Angiogenesis Inhibitor Drug-induced Benign Migratory Glossitis in a Patient of Juvenile-onset Recurrent Respiratory Papillomatosis under Maintenance Therapy.

Background: Benign migratory glossitis or geographic tongue is a chronic recurring inflammatory condition of the oral cavity. With its ephemeral characteristics, there has been reported literature showing its association with the administration of certain drugs including angiogenesis inhibitors. The antiangiogenic drugs act by selectively inhibiting the vascular endothelial growth factor (VEGF) signaling. It has been widely used as an adjunct and a maintenance agent for the treatment of various cancers. Aims: This study aims to report probable characteristic oral mucosal changes in a patient with juvenile-onset recurrent respiratory papillomatosis (JORRP) under maintenance therapy with an antiangiogenesis drug. Case description: The patient was presented with a burning sensation on having spicy food. This occurred after the completion of three cycles of bevacizumab infusion. It was associated with the appearance of migratory lesions over the tongue and evolved periods of remission and exacerbation. Clinical examination revealed lesions characteristic of the geographic tongue on the anterior two-thirds of the dorsal surface as well as the lateral surface of the tongue classified as type 2, according to Hume criteria. Oral examination revealed dental caries in relation to 52, 54, 62, 63, 74, and 85 teeth and grossly decayed 64. Topical lignocaine gel was instituted for symptomatic relief of the lesion. Full mouth rehabilitation with preventive and restorative therapeutic interventions was carried out. Clinical significance and conclusion: The documented literature along with this report put forth a probable association of geographic tongue with the use of bevacizumab drugs which requires further detailed studies. These lesions generally require symptomatic treatment with assurance only. The etiology is poorly understood. How to cite this article: Kalra N, Tyagi R, Khatri A, et al. Angiogenesis Inhibitor Drug-induced Benign Migratory Glossitis in a Patient of Juvenile-onset Recurrent Respiratory Papillomatosis under Maintenance Therapy. Int J Clin Pediatr Dent 2024;17(1):92-96.

Mitochondrial Ca2+ overload due to altered proteostasis amplifies apoptosis in C2C12 myoblasts under hypoxia: Protective role of nanocurcumin formulation.

Severe hypoxia triggers apoptosis leads to myofibers loss and is attributable to impaired intracellular calcium (iCa2+ ) homeostasis, resulting in reduced muscle activity. Hypoxia increases intracellular Ca2+ by activating the release of Ca2+ from iCa2+ stores, however, the effect of increased [iCa2+ ] on the mitochondria of muscle cells at high-altitude hypoxia is largely unexplored. This study examined mitochondrial Ca2+ overload due to altered expression of mitochondrial calcium uptake 1 (MICU1), that is, a gatekeeper of the mitochondrial Ca2+ uniporter, impaired mitochondrial membrane potential (ΔΨm). p53 stabilization and its translocation to the mitochondria were observed following disrupted mitochondrial membrane integrity in myoblasts under hypoxia. Furthermore, the downstream effects of p53 led to the upregulation of proapoptotic proteins (Bax, Caspase-3, and cytochrome C) in myoblasts under hypoxia. Nanocurcumin-pyrroloquinoline quinone formulation (NCF; Indian patent no. 302877), developed to address hypoxia-induced consequences, was found to be beneficial in maintaining mitochondrial Ca2+ homeostasis and limiting p53 translocation into mitochondria under hypoxia in muscle myoblasts. NCF treatment also modulates heat shock proteins and apoptosis-regulating protein expression in myoblasts. Conclusively, we proposed that mitochondrial Ca2+ overload due to altered MICU1 expression intensifies apoptosis and mitochondrial dysfunctionality. The study also reported that NCF could improve mitochondrial [Ca2+ ] homeostasis and antiapoptotic ability in C2C12 myoblasts under hypoxia.

Mitigation of radiation injury to reproductive system of male mice by Trichostatin A.

Trichostatin A (TSA), derived from the bacteria Streptomyces hygroscopicus, is a hydroxamic acid having various biological properties such as histone deacetylase inhibition, anticancer and radiomitigative action. However the mitigative activity of TSA against radiation-induced damages in the mouse reproductive system has not yet been elucidated. The present study unraveled the effects of 2 Gy whole body irradiation (60Co γ- radiation) on C57BL/6 mice male reproductive system including structural damages to testes, increase in apoptosis and reduction in germ cell viability, reduced fertility as well as increased genomic instability in the next generation. Moreover, hematological study and micronuclei assay were used to record chances of radiation-induced hematologic cancer and disruption of genomic integrity in F1 generation. Interestingly, TSA administration 1 and 24 h post-irradiation attenuated radiation-induced morphological damage and cellular apoptosis in testes. In male mice, TSA restored hematological parameters and micronuclei frequency to normal levels, restored sperm viability, and helped them overcome radiation-induced temporary sterility 5 weeks after the irradiation. Thus our results showed that TSA reduced the probability of radiation-induced hematologic cancers as well as genotoxicity and restored genomic integrity in the progenies of paternally exposed mice by reducing radiation-induced apoptosis in spermatogenic cells and restoring cell proliferation. This study suggested that TSA could be used as potential radiomitigator for male reproductive system.

Quercetin-3-Rutinoside alleviates radiation-induced lung inflammation and fibrosis via regulation of NF-κB/TGF-ß1 signaling.

BACKGROUND: Radiation exposure to lungs during nuclear catastrophes or radiotherapy poses long-term side effects and can induce pulmonary injury sufficient for causing death. The strategies for preventing or reversing radiation-induced lung injuries have not been yet developed. Quercetin-3-Rutinoside (Q-3-R), a polyphenolic bioflavonoid, has shown multifaceted pharmacological applications due to its high antioxidant and anti-inflammatory properties. PURPOSE: In the current study, the potential of Q-3-R against radiation-induced lung pneumonitis/fibrosis and the possible underlying mechanism was investigated. STUDY DESIGN: To evaluate the effect of Q-3-R against lung damage, C57Bl/6 mice were administered with Q-3-R (10 mg/kg b.wt.) and irradiated with a single dose of gamma radiation (12 Gy) at thoracic region. METHODS: 16 weeks after irradiation lung damage was seen by histopathological studies and staining for collagen deposition. Expression of Nuclear factor kappa-B (NF-κB), transforming growth factor-ß1 (TGF-ß1), Smad3, intercellular adhesion molecule 1 (ICAM-1), α-smooth muscle actin protein (α-SMA), Aquaporin 5 (AQP 5), Interleukins (IL-6, IL-18, IL-1ß), tumor necrosis factor-α (TNF-α) and caspase-3 was evaluated by immunohistochemistry/western blot/Elisa. Reactive oxygen species (ROS)/ Nitric oxide (NO) scavenging potential of Q-3-R and inhibition of cell death in irradiated lungs were also assessed. RESULTS: Mice showed signs of pneumonitis and fibrotic changes in lungs following radiation treatment. A dramatic increase in inflammatory cells and cytokines contributing to lung disease pathogenesis was observed. Furthermore, expression of NF-κB, TGF-ß1, Smad3, ICAM-1, AQP5and α-SMA was found markedly up-regulated. However, pretreatment of Q-3-R significantly attenuated radiation-induced pneumonitis and fibrosis. Histological examination revealed less structural and fibrotic changes with down-regulation of AQP 5, ICAM-1, α-SMA and caspase-3 in Q-3-R pretreated irradiated groups. The formulation significantly relieved lung injury by suppressing inflammatory and pro-fibrotic cytokines such as IL-6, IL-18, IL-1ß, TNF-α and TGF-ß1 via inhibition of NF-κB. Q-3-R also curtailed radiation-induced ROS/NO generation and minimized DNA damage in the irradiated lungs. CONCLUSION: The findings from the current study clearly demonstrate that Q-3-R provides radioprotection to the lungs by regulating NF-κB/TGF-ß1 signaling, scavenging free radicals, preventing perivascular infiltration and prolonged inflammatory cascade which could otherwise lead to chronic radiation fibrosis. Q-3-R can be proved as a potential therapeutic agent for alleviating radiation-induced lung injury in case of planned or unplanned radiation exposure scenario.

Efficacy of Resin Infiltration and Fluoride Casein Phosphopeptide Amorphous Calcium Phosphate Varnish on Non-cavitated Active White Spot Lesions in Children: A Randomized Clinical Trial

Abstract Objective: To compare the efficacy of resin infiltration and fluoride casein phosphopeptide amorphous calcium phosphate varnish on non-cavitated active white spot lesions in 5-8 years old children. Material and Methods: 60 non-cavitated active white spot lesions in 60 patients with ICDAS II score 2 from both genders in the age range of 5 to 8 years were taken. Thirty lesions were treated by resin infiltration (Group 1) and 30 by Fluoride CPP-ACP varnish (Group 2). Resin infiltration was performed on the same day, while Fluoride CPP-ACP varnish was applied once a week for 4 weeks. The follow-up was done at 3, 6 months, and 12 months. Results: At 3, 6, and 12 months change in mean ICDAS II Score in group 1 was 1.5±0.5,1.13±0.73 and 0.9±0.88, respectively, while in group 2, it was observed to be 0.30±0.59, 0.4±0.89 and 0.06±0.82, respectively (p<0.001). Conclusion: Resin infiltration was more successful than Fluoride CCP-ACP varnish in active non-cavitated white spot lesions (AU).

PTEN inhibitor bpV(HOpic) confers protection against ionizing radiation.

Exposure to Ionizing radiation (IR) poses a severe threat to human health. Therefore, there is an urgent need to develop potent and safe radioprotective agents for radio-nuclear emergencies. Phosphatidylinositol-3-kinase (PI3K) mediates its cytoprotective signaling against IR by phosphorylating membrane phospholipids to phosphatidylinositol 3,4,5 triphosphate, PIP3, that serve as a docking site for AKT. Phosphatase and Tensin Homolog on chromosome 10 (PTEN) antagonizes PI3K activity by dephosphorylating PIP3, thus suppressing PI3K/AKT signaling that could prevent IR induced cytotoxicity. The current study was undertaken to investigate the radioprotective potential of PTEN inhibitor (PTENi), bpV(HOpic). The cell cytotoxicity, proliferation index, and clonogenic survival assays were performed for assessing the radioprotective potential of bpV(HOpic). A safe dose of bpV(HOpic) was shown to be radioprotective in three radiosensitive tissue origin cells. Further, bpV(HOpic) significantly reduced the IR-induced apoptosis and associated pro-death signaling. A faster and better DNA repair kinetics was also observed in bpV(HOpic) pretreated cells exposed to IR. Additionally, bpV(HOpic) decreased the IR-induced oxidative stress and significantly enhanced the antioxidant defense mechanism in cells. The radioprotective effect of bpV(HOpic) was found to be AKT dependant and primarily regulated by the enhanced glycolysis and associated signaling. Furthermore, this in-vitro observation was verified in-vivo, where administration of bpV(HOpic) in C57BL/6 mice resulted in AKT activation and conferred survival advantage against IR-induced mortality. These results imply that bpV(HOpic) ameliorates IR-induced oxidative stress and cell death by inducing AKT signaling mediated antioxidant defense system and DNA repair pathways, thus strengthening its potential to be used as a radiation countermeasure.

Mild mitochondrial uncoupling protects from ionizing radiation induced cell death by attenuating oxidative stress and mitochondrial damage.

Ionizing radiation (IR) induced mitochondrial dysfunction is associated with enhanced radiation stimulated metabolic oxidative stress that interacts randomly with intracellular bio-macromolecules causing lethal cellular injury and cell death. Since mild mitochondrial uncoupling emerged as a valuable therapeutic approach by regulating oxidative stress in most prevalent human diseases including ageing, ischemic reperfusion injury, and neurodegeneration with comparable features of IR inflicted mitochondrial damage. Therefore, we explored whether mitochondrial uncoupling could also protect from IR induced cytotoxic insult. Our results showed that DNP, BHT, FCCP, and BAM15 are safe to cells at different concentrations range depending on their respective mitochondrial uncoupling potential. Pre-incubation of murine fibroblast (NIH/3T3) cells with the safe concentration of these uncouplers followed by gamma (γ)-radiation showed significant cell growth recovery, reduced ROS generation, and apoptosis, compared to IR treatment alone. We observed that DNP pre-treatment increased the surviving fraction of IR exposed HEK-293, Raw 264.7 and NIH/3T3 cells. Additionally, DNP pre-treatment followed by IR leads to reduced total and mitochondrial oxidative stress (mos), regulated calcium (Ca2+) homeostasis, and mitochondrial bioenergetics in NIH/3T3 cells. It also significantly reduced macromolecular oxidation, correlated with the regulated ROS generation and antioxidant defence system. Moreover, DNP facilitated DNA repair kinetics evidenced by reducing the number of γ-H2AX foci formation and fragmented nuclei with time. DNP pre-incubation restrained the radiation induced pro-apoptotic factors and inhibits apoptosis. Our findings raise the possibility that mild mitochondrial uncoupling with DNP could be a potential therapeutic approach for radiation induced cytotoxic insult associated with an altered mitochondrial function.

A rare case of Dandy-Walker syndrome in the 12-year-old girl.

Dandy-Walker syndrome (DWS) is a rare congenital cystic malformation of the posterior cranial fossa. Patients show signs and symptoms of complex clinical manifestations, ranging from cranial nerve and cerebellar dysfunctions to extracranial abnormalities, which may pose challenges in dental management. This article represents a rare case of a 12-year-old girl with DWS along with the involvement of the oral cavity.

Hexokinase II inhibition by 3-bromopyruvate sensitizes myeloid leukemic cells K-562 to anti-leukemic drug, daunorubicin.

An increased metabolic flux towards Warburg phenotype promotes survival, proliferation and causes therapeutic resistance, in leukemic cells. Hexokinase-II (HK-II) is expressed predominantly in cancer cells, which promotes Warburg metabolic phenotype and protects the cancer cells from drug-induced apoptosis. The HK-II inhibitor 3- Bromopyruvate (3-BP) dissociates HK-II from mitochondrial complex, which leads to enhanced sensitization of leukemic cells to anti-leukemic drugs. In the present study, we analyzed the Warburg characteristics viz. HK-II expression, glucose uptake, endogenous reactive oxygen species (ROS) level of leukemic cell lines K-562 and THP-1 and then investigated if 3-BP can sensitize the leukemic cells K-562 to anti-leukemic drug Daunorubicin (DNR). We found that both K-562 and THP-1 cells have multi-fold high levels of HK-II, glucose uptake and endogenous ROS with respect to normal PBMCs. The combined treatment (CT) of 3-BP and DNR showed synergistic effect on the growth inhibition (GI) of K-562 and THP-1 cells. This growth inhibitory effect was attributed to 3-BP induced S-phase block and DNR induced G2/M block, resulted in reduced proliferation due to CT. Further, CT resulted in low HK-II level in mitochondrial fraction, high intracellular calcium and elevated apoptosis as compared with individual treatment of DNR and 3-BP. Moreover, CT caused enhanced DNA damage and hyperpolarized mitochondria, leading to cell death. Taken together, these results suggest that 3-BP synergises the anticancer effects of DNR in the chronic myeloid leukemic cell K-562, and may act as an effective adjuvant to anti-leukemic chemotherapy.

Neonatal molar in a child with Langerhan cell histiocytosis.

Teeth which erupt in the 1st month of postnatal life are known as "neonatal tooth." The incidence of these teeth ranges from 1:2000 to 1:3500 live births. Natal teeth are more common in mandibular central incisor region, followed by maxillary incisor region and mandibular canine region. The neonatal or natal teeth in the maxillary molar region are a rare occurrence. This article represents a rare case of the neonatal tooth with Langerhans cell histiocytosis.

Mitochondrial biogenesis and metabolic hyperactivation limits the application of MTT assay in the estimation of radiation induced growth inhibition.

Metabolic viability based high throughput assays like MTT and MTS are widely used in assessing the cell viability. However, alteration in both mitochondrial content and metabolism can influence the metabolic viability of cells and radiation is a potential mitochondrial biogenesis inducer. Therefore, we tested if MTT assay is a true measure of radiation induced cell death in widely used cell lines. Radiation induced cellular growth inhibition was performed by enumerating cell numbers and metabolic viability using MTT assay at 24 and 48 hours (hrs) after exposure. The extent of radiation induced reduction in cell number was found to be larger than the decrease in MTT reduction in all the cell lines tested. We demonstrated that radiation induces PGC-1α and TFAM to stimulate mitochondrial biogenesis leading to increased levels of SDH-A and enhanced metabolic viability. Radiation induced disturbance in calcium (Ca2+) homeostasis also plays a crucial role by making the mitochondria hyperactive. These findings suggest that radiation induces mitochondrial biogenesis and hyperactivation leading to increased metabolic viability and MTT reduction. Therefore, conclusions drawn on radiation induced growth inhibition based on metabolic viability assays are likely to be erroneous as it may not correlate with growth inhibition and/or loss of clonogenic survival.

Mitigation of radiation-induced hematopoietic injury by the polyphenolic acetate 7, 8-diacetoxy-4-methylthiocoumarin in mice.

Protection of the hematopoietic system from radiation damage, and/or mitigation of hematopoietic injury are the two major strategies for developing medical countermeasure agents (MCM) to combat radiation-induced lethality. In the present study, we investigated the potential of 7, 8-diacetoxy-4-methylthiocoumarin (DAMTC) to ameliorate radiation-induced hematopoietic damage and the associated mortality following total body irradiation (TBI) in C57BL/6 mice. Administration of DAMTC 24 hours post TBI alleviated TBI-induced myelo-suppression and pancytopenia, by augmenting lymphocytes and WBCs in the peripheral blood of mice, while bone marrow (BM) cellularity was restored through enhanced proliferation of the stem cells. It stimulated multi-lineage expansion and differentiation of myeloid progenitors in the BM and induced proliferation of splenic progenitors thereby, facilitating hematopoietic re-population. DAMTC reduced the radiation-induced apoptotic and mitotic death in the hematopoietic compartment. Recruitment of pro-inflammatory M1 macrophages in spleen contributed to the immune-protection linked to the mitigation of hematopoietic injury. Recovery of the hematopoietic compartment correlated well with mitigation of mortality at a lethal dose of 9 Gy, leading to 80% animal survival. Present study establishes the potential of DAMTC to mitigate radiation-induced injury to the hematopoietic system by stimulating the re-population of stem cells from multiple lineages.

Mean frequency and relative fluorescence intensity measurement of γ-H2AX foci dose response in PBL exposed to γ-irradiation: An inter- and intra-laboratory comparison and its relevance for radiation triage.

Measurement of γ-H2AX protein changes in the peripheral blood lymphocytes (PBL) of individuals exposed to ionizing radiation is a simple, sensitive, and rapid assay for radiation triage and early marker of dose estimation. The qualitative and quantitative measurements of the protein changes were examined using flow cytometry and microscopy. Whole blood and isolated lymphocytes were exposed in vitro between 0.1 and 5 Gy doses of (60) Co γ-radiation at a dose rate of 1 Gy/min. Radiation induced γ-H2AX foci frequency (n = 3) and relative fluorescence intensity (n = 7) in PBL was measured at 0.5 and 2 hrs postexposure. The observed dose response for γ-H2AX foci frequency at both time points, for whole blood and isolated lymphocytes did not show any significant (P > 0.05) differences. However, when compared with γ-H2AX foci frequency scored manually (microscopy), the semiautomated analysis (captured images) showed a better correlation (r(2) = 0.918) than that obtained with automated (Metafer) scoring (r(2) = 0.690). It is noteworthy to mention that, the γ-H2AX foci frequency quantified using microscopy showed a dose dependent increase up to 2 Gy and the relative fluorescence intensity (RFI) measured with flow cytometry revealed an increase up to 5 Gy in the PBL exposed in vitro. Moreover, a better correlation was observed between the γ-H2AX foci frequency obtained by manual scoring and RFI (r(2) = 0.910). Kinetic studies showed that the γ-H2AX foci remain more or less unchanged up to 4 hrs and reduces gradually over 48 hrs of postexposure at 37°C. Further, inter and intra-laboratory comparisons showed consistency in the scoring of γ-H2AX foci frequency by manual and semiautomated scoring. The overall results suggest that measurement of γ-H2AX (microscopy and flow cytometry) should be employed within 4 to 6 hrs for a reliable dosimetry either by sharing the work load between the laboratories or investing more manpower; however, triage can be possible even up to 48 hrs of postirradiation.

Chronic Dietary Administration of the Glycolytic Inhibitor 2-Deoxy-D-Glucose (2-DG) Inhibits the Growth of Implanted Ehrlich's Ascites Tumor in Mice.

BACKGROUND: Dietary energy restriction (DER) has been well established as a potent anticancer strategy. Non-adoption of restricted diet for an extended period has limited its practical implementation in humans with a compelling need to develop agents that mimic effects similar to DER, without reduction in actual dietary intake. Glycolytic inhibitor, 2-deoxy-D-glucose (2-DG), has recently been shown to possess potential as an energy restriction mimetic agent (ERMA). In the present study we evaluated the effect of dietary 2-DG administration on a mouse tumor model, with a focus on several potential mechanisms that may account for the inhibition of tumorigenesis. METHODOLOGY/PRINCIPAL FINDINGS: Swiss albino strain 'A' mice were administered with 0.2% and 0.4% w/v 2-DG in drinking water for 3 months prior to tumor implantation (Ehrlich's ascites carcinoma; EAC) and continued till the termination of the study with no adverse effects on general physiology and animal growth. Dietary 2-DG significantly reduced the tumor incidence, delayed the onset, and compromised the tumor growth along with enhanced survival. We observed reduced blood glucose and serum insulin levels along with decreased proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine positive (BrdU+) tumor cells in 2-DG fed mice. Also, reduced levels of certain key players of metabolic pathways such as phosphatidylinositol 3-kinase (PI3K), phosphorylated-Akt and hypoxia inducible factor-1 alpha (HIF-1α) were also noted in tumors of 2-DG fed mice. Further, decrease in CD4+/CD8+ ratio and T-regulatory cells observed in 2-DG fed mice suggested enhanced antitumor immunity and T cell effector function. CONCLUSION/SIGNIFICANCE: These results strongly suggest that dietary 2-DG administration in mice, at doses easily achievable in humans, suitably modulates several pleotrophic factors mimicking DER and inhibits tumorigenesis, emphasizing the use of ERMAs as a promising cancer preventive strategy.

Transient elevation of glycolysis confers radio-resistance by facilitating DNA repair in cells.

BACKGROUND: Cancer cells exhibit increased glycolysis for ATP production (the Warburg effect) and macromolecular biosynthesis; it is also linked with therapeutic resistance that is generally associated with compromised respiratory metabolism. Molecular mechanisms underlying radio-resistance linked to elevated glycolysis remain incompletely understood. METHODS: We stimulated glycolysis using mitochondrial respiratory modifiers (MRMs viz. di-nitro phenol, DNP; Photosan-3, PS3; Methylene blue, MB) in established human cell lines (HEK293, BMG-1 and OCT-1). Glucose utilization and lactate production, levels of glucose transporters and glycolytic enzymes were investigated as indices of glycolysis. Clonogenic survival, DNA repair and cytogenetic damage were studied as parameters of radiation response. RESULTS: MRMs induced the glycolysis by enhancing the levels of two important regulators of glucose metabolism GLUT-1 and HK-II and resulted in 2 fold increase in glucose consumption and lactate production. This increase in glycolysis resulted in resistance against radiation-induced cell death (clonogenic survival) in different cell lines at an absorbed dose of 5 Gy. Inhibition of glucose uptake and glycolysis (using fasentin, 2-deoxy-D-glucose and 3-bromopyruvate) in DNP treated cells failed to increase the clonogenic survival of irradiated cells, suggesting that radio-resistance linked to inhibition of mitochondrial respiration is glycolysis dependent. Elevated glycolysis also facilitated rejoining of radiation-induced DNA strand breaks by activating both non-homologous end joining (NHEJ) and homologous recombination (HR) pathways of DNA double strand break repair leading to a reduction in radiation-induced cytogenetic damage (micronuclei formation) in these cells. CONCLUSIONS: These findings suggest that enhanced glycolysis generally observed in cancer cells may be responsible for the radio-resistance, partly by enhancing the repair of DNA damage.

Nanocurcumin protects cardiomyoblasts H9c2 from hypoxia-induced hypertrophy and apoptosis by improving oxidative balance.

Hypoxia-induced cardiomyocyte hypertrophy is evident; however, the distinct molecular mechanism underlying the oxidative stress-mediated damages to cardiomyocytes remains unknown. Curcumin (diferuloylmethane) is known for anti-hypertrophic effects, but low bioavailability makes it unsuitable to exploit its pharmacological properties. We assessed the efficacy of nanotized curcumin, i.e. nanocurcumin, in ameliorating hypoxia-induced hypertrophy and apoptosis in H9c2 cardiomyoblasts and compared it to curcumin. H9c2 cardiomyoblasts were challenged with 0.5 % oxygen, for 24 h to assess hypoxia-induced oxidative damage, hypertrophy and consequent apoptosis. The molecular mechanism underlying the protective efficacy of nanocurcumin was evaluated in regulating Raf-1/Erk-1/2 apoptosis by caspase-3/-7 pathway and oxidative stress. Nanocurcumin ameliorated hypoxia-induced hypertrophy and apoptosis in H9c2 cells significantly (p ≤ 0.01), by downregulating atrial natriuretic factor expression, caspase-3/-7 activation, oxidative stress and stabilizing hypoxia-inducible factor-1α (HIF-1α) better than curcumin. Nanocurcumin provides insight into its use as a potential candidate in curing hypoxia-induced cardiac pathologies by restoring oxidative balance.

Cytotoxic and radio-sensitizing effects of polyphenolic acetates in a human glioma cell line (BMG-1).

BACKGROUND AND AIMS: Polyphenolic acetates (PAs) have antioxidant/ pro-oxidant properties and can also acetylate proteins (enzymes) by a novel acetoxy drug: calreticulin transacetylase acetylation system. While PAs have been investigated as pharmacological agents for the treatment of various diseases, their potential as anti-cancer agents or their efficacy as an adjuvant in anti-cancer therapeutics remains to be explored. In the present study we investigated the cytotoxic and radio-sensitizing effects of 7, 8- diacetoxy-4-methyl coumarin (DAMC) and 7- acetoxy-4-methyl coumarin (7-AMC) in a human glioma cell line (BMG-1). METHODS: Cytotoxic and radio-sensitizing effects were investigated by studying reactive oxygen species (ROS) levels, metabolic viability, clonogenic survival, growth inhibition, cell cycle perturbation, DNA repair and cytogenetic damage, besides analyzing the histone (H3) acetylation. RESULTS: Exposure of cells to DAMC and 7-AMC for 24 h showed a dose dependent increase in toxicity as indicated by reduced metabolic viability, clonogenic survival and cell proliferation, with DAMC being more toxic than 7-AMC. The degree of radiosensitization by DAMC was also higher as compared to 7-AMC as reflected by a decrease in the clonogenicity, enhanced radiation-induced cell cycle perturbation and apoptosis. DAMC impaired the removal of radiation-induced DNA double stranded breaks (measured by γH2AX immuno- fluorescence) and enhanced the cytogenetic damage (micronuclei formation), leading to an increase in mitotic death. While DAMC alone induced pan nuclear γH2AX fluorescence, both pan nuclear and spatially restricted foci was observed with the combined treatment (DAMC + Radiation) suggesting a complex nature of DNA damage and repair. DAMC- induced cytotoxic and radio-sensitizing effects were independent of its pro-oxidant activity, whereas histone H3 lysine (9/14) hyperacetylation appeared to be a potential target, regulating cellular responses to ionizing radiation (IR). CONCLUSIONS: The polyphenolic acetate 7, 8- diacetoxy-4-methyl coumarin (DAMC) demonstrates both anticancer effects and radiosensitizing potential under in vitro conditions.

Calreticulin transacetylase mediated upregulation of thioredoxin by 7,8-diacetoxy-4-methylcoumarin enhances the antioxidant potential and the expression of vascular endothelial growth factor in peripheral blood mononuclear cells.

Extensive research carried out in our group on polyphenolic acetates (PAs) substantiated the potential role of PAs in causing diverse biological and pharmacological actions. Our earlier investigations firmly established the calreticulin transacetylase (CRTAase) catalyzed activation of nitric oxide synthase (NOS) by PAs. In this report, we have studied the effect of 7,8-diacetoxy-4-methylcoumarin (DAMC, a model PA) and other acetoxy coumarins on the thioredoxin and VEGF expression in human peripheral blood mononuclear cells (PBMCs), with a view to substantiate our earlier observation that DAMC was a superb inducer of angiogenesis. Real time RT-PCR analysis revealed the enhanced expression of thioredoxin reductase (TRXR) and diminished expression of thioredoxin interacting protein (TRXIP) leading to the increased expression and activity of thioredoxin (TRX) in PBMCs due to the the action of DAMC. The fact that TRX activity of PBMCs was enhanced by various acetoxy coumarins in tune with their affinity to CRTAase as substrate, suggested the possible activation of TRX due to acetylation. The overexpression of thioredoxin was found to correlate with that of VEGF as proved by real time RT-PCR and VEGF -ELISA results, apart from the DAMC-caused enhanced production of NO acting as an inducer of VEGF. Moreover, the intracellular ROS levels were also found to be reduced drastically, by DAMC thus reducing the oxidative stress in cells. These observations strongly evidenced the crucial role of TRX in DAMC-induced tissue angiogenesis with the involvement of VEGF.

Differences in DNA condensation and release by lysine and arginine homopeptides govern their DNA delivery efficiencies.

Designing of nanocarriers that can efficiently deliver therapeutic DNA payload and allow its smooth intracellular release for transgene expression is still a major constraint. The optimization of DNA nanocarriers requires thorough understanding of the chemical and structural characteristics of the vector-nucleic acid complexes and its correlation with the cellular entry, intracellular state and transfection efficiency. L-lysine and L-arginine based cationic peptides alone or in conjugation with other vectors are known to be putative DNA delivery agents. Here we have used L-lysine and L-arginine homopeptides of three different lengths and probed their DNA condensation and release properties by using a multitude of biophysical techniques including fluorescence spectroscopy, gel electrophoresis and atomic force microscopy. Our results clearly showed that although both lysine and arginine based homopeptides condense DNA via electrostatic interactions, they follow different pattern of DNA condensation and release in vitro. While lysine homopeptides condense DNA to form both monomolecular and multimolecular complexes and show differential release of DNA in vitro depending on the peptide length, arginine homopeptides predominantly form multimolecular complexes and show complete DNA release for all peptide lengths. The cellular uptake of the complexes and their intracellular state (as observed through flow cytometry and fluorescence microscopy) seem to be controlled by the peptide chemistry. The difference in the transfection efficiency of lysine and arginine homopeptides has been rationalized in light of these observations.