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Oncolytic adenoviruses are a new cancer treatment platform which aims to eliminate cancer through direct lysis of cancer cells by viral replication and the activation of the immune system by the release of tumor antigens upon oncolysis. In the PeptiCRAd technology, the activation of an anti-cancer immune response is enhanced by the addition of poly-lysine modified cancer peptides, where the antigen presentation to the immune system is improved in comparison to plain oncolytic viruses. PeptiCRAd complexes have been assumed to form solely by electrostatic interactions, but the thermodynamic profiles and mechanisms involved in the complexation have not been previously addressed. Thus, by adding isothermal titration calorimetry as part of the analysis repertoire provides valuable information of the characteristics of PeptiCRAd complexes. In this study, the applicability of isothermal titration calorimetry in PeptiCRAd complexation analyses was evaluated based on initial peptide-to-virus and virus-to-peptide titrations, and a method of analysis was created for the thermodynamics of the interactions of the complex. Optimization of the experimental method (i.e., titration protocol) and the data analysis (i.e., calculation models) remains inconclusive for quantitative analysis as data obtained from the measurements was mainly of bad quality, thus requiring further optimization to obtain reliable data. However, using surface plasmon resonance as an already established method for poly-lysine peptide-virus interaction studies gave robust data and can be used as a base or guideline to further develop isothermal titration calorimetry analyses for characterizing PeptiCRAd complexes. Although isothermal titration calorimetry measurements were unsuccessful for quantification purposes, it was possible to qualitate the mechanisms of PeptiCRAd complexation for four different peptides with fair confidence. The peptides showed low heats of binding, and positive and negative cooperative binding in ionic and non-ionic solutions, respectively. Based on this, the binding of peptides in PeptiCRAd complexes was determined to be driven by hydrophobic inter-peptide interactions on the virus surface, although an electrostatic attraction is indeed present at the virus-peptide interface, initiating the binding event. Also, improvements to the titration protocol for PeptiCRAd analyses with isothermal titration calorimetry are suggested for further optimizations in the future to conclusively determine the applicability of the isothermal titration calorimetry technique for characterizing peptide-virus interactions of PeptiCRAd complexes.

Making the treatment of these infections even harder is the fact, that Chlamydia pneumoniae can produce persistent forms of itself, which are immune to antibiotic treatment. When the bacteria sense a stress factor, for example the presence of a β-lactam antibiotic or interferon γ, they start producing these persistent forms called aberrant bodies. When the stress factor is removed, the bacteria can switch back to their replicating form and start infecting the tissues again. It is also known, that C. pneumoniae bacteria will trigger persistence when the bacteria migrate from lung epithelia into monocytes. Interestingly the onset of this mode of persistence does not require any other triggers besides the invasion of the monocyte. These persistence mechanisms enable latent, quiet, and recurring infections. This master’s thesis aimed to study the coculture of lung epithelial (HL cells) and monocytes (THP-1 cells), and by utilising the magnetic separation method presented by Kortesoja et al, to find a positive control compound in the prevention of Chlamydia pneumoniae internalisation into the THP-1 cells for said protocol. In these cocultures the inhibitory effect of different compound groups such as lignans present in Schisandra chinensis plant, MAPK-inhibitors, and β2,2-amino acid derivatives in C. pneumoniae migration from HL cells to THP-1 cells was assessed. Statistic relevance was observed in JNK inhibitor SP600125, MAPKAP-kinase-2 inhibitor SB203580, and ERK1/2 inhibitor FR180204 compounds. These compounds inhibited the internalisation of Chlamydia pneumoniae into THP-1 cells in the cell coculture by 61,05 ± 16,63 % (p = 0,0001), 54,06 ± 16,02 % (p = 0,0002), and 36,76 ± 10,33 % (p = 0,009) respectively. SP600125 and SB 203580 compounds also had an inhibitory effect on the internalisation of C. pneumoniae into the THP-1 cells in a cell monoculture (39,98 ± 18,92 %, p = 0,026 and 37,89 ± 19,47 %, p = 0,035 respectively), whereas FR180204 had no statistical significance, even though it inhibited the internalisation of C. pneumoniae into the THP-1 cells in cell monoculture by 27,53 ± 21,17 %. From the compounds used in the experiments, only MAPK inhibitors had an effect in inhibiting the C. pneumoniae internalisation into the THP-1 cells. The most potent compound in said inhibition was the JNK inhibitor SP600125. JNK pathway has been thought to take part in chlamydial infections but only little research has been done. The results of this master’s thesis’ experiments support the thought of JNK enzyme taking part in chlamydial infections but determining how exactly it affects the infection cycle of C. pneumoniae bacteria still needs further investigation.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder caused by degeneration of motor neurons in brain and spinal cord. The degeneration of motor neurons leads to muscle atrophy and paralysis. Currently there is no cure for ALS. Available drugs for ALS can lengthen the survival time by a couple of months. Several factors involve the pathophysiology of ALS, such as endoplasmic reticulum stress and neuroinflammation. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a protein which has shown neuroprotective effects on animal models of Parkinson disease and brain ischemia. C-terminal fragment of MANF can cross the blood-brain barrier, allowing it to be administered subcutaneously instead of injected directly into the brain. The experimental part consists of two parts. The aim of the first part was to study the pharmacokinetic properties of next generation MANF (C-MANF). The aim of the second part was to elucidate the effect of twice a week administered subcutaneous injection of C-MANF in genetic SOD1-G93A mouse model and its neuroprotective effects by assessing protection of lumbar motor neurons. Pharmacokinetic properties of C-MANF were determined in wild type mice after a single subcutaneous injection of C-MANF at different time points by using indirect ELISA assay. The effects of C-MANF in SOD1-G93A mouse model were assessed by subcutaneous injection of either C-MANF or PBS twice a week and by monitoring clinical score and motor behavior of mice from 10 weeks of age to clinical endpoint. Hematoxylin eosin staining was used to study neuroprotective effects of C-MANF. C-MANF administered subcutaneously is absorbed into the blood circulation and the highest serum concentration of C-MANF is after 60 minutes of dosing. Subcutaneously injected C-MANF also crosses the blood-brain barrier and reach the brain in 120 minutes. C-MANF did not preserve motor function or ameliorated ALS symptoms in SOD1-G93A mouse model. In this study C-MANF did not increase the survival of SOD1-G93A mice. C-MANF did not significantly protect motor neurons from degeneration even though there was a slight trend between the groups. No beneficial effects were observed with C-MANF in SOD1-G93A mouse model and therefore the dose and frequency of administration of C-MANF were not optimal. Subcutaneously injected C-MANF provides a safer dosing option for neurodegenerative disorders.

Viral promoters are an essential part of a normally functioning virus. Their main task is to drive the transcription of genes which govern hijacking of cell function and replication of viral particles. In addition to supporting normal function of a virus, they can be used to drive the transcription of transgenes which can be used in different therapies. In oncolytic therapies, transgenes can be used to prime the host system against neoplasms which has been shown to generate long term anti-tumour immunity. Human adenoviruses (Ad) are commonly used as a platform for oncolytic virotherapies. Human Ad’s replicate poorly in mouse tumour cell lines, yet some promoters, which are included in the viral constructs to drive the transcription of beneficial transgenes, are able to function. Currently it is unknown whether E3, the native promoter of adenovirus 5 of the E3 region, is capable of functioning in murine cell lines. In this thesis we study whether human cytomegalovirus promoter (CMV) and E3 differ in their efficacy to drive the transcription of the mOX40L and mCD40L transgenes. In the experimental part of this thesis, we compared the efficacies of two viral promoters, AdE3 and AdCVM, in transcribing mOX40Land mCD40L in vitro. Efficacy of transcription was assessed through immunofluorescence and flow cytometry in human and murine cell lines. Furthermore, the effects of promoters on viral infection, killing and replication were evaluated in burst assay and the colorimetric MTS proliferation assay. MTS and burst assay were conducted to confirm if viral infection, killing and replication occurs in human and murine cell lines. Both AdE3 and AdCMV were able to infect and kill human cell lines and cell viability decreased in correlation to the number of viral particles used. In murine cell lines, no decrease in cell viability was detected in the 4T1 cell line. In burst assay, viral replication was observed for both AdE3 and AdCMV in the human MDA-MB-436 cell line. In murine CT26 cell line, no replication was observed for AdE3 or AdCMV constructs. Immunofluorescence assay was performed to visualize transgene expression and localization. Results indicated that mOX40L was localized on cell surface while mCD40L was detected both outside and inside of the cytosolic compartment. Flow cytometry results revealed that both AdE3 and AdCMV constructs are capable of efficiently transcribing mOX40L in human cell lines. In the flow cytometry results for AdE3, two large cell populations with different fluorescence intensities were detected. AdCMV lacked this feature which is postulated to be due to higher lytic activity of the viral construct. In murine cell lines, HCMV could produce mOX40L, but production in murine cell lines was severely attenuated compared to human cell lines. mOX40L produced by the AdE3 construct did not differ from the baseline and was deemed incapable of producing mOX40L in murine cell lines. For the purpose of studying novel virotherapeutics the results of this thesis would indicate that human CMV can be used to drive expression of transgenes in murine cell lines. Despite this, it is preferable to use host specific viruses and promoter sequences for a better translation between mice and humans. Viruksen promoottorit ovat keskeisessä osassa toimintakykyisessä viruksessa. Virus promoottorin päätarkoituksena on geenien transkriptio, mitkä vastaavat solun keskeisten toimintojen kaappaamisesta ja virus partikkeleiden replikaatiosta. Näiden toimintojen lisäksi promoottoreita voidaan käyttää transgeenien transkriptiossa, mitä voidaan hyödyntää sairauksien hoidossa. Onkolyyttisissä terapioissa transgeenejä voidaan käyttää virittämään kehon immuunipuolustus taistelemaan kasvainkudosta vastaan. Ihmisen adenovirusta käytetään usein onkolyyttisten viroterapioiden alustana. Ihmisen adenovirus (Ad) replikoituu hyvin heikosti hiiren syöpäsoluissa, mutta osa adenovirukseen sisälletyistä eksogeenisistä promoottoreista, joita käytetään terapeuttisten transgeenien transkription ajamiseen, kykenee toimimaan ja tuottamaan haluttua proteiinia. Tällä hetkellä ei tiedetä, kykeneekö E3, joka on adenoviruksen E3 lokuksen promoottori, toimimaan hiiren solulinjoissa. Tässä tutkielmassa selvitämme ihmisen sytomegalovirus promoottorin (CMV) ja E3 eroa niiden tehossa ajaa mOX40L ja mCD40L transgeenien transkriptiota. Kokeellisessa osuudessa vertailimme kahden virus promoottorin, E3 ja CMV, eroa niiden tehossa ajaa mCD40L ja mOX40L transkriptiota in vitro. Transkription tehoa tutkittiin immunofluoresenssin ja virtaussytometrian avulla ihmisen ja hiiren syöpäsolulinjoissa. Tämän lisäksi promoottorien vaikutusta virus infektioon, replikaatioon ja kykyyn tappaa soluja arvioitiin burst kokeella ja kolorimetrisellä MTS menetelmällä. MTS ja burst kokeiden avulla varmistettiin AdE3 ja AdCMV virusten kyky infektoida, tappaa ja replikoitua ihmisen ja hiiren syöpäsolulinjoissa. Sekä Ad3 ja AdCMV todettiin kykenevän infektoimaan ja tappamaan ihmissyöpäsoluja ja solujen viabiliteetin lasku korreloi virus partikkeleiden määrän kanssa. Hiiren 4T1 syöpäsoluissa ei todettu solujen viabiliteetin laskevan. Burst kokeessa havaitsimme sekä AdE3 että AdCMV kykenevän replikoitumaan ihmisen MDA-MB-436 solulinjassa. Hiiren CT26 solulinjassa kummankaan viruksen ei havaittu kykenevän replikoitumaan. Immunofluoresenssi kokeessa visualisoimme transgeenien ilmentymisen ja paikantumisen. Tulokset osoittivat, että mOX40L paikantui solun pinnalle. mCD40L havaittiin puolestaan sekä solun ulkopuolella että sytosolissa. Virtaussytometria kokeen tulokset osoittivat, että sekä AdE3 ja AdCMV pystyivät tehokkaasti ilmentämään mOX40L ihmisen solulinjoissa. AdE3 virtausytometria tuloksissa löydettiin kaksi solupopulaatiota, joilla oli toisistaan poikkeavat fluoresenssi intensiteetit. Tätä ilmiötä ei havaittu AdCMV:lla infektoiduilla soluilla, mikä saattoi johtua korkeammasta lyyttisestä aktiivisuudesta. Hiirisolulinjoissa CMV kykeni ilmentämään mOX40L, mutta transkription teho oli selvästi alhaisempi verrattuna ihmissolulinjoihin. E3 promoottorin ilmentämä mOX40L ei eronnut kontrollista ja sen todettiin olevan kykenemätön tuottamaan mOX40L hiirisolulinjoissa. Tuloksemme osoittavat, että ihmisen CMV promoottori kykenee ilmentämään transgeenejä hiiren 4T1 ja CT26 solulinjoissa. On kuitenkin huomattava, että isäntälajille natiivien virusten ja promoottorien käyttö olisi tarkoituksenmukaisempaa tulosten käännettävyyden kannalta hiiristä ihmisiin.

Theoretical framework: The consolidated pharmaceutical market is becoming increasingly global and the same international pharmaceutical companies operate around the world in different countries, responsible for drug development and production. The high costs of developing novel medicines and the motive for higher profits has led to elevating price level of pharmaceuticals and health care services. Finland and the U.S. offer two extremes at the pharmaceutical market. The pharmaceutical market field in Finland is very structural and rigid, and medicine prices are regulated by law. In the U.S. the prices are based on the laws of supply and demand and the prices differ by different states, retailers and insurance policies. A small-scale longitudal price comparison is also reviewed to showcase the effect of continuously rising medicine prices. Study objective: The idea of this study is to describe and compare pricing mechanisms of pharmaceuticals and price differences between two very different market structures and review how these might affect the cost-effectiveness of national health care spending. These divergences are also mirrored to survey recent global pharmaceutical market problems such as drug shortages, possibly due to less appealing markets of higher price regulation policies. Materials and methods: Price data were collected from national, official, open-source databases. National health care expenditure and comparison to GDP was collected from publications by the OECD. All monetary values have been presented in both currencies (EUR and USD) to present more comparable values. Results: When compared to other OECD-countries the U.S. spent distinctly the largest amount of funds on health care per capita. Finland’s national health care costs were thousand times minor in total spending and less than a half per capita when compared to those of the U.S. With lower expenditure Finland manages to offer access to public, government-funded health insurance program. Meanwhile the prices of prescription medicines in Finland have decreased significantly, the prices for have continuously elevated in the U.S. Conclusions: The outcome of this study is that free markets and a complex supply chain, compared to more regulated markets with more transparency, have higher overall price level in pharmaceuticals and health care services. Free markets and sufficient intellectual property rights are more enticing to pharmaceutical companies. They promote new innovations and developing of much-needed novel therapies to modern health problems, such as AIDS and the global threat of worsening situation of antibiotic resistance. More regulated markets may create problems such as drug shortages and are often considered complex and less appealing market systems due to high level of administrative work but conserve the cost-effectiveness of the use of public funds.

The orexinergic system is a central regulator for sleep-wake rhythm and energy homeostasis. Dysfunction of the system is at least one of the reasons behind narcolepsy, in addition to which insomnia, obesity and certain cancers could be treated by targeting orexin receptors. The orexin system in human comprises two receptor subtypes, orexin receptor 1 and 2 (OX₁R and OX₂R respectively) as well as two cognate ligands, peptides orexin-A and -B. In this study the focus is on OX₁R and orexin-A. The aims of the study are (1) to propose a binding mode for orexin-A to OX₁R and (2) to understand the molecular interactions of OX₁R leading to receptor activation. I order to create 3D molecular models of OX₁R, a sequence alignment of the eight G proteincoupled receptors (GPCRs) that have been crystallized up to date was first generated by ClustalX and adjusted based on the superimposition by SYBYL-X. Structurally conserved regions were deduced from the alignment and used to add the orexin receptors. Five different models built with MODELLER were selected for their large binding cavity among a large pool of models. These models were constructed based on the chemokine receptor 4 (PDB Id:3ODU), as such and a modified version where TM3 was moved by 1 Å further from the center of the binding cavity, from the β₂-adrenoceptor (PDB Id: 2RH1) and from the adenosine receptor A2A (PDB Id: 2YD0), as such and with rotamer changes to few binding site residues. Orexin-A with straight conformation found by NMR (PDB Id:1WSO) was docked to these models using ZDOCK and RDOCK. In addition, an in-house docking protocol was implemented, but could not be validated. Docking poses were scored by purpose built knowledge based scoring function and clustered. High scoring clusters were then used to converge to three different binding modes. As a result, we suggest that the binding site of OX₁R consists of two hydrophobic walls, one from TM3 and TM5, the other from TM6 and TM7. Binding modes include a hydrogen bond network between the ligand and especially binding site residues Gln1263.32, Thr2235.46, Asn3186.55, Lys3216.58 and Tyr3117.43. Based on the binding modes, it is suggested that the OX₁R is activated by similar binding site contraction as β-adrenoceptors and adenosine A2A. The contraction in could result from the hydrogen bonds between ligand, Gln1263.32, Thr2235.46 and Asn3186.55. The hydrogen bonding of Thr2235.46 can also disrupt interactions between TM5 and TM3, an interaction which is identified as an important factor in keeping the receptor in the inactive state. The role of other ligand residues would be to direct ligand binding and keep the ligand in the helical conformation.

The most typical symptoms of dementia include impairment of cognitive brain functions, such as memory and thinking. Most common forms of dementia include Alzheimer's disease, vascular dementia, Lewy body dementia, and frontotemporal dementia, which is caused by degeneration of the frontotemporal lobe. Alzheimer's disease is the most common form of dementia, covering about 75% of all the cases. The pathophysiology of Alzheimer's disease includes beta-amyloid plaques and tau proteins, which accumulate in the brain, and which have been linked to damage to nerve pathways and the appearance of the typical symptoms of the disease. The disorder is progressive, but the exact cause remains unknown. However, old age (>65 years), the APOE-4 gene, lifestyle, and some comorbidities, such as cardiovascular diseases, are considered risk factors. Even though extensive research has been conducted, there is currently no curative treatment for Alzheimer's disease. Sleep disorders can be both a symptom of Alzheimer's disease and a risk factor for the onset of the disorder. Therefore, the mechanisms of sleep and circadian rhythm are connected to the pathophysiology of Alzheimer's disease, for example through the glymphatic system that cleans the brain mainly during deep sleep. Many drugs for Alzheimer's disease have a recommended time of administration. The dosing time can be very important issue in terms of the effectiveness of the drug. According to a recent study, sleep and circadian rhythm have not been considered in most studies on new rapid-acting antidepressants. Therefore, we carried out an analogous systematic literature review for Alzheimer's disease and dementia. The aim of this study was to find out whether sleep and circadian rhythm have been considered in the most cited preclinical and clinical drug research articles for Alzheimer's disease and dementia during the last decade (2010–2020). In addition, it was examined which drug groups the studied compounds belonged to, and what was the sex distribution of the test subjects in the studies. The number of subjects was also determined from clinical studies, and the animal species from preclinical studies. The research articles analysed in the study were collected with a systematic literature review of Scopus database. The study found that most studies did not include any consideration of sleep or circadian rhythm. Most of the investigated compounds were small molecules, followed by supplements and herbs, and rest classified as biological drugs. Most of the clinical trials were relatively small studies with less than a hundred subjects or hundreds of subjects. Among the 100 most cited clinical research articles, there were 14 reanalyses and observational studies that were not included in this analysis of subject numbers. In clinical studies, most of the test subjects were usually female, while preclinical studies used commonly male animals. To conduct more open and reliable science in the future, drug research should pay more attention to the subjects’ sleep patterns, the time of drug administration, and reporting on these issues in the articles, which is usually part of the requirements of scientific journals. This could potentially narrow the translational gap between preclinical and clinical research.

Adequate vaccine coverage and vaccine refusal have been prominently featured in the media during the COVID-19 pandemic. The decision-makers have considered adequate vaccine coverage important for maintaining the capacity of healthcare. The purpose of this study is to produce population-based research data about the factors affecting the willingness to take the COVID-19 vaccine. With the help of that information, it is possible to identify the factors that influence individual’s decision-making about whether to take the COVID-19 vaccine. The data of the study is the first Kansalaispulssi-data of the year 2022. Kansalaispulssi is a survey, made by the assignment of the State Council, which is used to research Finnish citizen’s views of the current topics. The research design is cross-sectional. The analysis of the study is done by crosstabulation using the Chi-square test. Age and financial situation of the person were related to the willingness to take the COVID-19 vaccine and the person's view of the role of the vaccine in preventing severe corona disease and getting rid of the COVID-19 pandemic. Age also influenced the person's view of the importance of the vaccine in preventing the COVID-19 disease. Gender, province, or educational level had no effect on a person's vaccine views in this study. Based on the research, Finnish citizens are very pro-vaccine. They also understand well the role of the vaccine in preventing a serious illness caused by the disease.

Digitalization of health care and the corona pandemic have increased availability and use of online services provided by community pharmacies. In Finland, willingness to use online pharmacy services has been studied from population approach. Less is known about the user satisfaction with the core online pharmacy services such as dispensing and medication counseling services. This study aimed to investigate satisfaction with the University Pharmacy’s online services (ya.fi) from customers’ approach. Primarily, customer satisfaction with dispensing and medication counseling services was assessed. In addition, characteristics affecting customer satisfaction were analyzed. The conceptual framework of the study was Andersen's Model of Health Services Use. The data for this study was collected by a cross-sectional survey conducted in August 2020 among University Pharmacy’s online pharmacy customers who had made a purchase during the last three months. The survey instrument consisted mainly of structured Likert-scale questions, which were used to form two sum variables: satisfaction on online dispensing services (3 variables, Cronbach's alpha 0.803) and satisfaction on online counseling services (2 variables, Cronbach's alpha 0.883). Satisfaction on online dispensing services was studied through willingness to recommend and use the services in the future. Satisfaction on online counseling services was studied through a comparison of medication counseling on an online pharmacy and a conventional pharmacy. IBM SPSS (28) -software was used for statistical analysis consisting of bivariate (Kruskal-Wallis and Mann-Whitney U tests) and multivariate (generalized linear model) analyses to identify factors affecting satisfaction with dispensing and medication counseling services. Of 15 172 invitations sent to fill out the survey, 2555 eligible responses were received (16 %). Of the respondents, 92 % had concomitantly used the services of a conventional pharmacy. . The mean of satisfaction on online dispensing services on a scale from 1 to 5 (5 being the most positive option "completely agree") was 4.3 (SD 0.8). Similarly, the mean of satisfaction on online counseling services was 3.7 (SD 0.9). According to the multivariate analyses, significant characteristics affecting satisfaction on online dispensing services were age, form of living (alone/family with children/couple), purchase of prescription or OTC medicine, frequency of internet use and previous visits to a conventional pharmacy. Characteristics affecting satisfaction on online counseling services were education, purchase of prescription medicine, use of chat information service, frequency of internet use and previous visits to a conventional University Pharmacy outlet. The services on ya.fi online pharmacy rated most important by the respondents were services about medicine availabilities (in conventional University Pharmacy outlets and during a shortage) and information about medicines (prices, Kela reimbursements and information about customers' prescriptions). Customers were satisfied with online dispensing and counseling services. Online dispensing services received a higher satisfaction rate than online counseling services. Customers who had used the chat service and purchased a prescription medicine online were more likely to assess online counseling services to be equal or better than in a conventional pharmacy. Active use of internet and purchases of medicines online were factors connected to higher satisfaction with online dispensing services. Most online pharmacy customers had also visited conventional pharmacies. The results from this study can be utilized in the development of online and other pharmacy services.

Complications of atherosclerosis such as myocardial infarction and stroke are the primary cause of death in Western societies. The development of atherosclerotic lesions is a complex process, including endothelial cell dysfunction, inflammation, extracellular matrix alteration and vascular smooth muscle cell (VSMC) proliferation and migration. Various cell cycle regulatory proteins control VSMC proliferation. Protein kinases called cyclin dependent kinases (CDKs) play a major role in regulation of cell cycle progression. At specific phases of the cell cycle, CDKs pair with cyclins to become catalytically active and phosphorylate numerous substrates contributing to cell cycle progression. CDKs are also regulated by cyclin dependent kinase inhibitors, activating and inhibitory phosphorylation, proteolysis and transcription factors. This tight regulation of cell cycle is essential; thus its deregulation is connected to the development of cancer and other proliferative disorders such as atherosclerosis and restenosis as well as neurodegenerative diseases. Proteins of the cell cycle provide potential and attractive targets for drug development. Consequently, various low molecular weight CDK inhibitors have been identified and are in clinical development. Tylophorine is a phenanthroindolizidine alkaloid, which has been shown to inhibit the growth of several human cancer cell lines. It was used in Ayurvedic medicine to treat inflammatory disorders. The aim of this study was to investigate the effect of tylophorine on human umbilical vein smooth muscle cell (HUVSMC) proliferation, cell cycle progression and the expression of various cell cycle regulatory proteins in order to confirm the findings made with tylophorine in rat cells. We used several methods to determine our hypothesis, including cell proliferation assay, western blot and flow cytometric cell cycle distribution analysis. We demonstrated by cell proliferation assay that tylophorine inhibits HUVSMC proliferation dose-dependently with an IC50 value of 164 nM ± 50. Western blot analysis was used to determine the effect of tylophorine on expression of cell cycle regulatory proteins. Tylophorine downregulates cyclin D1 and p21 expression levels. The results of tylophorine's effect on phosphorylation sites of p53 were not consistent. More sensitive methods are required in order to completely determine this effect. We used flow cytometric cell cycle analysis to investigate whether tylophorine interferes with cell cycle progression and arrests cells in a specific cell cycle phase. Tylophorine was shown to induce the accumulation of asynchronized HUVSMCs in S phase. Tylophorine has a significant effect on cell cycle, but its role as cell cycle regulator in treatment of vascular proliferative diseases and cancer requires more experiments in vitro and in vivo.