Colourimetric Method Research Articles

Association of iron-related biomarkers with severity and mortality in COVID-19 patients

BackgroundNutritional deficiency is associated with weaken immune system and increased susceptibility to infection. Among other nutrients, several trace elements have been shown to regulate immune responses. Iron is one of the most abundant trace elements present in our body, which is required in various biological processes. Iron has an immunomodulatory function and thus influence the susceptibility to the course and outcome of a variety of viral infections. So, this present study was aimed to study relations of different iron-related biomarkers in association to severity and mortality in SARS-CoV-2 patients. Materials and methodsA total of 150 individuals infected with COVID-19 and 50 healthy individuals were recruited. Cases were divided based on severity (mild, moderate, and severe) and outcome (discharged or deceased). Serum iron, TIBC, ferritin, transferrin, transferrin saturation levels were analyzed by the direct colourimetric method. ResultsIn cases the median levels of serum iron, TIBC, transferrin, transferrin saturation and ferritin are 29 µg/dL, 132.53 µg/dL, 106.3 mg/dL, 17.74 % and 702.9 ng/dL respectively. Similarly, in controls the median levels of serum iron, TIBC, transferrin, transferrin saturation and ferritin are 53 µg/dL, 391.88 µg/dL, 313.51 mg/dL, 12.81 % and 13.52 ng/dL respectively. On comparing the cases with the controls, a significant lower level of iron, TIBC, and transferrin were found in the cases along with the significant higher levels of ferritin and transferrin saturation. On comparing the Receiver operating characteristic (ROC) curves of Iron, Ferritin, Transferrin, Transferrin sat % and TIBC in relation to survival in COVID-19 patients it was found that iron, followed by transferrin and ferritin has the highest area under the curve (AUC) with 74 %, 63 % and 61 % respectively. Further, in pairwise analysis of ROC curve, a significant difference was found between the Iron-transferrin (p < 0.01), iron-TIBC (p < 0.001) and transferrin-ferritin (P < 0.01). The multiple regression model based on Iron and transferrin outperformed any other combination of variables via stepwise AIC selection with an AUC of 98.2 %. The cutoff point according to Youden’s J index is characterized with a sensitivity of 98 % and a specificity of 96.8 %, indicating that iron along with transferrin can be a useful marker that may contribute to a better assessment of survival chances in COVID-19. ConclusionOur study demonstrated a significantly decreased levels of iron, TIBC, & transferrin and a significantly increased levels of ferritin and transferrin saturation in COVID-19 patients when compared with controls. Further, Iron and transferrin were observed to be a good predictor of mortality in patients with COVID-19. From the above analysis we confirm that iron-related biomarkers play an important role in the development of oxidative stress and further lead to activation of the cytokine storm. So, continuous monitoring of these parameters could be helpful in the early detection of individuals developing the severe disease and can be used to decrease mortality in upcoming new waves of COVID-19.

Determination of Antioxidant Capacities with the Phenolic and Flavonoid Contents of Royal Jelly Mixtures

Royal jelly, which is used in functional foods due to its antioxidant capacity, has started to be widely used. In this study, the antioxidant capacities and phenolic contents of royal jelly mixtures were determined. Total phenolic substance contents (TPC) of royal jelly mixtures were specified using the Folin-Ciocalteu procedure, total flavonoid substance contents (TFC) by aluminium chloride colourimetric method, phenolic compound contents with LC-MS/MS and antioxidant activity with 2,2-diphenyl-1- picrylhydrazyl (DPPH) assay. TPC ranged from 0.6 to 38.2 mg GAE/100 g, and the mean value was determined as 11.08 mg GAE/100 g. TFC ranged from were ranged from 0.1 to 30.06 mg QE/100 g and a mean value of 9.2 mg QE/100 g, and DPPH ranged from 4.4 to 93.0 mg TE/mL and a mean value of 29.11 mg TE/mL. TPC, TFC and DPPH activities were highest in S6 and S7 samples, and lowest in S1 and S2 samples. Caffeic acid phenethyl ester was the highest yielding phenolic compound in all samples, and Luteolin was the lowest yielding compound. The highest phenolic compound contents were determined in the S6 and S7 samples. As a result, it has been observed that food products containing bee products are rich in phenolic contents and have high antioxidant properties. TPC, TFC, DPPH activity and phenolic contents were found to change as the type and ratio of bee products in the food changed.

The Effect of Gambier Catechin Isolate on Cervical Cancer Cell Death (HeLa Cell Lines)

BACKGROUND: Cervical cancer is the second most common type of cancer in women worldwide. Human Papilloma Virus infection on the surface of the cervix is the most common cause which can cause abnormal growth of cervical cells.&#x0D; AIM: This research was conducted in vitro which aims to determine whether catechin compounds can inhibit the growth and regulation of cervical cancer cells (HeLa cell line).&#x0D; METHODS: This is experimental research using the colourimetric assay method and qualitative observation of cervical cancer cell morphology (HeLa cell line) under a fluorescence microscope. The administration of catechin compounds was tested at different concentrations to HeLa cells, namely 1000 g/ml, 500 g/ml, 250 g/ml, 125 g/ml, 62.5 g/ml, 31.25 g/ml.&#x0D; RESULTS: The smallest cell viability was obtained from a concentration of 1000 g/ml which was 5.98% while the largest cell viability was found at a concentration of 31.25 g/ml, which was 40.01%. The resulting IC50 value was 22.91 g/ml. Gambier catechin compounds have very high antioxidants because they contain an IC50 value &lt; 50 g/ml. The effect of gambier catechin compounds on HeLa cell death can be found by increasing the percentage of dead cells. The difference in the fluorescence images of HeLa cells in the experimental group was assessed based on the percentage of the number of cells that died or underwent apoptosis, which was marked by a red or orange fluorescent image. At the concentration of IC25, 31.87% of dead cells were found, the concentration of IC50 was 51.09% of dead cells, and the concentration of IC75 was 82.51% of dead cells. The test results showed that there was a significant difference in the average percentage of cells undergoing apoptosis in all study groups with p &lt;0.05.&#x0D; CONCLUSION: Based on research, it can be concluded that catechin compounds could inhibit the growth and regulation of cervical cancer cells (HeLa cell line). Later, it has the potential to be developed as an anticancer candidate for cervical cancer.&#x0D; Keyword: Cervical cancer, Catechin, Apoptosis, HeLa cell line, Cell death.

In vitro antioxidant activity of Cocoa (Theobroma cacao L) peel

Free radicals are electron-deficient species that are very reactive to cause various diseases, such as diabetes, cholesterol, cardiovascular disease, cancer, hypertension, and others. For this reason, antioxidant compounds are needed that can inhibit the performance of free radicals. Caco is a plant that contains many phenolic and flavonoid compounds that have potential as antioxidants. This study aimed to evaluate the total phenolic and flavonoid content as well as in vitro antioxidant assay. Cocoa fruit powder was macerated with methanol, and then fractionated with n-hexane, chloroform, and ethyl acetate as solvents. The antioxidant power was measured by DPPH and ABTS methods. The phenolic content was determined by the Folin-Ciocalteau method, and the flavonoid content was measured using the AlCl3 colourimetric method. The ethyl acetate fraction showed the strongest antioxidant activity using both the DPPH and ABTS methods with IC50 values of 5.61±0.032 mg/mL and 5.773±0.018 mg/mL, respectively. The total phenolic and flavonoid content of the ethyl acetate fraction showed high values, namely 22.767±0.1097 mg GAE/g sample and 90.337±0.552 mg QE/g sample, respectively. The cocoa peel can be developed as a natural antioxidant and can be used as a functional food.

Plant products with acetylcholinesterase inhibitory activity for insect control

Acetylcholinesterase (AChE) inhibitors are widely used in Alzheimer’s treatment, but they are also crucial for their action on organophosphorus insecticides. The latter exert their toxicity by inhibiting the AChE enzyme in insects, leading to their death. Amaryllidaceae alkaloids have been proven to be potent AChE inhibitors. In the present study methanolic extracts and essential oils being obtained from species of Asteraceae, Lamiaceae, Brassicaceae and Amaryllidaceae were evaluated in vitro for AChE inhibitory activity. Ellman’s colourimetric method, with modifications, was used for AChE activity evaluation. According to the activity level, the tested plant products were divided into three categories. First: plant products with strong activity comparable to that of galanthamine; second: plant products with medium activity, with IC50 value about 1 mg/ml and the last group with low activity, with IC50 value greater than 1 mg/ml. Essential oils of Origanum vulgare subsp. hirtum Ietswaart., Satureja pilosa Vel., Monarda fistulosa L., Thymus longedentatus (Degen &amp;amp; Urum.) Ronniger and the methanolic extract of Leucojum aestivum L. showed the most potent activity and were referred to as the first group. Carvacrol was identified as the main component of the most active essential oils. In L. aestivum extract, galanthamine was found as the main alkaloid. The obtained results indicate that essential oils and alkaloid-rich plant extracts possess the strongest AChE inhibitory activity. This gives us a reason to recommend these plant products to be tested for insecticidal activity in the future.

Evaluation of a colourimetric method for the measurement of oxidation in butter

Butter is an emulsion of water in oil containing approximately 25% unsaturated fat. It is used in various types of cooking because of its delectable flavour. However, oxygen absorption by the unsaturated fatty acids alters its quality. Therefore, oxidation measurement is essential for the quality evaluation of butter. Although titrimetric analysis is mainly used for oxidation measurement in butter, it needs a large quantity of samples and reagents, and the results lack reproducibility. In this study, the colourimetric method was evaluated to measure oxidation levels in butter. A comparative analysis of the standard titrimetric methods and the colourimetric method revealed an increase in the oxidation levels with an increase in time. The findings demonstrated a positive correlation between the titrimetric and colourimetric methods. Furthermore, the measurement accuracy of the colourimetric method was less than 10% (1.7–9.5%) on all examination days. Overall, these findings suggest the efficiency of the colourimetric method to measure oxidation in butter with increased accuracy.

Synergistic Antibacterial Activity of 1-Methyl Ester-Nigericin and Methyl 5-(Hydroxymethyl) Furan-2-Carboxylate Against Proteus spp.

&lt;b&gt;Background and Objective:&lt;/b&gt; Synergistic combinations of antimicrobial agents with different mechanisms of action are successful approaches for combating bacterial infections. This study aimed to evaluate the synergistic effect of 1-methyl ester-nigericin &lt;b&gt;(1)&lt;/b&gt; and methyl 5-(hydroxymethyl) furan-2-carboxylate &lt;b&gt;(2)&lt;/b&gt; against &lt;i&gt;Proteus&lt;/i&gt; spp., isolates. &lt;b&gt;Materials and Methods:&lt;/b&gt; The synergistic antimicrobial activity of the compounds was tested by the checkerboard method and time-kill curves. To estimate the interaction between the compounds, the Fractional Inhibitory Concentration Index (FICI) of the combination was calculated. The cytotoxic activity of the compounds in combination was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on LLC-MK2 cell lines. The reduction percentage of biofilms was obtained using the colourimetric method. &lt;b&gt;Results:&lt;/b&gt; The MIC values for compounds &lt;b&gt;1&lt;/b&gt; and &lt;b&gt;2&lt;/b&gt; against test bacteria ranged from 39.06-78.12 μg mL&lt;sup&gt;1&lt;/sup&gt; and from 78.12-156.25 μg mL&lt;sup&gt;1&lt;/sup&gt;, respectively. The MIC was reduced to 1-8th as a result of the combination of compounds &lt;b&gt;1&lt;/b&gt; and &lt;b&gt;2&lt;/b&gt;. After 4-24 hrs of treatment with ½ MIC of compounds &lt;b&gt;1&lt;/b&gt; and &lt;b&gt;2&lt;/b&gt;, the killing rate (in CFU mL&lt;sup&gt;1&lt;/sup&gt;) increased to a greater degree than observed with either test compound alone. The combination of compounds &lt;b&gt;1&lt;/b&gt; and &lt;b&gt;2&lt;/b&gt; showed a synergistic effect with FICI of 0.50 and 0.28. The synergistic combination of compounds &lt;b&gt;1&lt;/b&gt; and &lt;b&gt;2&lt;/b&gt; was effective on the biofilm reduction of &lt;i&gt;Proteus&lt;/i&gt; &lt;i&gt;vulgaris&lt;/i&gt; NP16 (85.72%) and NP47 (89.14%). &lt;b&gt;Conclusion:&lt;/b&gt; This study recommends compounds &lt;b&gt;1&lt;/b&gt; and &lt;b&gt;2&lt;/b&gt; in combination as a potential alternative treatment agent for &lt;i&gt;Proteus&lt;/i&gt; spp. infections.

A Data Driven Approach to Assess Complex Colour Profiles in Plant Tissues.

The ability to quantify the colour of fruit is extremely important for a number of applied fields including plant breeding, postharvest assessment, and consumer quality assessment. Fruit and other plant organs display highly complex colour patterning. This complexity makes it challenging to compare and contrast colours in an accurate and time efficient manner. Multiple methodologies exist that attempt to digitally quantify colour in complex images but these either require a priori knowledge to assign colours to a particular bin, or fit the colours present within segment of the colour space into a single colour value using a thresholding approach. A major drawback of these methodologies is that, through the process of averaging, they tend to synthetically generate values that may not exist within the context of the original image. As such, to date there are no published methodologies that assess colour patterning using a data driven approach. In this study we present a methodology to acquire and process digital images of biological samples that contain complex colour gradients. The CIE (Commission Internationale de l’Eclairage/International Commission on Illumination) ΔE2000 formula was used to determine the perceptually unique colours (PUC) within images of fruit containing complex colour gradients. This process, on average, resulted in a 98% reduction in colour values from the number of unique colours (UC) in the original image. This data driven procedure summarised the colour data values while maintaining a linear relationship with the normalised colour complexity contained in the total image. A weighted ΔE2000 distance metric was used to generate a distance matrix and facilitated clustering of summarised colour data. Clustering showed that our data driven methodology has the ability to group these complex images into their respective binomial families while maintaining the ability to detect subtle colour differences. This methodology was also able to differentiate closely related images. We provide a high quality set of complex biological images that span the visual spectrum that can be used in future colorimetric research to benchmark colourimetric method development.

Comparative Analysis of Serum Zinc, Copper and Magnesium Level and Their Relations in Association with Severity and Mortality in SARS-CoV-2 Patients.

The deficiencies of trace elements and infectious diseases often coexist and exhibit complex interactions. Several trace elements such as zinc (Zn), copper (Cu) and magnesium (Mg) have immunomodulatory functions and thus influence the susceptibility to the course and outcome of a variety of viral infections. So, this present study was aimed to study relations of trace metals in association with severity and mortality in SARS-CoV-2 patients. A total of 150 individuals infected with COVID-19 and 50 healthy individuals were recruited. Cases were divided based on severity (mild, moderate and severe) and outcome (discharged or deceased). Serum Zn, Mg and Cu levels were analysed by direct colourimetric method. Both serum Cu and Zn levels were significantly decreased in cases when compared to those in controls (p < 0.005 and p < 0.0001). Serum magnesium levels although not significant were found to be slightly decreased in controls. On comparing the trace elements between the deceased and discharged cases, a significant difference was found between serum copper and zinc levels, but for magnesium, both groups have similar levels. The receiver operating characteristic (ROC) curve results indicate that a serum Cu/Zn ratio along with the age of patient provides some reliable information on COVID-19 course and survival odds by yielding an AUC of 95.1% with a sensitivity of 93.8% and specificity of 89.8%. Therefore, we would like to emphasize that measuring the serum copper and zinc along with their ratio can be used as routine investigations for COVID-19 patients in proper identification and management of severe cases in upcoming new waves of COVID-19.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12011-022-03124-7.

The Differences of Lipoprotein-Associated Phospholipase A2, Apolipoprotein B and Low Density Lipoprotein In Obese and Lean Men

ABSTRACT Background: An increase in fat accumulation in obesity has been suggested to link with an increase in inflammation. This inflammation may be associated with an elevated of Lipoprotein-Associated Phospholipase A2 (Lp-PLA2), Apolipoprotein B (Apo B), and Low-Density Lipoprotein (LDL), thereby associated with the risk of atherosclerosis.Objective: To investigate the differences between Lp-PLA2, Apo B, and LDL levels in obese and lean men.Methods: A cross-sectional study was conducted on 74 men (obese and lean) at the Faculty of Medicine, Diponegoro University, Indonesia, in 2020. The concentration of LDL was measured using the homogenous enzymatic colourimetric method, whereas the levels of Lp-PLA2 and Apo B were determined using the ELISA method. Data were analyzed using an Independent t-test, setting statistical significance at p &lt;0.05.Results: This study showed that Lp-PLA2 levels were significantly different between obese and lean men (p = 0.039). Furthermore, LDL levels were also significantly different between obese and lean men (p = 0.002). However, we did not find any differences in Apo B between obese and lean men (p = 0.640).Conclusion: Lp-PLA2 and LDL levels were slightly higher in obese compared to lean men, but no difference of Apo B.

The apoptotic effect of nandrolone on human gastric (AGS) and colon (HCT) cancer cells and evaluation of iNOS, MMP9 expression level, and caspase-3, -8 and -9 activity

Although androgens have been reported to induce apoptosis in cancer cells, there are few studies concerning with cytotoxic effects of nandrolone on human gastric (AGS) and colon (HCT) cancer cells. We evaluated the effects of nandrolone on apoptosis, iNOS, and MMP-9 expression level, and caspase-3, -8 and -9 activity in AGS and HCT cells. HCT and AGS cells were divided into control groups and groups treated with 0.625, 1.25, 2.5, 5 and 10 mg/ml of nandrolone. Cytotoxicity was measured using the MTT assay method. Flow cytometry was used to evaluate the apoptotic pathway that occurred in cells. The expression levels of iNOS and MMP-9 genes were evaluated using real-time PCR, and caspases activity was measured by the colourimetric method. Data were analyzed using ANOVA and an independent t-test. Cell viability significantly decreased in AGS and HCT cells treated with 2.5, 5 and 10 mg/ml of nandrolone. Treatment with the effective concentration of nandrolone (5.99 mg/ml) induced apoptosis in AGS and HCT cells and did not significantly alter the expression levels of iNOS and MMP-9 in AGS cells, however, led to a significant decrease in iNOS and MMP-9 expression levels in HCT cells. Activity levels of caspase-3, -8 and -9 significantly increased in AGS and HCT cells treated with the effective concentration of nandrolone. Higher concentrations of nandrolone had a significant cytotoxic effect and apoptotic pathway in AGS and HCT cells mediated by intrinsic and extrinsic pathways. It might also decrease the invasion and metastasis capability of colon cancer cells.&#x0D;

ROLE OF COPPER METAL AND BIOLOGICAL MARKERS IN PATIENTS WITH ENTEROBIASIS

The primary goal of this study was to determine the effect of copper in patients with Enterobius vermicularis infection, as well as its association with IgE and TRFC. The study was carried out with 583 suspected and thirty healthy respondents of the same age who visited the AL-Zahra maternity and pediatrics laboratory, AL-Hakeem hospital, in AL-Najaf province(Iraq) from July 2020 to June 2021. This study aimed to estimate the level of copper, IgE, and TRFC in patients suffering from enterobiasis. The concentration of three biomarkers (copper, IgE, and TRFC) in serum was determined using the ELISA technique as per the manufacturer's instructions while the concentration of copper was assessed by using the colourimetric method. Results of the study revealed that the concentrations of IgE and TRFC significantly increased (P≤0.05) in the blood sample of E. vermiculris infected patients, while the serum concentrations of copper decreased significantly (P≤0.05) compared to the control group. The results of the current study suggested that the E. vermicularis infection alters serum IgE and TRFC concentrations, which significantly impacts copper levels in the blood.

EOSINOPHIL CATIONIC PROTEIN AND IRON STATUS IN PATIENTS INFECTED WITH Enterobius vermicularis

The primary goal of this study was to determine the function of eosinophil cationic protein in iron status in patients infected with Enterobius vermicularis. For this, a total of 583 suspected patients and thirty healthy people of the same age who have visited the AL-Zahra maternity and pediatrics laboratory, AL-Hakeem hospital, AL-Sajad hospital AL-Fruit al-Awsat hospital, and AL-Munadira hospital in AL-Najaf province from July 2020 to June 2021 were screened. The presence of E. vermicularis eggs was estimated by using the saline wet mount technique from faeces samples of all respondents. Blood samples were collected from the 60 positive and 30 healthy control group and centrifuged at 3000 rpm for 5 minutes to separate serum, which was then collected in sterile tubes. Each serum sample was divided into three parts and stored in the deep freezer at -20°C until the serological test was performed. The level of ECP, iron and ferritin in enterobiasis patients was estimated from the isolated blood serum. According to the Manufacturer Company instructions, the concentration of two biomarkers (ECP, Ferritin) in serum samples was determined using the ELISA technique (Human reader, Germany). While the concentration of iron was evaluated using a colourimetric method. In comparison to the control group, the concentration of ECP was reported significantly higher (P&lt;0.05) in the E. vermiculris infected patients while the concentration of serum iron and ferritin was significantly decreased. The results of the current study can be concluded that E. vermicularis infection changes the serum ECP, iron, and ferritin concentration.

High-spatial and colourimetric imaging of histone modifications in single senescent cells using plasmonic nanoprobes

Histones are closely related to the state of chromatin, and epigenetic modification of their tail results in regulation in cells. Therefore, developing various analytical tools to map the changes in position and distribution of histone modifications is helpful in studying underlying mechanisms. Herein, we propose a high-spatial and colourimetric imaging method using plasmonic nanoparticles as probes to visualize heterochromatin histone markers in a single nucleus. We visualized the reorganization between repressive histone markers, H3K9me3 and H3K27me3, caused by oncogene-induced senescence based on the scattering colours and spectral shift of plasmonic nanoprobes to longer wavelengths using their distance-dependent coupling effect. The measured scattering profiles were correlated with the computation results simulating the scattering spectra according to the arrangements and distances among the plasmonic nanoprobes. The plasmonic nanoprobe-based high-spatial hyperspectral imaging provides an advanced way to study the dynamics of histone modifications for predicting the progression of diseases or senescence.

Evaluation of the growth, drought tolerance and biochemical compositions of introduced red currant cultivars and Russian breeding genotypes in temperate continental climate

Abstract The aim of the work was to study the growth, drought tolerance and biochemical characteristics of introduced cultivars (‘Jonkheer van Tets’, ‘Hollandische Rote’ and ‘Viksne’) and some selected Russian cultivars and red currant genotypes (‘Shchedraya’, ‘Natali’, 129-21-61, 111-19-81, 261-65-19 and 271-58-24). The studies were conducted between 2014 and 2018 under temperate continental climate conditions. The intensity of transpiration was determined by using a torsion balance. The soluble solid concentration (SSS – % Brix) of the fruits was determined by using a digital refractomer. The content of the sum of sugars was determined by the weight method according to Bertrand's method. Ascorbic acid content was then determined by the iodometric method. The total phenolic content was determined by a colourimetric method. Climatic conditions were found to have significant influence on the disease severity of the red currant genotypes, while the infections caused by Sphaerotheca mors-uvae increased in optimum seasons and damages caused by Pseudopeziza ribis increased in drought seasons. None of the selected genotypes was found to be resistant to any of the diseases/pests, but ‘Jonkheer van Tets’, ‘Hollandische Rote’ and 111-19-81 were less affected by these diseases/pests. Weight, yield and raceme length of berries and the number of berries in a raceme were found to be higher in optimum seasons, and different cultivars/genotypes had superior characteristics for different parameters. The highest berry weight was observed in the 261-65-19 genotype (0.65 g), while the highest yield was noted in ‘Hollandische Rote’ (15.6 t · ha−1). It was also found that the water content of leaves and transpiration have a strong positive relationship with soil moisture at a depth of 0–200 mm but a week correlation with soil moisture at a depth of 200–400 mm. Results also showed that the transpiration of leaves decreases in later developmental stages (July). Hierarchical clustering suggested four clusters: the introduced cultivars produced one cluster, Russian cultivars are another cluster, 261-65-19, 111-19-81 and 129-21-61 genotypes make up a third cluster and the 271-58-24 genotype (superior in terms of phenolic contents) forms the fourth cluster.

EVALUATION OF THE QUALITY OF DIFFERENT BRANDS OF ASCORBIC ACID IN FREETOWN, SIERRA LEONE

Objective: This study evaluates the registration status and the quality of nine brands of Vitamin C sold in Freetown, Sierra Leone, using official and non-official methods of analysis. Methods: The parameters taken into consideration during the study include non-official methods (friability and disintegration) and the official methods (identification test, uniformity of dosage unit, and assay by titrimetric and colorimetric tests). The different brands of vitamin C were selected and classified as registered and unregistered based on the data derived from the National Medicines Regulatory Authority. Results: One vitamin C product collected was unregistered at the National medicines regulatory authority (Pharmacy Board of Sierra Leone). All nine vitamin C products met the requirements for uniformity of dosage unit. The vitamin C products also conformed to the BP specification for friability and identification test (retention factor). The identification test showed that each brand contained vitamin C (ascorbic acid). The disintegration test was not applicable for chewable tablets. Three of the four non-chewable vitamin C products complied with the BP specification for disintegration, while one failed and did not meet the requirement. The assay results for ascorbic acid using titration and colourimetric method were comparable and appropriate for determining vitamin C. Out of a total of nine samples; seven met the requirement for BP specification (Passed) for assay. In contrast, one product did not meet the BP requirement (failed), and one sample had more vitamin C than the Pharmacopoeia limit. Conclusion: Periodic quality evaluation and routine checks for pharmaceutical products can ascertain the quality of products, their storage conditions and identify potential counterfeit medications.

Antioxidant, analgesic, anti-inflammatory and antipyretic properties, and toxicity studies of the aerial parts of Imperata cylindrica (L.) Beauv.

Imperata cylindrica (L.) Beauv. (Poaceae family) is a perennial weed growing in tropical and subtropical areas and it is used in several herbal preparations to treat specific pathologic factors inducing pain. This work aimed to determine the in vitro antioxidant and in vivo anti-inflammatory, analgesic and antipyretic activities of the aerial parts of this plant. The methanol extract (MEIC) was used for (i) phytochemical fingerprint by High-Performance Liquid Chromatography (HPLC), (ii) total phenolic content (TPC) evaluation by the Folin-Ciocalteu colourimetric method, (iii) 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenger spectrophotometric assay, (iv) antioxidant capacity by Ferric Reducing Antioxidant Power (FRAP) assay, (v) analgesic activity evaluated with the acetic acid-induced writhing test, (vi) anti-inflammatory activity evaluation by carrageenan-induced paw oedema, (vii) antipyretic effect on lipopolysaccharide (LPS)-induced fever in rats, and (viii) acute and sub-chronic toxicity in mice. The MEIC presented an average rate of TPC (1920.63 ± 360.62 mgGAE/100 g of dry weight (DW)), which is mostly represented by tannins (37.30%), organic acids (32.84%) and flavonols (10.88%). The DPPH free radical scavenger spectrometric assay showed the antioxidant capacity of the MEIC (IC50 = 192.07 ± 0.78 µg/mL) confirmed by the FRAP assay results (29.60 ± 0.55 mmol Fe2+/Kg of DW). The MEIC decreased significantly the number of writhing in a dose-dependent manner (p < 0.01) showing its analgesic activity; the extract inhibited the inflammation in a dose-dependent manner at the first stage (1st h, p < 0.01) and the second stage (3rd h, p < 0.001) post carrageenan induction and it demonstrated an antipyretic activity by lowering the body temperature (Tb) dose-dependently post LPS induction (i.p. route) and time-dependently at the dose of 200 mg/kg (p < 0.001) in mice. Moreover, the acute and sub-chronic toxicity in mice did not reveal any signs of toxicity and any changes in targeted biochemical and haematological parameters. The quantified phytocompounds could be at the origin of these pharmacological activities. These findings support the beneficial use of this plant to alleviate pains and fever in inflammatory or other diseases. Further studies on the isolation of the bioactive compounds and their action mechanisms should be carried out to confirm these results.

A portable, low-cost, smartphone assisted methodology for on-site measurement of NO2 levels in ambient air by selective chemical reactivity and digital image analysis

In this work, we propose a simple, sensitive, selective and inexpensive colourimetric method based on compact and portable instrumentation to monitor nitrogen dioxide (NO2) levels in ambient air, applicable to on-site measurements when needed. The NO2 concentration was determined by monitoring the Griess-Saltzman colourimetric reaction on filter paper pads exposed to ambient air, where NO2 was collected by active sampling (portable pump) on pads coated with triethanolamine (TEA). Digital images of the pads were captured by a smartphone camera inside a box under controlled lighting conditions. The images were analysed without any extraction procedures, using a dedicated smartphone application developed by our research group. The linear working range of the proposed method was from 19.1–191.0 μg m−3 with a correlation coefficient of 0.996. A limit detection of 4.85 μg m−3 was achieved using a sampling time of 60 min and a sampling flow rate of 400 mL min-1. The reproducibility of the proposed methodology was also studied, achieving a relative standard deviation value of 9 % (n = 5). The colourimetric method was tested in ambient air for the on-site determination of hourly NO2 concentrations in an urban area of Badajoz (Spain). The field measurements were validated by orthogonal regression against the reference method, with significant correlation at the 95 % confidence level, and a slope and intercept statistically equal from expected values. An expanded relative uncertainty of 15 % was estimated according to European guidelines for the demonstration of equivalence of ambient air monitoring methods.

Comparative lipid and uric acid suppressing properties of four common herbs in high fat-induced obese mice with their total phenolic and flavonoid index

Our present study was designed to investigate the comparative anti-obesity efficacy of ethanolic extract of Azadirachta indica A. Juss., Trigonella foenum-graecum L., Allium sativum L. and Zingiber officinale Roscoe in high fat-induced mice with their total phenolic and flavonoid profile. Total phenolic and flavonoid content were determined by Folin–Ciocalteu's and Aluminium chloride UV method respectively. In our study, 55 healthy mice were separated into 11 groups to take their respective treatments. Lipid and uric acid profile were estimated by using the enzymatic colourimetric method. Ethanolic extract of A. indica contained the highest phenolic and flavonoid content. A. indica normal and high fat diet group showed reduced weight gaining tendency than other extract groups. A. indica at a dose of 400 mg/kg body weight significantly (p < 0.001) reduced serum cholesterol (SC), triglyceride (TG), and uric acid (UA) level than other three extracts when compared with the control group. Thus, a considerable correlation was found between serum uric acid reducing potentials of the present experimental extracts with a lipid-lowering profile. Pathological examination revealed that the average weight of liver and kidney were significantly decreased in A. indica normal. Results obtained from the present study it can be concluded that ethanolic extract of A. indica possesses better lipid-lowering efficacy than the other three herbs.

Optimization and biological validation of an in vitro assay using the transfected Dm28c/pLacZ Trypanosoma cruzi strain.

There is an urgent need to develop safer and more effective drugs for Chagas disease, as the current treatment relies on benznidazole (BZ) and nifurtimox (NFX). Using the Trypanosoma cruzi Dm28c strain genetically engineered to express the Escherichia coli β-galactosidase gene, lacZ, we have adapted and validated an easy, quick and reliable in vitro assay suitable for high-throughput screening for candidate compounds with anti-T. cruzi activity. In vitro studies were conducted to determine trypomastigotes sensitivity to BZ and NFX from Dm28c/pLacZ strain by comparing the conventional labour-intensive microscopy counting method with the colourimetric assay. Drug concentrations producing the lysis of 50% of trypomastigotes (lytic concentration 50%) were 41.36 and 17.99 µM for BZ and NFX, respectively, when measured by microscopy and 44.74 and 38.94 µM, for the colourimetric method, respectively. The optimal conditions for the amastigote development inhibitory assay were established considering the parasite–host relationship (i.e. multiplicity of infection) and interaction time, the time for colourimetric readout and the incubation time with the β-galactosidase substrate. The drug concentrations resulting in 50% amastigote development inhibition obtained with the colourimetric assay were 2.31 µM for BZ and 0.97 µM for NFX, similar to the reported values for the Dm28c wild strain (2.80 and 1.5 µM, respectively). In summary, a colourimetric assay using the Dm28c/pLacZ strain of T. cruzi has been set up, obtaining biologically meaningful sensibility values with the reference compounds on both trypomastigotes and amastigotes forms. This development could be applied to high-throughput screening programmes aiming to identify compounds with anti-T. cruzi in vitro activity.