Antioxidant Activity of Total phenols and Flavonoids extracted from Echinops polyceras roots grown in Syria

Free radicals are reactive compounds, their excessive production is considered to be an important cause of oxidative damage in biomolecules causing degenerative diseases. Polyphenols are one of the most important groups of secondary metabolites of plants, which have an antioxidant activity depending on their properties as hydrogen donors. Echinops polyceras Boiss. (Asteraceae) is one of Echinops genus species that spread in Syria, Lebanon, and Palestine. Phytochemicals found in this species leaves have been extracted with gradient polarity solvents, and primary screening of the secondary metabolites was established. The phenolic compounds and flavonoids contents were determined. The free radicals scavenging activity was evaluated for all extracts with DPPH• in a 96-well microplate. The specificity study indicates that ascorbic acid was absent, and reducing sugars were exist in the aqueous extract. The identification tests showed the presence of polyphenols like flavonoids and coumarins. The methanolic extract of the E. polyceras leaves was the most effective scavengers of free radicals (90.22% in 30 min) with phenolic compounds content 682.5 mg GAE/g of dried extract (DE) and flavonoids content 194.5 mg QE/ g DE. The chloroform extract was the least effective as free radical scavenging (60% in 30 min) as the phenolic compounds content was 278.5 mg GAE/g DE and flavonoids content 94 mg QE/ g DE. In conclusion, the phenolic compounds and flavonoids from Echinops polyceras Boiss. are effective in free radicals scavenging and protecting from diseases caused by oxidative stress.

LANGUAGE SITUATION IN DARGO: STATE, SPECIFICITY, STUDY ISSUES

The article is devoted to an overview of the linguistic situation in Dargo, namely to the problems of the state, specificity and study of the linguistic situation. The degree of study of the ethno-regional linguistic picture of the world is shown. Particular attention is paid to the development and functioning of bilingualism and multilingualism among the Dargins. Attention is also drawn to such a region-specific feature as Russian-Dargin bilingualism, as well as the functioning of dialectal linguistic forms and the importance of studying RussianDargin language contacts. The need to support the codified form of the Dargin language is noted.

Aptasensor for the Detection of Mycobacterium Tuberculosis in Sputum Utilising CFP10-ESAT6 Protein as a Selective Biomarker

A portable electrochemical aptamer-antibody based sandwich biosensor has been designed and successfully developed using an aptamer bioreceptor immobilized onto a screen-printed electrode surface for Mycobacterium tuberculosis (M. tuberculosis) detection in clinical sputum samples. In the sensing strategy, a CFP10-ESAT6 binding aptamer was immobilized onto a graphene/polyaniline (GP/PANI)-modified gold working electrode by covalent binding via glutaraldehyde linkage. Upon interaction with the CFP10-ESAT6 antigen target, the aptamer will capture the target where the nano-labelled Fe3O4/Au MNPs conjugated antibody is used to complete the sandwich format and enhance the signal produced from the aptamer–antigen interaction. Using this strategy, the detection of CFP10-ESAT6 antigen was conducted in the concentration range of 5 to 500 ng/mL. From the analysis, the detection limit was found to be 1.5 ng/mL, thereby demonstrating the efficiency of the aptamer as a bioreceptor. The specificity study was carried out using bovine serum albumin (BSA), MPT64, and human serum, and the result demonstrated good specificity that is 7% higher than the antibody–antigen interaction reported in a previous study. The fabricated aptasensor for M. tuberculosis analysis shows good reproducibility with an relative standard deviation (RSD) of 2.5%. Further analysis of M. tuberculosis in sputum samples have shown good correlation with the culture method with 100% specificity and sensitivity, thus making the aptasensor a promising candidate for M. tuberculosis detection considering its high specificity and sensitivity with clinical samples.

Analytical Method Development and Validation for Estimation of Ranitidine in Solid Dosage Form by UV-Spectrophotometric Method

Ranitidine is a histamine-2 receptor blocker and it is effective against peptic ulcer, gastroesophageal reflux disease and heart burn. The main objective of this study was to develop and validate an easy, affordable and cost-effective method for the determination of ranitidine in tablet dosage form. The development and validation study was performed under the guidance of ICH and USP. Results showed that the proposed validated method has good accuracy with % RSD of 0.60. Repeatability and intermediate precision suggested good precision whereas the value of correlation coefficient 0.9999 confirmed about the linearity of the method. The system suitability data and similarity factors were also found within the permissible range. The specificity study revealed that there was no placebo and diluent effect on the absorbance. Further, stability study of analytical solutions as well as estimation of drug content from market products were also performed.

Validation of mobile-based funduscope for diabetic retinopathy screening in Estonia

Aim: To validate mobile-based funduscope for diabetic retinopathy screening in Estonia. Methods: Quality validation comparison of HEINE® iC2 funduscope and Zeiss Visucam camera with image scoring and diagnostic test accuracy measurement by sensitivity and specificity. Study took place from January 2020 until March 2020 in East-Tallinn Central Hospital’s eye clinic. Results: Based on 90 patients, the Zeiss Visucam showed 35.6% DR prevalence while iC2 had 18.9% for images and 17.8% for videos. The average Likert score was 4.7 for Zeiss Visucam and 2.4 for both iC2 images and iC2 videos. The sensitivity of iC2 images was 72.7% (95%CI 49.6–88.4) for grader 1 and 61.9% (95%CI 38.7–81.0) for grader 2, iC2 video sensitivity was 57.1% (95%CI 37.4–75.0) and 65.4% (95%CI 44.4–82.1), respectively. The grader-based specificity for iC2 images was 96.7% (95%CI 80.9–99.8) and 93.5% (95%CI 77.2–98.9). iC2 videos had a 100% (95%CI 91.7–1.0; 92.0–1.0) specificity by both graders. Cohen’s kappa agreement was 0.82 and 0.96 for images and videos. Conclusion: Mobile-based funduscope iC2 is not valid for DR screening with non-dilated pupils and thus not suitable for clinics that do not have experienced specialist present. Moreover, the screening specialist needs to be experienced fundus photographer with extra multiple day training for funduscope use. As main resolution, mobile-based funduscope was not validated for DR screening in Estonia based on pre-set study criteria. Additional research and development of funduscope algorithm for image stripping from videos is needed for validation as iC2 benefits do not offset the gold standard at the moment.

Development and Validation of UV-Spectrophotometric Method for Estimation of Doxofylline in Bulk and Tablets

Doxofylline is a xanthine derivative and it has its application as a bronchodilator in different pulmonary conditions like asthma and COPD (chronic obstructive pulmonary disease). The research was conducted with the objective to develop and validate a simple, easy, rapid and cost-effective UV-Spectrophotometric method to estimate the amount of doxofylline in bulk and tablets. The validating parameters and methodology were selected and performed according to ICH and USP guidelines. In the accuracy study, the mean % recovery was within the limit (100.20%) with %RSD 0.77. The mean of % assay and %RSD of intra-assay precision study was found 99.81 and 0.79 respectively with only 0.57% variation between two analysts in intermediate precision study. The linearity study demonstrated the value of the correlation coefficient is 0.9999 whereas the robustness studies showed a slight but negligible variation of absorbance while changing different operating parameters. In system suitability study, the %RSD was found less than 2.00%. According to the specificity study, there were no placebo and diluent effect on the absorbance measurements.

Physicochemical Properties of 3-Mercaptopyruvate Sulfurtransferase: A Cyanide Detoxifying Enzyme from the Hemolymph of Limicolaria flammae (Garden Snail)

Background: 3-Mercaptopyruvate sulfurtransferase (3-MST) is a multifunctional, mitochondrial and cytoplasmic sulphurtransferase that catalyses the detoxification of cyanide to a less toxic thiocyanate. Limicolaria flammea feeds majorly on green leaves, plants and other cyanide containing foods. Methods: 3-MST from the hemolymph of Limicolaria flammae was purified by 70 % ammonium sulphate precipitation and ion exchange chromatography. The purified enzyme was characterized at different levels such as optimal activity, inhibitors, substrate preference, thermal stability and analysis of ki-netic parameters. Results: 3-MST from the hemolymph of Limicolaria flammae had a yield of 0.75 % with specific activity of 0.42 μ/mg/ml. The Km values for the substrates; KCN and 2-Mercaptoethanol were 1.09 and 2.83 mM, while the Vmax values were 3.08 μml/mol/min and 6.17 μml/mol/min respectively. The optimum pH and temperature of the enzyme were 5.0 and 60° C respectively. The metals (Al3+, Ca2+, and K+) demonstrated inhibitory activity in a concentration dependent manner. The substrate specificity study showed that sodium sulphite, ammonium per sulphate and ammonium sulphite showed enzymatic interference. Conclusion: This study affirmed the presence of 3-MST activity in the hemolymph of Limicolaria flammea, an indication that the enzyme possesses functional cyanide detoxification mechanism necessary for the survival of the animal in the environment.

X6: A Novel Antibody for Potential Use in Gluten Quantification

Gliadin is a fraction of gluten, known to trigger celiac disease in susceptible people. To date, the life-long gluten-free diet is used for the prevention of this disease. Hence, methods for gluten control in foods are of significant importance. Being one of the most-used methods used for this purpose, ELISA should use high-affinity antibodies to gliadin peptides involved into celiac process. This study investigates the characteristics of a novel anti-gliadin antibody X6. We found the QXQPFPXP site to be a recognized epitope that provides specific binding of the antibody to cereal prolamins involved in celiac disease manifestation. A specificity study using immunoblotting shows the recognition of wheat, barley and rye proteins—as well as α-gliadin homologs from non-edible cereals (Dasypyrum villosum). Reactivity to avenin was less pronounced, as this protein does not contain the PFP motif most critical for antibody recognition. The proteins of Zea mays and Setaria italica were not recognized by X6. X6-based ELISA highly correlated with R5 and G12, which are Codex Alimentarius standards in the quantitative assessment of gluten content (Pearson’s R = 0.86 and 0.87, respectively). Qualitative assessment revealed no significant differences between R5 and G12 and X6.

A NOVEL VALIDATED UHPLC METHOD FOR ESTIMATION OF ASSAY AND ITS RELATED SUBSTANCES OF TRICHOSTATIN-A

Objective: The main objective of the research work is to develop and validate a rapid UHPLC method for the estimation of assay and its related substances of Trichostatin A (TSA) in pharmaceutical samples. Methods: The UHPLC method developed for chromatographic separation between TSA and its related compounds on Poroshell 120 SB C18(50×4.6) mm; 2.7 µm RRLC column using Agilent RRLC (UHPLC) system with linear gradient elution. Results: The developed UHPLC method has shown excellent chromatographic separation between TSA and its related compounds within 12 min run time, during validation experiments, specificity study revealed that the peak threshold was more than the peak purity and no purity flag was observed. Repeatability, intra, and inter-day precision results were well within the tolerable limits. Limits of detection concentrations were found between 0.075 to 0.077 ppm and the limit of quantitation is between 0.252 to 0.258 ppm for related compounds and TSA. The related substances method recoveries were found between 80 and 120 % and assay method recovery was found between 98.0 to 102.0%. Conclusion: The developed method capability was proven for the assay of TSA and its related compounds in pharmaceutical samples and the method shows eco-friendlier than routine, conventional HPLC methods in terms of analysis time, cost and HPLC effluent waste.

Extraction and Partial Characterization of Lectin from Indonesian Brown Algae Padina australis and Padina minor

Extraction and partial characterization of lectin from Indonesian Padina australis and Padina minor had been carried out. The crude extract of the P. australis and P. minor were examined for hemagglutination activity (HA) using native and trypsin-treated of rabbit and human A, B, O type erythrocytes. Both extracts agglutinated all of the trypsin-treated erythrocytes tested in the HA assay. Strong HA was detected in the crude extract of P. minor with trypsin-treated of human type A and O erythrocytes. However, the sugar-binding specificity study through the quantitative hemagglutination inhibition (HI) assay showed that P. minor extract could not specifically recognize the glycans tested. Apparently, the HA of the P. minor was more due to its co-extracted polyphenols content than its lectin content. On the other hand, the HI assay showed that asialo transferrin human (aTf) and asialo porcine thyroglobulin (aPTG) were the most powerful in inhibiting the HA of P. australis. Those indicated that P. australis protein extract was able to specifically recognized aTf and aPTG. The stability of P. australis and P. minor HA over various temperatures, pH ranges, and divalent cations studies showed that the P. minor HA was stable on a wide range of pH and temperature; not affected by the presence of EDTA, but decreased by Ca2+ and Mg2+ additions showed that P. minor protein extract was not a metallic protein. The HA of P. australis decreased at 60 oC and was inactivated at 90 oC; increased at strong acidic (pH 3 & 4) and strong basic (pH 9 & 10) and dependent by the presence of either EDTA or Ca2+ and Mg2+ divalent cation.