Exploring the impact of polyphenolic compounds on the chromatic characteristics in flowers of Rhododendron arboreum Sm. collected from different altitudinal locations.

INTRODUCTION: Rhododendron arboreum Sm. flowers grow in the Himalayan region and have traditionally been used in beverages and food. These wild edible Himalayan flowers are known for their sweet-sour flavor and beautiful scarlet red color. The primary pigments responsible for the scarlet red color of these flowers are anthocyanins. OBJECTIVE: In the present study, we conducted chemo-profiling and elucidated the chromatic characteristics of R. arboreum flower petals growing in the wild in different altitudinal areas. METHODOLOGY: The content of anthocyanins, phenolics, and other flavonoids was determined in R. arboreum flower petals collected from 38 different locations in two provinces in India (Himachal Pradesh and Uttarakhand) to obtain a distinguishable chemical index. A UHPLC method has also been developed and validated for the quantitative analysis. Besides, the color characteristics of each collected floral sample were also analyzed. RESULTS: Chemometric analysis (principal component analysis [PCA] and heatmap analysis) revealed that floral samples collected from different altitudes exhibited similar chemical diversity, whereas statistical analysis (bivariate linear correlation) revealed a positive correlation between the color parameter a*/b* and cyanidin glycosides. Besides, non-targeted metabolomics analysis was carried out, which resulted in the tentative identification of 150 metabolites. CONCLUSION: The results revealed that there is a direct influence of accumulated anthocyanins to color parameter a*/b* values in the floral samples irrespective of altitude.

Identification of G4 motifs of various stem cell markers and their biophysical and biochemical characterization.

Regulatory regions in the human genome, enriched in guanine-rich DNA sequences have a remarkable enrichment of G-rich sequences having a tendency to fold into G-quadruplex structures. To identify the G-quadruplex forming motifs in regulatory regions of stem cell markers, gene sequences of various stem cell markers were downloaded and analyzed to see the abundance of G-rich sequences. We observed the enrichment of G-rich sequences in stem cell markers (CD13, CD19, CD24 and CD38) which could possibly play a critical role in its regulation. We used Circular Dichroism (CD), UV-Thermal denaturation (UV-Tm) and polyacrylamide gel electrophoresis (PAGE) to demonstrate the formation of a G-quadruplex by G-rich sequences present in these stem cell markers. We observed that these G-rich sequences containing minimum consecutive G3 stretch separated by loop length ranging from one to three bases long adopt G-quadruplexes with different molecularity involving two-strands, three-strand and four-strand with parallel and antiparallel conformation. Interestingly, we proposed the formation of three-stranded G-quadruplex by CD13 in 100 mM Na+, CD19 in 100 mM K+, 100 mM K+ with 40 wt% PEG 200, and CD38 in 100 mM K+ + 40 wt% PEG 200. The formation of such diverse G-quadruplex structures in the regulatory regions leaves the fair possibility of recognition by regulatory factors to modulate the gene expression. First time, this study may give insight into the structural polymorphism of G4 forming motifs in different stem cell markers to design the best suitable ligand and to target them for therapeutic development.Communicated by Ramaswamy H. Sarma.

Multiple Electrolytes Solution Versus Saline as Bolus Fluid for Resuscitation in Pediatric Septic Shock: A Multicenter Randomized Clinical Trial.

OBJECTIVE: To determine if initial fluid resuscitation with balanced crystalloid (e.g., multiple electrolytes solution [MES]) or 0.9% saline adversely affects kidney function in children with septic shock. DESIGN: Parallel-group, blinded multicenter trial. SETTING: PICUs of four tertiary care centers in India from 2017 to 2020. PATIENTS: Children up to 15 years of age with septic shock. METHODS: Children were randomized to receive fluid boluses of either MES (PlasmaLyte A) or 0.9% saline at the time of identification of shock. All children were managed as per standard protocols and monitored until discharge/death. The primary outcome was new and/or progressive acute kidney injury (AKI), at any time within the first 7 days of fluid resuscitation. Key secondary outcomes included hyperchloremia, any adverse event (AE), at 24, 48, and 72 hours, and all-cause ICU mortality. INTERVENTIONS: MES solution ( n = 351) versus 0.9% saline ( n = 357) for bolus fluid resuscitation during the first 7 days. MEASUREMENTS AND MAIN RESULTS: The median age was 5 years (interquartile range, 1.3-9); 302 (43%) were girls. The relative risk (RR) for meeting the criteria for new and/or progressive AKI was 0.62 (95% CI, 0.49-0.80; p < 0.001), favoring the MES (21%) versus the saline (33%) group. The proportions of children with hyperchloremia were lower in the MES versus the saline group at 24, 48, and 72 hours. There was no difference in the ICU mortality (33% in the MES vs 34% in the saline group). There was no difference with regard to infusion-related AEs such as fever, thrombophlebitis, or fluid overload between the groups. CONCLUSIONS: Among children presenting with septic shock, fluid resuscitation with MES (balanced crystalloid) as compared with 0.9% saline resulted in a significantly lower incidence of new and/or progressive AKI during the first 7 days of hospitalization.

Why to target G-quadruplexes using peptides: Next-generation G4-interacting ligands.

Guanine-rich oligonucleotides existing in both DNA and RNA are able to fold into four-stranded DNA secondary structures via Hoogsteen type hydrogen-bonding, where four guanines self-assemble into a square planar arrangement, which, when stacked upon each other, results in the formation of higher-order structures called G-quadruplexes. Their distribution is not random; they are more frequently present at telomeres, proto-oncogenic promoters, introns, 5'- and 3'-untranslated regions, stem cell markers, ribosome binding sites and so forth and are associated with various biological functions, all of which play a pivotal role in various incurable diseases like cancer and cellular ageing. Several studies have suggested that G-quadruplexes could not regulate biological processes by themselves; instead, various proteins take part in this regulation and can be important therapeutic targets. There are certain limitations in using whole G4-protein for therapeutics purpose because of its high manufacturing cost, laborious structure prediction, dynamic nature, unavailability for oral administration due to its degradation in the gut and inefficient penetration to reach the target site because of the large size. Hence, biologically active peptides can be the potential candidates for therapeutic intervention instead of the whole G4-protein complex. In this review, we aimed to clarify the biological roles of G4s, how we can identify them throughout the genome via bioinformatics, the proteins interacting with G4s and how G4-interacting peptide molecules may be the potential next-generation ligands for targeting the G4 motifs located in biologically important regions.

Ionic liquid treated leaves of Juglans regia as an adsorbent for the removal of methyl orange dye: experimental, computational, and statistical approach.

The novel biosorbents prepared by surface modification from leaves of Juglans regia plant were exploited for removal of methyl orange dye from aqueous solution. The leaves in the form of dust and charcoal were separately impregnated with 1-butyl-3-methyl imidazolium bromide (I) to obtain adsorbents namely J. regia dust/charcoal impregnated with I (JRDI/JRCI) which were characterized using advanced analytical approaches. The impregnation of ionic liquid was confirmed by the appearance of new bands. Langmuir isotherm fitted well; the calculated adsorption capacity being 59.37 (JRDI) and 102.72 mg g-1 (JRCI). The kinetic study revealed that sorption obeyed the pseudo-first order model; the experimental adsorption capacity being 53.53 (JRDI) and 86.82 mg g-1 (JRCI) at selected conditions of pH 3, initial dye concentration 100 ppm, dosage of adsorbent 0.3 g and contact time 70 min. The mathematical models which predicted adsorption capacity as 51.5 (JRDI) and 82.1 mg g-1 (JRCI) were found at par with experimental values. Fukui condensed functions revealed that adsorbents had electron deficient electrophilic reaction sites while dye had electron-rich nucleophilic reaction sites. The structural properties and good adsorption capability of adsorbents indicate that they could be used as potential, eco-friendly adsorbents for the treatment of negatively charged dye pollutants.

The research work is the first study on the sorption of methyl orange dye from an aqueous solution using ionic liquid impregnated leaves of J. regia plant in powder and biochar form. Juglans regia leaves are eco-friendly and cheap precursors for selected adsorbents. Impregnation of ionic liquid which makes the adsorbent surface positively charged is responsible for enhancing the adsorption capacity for negatively charged methyl orange dye. To the best of our knowledge, the use of impregnated ionic liquid in the leaves of plants as an adsorbent for the efficient removal of dye is very sparse. This motivated us to fill the gap by choosing ionic liquid and demonstrating the enhanced adsorption capacity of dye.

Significant destabilization of human telomeric G-quadruplex upon peptide binding: dramatic effect of flanking bases.

Human telomere is composed of highly repeated hexanucleotide sequence TTAGGG and a 3' single-stranded DNA tail. Many telomere G4 topologies characterized at atomic level by X-ray crystallography and NMR studies. Until now, various small ligands developed to interact with G-quadruplex mainly to stabilize the structure and least is known for its destabilization. In this study, we provide the first evidence of human telomeric G4 destabilization upon peptide binding in dilute and cell-mimicking molecular crowing conditions due to the changes in flanking bases of human telomeric sequences. Hence, our findings will open the new ways to target diseases related with increasing the efficiency of DNA replication, transcription or duplex reannealing.Communicated by Ramaswamy H. Sarma.

Short designed peptide unfolding human telomeric G-quadruplex: mimicking the helicase function.

Human telomeric DNA can fold into G-quadruplex structures involving the interaction of four guanine bases in a square planar arrangement. The highly distinctive nature of quadruplex topologies suggests that they can act as novel therapeutic targets. In this study, we provide the evidence of human telomeric G4 destabilization in dilute and cell-mimicking molecular crowing conditions upon peptide binding. We have used three human telomeric sequences of different lengths. CD data showed that these sequences folded into anti-parallel G-quadruplex and CD intensity decreased significantly on increasing the peptide concentration. UV-thermal melting results showed significant decrease in hypochromicity due to formation of G4-peptide complex at 295 nm. Fluorescence data showed the quenching on titrating the peptide with human telomere G4. Electrophoretic mobility shift assay confirmed the unfolding of G4 structure. Cell viability was significantly reduced in the presence of QW5 peptide with IC50 values as 8.78 µM and 7.72 µM after 72 and 96 hours of incubation respectively. These results confirmed that QW5 peptide has an ability to bind and unfold to human telomeric G-quadruplex and hence might be the key modulator for targeting diseases having over-representation of G4 motifs and their destabilization will be helpful in increasing the efficiency of DNA replication, transcription or duplex reannealing.Communicated by Ramaswamy H. Sarma.

Recognition and unfolding of human telomeric G-quadruplex by short peptide binding identified from the HRDC domain of BLM helicase.

Research in recent decades has revealed that the guanine (G)-quadruplex secondary structure in DNA modulates a variety of cellular events that are mostly related to serious diseases. Systems capable of regulating DNA G-quadruplex structures would therefore be useful for the modulation of various cellular events to produce biological effects. A high specificity for recognition of telomeric G-quadruplex has been observed for BLM helicase. We identified peptides from the HRDC domain of BLM using a molecular docking approach with various available solutions and crystal structures of human telomeres and recently created a peptide library. Herein, we tested one peptide (BLM HRDC peptide) from the library and examined its interaction with human telomeric variant-1 (HTPu-var-1) to understand the basis of G4-protein interactions. Our circular dichroism (CD) data showed that HTPu-var-1 folded into an anti-parallel G-quadruplex, and the CD intensity significantly decreased upon increasing the peptide concentration. There was a significant decrease in hypochromicity due to the formation of G-quadruplex-peptide complex at 295 nm, which indicated the unfolding of structure due to the decrease in stacking interactions. The fluorescence data showed quenching upon titrating the peptide with HTPu-var-1-G4. Electrophoretic mobility shift assay confirmed the unfolding of the G4 structure. Cell viability was significantly reduced in the presence of the BLM peptide, with IC50 values of 10.71 µM and 11.83 µM after 72 and 96 hours, respectively. These results confirmed that the selected peptide has the ability to bind to human telomeric G-quadruplex and unfold it. This is the first report in which a peptide was identified from the HRDC domain of the BLM G4-binding protein for the exploration of the G4-binding motif, which suggests a novel strategy to target G4 using natural key peptide segments.

Significant structural change in human c-Myc promoter G-quadruplex upon peptide binding in potassium.

We selected the G-quadruplex motif located in the nuclease-hypersensitive elements (NHE) III1 region of the c-Myc promoter and for the first time performed its interaction studies with a designed peptide (QW10). Our CD results showed that the peptide bound to the c-Myc G-quadruplex and induced a significant blue shift in the positive peak of 20 nm in KCl alone or with 40wt% PEG200 or 20wt% PEG8000 in comparison to NaCl. Our Native Gel results confirmed that peptide binding destabilized the duplex and stabilized the unimolecular G-quadruplex and not binding to i-motif. UV thermal results confirmed destabilization of bimolecular structure and stabilization of unimolecular G-quadruplex. QW10 showed preferential binding towards c-MYC promoter G4 with binding constant (K b) values of the order of 0.05 ± 0.2 µM, 0.12 ± 0.1 µM and 0.05 ± 0.3 µM for complexes in K+ alone or 40wt% PEG 200 or 20wt% PEG 8000 respectively. QW10 showed preferential cytotoxicity with IC50 values of 11.10 µM and 6.44 µM after 72 and 96 hours' incubation on Human Breast Carcinoma MDA-MB 231 cells and was found to be non-toxic with Human Embryonic Kidney (HEK-1) cells. Interestingly, we observed reduction of c-Myc gene expression by 2.5 fold due to QW10 binding and stabilizing c-MYC G4. Our study for the first time provides an expanded overview of significant structural change in human c-Myc promoter G-quadruplex upon peptide binding in potassium.

Selective recognition of human telomeric G-quadruplex with designed peptide via hydrogen bonding followed by base stacking interactions.

We described a novel synthetic peptide in which a glutamine residue binds through hydrogen bonding to a guanine-base and a trytophan residue intercalates with K+ resulting in stabilization of a human telomeric G-quadruplex with high selectivity over its complementary c-rich strand and a double-stranded DNA and its complementary C-rich strand. This peptide offers great potential for cancer treatment by inhibiting the telomere extension by telomerase.

Type 2 lepra reaction in an immunocompromised patient precipitated by filariasis.

Though patients affected with both acquired immuno deficiency syndrome (AIDS) and leprosy commonly present with type 1 lepra reaction, there are few isolated reports of type 2 lepra reaction in retropositive patients affected with leprosy. We are presenting a case report of 35-year-old male affected with AIDS, tubercular lymphadenitis, and lepromatous leprosy with recurrent episodes of type 2 lepra reaction manifesting as erythema nodosum leprosum (ENL). Dipstick enzyme-linked immunosorbent assay (ELISA) for filarial antigen was also positive. The patient was treated with 100 mg thalidomide daily, 300 mg diethylcarbamazine, and modified multidrug therapy (MDT) for leprosy. He responded well and has not had any further reaction in the last 6 months.

A rare case of keloidal granuloma faciale with extra-facial lesions.

Granuloma faciale (GF) is an uncommon, cutaneous disorder characterized by one to several soft, erythematous to livid papules, plaques, or nodules, usually occurring on the face. Extra-facial lesions occur rarely. We present a case report of 33-year-old male who presented with keloidal lesions on face and left shoulder. The patient didn't respond with intralesional triamcinolone and showed poor response with the addition of topical tacrolimus. Surgical excision in consultation with plastic surgeons is planned.

Lymphocutaneous sporotrichosis in an adolescent girl presenting as mycetoma.

A 13-year-old girl presented with multiple painless purulent ulcers with raised borders on the medial aspect of the sole of her right foot associated with inguinal lymphadenopathy for the past 4 years. There was history of local trauma at the site prior to the formation of ulcers. There were no other significant associated signs or symptoms. The patient was initially treated with multiple antibiotics with minimal improvement. Fungal cultures of biopsy specimens demonstrated the presence of colonies of Sporothrix schenckii thus confirming the diagnosis of sporotrichosis. Oral itraconazole at the dose of 100 mg twice daily was initiated with marked response at 4 weeks. This case demonstrated a rare morphological presentation of the lymphocutaneous sporotrichosis as mycetoma. The possible diagnosis of sporotrichosis should be kept in mind in such a clinical presentation not responding to antibiotics. Cutaneous sporotrichosis should be diagnosed and treated as early as possible because untreated cases may disseminate to cause visceral involvement with fatal outcome in immunocompromised patients.