In-silico Studies and Wet-Lab Validation of Camptothecin Derivatives for Anti-Cancer Activity Against Liver (HepG2) and Lung (A549) Cancer Cell Lines.

BACKGROUND: In the present study, we have explored the utility of QSAR modelling, in silico ADMET, docking, chemical semi-synthesis, and in vitro evaluation studies for the identification of active camptothecin (CPT) derivatives against cancer-targeting human liver (HepG2) and lung (A549) cancer cell lines. METHODS: Two QSAR models were developed as screenings tools using the multiple linear regression (MLR) method followed by ADMET and docking studies. The regression coefficient (r2) and cross-validation regression coefficients (rCV2T) of the QSAR model for the HepG2 cell line was 0.95 and 0.90, respectively, and for the A549 cell line, it was 0.93 and 0.81, respectively. RESULTS: In silico studies show that CPT derivatives (CPT-1 and CPT-6) possess drug-like properties. Docking performed on DNA Topoisomerase-I showed significant binding affinity. Finally, predicted active derivatives were chemically semi synthesized, spectroscopically characterized, and evaluated in-vitro for cytotoxic/anticancer activity against HepG2 and A549 cell lines. CONCLUSION: The experimental results are consistent with the predicted results. These findings may be of immense importance in the anticancer drug development from an inexpensive and widely available natural product, camptothecin.

Neuroprotective Effects of Withania somnifera on 4-Hydroxynonenal Induced Cell Death in Human Neuroblastoma SH-SY5Y Cells Through ROS Inhibition and Apoptotic Mitochondrial Pathway.

The antioxidant, anti-inflammatory, and anticancer activities of Withania somnifera (WS) are known for a long time. This study was aimed to examine whether WS also diminishes 4-hydroxy-trans-2-nonenal (HNE)-induced neurotoxicity in human neuroblastoma (SH-SY5Y) cell line. The cytotoxic response of HNE (0.1-50 µM) and WS (6.25-200 µg/ml) was measured by MTT assay after exposing SH-SY5Y cells for 24 h. Then neuroprotective potential was assessed by exposing the cells to biologically safe concentrations of WS (12.5, 25, and 50 µg/ml) then HNE (50 µM). Results showed a concentration-dependent protective effect of WS at 12.5, 25, and 50 µg/ml against HNE (50 µM) induced cytotoxicity and cell inhibition. Pre-exposure to WS resulted in a strong inhibition of 24, 55 and 83% in malondialdehyde (MDA) level; 5, 27 and 60% in glutathione (GSH) level; 12, 36 and 68% in catalase activity; 11, 33 and 67% in LDH leakage; and 40, 80 and 120% in cellular LDH activity at 12.5, 25, and 50 µg/ml, respectively, induced by 50 µM HNE in SH-SY5Y cells. The HNE-mediated cellular changes (cell shrinkage, rounded bodies, and inhibition of outgrowth) and increased caspase-3 activity were also prevented by WS. The HNE-induced upregulation of proapoptotic markers (p53, caspase-3, and -9, and Bax) and downregulation of antiapoptotic marker Bcl-2 genes were also blocked by pretreatment with WS. Altogether, our findings indicate that WS possesses a protective potential against HNE-induced neurotoxicity.

The Implementation of the Three Rs in Regulatory Toxicity and Biosafety Assessment: The Indian Perspective.

Animal models have long served as a basis for scientific experimentation, biomedical research, drug development and testing, disease modelling and toxicity studies, as they are widely thought to provide meaningful, human-relevant predictions. However, many of these systems are resource intensive and time-consuming, have low predictive value and are associated with great social and ethical dilemmas. Often drugs appear to be effective and safe in these classical animal models, but later prove to be ineffective and/or unsafe in clinical trials. These issues have paved the way for a paradigm shift from the use of in vivo approaches, toward the 'science of alternatives'. This has fuelled several research and regulatory initiatives, including the ban on the testing of cosmetics on animals. The new paradigm has been shifted toward increasing the relevance of the models for human predictivity and translational efficacy, and this has resulted in the recent development of many new methodologies, from 3-D bio-organoids to bioengineered 'human-on-a-chip' models. These improvements have the potential to significantly advance medical research globally. This paper offers a stance on the existing strategies and practices that utilise alternatives to animals, and outlines progress on the incorporation of these models into basic and applied research and education, specifically in India. It also seeks to provide a strategic roadmap to streamline the future directions for the country's policy changes and investments. This strategic roadmap could be a useful resource to guide research institutions, industries, regulatory agencies, contract research organisations and other stakeholders in transitioning toward modern approaches to safety and risk assessment that could replace or reduce the use of animals without compromising the safety of humans or the environment.

Correction to: Differentiating neurons derived fromhuman umbilical cord blood stem cells work as a test system for developmental neurotoxicity.

The original version of this article unfortunately contained a mistake. The acknowledgment published was incomplete.

PI3K/Akt/GSK3ß induced CREB activation ameliorates arsenic mediated alterations in NMDA receptors and associated signaling in rat hippocampus: Neuroprotective role of curcumin.

Protective efficacy of curcumin in arsenic induced NMDA receptor dysfunctions and PI3K/Akt/ GSK3ß signalling in hippocampus has been investigated in vivo and in vitro. Exposure to sodium arsenite (in vivo - 20 mg/kg, body weight p.o. for 28 days; in vitro - 10 µM for 24 h) and curcumin (in vivo - 100 mg/kg body weight p.o. for 28 days; in vitro - 20 µM for 24 h) was carried out alone or simultaneously. Treatment with curcumin ameliorated sodium arsenite induced alterations in the levels of NMDA receptors, its receptor subunits and synaptic proteins - pCaMKIIα, PSD-95 and SynGAP both in vivo and in vitro. Decreased levels of BDNF, pAkt, pERK1/2, pGSK3ß and pCREB on sodium arsenite exposure were also protected by curcumin. Curcumin was found to decrease sodium arsenite induced changes in hippocampus by modulating PI3K/Akt/GSK3ß neuronal survival pathway, known to regulate various cellular events. Treatment of hippocampal cultures with pharmacological inhibitors for ERK1/2, GSK3ß and Akt individually inhibited levels of CREB and proteins associated with PI3K/Akt/GSK3ß pathway. Simultaneous treatment with curcumin was found to improve sodium arsenite induced learning and memory deficits in rats assessed by water maze and Y-maze. The results provide evidence that curcumin exercises its neuroprotective effect involving PI3K/Akt pathway which may affect NMDA receptors and downstream signalling through TrKß and BDNF in arsenic induced cognitive deficits in hippocampus.

Ionic liquid based ultrasound assisted dispersive liquid-liquid micro-extraction for simultaneous determination of 15 neurotransmitters in rat brain, plasma and cell samples.

Neurotransmitters are signaling molecules which play a key role in the central nervous system allowing signal transmission in the neuronal synapses. The role of these compounds is very crucial in the biological systems. A rapid, sensitive, economical and derivatisation free method has been developed for the analysis of 15 neurotransmitters in a single run on liquid chromatography tandem mass spectrometry. These 15 neurotransmitters are categorized into 5 groups on the basis of their fragmentation pattern. The proposed method "ionic liquid based ultrasound assisted dispersive liquid-liquid microextraction" hyphenated with tandem mass spectrometry is the first report for the analysis of neurotransmitters in cell samples along with other two matrices (rat brain and plasma). All the parameters that influence the extraction efficiency are optimized with aid of response surface methodology and desirability profile. Under these optimized conditions the developed method has been validated. The limit of detection was in the range of (1) 0.021-0.912 µg L-1 for rat brain samples, (2) 0.028-0.978 µg L-1 for plasma samples and (3) 0.025-0.945 µg L-1 for cell samples with good linearity behavior for all analytes in the concentration range of 0.04-200 µg L-1 in all the three matrices. The coefficient of determination for all the neurotransmitters was found in the range of (1) (R2) ≥ 0.996 to 0.999 for rat brain samples and (2) (R2) ≥ 0.991 to 0.999 for plasma and cell samples. The intra-day and inter-day variations were found less than (1) 1.78% and 8.94% for rat brain samples, (2) 1.83% and 8.37% for plasma samples and (3) 1.64% and 8.04% for cell samples respectively. The method has mean recoveries varied between (1) 81-128% for brain samples, (2) 88-107% for plasma samples and (3) 91-104% for cell samples at different spiking levels. The optimized and validated method was found free from matrix interferences and successfully applied for quantitative determination of 15 neurotransmitters in the rat brain, plasma and cell samples.

Involvement of PKA/DARPP-32/PP1α and ß- arrestin/Akt/GSK-3ß Signaling in Cadmium-Induced DA-D2 Receptor-Mediated Motor Dysfunctions: Protective Role of Quercetin.

Given increasing risk of cadmium-induced neurotoxicity, the study was conducted to delineate the molecular mechanisms associated with cadmium-induced motor dysfunctions and identify targets that govern dopaminergic signaling in the brain involving in vivo, in vitro, and in silico approaches. Selective decrease in dopamine (DA)-D2 receptors on cadmium exposure was evident which affected the post-synaptic PKA/DARPP-32/PP1α and ß-arrestin/Akt/GSK-3ß signaling concurrently in rat corpus striatum and PC12 cells. Pharmacological inhibition of PKA and Akt in vitro demonstrates that both pathways are independently modulated by DA-D2 receptors and associated with cadmium-induced motor deficits. Ultrastructural changes in the corpus striatum demonstrated neuronal degeneration and loss of synapse on cadmium exposure. Further, molecular docking provided interesting evidence that decrease in DA-D2 receptors may be due to direct binding of cadmium at the competitive site of dopamine on DA-D2 receptors. Treatment with quercetin resulted in the alleviation of cadmium-induced behavioral and neurochemical alterations. This is the first report demonstrating that cadmium-induced motor deficits are associated with alteration in postsynaptic dopaminergic signaling due to a decrease in DA-D2 receptors in the corpus striatum. The results further demonstrate that quercetin has the potential to alleviate cadmium-induced dopaminergic dysfunctions.

Protective Effect of Curcumin by Modulating BDNF/DARPP32/CREB in Arsenic-Induced Alterations in Dopaminergic Signaling in Rat Corpus Striatum.

Earlier, protective role of curcumin in arsenic-induced dopamine (DA)-D2 receptor dysfunctions in corpus striatum has been demonstrated by us. In continuation to that, the present study is focused to decipher the molecular mechanisms associated with alterations in dopaminergic signaling on arsenic exposure in corpus striatum and assess the protective efficacy of curcumin. Exposure to arsenic (20 mg/kg, body weight p.o. for 28 days) in rats resulted to decrease the expression of presynaptic proteins-tyrosine hydroxylase and VMAT2 while no effect was observed on the expression of DAT in comparison to controls. A significant decrease in the expression of DA-D2 receptors associated with alterations in the expression of PKA, pDARPP32 (Thr 34), and PP1 α was clearly evident on arsenic exposure. Expression of BDNF and pGSK3ß in corpus striatum was found decreased in arsenic-exposed rats. Simultaneous treatment with curcumin (100 mg/kg, body weight p.o. for 28 days) resulted to protect arsenic-induced alterations in the expression of DA-D2 receptors, PKA, pDARPP32, pCREB, and pPP1α. Neuroprotective efficacy of curcumin can possibly be attributed to its antioxidant potential which significantly protected arsenic-induced mitochondrial dysfunctions by modulating the ROS generation and apoptosis. Modulation in the expression of BDNF and pGSK3ß in corpus striatum by curcumin exhibits the importance of neuronal survival pathway in arsenic-induced dopaminergic dysfunctions. Interestingly, curcumin was also found to protect arsenic-induced ultrastructural changes in corpus striatum. The results exhibit that curcumin modulates BDNF/DARPP32/CREB in arsenic-induced alterations in dopaminergic signaling in rat corpus striatum.

Prenatal exposure to lambda-cyhalothrin alters brain dopaminergic signaling in developing rats.

The present study is focused to decipher the molecular mechanisms associated with dopaminergic alterations in corpus striatum of developing rats exposed prenatally to lambda-cyhalothrin (LCT), a new generation type II synthetic pyrethroid. There was no significant change in the mRNA and protein expression of DA-D1 receptors at any of the doses of LCT (0.5, 1 and 3mg/kg body weight) in corpus striatum of developing rats exposed prenatally to LCT on PD22 and PD45. Prenatal exposure to LCT (1 and 3mg/kg body weight) resulted to decrease the levels of mRNA and protein of DA-D2 receptors in corpus stratum of developing rats on PD22 as compared to controls. Decrease in the binding of 3H-Spiperone in corpus striatum, known to label DA-D2 receptors was also distinct in developing rats on PD22. These rats also exhibited decrease in the expression of proteins - TH, DAT and VMAT2 involved in pre-dopaminergic signaling. Further, decrease in the expression of DARPP-32 and pCREB associated with increased expression of PP1α was evident in developing rats on PD22 as compared to controls. Interestingly, a trend of recovery in the expression of these proteins was observed in developing rats exposed to LCT at moderate dose (1.0mg/kg body weight) while alteration in the expression of these proteins continued to persist in those exposed at high dose (3.0mg/kg body weight) on PD45 as compared to respective controls. No significant change in the expression of any of these proteins was observed in corpus striatum of developing rats prenatally exposed to LCT at low dose (0.5mg/kg body weight) on PD22 and PD45 as compared to respective controls. The results provide interesting evidence that alterations in dopaminergic signaling on LCT exposure are due to selective changes in DA-D2 receptors in corpus striatum of developing rats. Further, these changes could be attributed to impairment in spontaneous motor activity on LCT exposure in developing rats.

Prenatal exposure to lambda-cyhalothrin impairs memory in developing rats: Role of NMDA receptor induced post-synaptic signalling in hippocampus.

Effect of prenatal exposure to lambda-cyhalothrin (LCT) has been assessed on the integrity of NMDA receptors and associated post-synaptic signalling in hippocampus of developing rats. Decrease in the binding of [3H]-MK 801, known to label NMDA receptors was observed in hippocampus of rats prenatally exposed to LCT (1 and 3mg/kg body weight) on PD22, compared to controls. Consistent with this, decrease in the mRNA and protein expression of NR1 and NR2B subunits of NMDA receptors was evident in rats prenatally exposed to LCT (1 and 3mg/kg body weight) on PD22. There was no change in mRNA and protein expression of NR2A subunit of NMDA receptors. Prenatal exposure to LCT (1 and 3mg/kg body weight) decreased the expression of positive regulators (PSD95, pERK1/2, CaMKIIα & pCREB) and increased the expression of negative regulators (Cdk5 & SynGAP) associated with NMDA receptor dependent synaptic plasticity in hippocampus and impaired learning and memory of rats on PD22. The neurobehavioral changes continued to persist in rats exposed to LCT at high dose (3mg/kg body weight) while exhibited trend of recovery in those exposed at moderate dose (1mg/kg body weight) on PD45, compared to controls. No change in any of the neurobehavioral endpoint was observed in developing rats prenatally exposed to LCT at low dose (0.5mg/kg body weight) on PD22 and PD45. The results exhibit that alterations in NMDA receptors on prenatal exposure to LCT may affect postsynaptic signalling associated with impaired learning and memory in developing rats.

Design, Synthesis, and Biological Evaluation of Novel 1,2,4-Trioxanes as Potential Antimalarial Agents.

A series of substituted 1,2,4-trioxanes were synthesized and evaluated for their antimalarial potential, in silico ADME properties and cytotoxicity on neuronal cell lines. Among the 15 synthesized substituted 1,2,4-trioxanes, two compounds (compound 15, IC50 = 25.71 nM; compound 21, IC50 = 19.6 nM) exhibited promising in vitro antimalarial potential comparable to those of the existing drugs chloroquine and artemisinin. Both of these compounds were found to be nontoxic up to 20 µM concentration in neuronal PC-12 cells. Compound 21 may serve as an optimized lead compound because of its less in vitro toxicity and lower probability to cross the blood brain barrier.

Protective Role of Quercetin in Cadmium-Induced Cholinergic Dysfunctions in Rat Brain by Modulating Mitochondrial Integrity and MAP Kinase Signaling.

With the increasing evidences of cadmium-induced cognitive deficits associated with brain cholinergic dysfunctions, the present study aimed to decipher molecular mechanisms involved in the neuroprotective efficacy of quercetin in rats. A decrease in the binding of cholinergic-muscarinic receptors and mRNA expression of cholinergic receptor genes (M1, M2, and M4) was observed in the frontal cortex and hippocampus on exposure of rats to cadmium (5.0 mg/kg body weight, p.o.) for 28 days compared to controls. Cadmium exposure resulted to decrease mRNA and protein expressions of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) and enhance reactive oxygen species (ROS) generation associated with mitochondrial dysfunctions, ultrastructural changes, and learning deficits. Enhanced apoptosis, as evidenced by alterations in key proteins involved in the pro- and anti-apoptotic pathway and mitogen-activated protein (MAP) kinase signaling, was evident on cadmium exposure. Simultaneous treatment with quercetin (25 mg/kg body weight, p.o.) resulted to protect cadmium-induced alterations in cholinergic-muscarinic receptors, mRNA expression of genes (M1, M2, and M4), and expression of ChAT and AChE. The protective effect on brain cholinergic targets was attributed to the antioxidant potential of quercetin, which reduced ROS generation and protected mitochondrial integrity by modulating proteins involved in apoptosis and MAP kinase signaling. The results exhibit that quercetin may modulate molecular targets involved in brain cholinergic signaling and attenuate cadmium neurotoxicity.

Influence of immobilization and forced swim stress on the neurotoxicity of lambda-cyhalothrin in rats: Effect on brain biogenic amines and BBB permeability.

Experimental studies have been carried out on rats to understand the influence of immobilization stress (IMS), a psychological stressor and forced swim stress (FSS), a physical stressor in the neurotoxicity of lambda-cyhalothrin (LCT), a new generation type II synthetic pyrethroid with extensive applications. No significant change in plasma corticosterone levels and blood brain barrier (BBB) permeability was observed in rats subjected to IMS (one session of 15min/day), FSS (one session of 3min/day) for 28days or LCT treatment (3.0mg/kg body weight, p.o. suspended in groundnut oil) for 3days (26th, 27th and 28th day) as compared to controls. Marginal changes in the levels of biogenic amines and their metabolites (NE, EPN, DA, HVA, DOPAC, 5-HT) in hypothalamus, frontal cortex, hippocampus, and corpus striatum were observed in rats subjected to IMS or FSS or LCT alone as compared to controls. It was interesting to note that pre-exposure to IMS or FSS followed by LCT treatment for 3days caused a marked increase in plasma corticosterone levels associated with disruption in the BBB permeability as compared to rats exposed to IMS or FSS or LCT alone. Pre-exposure to IMS or FSS followed by LCT treatment for 3days resulted to alter the levels of biogenic amines and their metabolites in hypothalamus, frontal cortex, hippocampus, and corpus striatum as compared to rats exposed to IMS or FSS or LCT alone. Although neurochemical changes were more intense in rats pre-exposed to IMS as compared to those subjected to FSS on LCT treatment, the results indicate that both psychological and physical stress could be important influencing factors in the neurotoxicity of LCT.

Effect of L-pGlu-(1-benzyl)-l-His-l-Pro-NH2 against in-vitro and in-vivo models of cerebral ischemia and associated neurological disorders.

Central nervous system plays a vital role in regulation of most of biological functions which are abnormally affected in various disorders including cerebral ischemia, Alzheimer's and Parkinson's (AD and PD) worldwide. Cerebral stroke is an extremely fatal and one of the least comprehensible neurological disorders due to limited availability of prospective clinical approaches and therapeutics. Since, some endogenous peptides like thyrotropin-releasing hormone have shown substantial neuroprotective potential, hence present study evaluates the newer thyrotropin-releasing hormone (TRH) analogue L-pGlu-(1-benzyl)-l-His-l-Pro-NH2 for its neuroprotective effects against oxygen glucose deprivation (OGD), glutamate and H2O2 induced injury in pheochromocytoma cell lines (PC-12 cells) and in-vivo ischemic injury in mice. Additionally, the treatment was further analyzed with respect to models of AD and PD in mice. Cerebral ischemia was induced by clamping both bilateral common carotid arteries for ten minutes. Treatment was administered to the mice five minute after restoration of blood supply to brain. Consequential changes in neurobehavioural, biochemical and histological parameters were assessed after a week. L-pGlu-(1-benzyl)-l-His-l-Pro-NH2 showed significant reduction in glutamate, H2O2 and OGD -induced cell death in concentration and time dependent manner. Moreover, L-pGlu-(1-benzyl)-l-His-l-Pro-NH2 resulted in a substantial reduction in CA1 (Cornus Ammonis 1) hippocampal neuronal cell death, inflammatory cytokines, TNF-α, IL-6 and oxidative stress in hippocampus. In addition, L-pGlu-(1-benzyl)-l-His-l-Pro-NH2 was found to be protective in two acute models of AD and PD as well these findings demonstrate the neuroprotective potential of L-pGlu-(1-benzyl)-l-His-l-Pro-NH2 in cerebral ischemia and other diseases, which may be mediated through reduction of excitotoxicity, oxidative stress and inflammation.

Brain cholinergic alterations in rats subjected to repeated immobilization or forced swim stress on lambda-cyhalothrin exposure.

Role of immobilization stress (IMS), a psychological stressor and forced swim stress (FSS), a physical stressor was investigated on the neurobehavioral toxicity of lambda-cyhalothrin (LCT), a new generation type-II synthetic pyrethroid. Pre-exposure of rats to IMS (15 min/day) or FSS (3 min/day) for 28 days on LCT (3.0 mg/kg body weight, p.o.) treatment for 3 days resulted to decrease spatial learning and memory and muscle strength associated with cholinergic-muscarinic receptors in frontal cortex and hippocampus as compared to those exposed to IMS or FSS or LCT alone. Decrease in acetylcholinesterase activity, protein expression of ChAT and PKC-ß1 associated with decreased mRNA expression of CHRM2, AChE and ChAT in frontal cortex and hippocampus was also evident in rats pre-exposed to IMS or FSS on LCT treatment, compared to rats exposed to IMS or FSS or LCT alone. Interestingly, changes both in behavioral and neurochemical endpoints were marginal in rats subjected to IMS or FSS for 28 days or those exposed to LCT for 3 days alone, compared to controls. The results suggest that stress is an important contributor in LCT induced cholinergic deficits.

Monocrotophos induced oxidative stress and alterations in brain dopamine and serotonin receptors in young rats.

Human exposure to monocrotophos, an organophosphate pesticide, could occur due to its high use in agriculture to protect crops. Recently, we found that postlactational exposure to monocrotophos impaired cholinergic mechanisms in young rats and such changes persisted even after withdrawal of monocrotophos exposure. In continuation to this, the effect of monocrotophos on noncholinergic targets and role of oxidative stress in its neurotoxicity has been studied. Exposure of rats from postnatal day (PD)22 to PD49 to monocrotophos (0.50 or 1.0 mg kg(-1) body weight, perorally) significantly impaired motor activity and motor coordination on PD50 as compared to controls. A significant decrease in the binding of (3)H-spiperone to striatal membrane (26%, p < 0.01; 30%, p < 0.05) in rats exposed to monocrotophos at both the doses and increase in the binding of (3)H-ketanserin to frontocortical membrane (14%, p > 0.05; 37%, p < 0.05) in those exposed at a higher dose, respectively, was observed on PD50 compared with the controls. Alterations in the binding persisted even after withdrawal of monocrotophos exposure on PD65. Increased oxidative stress in brain regions following exposure of rats to monocrotophos was also observed on PD50 that persisted 15 days after withdrawal of exposure on PD65. The results suggest that monocrotophos exerts its neurobehavioral toxicity by affecting noncholinergic functions involving dopaminergic and serotonergic systems associated with enhanced oxidative stress. The results also exhibit vulnerability of developing brain to monocrotophos as most of the changes persisted even after withdrawal of its exposure.

Critical role of the miR-200 family in regulating differentiation and proliferation of neurons.

The generation of differentiated and functional neurons is a complex process, which requires coordinated expression of several proteins and microRNAs (miRNAs). The present study using nerve growth factor (NGF)-differentiated PC12 cells led to the identification of miR-200, miR-221/222 and miR-34 families as major up-regulated miRNAs in fully differentiated neurons. Similar to PC12 cells, induction of miR-200 family was observed in differentiating neural stem cells, demonstrating a direct role of miR-200 family in neuronal differentiation. Over-expression of miR-200 induced neurite formation in PC12 cells and regulated neuronal markers in favour of differentiation. However, inhibition of miR-200 induced proliferation of PC12 cells. In differentiating PC12 cells and neural stem cells, an inverse relationship was observed between expression of reprogramming transcription factors (SOX2, KLF4, NANOG, OCT4 and PAX6) and miR-200. Over-expression of miR-200 in PC12 cells significantly down-regulated mRNA and protein levels of SOX2 and KLF4. Moreover, we observed two phases of dramatic down-regulation of miR-200 expression in developing rat brains correlating with periods of neuronal proliferation. In conclusion, our results indicate that increased expression of the miR-200 family promotes neuronal differentiation, while decreased expression of the miR-200 family promotes neuronal proliferation by targeting SOX2 and KLF4.

Bromelain nanoparticles protect against 7,12-dimethylbenz[a]anthracene induced skin carcinogenesis in mouse model.

Conventional cancer chemotherapy leads to severe side effects, which limits its use. Nanoparticles (NPs) based delivery systems offer an effective alternative. Several evidences highlight the importance of Bromelain (BL), a proteolytic enzyme, as an anti-tumor agent which however has been limited due to the requirement of high doses at the tumor site. Therefore, we illustrate the development of BL loaded poly (lactic-co-glycolic acid) NPs that show enhanced anti-tumor effects compared to free BL. The formulated NPs with a mean particle size of 130.4 ± 8.81 nm exhibited sustained release of BL. Subsequent investigation revealed enhanced anti-tumor ability of NPs in 2-stage skin tumorigenesis mice model. Reduction in average number of tumors (∼ 2.3 folds), delay in tumorigenesis (∼ 2 weeks), percent tumorigenesis (∼ 4 folds), and percent mortality rate as well as a reduction in the average tumor volume (∼ 2.5 folds) in mice as compared to free BL were observed. The NPs were found to be superior in exerting chemopreventive effects over chemotherapeutic effects at 10 fold reduced dose than free BL, validated by the enhanced ability of NPs (∼ 1.8 folds) to protect the DNA from induced damage. The effects were also supported by histopathological evaluations. NPs were also capable of modulating the expression of pro-apoptotic (P53, Bax) and anti-apoptotic (Bcl2) proteins. Therefore, our findings demonstrate that developed NPs formulation could be used to improve the efficacy of chemotherapy by exerting chemo-preventive effects against induced carcinogenesis at lower dosages.