The coronavirus disease (COVID-19) pandemic is a leading global health and economic challenge. What defines the disease’s progression is not entirely understood, but there are strong indications that oxidative stress and the defense against reactive oxygen species are crucial players. A big influx of immune cells to the site of infection is marked by the increase in reactive oxygen and nitrogen species. Our article aims to highlight the critical role of oxidative stress in the emergence and severity of COVID-19 and, more importantly, to shed light on the underlying molecular and genetic mechanisms. We have reviewed the available literature and clinical trials to extract the relevant genetic variants within the oxidative stress pathway associated with COVID-19 and the anti-oxidative therapies currently evaluated in the clinical trials for COVID-19 treatment, in particular clinical trials on glutathione and N-acetylcysteine.

Chemotherapy resistance is one of the major challenges in cancer treatment, including leukemia. A massive array of research is evaluating combinations of drugs directed against different intracellular signaling molecules to overcome cancer resistance, increase therapy effectiveness, and decrease its adverse effects. Combining chemicals with proven safety profiles, such as drugs already used in therapy and active substances isolated from natural sources, could potentially have superior effects compared to monotherapies. In this study, we evaluated the effects of metformin and thymoquinone (TQ) as monotherapy and combinatorial treatments in chronic myeloid leukemia (CML) cell lines sensitive and resistant to imatinib therapy. The effects were also evaluated in primary monocytic acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL) cells. Both compounds induced a dose- and time-dependent decrease of viability and proliferation in tested cells. Metformin had similar IC50 values in imatinib-sensitive and imatinib-resistant cell lines. IC50 values of TQ were significantly higher in imatinib-resistant cells, but with a limited resistance index (2.4). Synergistic effects of combinatorial treatments were observed in all tested cell lines, as well as in primary cells. The strongest synergistic effects were observed in the inhibition of imatinib-resistant cell line proliferation. Metformin and TQ inhibited the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling and induced apoptosis in tested cell lines and primary cells. The enhanced effects of combinatorial treatments on the induction of apoptosis were more dominant in imatinib-resistant compared to imatinib-sensitive CML cells. Primary cells were more sensitive to combinatorial treatments compared to cell lines. A combination of 1.25 mM metformin and 0.625 µM TQ increased the levels of cleaved poly (ADP-ribose) polymerase (PARP), decreased the levels of proliferation regulatory proteins, and inhibited protein kinase B (Akt) and NF-κB signaling in primary CLL cells. This study demonstrates that combinatorial treatments of imatinib-resistant malignant clones with metformin and TQ by complementary intracellular multi-targeting represents a promising approach in future studies.

Objective. This study aimed to evaluate the efficacy and safety of lysozyme-based oral antiseptic in the therapy of non-infectious sore throat in teachers. Materials and Methods. A non-interventional, prospective, pilot study was conducted with two examinations. The first was performed as part of a general medical examination. If a non-infectious sore throat was confirmed by clinical checkup and all other inclusion and non-exclusion criteria confirmed, patients were offered to be enrolled in the study. After signing the informed consent form, patients were advised to use lysozyme-based lozenges, six times a day, for a period of five days. A telephone call follow-up examination was performed within 24 hours from the therapy completion. Results. This was a pilot study involving 25 adult patients of both genders. Lysozyme-based lozenges showed positive effects in relieving the symptoms of non-infectious sore throat in teachers. At the same time, the lozenges showed excellent tolerability, and no side effects were reported during the study. 92% of patients confirmed they would take the same medicine again due to the same problem. Conclusion. The results of this “proof-of-concept” study indicated that lysozyme-based antiseptic could be effective and safe in the treatment of non-infectious sore throat in teachers and should be further evaluated as treatment option in this condition.

Healthy and controlled immune response in COVID-19 is crucial for mild forms of the disease. Although CD8+ T cells play important role in this response, there is still a lack of studies showing the gene expression profiles in those cells at the beginning of the disease as potential predictors of more severe forms after the first week. We investigated a proportion of different subpopulations of CD8+ T cells and their gene expression patterns for cytotoxic proteins (perforin-1 (PRF1), granulysin (GNLY), granzyme B (GZMB), granzyme A (GZMA), granzyme K (GZMK)), cytokine interferon-γ (IFN-γ), and apoptotic protein Fas ligand (FASL) in CD8+ T cells from peripheral blood in first weeks of SARS-CoV-2 infection. Sixteen COVID-19 patients and nine healthy controls were included. The absolute counts of total lymphocytes (p = 0.007), CD3+ (p = 0.05), and CD8+ T cells (p = 0.01) in COVID-19 patients were significantly decreased compared to healthy controls. In COVID-19 patients in CD8+ T cell compartment, we observed lower frequency effector memory 1 (EM1) (p = 0.06) and effector memory 4 (EM4) (p < 0.001) CD8+ T cells. Higher mRNA expression of PRF1 (p = 0.05) and lower mRNA expression of FASL (p = 0.05) at the fifth day of the disease were found in COVID-19 patients compared to healthy controls. mRNA expression of PRF1 (p < 0.001) and IFN-γ (p < 0.001) was significantly downregulated in the first week of disease in COVID-19 patients who progressed to moderate and severe forms after the first week, compared to patients with mild symptoms during the entire disease course. GZMK (p < 0.01) and FASL (p < 0.01) mRNA expression was downregulated in all COVID-19 patients compared to healthy controls. Our results can lead to a better understanding of the inappropriate immune response of CD8+ T cells in SARS-CoV2 with the faster progression of the disease.

Using X-ray single crystal diffraction, the crystal structures of biologically active benzoxazole derivatives were determined. DFT calculation was performed with standard 6-31G*(d), 6-31G** and 6-31+G* basis set to analyze the molecular geometry and compare with experimentally obtained X-ray crystal data of compounds. The calculated HOMO-LUMO energy gap in compound 2 (2-(2-hydroxynaphtalen-1-yl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol) is 3.80 eV and this small gap value indicates that compound 2 is chemically more reactive compared to compounds 1 (4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazol-5-ol) and 3 (2-(4-chlorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol). The crystal structures are stabilized by both intra- and intermolecular hydrogen bonds in which an intermolecular O-H⋅⋅⋅N hydrogen bond generates N3 and O7 chain motif in compounds 1, 2, and 3, respectively. The calculated bond lengths and bond angles of all three compounds are remarkably close to the experimental values obtained by X-ray single crystal diffraction.

Sore throat is a common reason for seeking medical help [1]. It can have infectious and non-infectious etiology [2]. The term “sore throat” is usually associated with an infectious agent (bacteria, viruses, and less commonly fungi) [1,3,4]. The terms “throat discomfort“, “throat irritation“, or “functional dysphonia due to the occupational diseases“ (which represents voice disorder) are often used in the same sense as non-infectious sore throat [2,3]. It is identified by the exclusion of infectious etiology symptoms accompanied with persistent sore throat symptoms (tingling and scratching sensation in the throat, hoarseness or muffled voice, foreign body sensation in the throat, coughing, and difficulty in swallowing accompanied by pain) [2,5]. Various factors can lead to non-infectious sore throat. The most important are: environmental (exposure to smog and irritants), individual risk factors (smoking, alcohol and excessive caffeine consumption, incorrect technique of using voice, and snoring), existence of other diseases (allergies, hormonal disorders, gastroesophageal refluxes, and anxiety disorders), and the use of some medications [2,6]. Epidemiological studies for non-infectious sore throat are rare. In a study performed on 1326 adults in the USA, it was found that 6.6% of respondents had current voice disorders while lifetime prevalence was 29.9% [6]. Professions more susceptible to non-infectious sore throat have high demands on vocal performance (for example, teachers, singers, sports coaches, receptionists, television and radio presenters, lawyers, touristic tour guides, and politicians) [2,3,7]. In modern societies, about one-third of the working population belongs to occupations in which the voice is the primary tool [8]. Teaching is a high-risk occupation for developing voice disorders. In a study performed on 2531 adults in the USA, teachers had higher prevalence of lifetime voice disorders (57.7%) as compared to other professions (28.8%) [5]. Voice problems may lead to a lower quality of teaching and a serious personal and emotional burden. This can have detrimental effects on the career of teachers, with negative consequences on pupils and employers [9]. Despite the adverse impact of non-infectious sore throat on professional performance and reduced quality of life, only a small number of teachers is seeking professional medical help [10]. This can be due to a low level of awareness on this topic. Although exact mechanisms of non-infectious sore throat development vary with etiology, inflammation can be found in the majority of cases [2], with elevated pro-inflammatory cytokines such as interleukin (IL)-6, IL-β, and tumor necrosis factor-α (TNF-α) [2,11,12]. There has been little systematic assessment of treatments for non-infectious sore throat. The field lacks objective outcomes, with most studies relying on subjective (self-reported) endpoints [2]. Although there is no unique doctrine in the treatment, anti-inflammatory medicines and antiseptics are usually used. Inflammation is the pathophysiological mechanism of both infectious and non-infectious sore throat, so similar anti-inflammatory therapies have beneficial effects in both etiologies [2]. Few studies showed positive effects of non-steroidal anti-inflammatory medicines, paracetamol, and steroids [13]. Various herbal formulations and antiseptic lozenges, sprays, and mouthwashes (with or without the addition of an anesthetic or analgesic) are most commonly used [2,12]. Lysozyme is natural enzybiotic with properties that could be beneficial in the treatment of non-infectious sore throat. Different types of lysozymes can be found in nature. They have similar structures and share the ability to hydrolyze bacterial cell wall peptidoglycan [14]. Lysozyme is a significant part of the immune system. In humans, it can be found in body secretions, mucosal surfaces, liver, blood, and immune cells [14]. Human milk is rich in lysozyme, which plays an important role in our immunity from the first days of life [15]. The pharmaceutical industry is mainly using hen egg white lysozyme in products for treatment of certain infectious and inflammatory diseases [16]. Besides its direct antibacterial activity, lysozyme has immunomodulatory and anti-inflammatory effects. Immunomodulatory effects have been demonstrated in cancer patients after chemotherapy, where it improved the recovery of CD4+/CD8+ lymphocyte ratio [17]. One of the proposed mechanisms is through the release of immunomodulatory Lysozyme in the treatment of non-infectious sore throat

OBJECTIVE Lysozyme is a natural antimicrobial and immunomodulatory enzyme, which is produced as a host response to infectious agents. The objective of this study was to compare the efficacy and safety of lysozyme-based versus benzydamine and chlorhexidinebased oral spray in patients with an acute tonsillopharyngitis associated with a common cold. PATIENTS AND METHODS A prospective twoarm pilot study (lysozyme/cetylpyridinium/lidocaine spray versus: benzydamine spray-arm 1; chlorhexidine/lidocaine spray-arm 2) was conducted in the primary health care unit. Efficacy was evaluated by the patient's self-assessment of pain, difficulty in swallowing and the throat swelling, by using the visual analog scale (VAS) at baseline and three follow-up visits. Safety was evaluated by the assessment of the frequency and severity of adverse effects. RESULTS Lysozyme-based spray reduced pain faster than benzydamine-based spray and slower than chlorhexidine-based spray. Lysozyme-based and chlorhexidinebased sprays similarly reduced difficulty in swallowing, but were faster than benzydamine-based spray. Similar effects on the reduction of throat swelling were seen in all treated groups. All tested products showed proper safety and were well tolerated, with no serious adverse events reported. CONCLUSIONS The lysozyme-based oral spray was shown to be effective and safe in the reduction of pain, difficulty in swallowing and throat swelling in patients with acute tonsillopharyngitis associated with a common cold. Lysozyme-based oral spray (containing natural compound with advantages of influencing immune system and preventing recurrences) had similar activity to benzydamine and chlorhexidine-based oral antiseptic sprays.

Thymoquinone (TQ), a natural compound with antimicrobial and antitumor activity, was used as the starting molecule for the preparation of 3-aminothymoquinone (ATQ) from which ten novel benzoxazole derivatives were prepared and characterized by elemental analysis, IR spectroscopy, mass spectrometry and NMR (1H, 13C) spectroscopy in solution. The crystal structure of 4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazole-5-ol (1a) has been determined by X-ray diffraction. All compounds were tested for their antibacterial, antifungal and antitumor activities. TQ and ATQ showed better antibacterial activity against tested Gram-positive and Gram-negative bacterial strains than benzoxazoles. ATQ had the most potent antifungal effect against Candida albicans, Saccharomyces cerevisiae and Aspergillus brasiliensis. Three benzoxazole derivatives and ATQ showed the highest antitumor activities. The most potent was 2-(4-fluorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1f). Western blot analyses have shown that this compound inhibited phosphorylation of protein kinase B (Akt) and Insulin-like Growth Factor-1 Receptor (IGF1R β) in HeLa and HepG2 cells. The least toxic compound against normal fibroblast cells, which maintains similar antitumor activities as TQ, was 2-(4-chlorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1e). Docking studies indicated that 1e and 1f have significant effects against selected receptors playing important roles in tumour survival.

Aim To compare individual case safety reports (ICSR) rates and characteristics between Croatia, Serbia, Montenegro, and Bosnia and Herzegovina (B&H). Methods This retrospective pharmacoepidemiological study used the data from ICSR received by the Agency for Medicines and Medical Devices in B&H in 2011-2016. The number, characteristics, and sources of reports, suspected drugs, and patient characteristics were analyzed. The results were compared with the publicly available data from Croatia, Serbia, and Montenegro. Results The number of reported adverse drug reactions per one million of inhabitants was lowest in B&H and highest in Croatia. There were significant differences in reporter characteristics, sources of reports, and the percentage of missing data in ICSR, while the Anatomical Therapeutic Chemical product classes, patient’s sex, and adverse drug reaction System Organ Classes were similar. Conclusion Despite the historical and geographical vicinity of B&H and its neighboring countries, there were significant differences in indicators of pharmacovigilance development.

Electricity demand forecasting is one of the most important components in the power system analysis. Furthermore, it is difficult and complicated process to forecast energy consumption. This study deals with modeling of the electrical energy consumption in Bosnia and Herzegovina in order to forecast future consumption of electrical loads based on temperature variables using machine learning methods. We used three different  machine learning methods for analyzing short term forecasting. The methods were trained using historical load data, collected from JP Elektroprivreda electrical power utility in BiH, and also considering weather data which is known to have a big impact on the use of electric power. Comparing the results it was seen that prediction for 500 hours is pretty good in range from 92,92% for reactive power till 98.84% for active power. Four different parameters were analyzed mean absolute error, root mean squared error, relative absolute error and root relative square error. The best results for apparent power were gotten with linear regression and are presented as for mean absolute error 9.84, root mean squared error 13.62, relative absolute error 14.06%, root relative squared error 14.39%. It is also seen from the results that,  the short term power consumption can be predicted which is important for maintaining of the voltage at the consumer side.