Co-encapsulated resveratrol and quercetin in chitosan and peg modified chitosan nanoparticles: For efficient intra ocular pressure reduction

Natural anti-oxidants resveratrol (RES) and quercetin (QUR) posses the ability to reduce intra ocular pressure efficiently. Concurrent administration of RES and QUR was able to enhance the bioavailability of RES. Present research work describes upsurge of QUR in RES loaded chitosan (CS) nanoparticles (NPs) and polyethylene glycol (PEG) modified CS NPs for improved delivery and synergic effects on reducing intra ocular pressure for the treatment of glaucoma. CS NPs and PEG modified CS NPs were prepared by ionic gelation of tripolyphosphate and CS. The synthesised NPs were spherical in shape and RES entrapment and loading efficiency in the formulation decreased with increasing PEG concentration. Particle size of the formulation increased while incorporating PEG and drugs. The crystalline nature of RES and QUR changed in the NPs and that was confirmed by XRD study. Free radical neutralising efficiency improved while incorporating QUR in the formulation. Ex-vivo corneal permeation of RES was higher from RES and QUR loaded formulation than RES alone containing NPs and free RES dispersion. RES and QUR loaded PEG modified CS NPs showed sustained and enhanced reduction of intra ocular pressure (5.5±0.5mmHg) in normotensive rabbits.

Dimesitylketone O-oxide: spectroscopic characterization, conformation, and reaction modes: OH formation and OH capture

Dimesitylketone O-oxide 1b was synthesized by photolysis of dimesityldiazomethane dissolved in an oxygen saturated CCl3F solution at 140 K. Conformation and geometry of 1b were determined by comparing measured NMR chemical shifts with the corresponding chemical shifts calculated at the DFT-IGLO level of theory where it had to be considered that the molecule exists in two enantiomeric forms. Measured and calculated 1H chemical shifts agree within 0.1 ppm while the calculated 13C shift of the COO carbon (210.6 ppm) differs by only 0.4 ppm from the measured shift of 211.0 ppm. The two mesityl rings are perpendicular to each other and enclose angles of 40 and 57 degrees with the COO plane. The preferred rearrangement process of 1b is an H migration from one of the ortho-methyl groups to the terminal O atom of the COO unit. The calculated activation enthalpy of this process is 12.7 kcal/mol (B3LYP/cc-pVTZ). In contrast, the activation enthalpy for isomerization to dioxirane is 5 kcal/mol higher. In CCl3F, the activation barrier for the thermal decay was determined to be 13.8 +/- 0.2 kcal/mol and in acetonitrile 13.1 +/- 0.4 kcal/mol. H migration initiates cleavage of the OO bond and the production of an OH and a benzyl radical. Recombination of the latter in the solvent cage leads to the formation of 2-methylhydroxy-pentamethylbenzophenone, while escape of the OH radical from the solvent cage yields a ketone. These results confirm the possibility of OH production from carbonyl oxides in the solution phase.

Phototoxicity of some novel porphyrin hybrids against the human leukemic cell line TF-1

Photodynamic induced cytotoxicity by porphyrin-DNA cross linker/intercalator hybrid diads and triads has been studied on the human leukemic cell line TF-1. Cells were incubated for 1 to 4 h with these new photosensitizers and irradiated with white light. Cell survival was assessed by the propidium iodide staining, using flow cytometry analysis. A comparison of the dark and light cell survival factor values suggests that irradiation has a significant effect on the toxicity at low concentrations for the porphyrin-chlorambucil diad and to a lesser extent at high concentrations for the porphyrin-acridone diad, the porphyrin-acridine diad and the porphyrin-cholic acid-chlorambucil triad. While the intrinsic antileukemic (via DNA cross-linking) activity of the chlorambucil moiety and the structural details may be responsible for the photoenhancement of the toxicity, the presence of acridine or acridone which are avid intercalators of DNA, is responsible for a similar effect seen for diads.

Submarine groundwater discharge and associated nutrient influx in surroundings of the estuary region at Gulf of Mannar coast, Indian Ocean

The influx of fresh groundwater and re-circulated sea water into coastal ecosystem occurs through the submarine groundwater discharge (SGD). Measurement of salinity, radium tracers (²²⁴Ra, and ²²⁶Ra isotopes) and nutrients in estuarine water, coastal surface water and groundwater during December 2019 estimated the SGD and associated nutrient fluxes near the Karameniyar estuary (Gulf of Mannar) and surroundings of the Manapad region at southern part of Tamil Nadu state in India. The presence of excessive radium tracers revealed that the SGD was contributing to Ra desorption from the sediments and enrichment in the coastal waters. We estimated SGD of approximately 0.03-0.59 m³ m^-2 d^-1 for the Manapad region and relatively more homogeneous but comparatively less values in the Karameniyar estuary (0.03-0.34 m³ m^-2 d^-1). Higher average values of dissolved inorganic nitrogen (DIN; 43.62 μmol L^-1) and soluble reactive phosphate (SRP; 1.848 μmol L^-1) suggested greater influence of SGD on the overall coastal water nutrient budget. This study also indicated simultaneous occurrence of fresh and saline SGD in this region.

Colloidal synthesis and electrical behaviour of n-ZnGdO/p-Si heterojunction diodes

Studies on manoeuvring the optoelectronic characteristics of a semiconducting nanostructure are of recent specific interest for a wide range of photonic applications. In this regard, the optical and electrical characteristics of ZnO nanostructures have been tuned and studied systematically using Gd ions. The structural and morphological characteristics of the solution processed ZnGdO nanostructures were studied in detail using the results of X-ray diffraction and microscopic measurements. The absorption band edge in ZnO was noted to shift towards the lower wavelength values on Gd substitution, suggesting an increase in its energy band gap. The blue emissivity from ZnO complexes was also noted to improve as a function of Gd composition in ZnO. The potential of ZnGdO nanostructures for optoelectronic functions was evaluated by fabricating heterojunction diodes based on n-ZnGdO/p-Si. The diode characteristics revealed an improved electrical conductivity and rectifying behaviour from the fabricated architectures upon Gd substitution and photon illumination. The findings are correlated with the increased charge carrier concentration and defect states existing within ZnGdO species, through appropriate mechanisms.

Safety assessment of a standardized cucumber extract (Q-Actin™): Oral repeat-dose toxicity and mutagenicity studies

Cucumus sativus (cucumber) is one of the most widely consumed fruit vegetables worldwide. Recent discovery of iminosugars in commonly consumed fruits and vegetables has promoted the interest in isolating these compounds and understanding the potential benefits to human health. The objective of the present study was to investigate the general toxicity and mutagenic effects of an aqueous extract of cucumber (Q-Actin), standardized to ≥1% (1-2%) ido-BR1 iminosugar. Single dose of Q-Actin was well tolerated without mortality at 2000 mg/kg body weight (bw) in Sprague Dawley rats. Oral (gavage) administration of Q-Actin up to 1000 mg/kg bw/day was well tolerated followed by repeated administration for a maximum period of 90 days in Sprague-Dawley rats. There were no treatment related changes in clinical observations, ophthalmic examinations, body weights and body weight gains or feed consumption, clinical chemistry and pathological changes compared to control. The mutagenicity as evaluated by Ames assay, in vitro chromosomal aberration test and in vivo micronucleus assay did not reveal any potential of Q-Actin to induce genotoxicity. The results showed that Q-Actin is well tolerated in general toxicity studies and did not induce mutagenicity. The no-observed-adverse-effect level (NOAEL) of the standardized aqueous cucumber extract (Q-Actin) is considered to be ≥1000 mg/kg bw/day, followed by repeated administration for90 days.

Anxiolytic effects of silibinin and naringenin on zebrafish model: A preclinical study

OBJECTIVE

Stress exacerbates the pathophysiology of major neurodegenerative disorders. In this study, the zebrafish (Danio rerio), the frequently used model for experimental studies of stress and other central nervous system disorders, was used to evaluate the anxiolytic potential of flavonoids, namely silibinin and naringenin on alleviating acute stress-induced anxiety.

MATERIALS AND METHODS

A molecular docking study with Molegro Virtual Docker software was done to assess the binding potential of flavonoids on serotonin and dopamine receptors. To determine the bioactivity and investigate the toxicity of the flavonoids, silibinin, and naringenin, brine shrimp lethality assay, and an acute toxicity study was conducted according to Organization for Economic Co-operation and Development (OECD) Test Guideline 203. The effect of silibinin and naringenin was assessed using behavioral tasks such as the novel tank assay and the light-dark test on the zebrafish model of acute stress.

RESULTS

Molecular docking studies showed a higher affinity of silibinin and naringenin for the serotonin and dopamine receptors. In comparison to the LC50 value, 13.15 μg/ml of the reference standard potassium dichromate, silibinin, and naringenin yielded higher LC50 values, 34.10 μg/ml and 91.33 μg/ml, respectively. The LC50 value of silibinin and naringenin was observed to be >100 mg/l from the acute toxicity study on adult zebrafish. After transferring to a novel tank, silibinin and naringenin-treated zebrafish groups were found to explore the upper level of the tank, similar to standard drugs, and spent a long time in the upper level of the tank compared to the control group (p < 0.01). Both silibinin and naringenin treatment group spent increased amounts of time in the tank's illuminated part in contrast to that of the dark side as evidenced by the number of zebrafish entering or remaining in the illuminated part of the tank through the light-dark test. Silibinin and naringenin treated groups were found to spend increased time in the light side significantly on the day 15th of evaluation as compared to the control group (p < 0.05 and p < 0.001, respectively).

CONCLUSION

The flavonoids, silibinin, and naringenin were found to mitigate acute stress-induced anxiety, owing to their anxiolytic properties in the zebrafish model and may be explored as the potential therapeutic agents for treating anxiety.

Is Daclatasvir a suitable substitute for Amphotericin B in the treatment of Mucormycosis when Amphotericin B is scarce?

BACKGROUND

Mucormycosis has been infesting the universe for a while back, often with no prompt treatments. The disease devastation is spreading at an alarming rate. Many researchers are still hoping for a good potential drug that could help the healthcare system in this tussle. Molecular docking is an in silico tool that has gained popularity over the last few decades. Knowing the mechanism of enzymatic action is aided by imitating membrane protein actions in binding ligands.

AIM

The aim of this perspective is to determine whether an existing drug, daclatasvir, has antifungal activity.

OBJECTIVE

The primary objective of this in silico study was to investigate the potential effects of the binding affinity of daclatasvir with the crucial protein (1XFF) of mucormycosis, as well as the binding pattern of the active site amino acids with the drug molecule.

MATERIALS AND METHODS

To calculate the binding affinity of daclatasvir to the fungal protein 1XFF, Auto Dock Vina was used for molecular docking studies. The CDOCKER protocol was used to determine the receptor-ligand interaction by configuring various parameters.

RESULTS

The docking energy of the ligand (daclatasvir) on the protein (1XFF) was found to be -16.7216 kcal/mol, while the interaction energy was found to be - 42.1314 kcal/mol.

CONCLUSION

The binding pattern completely alters the dynamics of the protein, resulting in the breakdown of the fungal wall. The vital protein (1XFF) of Rhizopus oryzae is proposed as a possible protein target for the non-structural protein 5A inhibitor/antiviral drug daclatasvir in this study.

CD56 expression in benign and malignant thyroid lesions

INTRODUCTION

Thyroid cancer is the most common endocrine malignancy with more than 95% originating from follicular epithelial cells. Diagnostic dilemma may arise in occasional cases such as when an encapsulated nodule with a follicular growth pattern exhibits clear nuclei with grooves making it difficult to distinguish a follicular adenoma from encapsulated follicular variant papillary thyroid carcinoma. This study aimed to evaluate the diagnostic utility of an immunohistochemical marker, CD56, to distinguish between benign and malignant thyroid lesions.

MATERIALS AND METHODS

We retrospectively studied CD56 expression in 54 benign and 54 malignant thyroid lesions using archival formalin fixed paraffin-embedded tissue blocks for the study period from January 2010 to December 2015, diagnosed in a tertiary hospital.

RESULTS

CD56 was expressed in 52/54 (96.3%) of benign specimens and only 24/54 (44.4%) of malignant ones. The malignant specimens comprised 31 (57.4%) papillary thyroid carcinomas (PTC), 11 (20.3%) follicular carcinomas (FC), seven (13%) medullary thyroid carcinomas (MC), one (1.9%) poorly differentiated carcinoma (PC) and four (7.4%) anaplastic carcinomas (AC). CD56 was not expressed in 28/31 (90.3%) of the PTCs, 1/11 (9.1%) FCs, 1/4 (25%) of ACs while all MCs and the PD were positive. The benign group comprised nodular hyperplasias (29/54), lymphocytic thyroiditis (10/54), follicular adenomas (FA) (14/54) and one hyalinising trabecular tumour. CD56 was expressed in all the benign cases except one FA and one nodular hyperplasia. Thirteen of the 14 FAs were CD56 positive. The difference in expression between benign and malignant tumours was statistically significant as the p value was <0.01.

CONCLUSION

CD56 is a potentially good immunohistochemical marker for differentiating papillary thyroid carcinoma from other benign follicular lesions of the thyroid especially in differentiating follicular variant PTC from FA in equivocal cases.

AB0458 SURVIVAL OF SCLERODERMA PATIENTS WITH INTERSTITIAL LUNG DISEASE: OBSERVATION DATA FROM A MALAYSIAN TERTIARY CENTRE

Background:

Interstitial lung disease (ILD) is the leading cause of death in scleroderma (SSc) with decline in FVC as a predictor of mortality in patients with SSc-ILD, especially in the early course of the disease.

Objectives:

The aim of this study is to determine the survival rate of SSc-ILD in a Malaysian cohort of patients from University Malaya Medical Centre (UMMC).

Methods:

61 patients clinically diagnosed with SSc-ILD were identified and prospectively recruited. Baseline demographic data were collected. Kaplan-Meier analysis was used to estimate the survival.

Results:

Females were predominant (56, 91.8%). 39 (64%) had limited cutaneous SSc. Majority were ethnicity Chinese 30 (49.2%), followed by Malays 20 (32.8%), Indians 7 (11.4%) and others 4 (6.6%). Mean age was 56.25 (SD ± 12.5) years while mean duration of disease (non-Raynaud’s disease onset) was 10.5 years (SD ± 9.2) (range of 1 year to 44 years) years. 29 (47.5%) patients were positive for anti-ScL-70, whereas 6 (9.8%) patients were anti-centromere positive. There were 16 (26.2%) deaths. Median survival was 24 years. Patients had a sharper drop in survival probability for the first 10 years compared to the next 20 years (Figure 1). Median survival in limited subset was 24 years whereas in diffuse subset was 11 years. Patients from the limited subset appeared to have higher chance of surviving for 10 years and above, compared to those in the diffuse subset (Figure 2).

Conclusion:

The results demonstrate the poor survival in SSc-ILD patients. The survival rate tends to be worse in the first 10 years of SSc disease duration. Survival rate was poorer in patients with diffuse cutaneous subset.

References:

[1]Parelas A et al. Lancet Resp Med 2020

[2]Goh NS et al. Am J Respir Crit Care Med 2008

Disclosure of Interests:

JASMIN RAJA Speakers bureau: For Boehringer Ingelheim for topic on Scleroderma-ILD, Grant/research support from: From Boehringer Ingelheim for scleroderma research, Shantini Muthusamy: None declared., CHOUNG MIN NG: None declared.