Successful Indirect Regeneration of Arnebia pulchra (Roemer and Schultes) as Medicinal Plant

Arnebia pulchra (Willd. ex Roem. & Schult.) Edm. is an endangered, perennial member of Boraginaceae family. Spectrophotometric and LC-Mass analysis confirmed the existence of shikalkin derivatives in its root skin and polyphenolic compounds in the inner part of its root. Studies on the regeneration of A. pulchra from its callus resulted in successful callus induction in the root explants excised from the young plantlets on MS medium amended with 2,4-D (1 mg.l-1) and kinetin (0.5 mg.l-1) at 25°C in darkness. The highest frequency of shooting (15 shoots per callus) was achieved for the calli sub-cultured on MS medium supplemented with 2,4-D (0.1 mg.l-1) and kinetin (2 mg.l-1) in 2 weeks. The concentration and type of auxin were found critical for successful rooting. The best rooting conditions with a frequency rate of 80% were obtained for the regenerates which were sub-cultured on half-strength MS medium supplemented with IBA (1 mg.l-1), NAA (1 mg.l-1) and kinetin (0.2 mg.l-1). The regeneration method developed in this work provides a basis for germplasm conservation of A. pulchra

The Relationship between the Results of Coagulation Profile and Severity of Pulmonary Involvement in COVID-19 Patients

Introduction: COVID-19 is currently a global pandemic, and coagulation-related mortality has been widely reported in patients suffering from it. Objective: this article aimed to investigate the coagulation profile of COVID-19 patients. Methods: This was a cross-sectional study conducted using a retrospective research design. We recruited patients with COVID-19 admitted to a hospital from June 15th to July 7th, 2020. Upon patients' entering a blood sample was drawn from each patient for assessing patient’s coagulation profile (PT, PTT, INR, Platelet count); and a chest high-resolution computed tomography (HRCT) scan was performed for each patient. The study patients were divided in to sever group (CO-RADS score 5) and non-sever group (CO-RADS score <5). Results: Thirty-six patients (20 males and 16 females) with a mean age of 54.7±17.5 years were studied. Of them, 11 cases (30.56%) had severe pulmonary involvement. Also, the coagulation profiles were longer in the severe group than non-sever group. As well, the means of platelet count that were 232.440 per microliter in the non-severe group and 289.180 per microliter in the severe and non-sever groups, respectively; but still not statistically significant (p>0.05). The Area under the ROC Curve (AUC) for PT and INR was 0.615 and 0.611, respectively. The AUC for platelet count was 0.680 (95% CI: 0.501 to 0.859) and had an acceptable discriminating power. Conclusions: In this study, we did not find any statistically significant relationship between the results of coagulation tests and the severity of pulmonary involvement according to HRCT scan findings in COVID-19 patients. But further analyses suggest that, except PTT, the other coagulation tests (PT, INR, and platelet count) may discriminate severe COVID-19 patients

Advanced oxidation processes against alkyl phenols in groundwater samples

Spectrophotometric examinations showed the presence of phenolic compounds in the organic residue collected from four groundwater resources located in vicinity of an oil refinery at the outskirt of Tehran. The average concentration of total phenolic compounds was about 0.38 mg.L-1 in these samples using Folin-Ciocalteu method. GC-Mass analysis disclosed that alkylphenols were the major phenolic contaminants in the samples. Evaluation of the Advanced Oxidation Processes (AOPs) efficacy for removal of alkylphenols from real water samples is a hot topic of recent Environmental Research due to the decomposition of these compounds in soil and by microorganisms which may results in the formation of structures more resistance against various types of oxidation. To explore the efficacy of AOPs for removal of alkylphenols from the examined groundwater resources, the optimal conditions for three important AOP including Fe2+/H2O2/UV (Photo-Fenton), O3/UV and O3/UV/H2O2 were first sought using a recalcitrant lab sample containing different aromatic compounds with total concentration of 2 mg L^-1. Consequently, two methods of O3/UV (2 mg L-1 O3, 15 min UVC), and O3/UV/H2O2 (2 mg L^-1 O3, 5000 mg L^-1 H2O2, 15 min UVC) were selected to be examined on the real samples. Although the selected methods were quantitatively effective on the lab sample, they resulted in average removal efficiencies of 79.71% and 84.16% on the real samples, respectively. With respect to the safety regulations, costs and easiness of implementation, the O3/UV method seems to be more promising for large-scale plans

Detailed Investigations on the Solid Cell Culture and Antimicrobial Activities of the Iranian Arnebia euchroma

In pursuit of strong shikalkin-producing cell lines, seeds of the Iranian Arnebia euchroma were collected from Dena altitudes in the central Zagross. Chemical analysis showed that the dried root of the plant contained about 8.5% (w/w) shikalkin pigment. The root explants of the young plantlets, obtained from the germinated seeds, were used for establishing callus. Then, parameters effective on proliferation and pigment production of the resulting calli were studied in detail. Accordingly, two modified media called mLS and mM9 were optimized for propagation and pigment production, respectively. Using these media, the biomass of the A.euchroma calli was increased to 600%, and the pigment production reached to a maximum of 16.3 mg per gram of the wet biomass in a period of a subculture (21 days). Parallel to these experiments, the antimicrobial activity of shikalkin pigment was examined on some fungi and Gram-positive and Gram-negative bacteria. Results indicated that the pigment was almost ineffective on fungi and Gram-negative bacteria, but it was meaningfully effective against Micrococcus luteus

New insight into the allosteric effect of L-tyrosine on mushroom tyrosinase during L-dopa production

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.ijbiomac.2018.03.185 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Kinetics studies of L-tyrosine (LTy) ortho-hydroxylation by mushroom tyrosinase (MT) confirmed that MT was severely, but not completely, inhibited at higher concentrations of LTy. Despite the availability of the crystal structure reports, no allosteric site has been identified on MT. To examine the assumption that a non-specific binding site works as a regulatory site, docking simulations were run for the second molecule of L-tyrosine (LTy(2)) on the complexes of the first L-tyrosine molecule (LTy(1)) with the heavy chain (H) of MT (LTy(1)/HMT) and its dimer with the light chain (Ty(1)/LHMT). In both, LTy(2) occupied a non-specific binding site (MTPc). MD simulations revealed LTy(2)/HMT/LTy(1) and LTy(2)/LHMT/LTy(1) were stable. Binding free-energy analysis supported the formation of LTy(2)/HMT/LTy(1) and LTy(2)/LHMT/LTy(1) at higher concentrations of LTy and disclosed the importance of Delta E-elec and Delta G(polar) during binding of LTy(2) to MTPc. Upon LTy(2) binding to MTPc, the Cu-Cu distance remained unchanged while the spatial position of LTy(1) in the active site (MTPa) changed so that it would not be able to participate in ortho-hydroxylation. This study suggests a tuning role for L chain during binding of the ligands to MTPa and MTPc. Given these results, a plausible mechanism was proposed for the MT substrate inhibition.Iran National Science Foundation [93031596

Gender Differences in COVID-19 Deceased Cases in Jahrom City, South of Iran

Objective: To evaluate the clinical and epidemiological features of deceased patients and comparing the discrepancies between male and female patients based on high prevalence of coronavirus disease 2019 (COVID-19), its irreversible effects and the rising mortality rate in Jahrom city. Methods: This is a descriptive-analytical retrospective study that was conducted from the beginning of March 2020 to the end of November 2020. The study population were included all patients with COVID-19 who admitted to Peymaniyeh Hospital in Jahrom and died of COVID-19. Clinical and demographic data were collected from medical records and analyzed by SPSS software. Results: In this study, 61 patients (57.54%) were men and 45 patients (42.36%) were women. The mean age was 68.7±18.33 in men and 68.82±14.24 in women. The mean hospitalization length was 9.69±7.75 days in men and 9.69±7.75 days in women patients. There was no statistically significant difference between men and women patients (p>0.05). The results showed that 17 (27.87%) men and 28 (45.9%) of women patients had hypertension and the prevalence of this disease was significantly higher in women than men (p=0.01). In this study, 7 (11.48%) men and 13 (21.31%) women had hyperlipidemia. The frequency of hyperlipidemia in women caseswas significantly higher than in men patients (p=0.024). Men cases’ diastolic blood pressure (mean=77.53) was significantly higher than women’s diastolic blood pressure at the same time with a mean of 71.42 (p <0.05). Conclusion: The findings of the study represented the mortality rate in men which is higher than women patients. The prevalence of underlying diseases such as hypertension and hyperlipidemia were higher in women than men. Despite higher mortality among women, symptoms such as fever and dyspnea were less common in women than men

An Updated Review of Tyrosinase Inhibitors

Tyrosinase is a multifunctional, glycosylated, and copper-containing oxidase, which catalyzes the first two steps in mammalian melanogenesis and is responsible for enzymatic browning reactions in damaged fruits during post-harvest handling and processing. Neither hyperpigmentation in human skin nor enzymatic browning in fruits are desirable. These phenomena have encouraged researchers to seek new potent tyrosinase inhibitors for use in foods and cosmetics. This article surveys tyrosinase inhibitors newly discovered from natural and synthetic sources. The inhibitory strength is compared with that of a standard inhibitor, kojic acid, and their inhibitory mechanisms are discussed

Characterization of inhibitory effects of the potential therapeutic inhibitors, benzoic acid and pyridine derivatives, on the monophenolase and diphenolase activities of tyrosinase

Objective(s): Involvement of tyrosinase in the synthesis of melanin and cell signaling pathway has made it an attractive target in the search for therapeutic inhibitors for treatment of different skin hyperpigmentation disorders and melanoma cancers. Materials and Methods: In the present study, we conducted a comprehensive kinetic analysis to understand the mechanisms of inhibition imposed by 2-amino benzoic acid, 4-amino benzoic acid, nicotinic acid, and picolinic acid on the monophenolase and diphenolase activities of the mushroom tyrosinase, and then MTT assay was exploited to evaluate their toxicity on the melanoma cells. Results: Kinetic analysis revealed that nicotinic acid and picolinic acid competitively restricted the monophenolase activity with inhibition constants (Ki) of 1.21 mM and 1.97 mM and the diphenolase activity with Kis of 2.4 mM and 2.93 mM, respectively. 2-aminobenzoic acid and 4-aminobenzoic acid inhibited the monophenolase activity in a non-competitive fashion with Kis of 5.15 μM and 3.8 μM and the diphenolase activity with Kis of 4.72 μM and 20 μM, respectively. Conclusion: Our cell-based data revealed that only the pyridine derivatives imposed cytotoxicity in melanoma cells. Importantly, the concentrations of the inhibitors leading to 50% decrease in the cell density (IC50) were comparable to those causing 50% drop in the enzyme activity, implying that the observed cytotoxicity is highly likely due to the tyrosinase inhibition. Moreover, our cell-based data exhibited that the pyridine derivatives acted as anti-proliferative agents, perhaps inducing cytotoxicity in the melanoma cells through inhibition of the tyrosinase activities