confirmed. It is worthwhile to extrapolate from its proven therapeutic effects as there is a high similarity in the structure and genome of SARS‐CoV and SARS‐CoV‐2. There are many possible mechanisms through which GZ acts against viruses: increasing nitrous oxide production in macrophages, affecting transcription factors and cellular signalling pathways, directly altering the viral lipid‐bilayer membrane, and binding to the ACE2 receptor. In this review, we discuss the possible use of GZ in the COVID‐19 setting, where topical administration appears to be promising, with the nasal and oral cavity notably being the potent location in terms of viral load. The most recently published papers on the distribution of ACE2 in the human body and documented binding of GZ to this receptor, as well as its antiviral activity, suggest that GZ can be used as a therapeutic for COVID‐19 and as a preventive agent against SARS‐CoV‐2.

Aim:Linoleic acid (LA) and telmisartan as PPARgamma agonists exhibit anticancer activity. The LA effect is observed for high non-achievable in vivo concentrations and in short treatment period, therefore we evaluate the effect of supplemental LA and pharmacological telmisartan plasma concentrations on human primary (SW480) and metastatic (SW620) colon cancer cells and immortal keratinocytes (HaCaT) cells in long-term treatment. Methods:Cell viability and proliferation were determined by TB and MTT and pro-apoptotic effect was measured by Annexin V binding assays, respectively. Results: LA decreased cancer cell viability and proliferation in a concentration-dependent manner, whereas no significant effect was found for HaCaT cells. Telmisartan (0.2 mu M) suppresses antiproliferative effect of 60 mu M LA on cancer cells in short-term treatment. Long-term administration of 60 mu M LA reduced cancer cells viability after one week, while telmisartan delayed this effect by two weeks. Growth of all cell lines with 20 mu M LA was unchanged during all treatment time. Telmisartan decreased late apoptosis of cancer and normal cells with 60 and 120 mu M LA. Conclusion: The cytotoxic LA action depends not only on its concentration but also duration of treatment. Telmisartan exhibits biphasic but not synergistic effect on LA cytotoxicity in cancer cells.