Santu Kumar Saha

Molecular Approaches Toward Targeted Cancer Prevention with Some Food Plants and Their Products: Inflammatory and Other Signal Pathways

In recent years, there has been growing interest in cancer prevention by food plants and their products. Although several plant parts have potentials for chemoprevention and other therapeutic use, their molecular mechanisms of action are not always well understood. Extensive research has identified several molecular targets that can potentially be used for the prevention and/or treatment of cancer. In this review, we accumulate evidences of modulating abilities of some dietary plants and their products on several signaling pathways, including the inflammatory and apoptotic ones, which may be targeted for cancer therapy. We have mainly focused on several phytochemicals like resveratrol (red grapes and peanuts), allicin (garlic), lycopene (tomato), indole-3-carbinol (cruciferous vegetables), vitamin C (citrus fruits), [6]-gingerol (ginger), emodin (aloe), natural antioxidant mixture (spinach), beta carotenoids (carrots), sulphoraphane (mustard), ellagic acid (pomegranate), myrecitin (cranberry), carnosol (rosemary), vanillin (vanilla) and eugenol (cloves). They act through one or more signaling pathways like nuclear factor kappa B, cyclooxygenase-2, signal transducer and activator of transcription 3, Akt, mitogen activated protein kinase/extracellular regulated kinase, Bcl-2, caspases, poly (ADP-ribose) polymerase, matrix metalloproteinase 2/9, and cyclin D1. Critical knowledge on these compounds and their signaling pathways may help in formulation of effective anticancer drugs.

Poly(lactic-co-glycolic) acid loaded nano-insulin has greater potentials of combating arsenic induced hyperglycemia in mice: Some novel findings

Diabetes is a menacing problem, particularly to inhabitants of groundwater arsenic contaminated areas needing new medical approaches. This study examines if PLGA loaded nano-insulin (NIn), administered either intraperitoneally (i.p.) or through oral route, has a greater cost-effective anti-hyperglycemic potential than that of insulin in chronically arsenite-fed hyperglycemic mice. The particle size, morphology and zeta potential of nano-insulin were determined using dynamic light scattering method, scanning electronic and atomic force microscopies. The ability of the nano-insulin (NIn) to cross the blood-brain barrier (BBB) was also checked. Circular dichroic spectroscopic (CD) data of insulin and nano-insulin in presence or absence of arsenic were compared. Several diabetic markers in different groups of experimental and control mice were assessed. The mitochondrial functioning through indices like cytochrome c, pyruvate-kinase, glucokinase, ATP/ADP ratio, mitochondrial membrane potential, cell membrane potential and calcium-ion level was also evaluated. Expressions of the relevant marker proteins and mRNAs like insulin, GLUT2, GLUT4, IRS1, IRS2, UCP2, PI3, PPARγ, CYP1A1, Bcl2, caspase3 and p38 for tracking-down the signaling cascade were also analyzed. Results revealed that i.p.-injected nano-encapsulated-insulin showed better results; NIn, due to its smaller size, faster mobility, site-specific release, could cross BBB and showed positive modulation in mitochondrial signaling cascades and other downstream signaling molecules in reducing arsenic-induced-hyperglycemia. CD data indicated that nano-insulin had less distorted secondary structure as compared with that of insulin in presence of arsenic. Thus, overall analyses revealed that PLGA nano-insulin showed better efficacy in combating arsenite-induced-hyperglycemia than that of insulin and therefore, has greater potentials for use in nano-encapsulated form.

Berberine alters epigenetic modifications, disrupts microtubule network, and modulates HPV-18 E6-E7 oncoproteins by targeting p53 in cervical cancer cell HeLa: a mechanistic study including molecular docking.

Increased evidence of chemo-resistance, toxicity and carcinogenicity necessitates search for alternative approaches for determining next generation cancer therapeutics and targets. We therefore tested the efficacy of plant alkaloid berberine on human papilloma virus (HPV) -18 positive cervical cancer cell HeLa systematically-involving certain cellular, viral and epigenetic factors. We observed disruptions of microtubule network and changes in membrane topology due to berberine influx through confocal and atomic force microscopies (AFM). We examined nuclear uptake, internucleosomal DNA damages, mitochondrial membrane potential (MMP) alterations and cell migration assays to validate possible mode of cell death events. Analytical data on interactions of berberine with pBR322 through fourier transform infrared (FTIR) and gel migration assay strengthen berberine׳s biologically significant DNA binding abilities. We measured cellular uptake, DNA ploidy and DNA strand-breaks through fluorescence activated cell sorting (FACS). To elucidate epigenetic modifications, in support of DNA binding associated processes, if any, we conducted methylation-specific restriction enzyme (RE) assay, methylation specific-PCR (MSP) and expression studies of histone proteins. We also analyzed differential interactions and localization of cellular tumor suppressor p53 and viral oncoproteins HPV-18 E6-E7 through siRNA approach. We further made in-silico approaches to determine possible binding sites of berberine on histone proteins. Overall results indicated cellular uptake of berberine through cell membrane depolarization causing disruption of microtubule networks and its biological DNA binding abilities that probably contributed to epigenetic modifications. Results of modulation in p53 and viral oncoproteins HPV-18 E6-E7 by berberine further proved its potential as a promising chemotherapeutic agent in cervical cancer.

Ultra-highly diluted plant extracts of Hydrastis canadensis and Marsdenia condurango induce epigenetic modifications and alter gene expression profiles in HeLa cells in vitro

OBJECTIVE Methylation-specific epigenetic process and gene expression profiles of HeLa cells treated with ultra-high dilutions (HDs) of two plant extracts, Hydrastis canadensis (HC-30) and Marsdenia condurango (Condu-30), diluted 1060 times, were analyzed against placebo 30C (Pl-30) for alterations in gene profiles linked to epigenetic modifications. METHODS Separate groups of cells were subjected to treatment of Condu-30, HC-30, and Pl-30 prepared by serial dilutions and succussions. Global microarray data recorded on Affymetrix platform, using 25-mer probes were provided by iLifeDiscoveries, India. Slides were scanned with 3000 7G microarray scanner and raw data sets were extracted from Cel (raw intensity) files. Analyses of global microarray data profile, differential gene expression, fold change and clusters were made using GeneSpring GX12.5 software and standard normalization procedure. Before microarray study, concentration of RNA (ng/μL), RIN value and rRNA ratio for all the samples were analysed by Agilant Bioanalyzer 2100. Reverse transcriptase polymerase chain reaction (RT-PCR) and quantitative RT-PCR were done for analyzing SMAD-4 expression. Fluorescence-activated cell sorting study was further made to elucidate fate of cells at divisional stages. Methylation-specific restriction enzyme assay was conducted for ascertaining methylation status of DNA at specific sites. RESULTS HDs of HC-30 and Condu-30 differentially altered methylation in specific regions of DNA and expression profiles of certain genes linked to carcinogenesis, as compared to Pl-30. Two separate cut sites were found in genomic DNA of untreated and placebo-treated HeLa cells when digested with McrBC, compared to a single cut observed in Condu-30-treated genomic DNA. SMAD-4 gene expression validated the expression pattern observed in microarray profile. Methylation-specific restriction enzyme assay elucidated differential epigenetic modifications in drug-treated and control cells. CONCLUSION HDs triggered epigenetic modifications and alterations in microarray gene expression profiles of many genes associated with carcinogenesis in HeLa cells in vitro.

Post-cancer Treatment with Condurango 30C Shows Amelioration of Benzo[a]pyrene-induced Lung Cancer in Rats Through the Molecular Pathway of Caspa- se-3-mediated Apoptosis Induction: -Anti-lung cancer potential of Condurango 30C in rats.

Objectives: The present investigation aimed at examining if post-cancer treatment with a potentized homeopathic drug, Condurango 30C, which is generally used to treat oesophageal cancer, could also show an ameliorating effect through apoptosis induction on lung cancer induced by benzo[a]pyrene (BaP) in white rats (Rattus norvegicus). Methods: Lung cancer was induced after four months by chronic feeding of BaP to rats through gavage at a dose of 50 mg/kg body weight for one month. After four months, the lung-cancer-bearing rats were treated with Condurango 30C for the next one (5th), two (5th-6th) and three (5th-7th) months, respectively, and were sacrificed at the corresponding time- points. The ameliorating effect, if any, after Condurango 30C treatment for the various periods was evaluated by using protocols such as histology, scanning electron microscopy (SEM), annexinV-FITC/PI assay, flow cytometry of the apoptosis marker, DNA fragmentation, reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and western blot analyses of lung tissue samples. Results: Striking recovery of lung tissue to a near normal status was noticed after post-cancerous drug treatment, as evidenced by SEM and histology, especially after one and two months of drug treatment. Data from the annexinV-FITC/PI and DNA fragmentation assays revealed that Condurango 30C could induce apoptosis in cancer cells after post-cancer treatment. A critical analysis of signalling cascade, evidenced through a RT-PCR study, demonstrated up-regulation and down-regulation of different pro- and anti-apoptotic genes, respectively, related to a caspase-3-mediated apoptotic pathway, which was especially discernible after one-month and two- month drug treatments. Correspondingly, Western blot and immunohistochemistry studies confirmed the ameliorative potential of Condurango 30C by its ability to down-regulate the elevated epidermal growth factor receptor (EGFR) expression, a hallmark of lung cancer. Conclusion: The overall result validated a positive effect of Condurango 30C in ameliorating lung cancer through caspase-3-mediated apoptosis induction and EGFR down-regulation.

Molecular Approaches Toward Targeted Cancer Therapy with Some Food Plant Products: On the Role of Antioxidants

Abstract Cells in humans are constantly exposed to a variety of oxidizing agents from naturally occurring processes, environmental stimuli/pollutants, and lifestyle stress/activities. The key factor in a biological system is to maintain a balance between oxidants and antioxidants to sustain optimal physiological conditions. Imbalance of the process leads to oxidative stress, which causes oxidative damage to the biomolecules such as lipids, proteins, and DNA, resulting in an increased risk of diseases like cancer. Epidemiological studies have shown that effects of various dietary antioxidants and their bioactive components can perform a great role in cancer chemoprevention. This chapter summarizes the current knowledge on some food plants and their phytochemicals acting as antioxidants in targeted cancer therapy and discusses the molecular approaches that can possibly be made with them in order to achieve some effective anticancer drug formulation. This chapter also focuses on some areas where further research is needed.