Compounds Of Natural Origin Research Articles

On the Possible Effect of Phytic Acid (Myo-Inositol Hexaphosphoric Acid, IP6) on Cytochromes P450 and Systems of Xenobiotic Metabolism in Different Hepatic Models.

As compounds of natural origin enter human body, it is necessary to investigate their possible interactions with the metabolism of drugs and xenobiotics in general, namely with the cytochrome P450 (CYP) system. Phytic acid (myo-inositol hexaphosphoric acid, IP6) is mainly present in plants but is also an endogenous compound present in mammalian cells and tissues. It has been shown to exhibit protective effect in many pathological conditions. For this paper, its interaction with CYPs was studied using human liver microsomes, primary human hepatocytes, the HepG2 cell line, and molecular docking. Docking experiments and absorption spectra demonstrated the weak ability of IP6 to interact in the heme active site of CYP1A. Molecular docking suggested that IP6 preferentially binds to the protein surface, whereas binding to the active site of CYP1A2 was found to be less probable. Subsequently, we investigated the ability of IP6 to modulate the metabolism of xenobiotics for both the mRNA expression and enzymatic activity of CYP1A enzymes. Our findings revealed that IP6 can slightly modulate the mRNA levels and enzyme activity of CYP1A. However, thanks to the relatively weak interactions of IP6 with CYPs, the chances of the mechanisms of clinically important drug-drug interactions involving IP6 are low.

Derivatives of Betulin and Betulinic Acid Containing a Phosphonate Group—In Silico Studies and Preliminary In Vitro Assessment of Antiviral Activity

Viral diseases affecting both humans and animals are a serious public problem. Chemical modifications of the structure of compounds of natural origin, e.g., betulin, seem to be a promising model in the search for new antiviral agents. The subject of our work was to conduct preliminary tests on the antiviral activity of phosphonic derivatives of betulin and betulinic acid and to assess the pharmacokinetic profile of target compounds. Human (HHV-1, HAdV-5) and animal viruses (BEV, VSV) were used in the in vitro tests. Additionally, this paper presents the results of research using in silico methods (ADMET and molecular docking). Two compounds (betulin 29-phosphonate 3 and 3-(3′,3′-dimethylsuccinyl)betulin acid 29-phosphonate 8a) showed antiviral activity against BEV, and compound 3 was also active against HAdV-5. For compound 3, which showed advantageous pharmacokinetic parameters, molecular docking was performed to determine possible interactions with the cellular target HAdV-5 endopeptidase, which plays an important role in various functions of the virus. Selecting the most active derivatives makes it possible to plan tests on an animal model.

Phytochemicals Showing Antiangiogenic Effect in Pre-clinical Models and their Potential as an Alternative to Existing Therapeutics.

Angiogenesis, the formation of new blood vessels from a pre-existing vascular network, is an important hallmark of several pathological conditions, such as tumor growth and metastasis, proliferative retinopathies, including proliferative diabetic retinopathy and retinopathy of prematurity, age-related macular degeneration, rheumatoid arthritis, psoriasis, and endometriosis. Putting a halt to pathology-driven angiogenesis is considered an important therapeutic strategy to slow down or reduce the severity of pathological disorders. Considering the attrition rate of synthetic antiangiogenic compounds from the lab to reaching the market due to severe side effects, several compounds of natural origin are being explored for their antiangiogenic properties. Employing pre-clinical models for the evaluation of novel antiangiogenic compounds is a promising strategy for rapid screening of antiangiogenic compounds. These studies use a spectrum of angiogenic model systems that include HUVEC two-dimensional culture, nude mice, chick chorioallantoic membrane, transgenic zebrafish, and dorsal aorta from rats and chicks, depending upon available resources. The present article emphasizes the antiangiogenic activity of the phytochemicals shown to exhibit antiangiogenic behavior in these well-defined existing angiogenic models and highlights key molecular targets. Different models help to get a quick understanding of the efficacy and therapeutics mechanism of emerging lead molecules. The inherent variability in assays and corresponding different phytochemicals tested in each study prevent their immediate utilization in clinical studies. This review will discuss phytochemicals discovered using suitable preclinical antiangiogenic models, along with a special mention of leads that have entered clinical evaluation.

Enhancing Sustainability and Antifungal Properties of Biodegradable Composites: Caffeine-Treated Wood as a Filler for Polylactide.

This study investigates the suitability of using caffeine-treated and untreated black cherry (Prunus serotina Ehrh.) wood as a polylactide filler. Composites containing 10%, 20%, and 30% filler were investigated in terms of increasing the nucleating ability of polylactide, as well as enhancing its resistance to microorganisms. Differential scanning calorimetry studies showed that the addition of caffeine-treated wood significantly altered the crystallization behavior of the polymer matrix, increasing its crystallization temperature and degree of crystallinity. Polarized light microscopic observations revealed that only the caffeine-treated wood induced the formation of transcrystalline structures in the polylactide. Incorporation of the modified filler into the matrix was also responsible for changes in the thermal stability and decreased hydrophilicity of the material. Most importantly, the use of black cherry wood treated with caffeine imparted antifungal properties to the polylactide-based composite, effectively reducing growth of Fusarium oxysporum, Fusarium culmorum, Alternaria alternata, and Trichoderma viride. For the first time, it was reported that treatment of wood with a caffeine compound of natural origin alters the supermolecular structure, nucleating abilities, and imparts antifungal properties of polylactide/wood composites, providing promising insights into the structure-properties relationship of such composites.

Chemical composition and physicochemical properties of natural therapeutic mud of Kazakhstan salt lakes: a review.

In recent years, interest in natural therapeutic mud has been growing all over the world. This natural product has a positive therapeutic effect on the skin and has fewer side effects on the human body. There are more than 40 thousand salt lakes in Kazakhstan. Most of them have natural mud sources, the potential of which has not yet been fully explored. The review presents an analysis of the available information on the physical and chemical properties of the main sources of natural mud from salt lakes in Kazakhstan and Kazakh sanatoriums that use natural mud in the treatment. All available publications, presenting the systematic studies, were used for data analysis. A comparative analysis of the mineralization of water, brine, and silt in one reservoir shows that the mineralization of water is not always the least. The available data indicate a point and partial nature of peloid studies, e.g., inorganic composition of natural muds from Western and Southern Kazakhstan is well described in the literature. In turn, there is a lack of these data from Northern and Eastern Kazakhstan. Studies of peloids in these regions seem to be a promising direction of the future research for both local and world scientists. What is more, there is also a big gap in the analysis of organic matter of muds from the Kazakh lakes. Comparing the state of the art, i.e., the studies from other parts of Asia and Europe, the identification of the organic part of muds is another desirable direction as a potential source of biologically active compounds of natural origin.

Coupling deep eutectic solvents with innovative extraction techniques towards plant derived bioactive compositions

This review outlines the evolution, current status, and future trends in utilizing DESs as extraction solvents with innovative techniques to recover valuable compounds from natural sources for diverse laboratory and industrial applications.

Glutathione: synthesis, mechanism of action, antioxidant and detoxifying role

Annotation. Under the conditions of entry of toxic substances into the body and activation of redox processes, compounds of natural origin with antioxidant properties are widely used to correct metabolic disorders. The purpose of the work is to conduct an analysis and systematization of basic and modern scientific sources of literature on the role of the glutathione system in the development of pathologies. For the scientific review, data from the scientometric databases PubMed, ScienceDirect, Web of Science, Google Scholar, etc. were used, and the analysis of scientific textbooks and monographs was carried out. Among water-soluble antioxidants, low- and high-molecular compounds containing SH-groups are popular in medicine, mono-, di- and tricarboxylic acids and other anions. Glutathione, a thiol-containing tripeptide, is the main endogenous non-enzymatic antioxidant that exerts cytoprotective and detoxifying properties. Various epithelial cells – enterocytes, endotheliocytes, alveolar cells of the lungs, epithelium of the proximal renal tubules, absorb and use glutathione most intensively, in particular, taken orally, so the idea of using glutathione in diseases of organs that actively participate in detoxification processes: kidneys, liver, lungs, as well as under the conditions of systemic diseases accompanied by endothelial dysfunction and oxidative stress – diabetes, atherosclerosis, nephropathy. Under physiological conditions, the body maintains a dynamic balance between the content of oxidants, which stimulate the processes of free radical oxidation of biomolecules, and the activity of antioxidant systems. But under the conditions of damage to any link of the living system, increased formation of reactive oxygen species (ROS) and inhibition of antioxidant systems contributes to the activation of free radical oxidation processes, the intensity of which depends on the concentration of oxygen in the tissues and on the enzymatic and non-enzymatic systems of antioxidant protection, which prevents the destruction of cells by active forms of oxygen.

Autophagy modulation changes mechano-chemical sensitivity of T24 bladder cancer cells

Bladder cancer cells possess unique adaptive capabilities: shaped by their environment, cells face a complex chemical mixture of metabolites and xenobiotics accompanied by physiological mechanical cues. These responses might translate into resistance to chemotherapeutical regimens and can largely rely on autophagy. Considering molecules capable of rewiring tumor plasticity, compounds of natural origin promise to offer valuable options. Fungal derived metabolites, such as bafilomycin and wortmannin are widely acknowledged as autophagy inhibitors. Here, their potential to tune bladder cancer cells´ adaptability to chemical and physical stimuli was assessed. Additionally, dietary occurring mycotoxins were also investigated, namely deoxynivalenol (DON, 0.1–10 µM) and fusaric acid (FA, 0.1–1 mM). Endowing a Janus’ face behavior, DON and FA are on the one side described as toxins with detrimental health effects. Concomitantly, they are also explored experimentally for selective pharmacological applications including anticancer activities. In non-cytotoxic concentrations, bafilomycin (BAFI, 1–10 nM) and wortmannin (WORT, 1 µM) modified cell morphology and reduced cancer cell migration. Application of shear stress and inhibition of mechano-gated PIEZO channels reduced cellular sensitivity to BAFI treatment (1 nM). Similarly, for FA (0.5 mM) PIEZO1 expression and inhibition largely aligned with the modulatory potential on cancer cells motility. Additionally, this study highlighted that the activity profile of compounds with similar cytotoxic potential (e.g. co-incubation DON with BAFI or FA with WORT) can diverge substantially in the regulation of cell mechanotransduction. Considering the interdependence between tumor progression and response to mechanical cues, these data promise to provide a novel viewpoint for the study of chemoresistance and associated pathways.

Research on the structuring of water clusters in Chlorella vulgaris water suspension

Many bioactive compounds of natural origin have beneficial effects on human health and are used to treat different diseases. Chlorella is a genus of green algae with a high potential for producing biologically active substances. Exposure to extreme conditions can enhance its antioxidant activity and the production of concrete metabolites. C. vulgaris is cultivated in plantations. It is accessible in pharmacies and drugstores. The Health Act of 2005 in Bulgaria allows the therapeutic and prophylactic use of herbs, both independently by patients and as prescribed by a doctor. This study performed comparative spectral analyses of C. vulgaris using a 1% suspension of C. vulgaris in deionized water (v/v) by the methods of Non-equilibrium energy spectrum (NES) and Differential non-equilibrium energy spectrum (DNES). The research was performed in order to make indirect studies of the biological effects of C. vulgaris, which are connected with calcium conductivity and anti-inflammatory and anti-tumor effects. The effects of structuring of water clusters by C. vulgaris were examined. The data from spectral analyses, connected with a peak at (E =-0.1312 eV)(?=9.45 ?m) (?=1058 cm-1), revealed anti-inflammatory effects. The anti-oxidant and anti-tumor effects of C. vulgaris were shown at (E=-0.1387 eV)(?=8.95 ?m)(?=1117 cm-1). The results showed effects of improvement of calcium conductivity and anti-inflammatory, antioxidant and antitumor effects of C. vulgaris on human health.

Phenolics from Dendrobium officinale Leaf Ameliorate Dextran Sulfate Sodium-Induced Chronic Colitis by Regulating Gut Microbiota and Intestinal Barrier.

The increasing incidence of colitis and the side effects of its therapeutic drugs have led to the search for compounds of natural origin, including phenolics, as new treatments for colitis. In this study, the potential mechanism of Dendrobium officinale leaf phenolics (DOP) on the relief of dextran sulfate sodium (DSS)-induced colitis was explored. The results showed that DOP treatment for 36 days reduced the symptoms of colitis caused by DSS, including reduction of the disease activity index and alleviation of colonic tissue damage. In addition, DOP downregulated the expression of key proteins of the TLR4/NF-κB signaling pathway and reduced the production of inflammatory cytokines. Furthermore, DOP could enhance the expression of tight junction proteins including ZO-1, Occludin, and Claudin-1 to restore intestinal mucosal barrier function. DOP also effectively regulates disordered intestinal flora and enhances the production of short-chain fatty acids, which is also beneficial in modulating gut internal environmental homeostasis, inhibiting inflammation, and restoring the intestinal barrier. These findings indicated that DOP can ameliorate DSS-induced chronic colitis by regulating gut microbiota, intestinal barrier, and inflammation, and it is a promising ingredient from D. officinale.

Detection of Various Traditional Chinese Medicinal Metabolites as Angiotensin-Converting Enzyme Inhibitors: Molecular Docking, Activity Testing, and Surface Plasmon Resonance Approaches.

Angiotensin-converting enzyme 1 (ACE1) is a peptide involved in fluid and blood pressure management. It regulates blood pressure by converting angiotensin I to angiotensin II, which has vasoconstrictive effects. Previous studies have shown that certain compounds of natural origin can inhibit the activity of angiotensin-converting enzymes and exert blood pressure-regulating effects. Surface Plasmon Resonance (SPR) biosensor technology is the industry standard method for observing biomolecule interactions. In our study, we used molecular simulation methods to investigate the docking energies of various herbal metabolites with ACE1 proteins, tested the real-time binding affinities between various herbal metabolites and sACE1 by SPR, and analyzed the relationship between real-time binding affinity and docking energy. In addition, to further explore the connection between inhibitor activity and real-time binding affinity, several herbal metabolites' in vitro inhibitory activities were tested using an ACE1 activity test kit. The molecular docking simulation technique's results and the real-time affinity tested by the SPR technique were found to be negatively correlated, and the virtual docking technique still has some drawbacks as a tool for forecasting proteins' affinities to the metabolites of Chinese herbal metabolites. There may be a positive correlation between the enzyme inhibitory activity and the real-time affinity detected by the SPR technique, and the results from the SPR technique may provide convincing evidence to prove the interaction between herbal metabolites and ACE1 target proteins.

Binding of Quercetin Derivatives toward G-Tetrads as Studied by the Survival Yield Method.

Recently, much interest has been devoted to finding effective G-quadruplex ligands, both of synthetic or natural origins, which may be of potential use in the field of cancer therapy. Among compounds of natural origin, a common flavonol quercetin has attracted notable attention. Yet, only a modest number of papers have been concerned with a comparison of quercetin conjugates binding to G-quadruplexes. In this study, we applied the survival yield (SY) method in order to compare the stability of G-tetrad complexes with quercetin and its conjugates, namely, 3-O-glycosides and O-methylated conjugates. According to the determined values of Ecomδ50, flavonol glycosides bind most effectively with G-tetrads, whereas, among flavonols, 3-O-methylquercetin makes the most effective bonds. Because the aglycone structure is of crucial importance for biological processes, 3-O-methylquercetin seems to be a suitable candidate for anticancer therapeutics, and the extracts from the plants, which contain high amounts of 3-O-methylquercetin or its glycosides, should be considered as interesting materials for preparation of pharmaceuticals or dietary supplements.

A new isoflavone from the stems of Derris eriocarpa How

A preliminary screening test was performed to discover new antihyperlipidaemic active compounds from the leguminous plant Derris eriocarpa How. A new compound, derris-isoflavone F (1), and derrubone dimethyl ether (6), a known synthetic compound of natural origin, were isolated from the stems of D. eriocarpa alongside eight recognised compounds. To our knowledge, this is the first instance of documenting the identification of compounds 1–10 from this plant. The new compound were evaluated for their antihyperlipidemic and antiproliferative properties. Compound 1 evidently reduced the triglyceride (TG) content in oleic acid-treated HepG2 cells, which validated its efficacy as a potential TG-lowering agent.

The Effect of Natural Substances Contained in Bee Products on Prostate Cancer in In Vitro Studies.

Prostate cancer is a common cancer in men in older age groups. The WHO forecasts an increase in the incidence of prostate cancer in the coming years. Patients may not respond to treatment, and may not tolerate the side effects of chemotherapy. Compounds of natural origin have long been used in the prevention and treatment of cancer. Flavonoids obtained from natural products, e.g., propolis, are compounds with proven antibacterial and antiviral efficacy which modulate the immune response and may be useful as adjuvants in chemotherapy. The main aim of the present study was to evaluate the cytotoxic and pro-apoptotic properties of selected flavonoids on prostate cancer cells of the LNCaP line. The compounds used in this study were CAPE, curcumin (CUR), and quercetin (QUE). Mitochondrial and lysosome metabolism was assessed by the XTT-NR-SRB triple assay as well as by the fluorescent staining techniques. Staining for reactive oxygen species was performed as well. The experiment showed that each of the tested compounds has a cytotoxic effect on the LNCaP cell line. Different types of cell death were induced by the tested compounds. Apoptosis was induced by quercetin, while autophagy-specific changes were observed after using CAPE. Compounds obtained from other bee products have antiproliferative and cytotoxic activity against LNCaP prostate cancer cells.

Selected substances of natural origin with anticancer activity

Cancer is one of the most serious problems facing modern medicine. Research on new methods of treating this disease is being conducted. Existing methods are increasingly effective, but they also have risks to human health. The attention of scientists is focused on compounds of natural origin, as they are less toxic to human body than traditional chemotherapeutics. They are also much more accessible and their production is much less complex and expensive. There are several natural compounds with anticancer potential. In this article, we present three groups of potential therapeutic importance - polyphenols, brassinosteroids, and flavonoids.

Natural Bacterial and Fungal Peptides as a Promising Treatment to Defeat Lung Cancer Cells.

Despite the increasing availability of modern treatments, including personalized therapies, there is a strong need to search for new drugs that will be effective in the fight against cancer. The chemotherapeutics currently available to oncologists do not always yield satisfactory outcomes when used in systemic treatments, and patients experience burdensome side effects during their application. In the era of personalized therapies, doctors caring for non-small cell lung cancer (NSCLC) patients have been given a powerful weapon, namely molecularly targeted therapies and immunotherapies. They can be used when genetic variants of the disease qualifying for therapy are diagnosed. These therapies have contributed to the extension of the overall survival time in patients. Nevertheless, effective treatment may be hindered in the case of clonal selection of tumor cells with acquired resistance mutations. The state-of-the-art therapy currently used in NSCLC patients is immunotherapy targeting the immune checkpoints. Although it is effective, some patients have been observed to develop resistance to immunotherapy, but its cause is still unknown. Personalized therapies extend the lifespan and time to cancer progression in patients, but only those with a confirmed marker qualifying for the treatment (gene mutations/rearrangements or PD-L1 expression on tumor cells) can benefit from these therapies. They also cause less burdensome side effects than chemotherapy. The article is focused on compounds that can be used in oncology and produce as few side effects as possible. The search for compounds of natural origin, e.g., plants, bacteria, or fungi, exhibiting anticancer properties seems to be a good solution. This article is a literature review of research on compounds of natural origin that can potentially be used as part of NSCLC therapies.

Antiviral activity of basidial fungus Inonotus obliquus aqueous extract against SARS-CоV-2 virus (Coronaviridae: Betacoronavirus: Sarbecovirus) in vivo in BALB/c mice model

The COVID-19 pandemic combined with seasonal epidemics of respiratory viral diseases requires targeted antiviral prophylaxis with restorative and immunostimulant drugs. The compounds of natural origin are low-toxic, but active against several viruses at the same time. One of the most famous compounds is Inonotus obliquus aqueous extract. The fruit body of basidial fungus I. obliquus is called Chaga mushroom. The aim of the work ‒ was to study the antiviral activity of I. obliquus aqueous extract against the SARS-CoV-2 virus in vivo. Antiviral activity of I. obliquus aqueous extract sample (#20-17) was analyzed against strain of SARS-CoV-2 Omicron ВА.5.2 virus. The experiments were carried out in BALB/c inbred mice. The SARS-CoV-2 viral load was measured using quantitative real-time PCR combined with reverse transcription. The severity of lung tissue damage was assessed by histological methods. The peak values of the viral load in murine lung tissues were determined 72 hours after intranasal inoculation at dose of 2,85 lg TCID50. The quantitative real-time PCR testing has shown a significant decrease in the viral load compared to the control group by 4,65 lg copies/ml and 5,72 lg copies/ml in the lung tissue and nasal cavity samples, respectively. Histological methods revealed that the decrease in the number and frequency of observed pathomorphological changes in murine lung tissues depended on the introduction of the compound under study. The results obtained indicate the possibility of using basidial fungus Inonotus obliquus aqueous extract as a preventive agent against circulating variants of SARS-CoV-2 virus.

Essential oil of Piper macedoi Yunck. leaves, potential alternative for the management of banana anthracnose disease

The fungus Colletotrichum musae could cause a disease called anthracnose which reduces the quality of the banana fruit in the postharvest period. Anthracnose causes rots, peel lesions and generate great economic losses. Synthetic fungicides, used as an attempt to reduce the pathogen population, although effective, when used in amounts and frequency above the recommended, cause damage the environment and human health and can induce resistance. Research has focused in the search for alternative methods to reduce the use of synthetic substances in managing of agricultural diseases. The control of pathogens using compounds of natural origin is highlighted among new management techniques. Thus, we aimed to extract and characterize the essential oil from Piper macedoi leaves and evaluate its effect in the inhibiting the mycelial growth of the fungus C. musae in vitro. The essential oil was extracted by hydrodistillation, analyzed and characterized by Gas Chromatography and submitted to assays of fungicidal activity with C. musae. In comparison with dry plant material, yield of P. macedoi essential oil was 0.93 %. Piperitone (26.48 %), silvestrene (13.03 %), and bicyclogermacrene (10.45 %), were the major compounds identified in the essential oil composition considering the percentage in area. Regarding the antifungal activity tests, the essential oil showed a low inhibitory concentration (IC) for the IC50 (0.804 mL.L−1) and IC90 (1.80 mL.L−1), showing that the essential oil from P. macedoi leaves has great potential to control C. musae.

Chemical Constituents, Biological Activities, and Proposed Biosynthetic Pathways of Steroidal Saponins from Healthy Nutritious Vegetable-Allium.

Allium is a common functional vegetable with edible and medicinal value. Allium plants have a special spicy taste, so they are often used as food and seasoning in people's diets. As a functional food, Allium also has abundant biological activities, some of which are used as drugs to treat diseases. By consuming Allium on a daily basis, people can receive active compounds of natural origin, thereby improving their health status and reducing the likelihood of disease. Steroidal saponins are important secondary metabolites of Allium, which are formed by the steroidal aglycone group and sugar. Steroidal saponins have various physiological activities, such as hypoglycemic, antiplatelet aggregation, anti-inflammatory, antitumor, antimicrobial, and enzyme activity inhibition, which is one of the key reasons why Allium has such significant health benefits. The structural diversity and rich biological activities of steroidal saponins make Allium important plants for both food and medicine. In this paper, the chemical structures, biological activities, and structure-activity relationships of steroidal saponins isolated from Allium are reviewed, and the biosynthetic pathways of some key compounds are proposed as well, to provide a molecular reference basis based on secondary metabolites for the health value of Allium.

Effect of Hypericin-Mediated Photodynamic Therapy on the Secretion of Soluble TNF Receptors by Oral Cancer Cells.

Squamous cell carcinoma is the most common cancer of the head and neck region. In addition to the classic surgical treatment method, alternative therapy methods are sought. One such method is photodynamic therapy (PDT). In addition to the direct cytotoxic effect, it is essential to determine the effect of PDT on persistent tumor cells. The study used the SCC-25 oral squamous cell carcinoma (OSCC) cell line and the HGF-1 healthy gingival fibroblast line. A compound of natural origin-hypericin (HY)-was used as a photosensitizer (PS) at concentrations of 0-1 µM. After two hours of incubation with the PS, the cells were irradiated with light doses of 0-20 J/cm2. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test was used to determine sublethal doses of PDT. Cell supernatants subjected to sublethal PDT were assessed for soluble tumor necrosis alpha receptors (sTNF-R1, sTNF-R2). The phototoxic effect was observed starting with a light dose of 5 J/cm2 and amplified with the increase in HY concentration and light dose. A statistically significant increase in sTNF-R1 secretion by SCC-25 cells was demonstrated after the PDT with 0.5 µM HY and irradiation with 2 J/cm2 (sTNF-R1 concentration = 189.19 pg/mL ± 2.60) compared to the control without HY and irradiated with the same dose of light (sTNF-R1 concentration = 108.94 pg/mL ± 0.99). The baseline production of sTNF-R1 was lower for HGF-1 than for SCC-25, and secretion was not affected by the PDT. The PDT had no effect on the sTNF-R2 production in the SCC-25 or HGF-1 lines.