Bijoy Krishna Roy

Assessment of genotoxicity of some common food preservatives using Allium cepa L. as a test plant

Food preservatives play important role in todays food supplies that are used to prolong the self-life of products by protecting them from deterioration caused by micro-organisms. In this study, investigations were carried out to study the impacts of food preservatives like butylated hydroxytoluene, butylated hydroxyanisole, sorbic acid, propyl gallate and sodium nitrate. The effects of these preservatives at concentration of 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm for 4 h, 8 h and 16 h of exposure period were studied on the root tips of Allium cepa. Cytological studies revealed statistically significant (p < 0.05) inhibition in mitotic index with an increase in concentration of the food preservatives when compared with the control. Most frequent cytological abnormalities observed were bridges, multipolarity, C-mitosis, stickiness and cell death. The total percentages of abnormalities were also increased with increasing concentration and time duration. The abnormalities (%) in root system caused by used preservatives were recorded as butylated hydroxytoluene < butylated hydroxyanisole < sodium nitrate < sorbic acid < propyl gallate.

Karyotype studies in dominant species of Aloe from eastern India

Abstract The karyotype asymmetry/ symmetry of three species of Aloe i.e. A.vera, A. indica and A. ferox was evaluated by eight different methods- TF%, As K%, Stebbins classification, Rec and Syi, A1 and A2, A, DI and AI and also elucidated the relationship between the species. Among all the methods, Stebbins classifi cation found to be less sensible than quantitative parameters. TF%, the Syi, As K%, A1, DI and A indices were unable to express correct parameters to study karyotype asymmetry on the basis of the variation in centromeric position. A2 (interchromosomal asymmetry) index was correctly described karyotype asymmetry on the basis of variation in chromosome length. AI (Asymmetry index) proved to be the most suitable method used to elucidate karyotype asymmetry. Scattered diagrams of correlations among the indices seems to be the best suited to draw overall quantitative relationship and displayed relationship among species with respect to karyotype asymmetry. Signifi cant correlations among AI-DI, A1-A2, Syi-Rec and CVCL-CVCI tried to describe the variation among centromeric position in a chromosome complement at 0.05 and 0.01 levels. The A1 index, CVCI and CVCL have indicated the minor karyotype variations. These methods assessed and analyzed the karyotype asymmetry in chromosome set and compared the karyotypes to related taxa and draw the relationship among closely related species.

In Silico Profiling of the Potentiality of Curcumin and Conventional Drugs for CagA Oncoprotein Inactivation.

The oncoprotein cytotoxic associated gene A (CagA) of Helicobacter pylori plays a pivotal role in the development of gastric cancer, so it has been an important target for anti‐H. pylori drugs. Conventional drugs are currently being implemented against H. pylori. The inhibitory role of plant metabolites like curcumin against H. pylori is still a major scientific challenge. Curcumin may represent a novel promising drug against H. pylori infection without producing side effects. In the present study, a comparative analysis between curcumin and conventional drugs (clarithromycin, amoxicillin, pantoprazole, and metronidazole) was carried out using databases to investigate the potential of curcumin against H. pylori targeting the CagA oncoprotein. Curcumin was filtered using Lipinskis rule of five and the druglikeness property for evaluation of pharmacological properties. Subsequently, molecular docking was employed to determine the binding affinities of curcumin and conventional drugs to the CagA oncoprotein. According to the results obtained from FireDock, the binding energy of curcumin was higher than those of amoxicillin, pantoprazole, and metronidazole, except for clarithromycin, which had the highest binding energy. Accordingly, curcumin may become a promising lead compound against CagA+ H. pylori infection.

Chilli Anthracnose: A Review of Causal Organism, Resistance Source and Mapping of Gene

Anthracnose disease is one of the major economic constraints to chilli production in tropical and subtropical regions of the world and it is gaining much attention towards causes of damage in the field. Growing understanding has been based on conventional methods of characterisation of Colletotrichum species and its interaction with the host but it was not clear enough to recognise the differentiation among species, host–pathogen relationship and genetics of resistance in chilli. In this chapter, emphasis has been made on the evaluation of the isolates of Colletotrichum capsici causing chilli anthracnose for their morphological and cultural characteristics, pathogenic variability on chilli fruits and genetic diversity with the help of random amplified polymorphism (RAPD-PCR) analysis and designated into different major clusters. Simultaneously, screening of Capsicum genotypes against anthracnose for testing the resistance has been highlighted under in vitro condition. Further, on the basis of inheritance and the segregation ratio of resistance to susceptibility, gene controlling resistance at different fruit maturity stages has been discussed. More importantly, by QTL mapping, distribution of resistance gene/s located on chromosomes by using simple sequence repeats (SSR) primers, linkage groups are indicated. A number of complementary resistant component (host–parasitic interaction) controlled by one or multiple genes with small quantification effects have been emphasized. This information will be valuable to overcome the use of agrochemicals, impact of environmental factors and in the management of this serious threat to chilli through the development of resistant varieties as a donor candidate in commercial and resistance-breeding program.

Structural Interactions of Curcumin Biotransformed Molecules with the N-Terminal Residues of Cytotoxic-Associated Gene A Protein Provide Insights into Suppression of Oncogenic Activities

Curcumin as a natural product has drawn considerable attention in recent years for its multiple pharmacological activities against various diseases, but more studies are required to understand the curcumin pharmacological action considering its low bioavailability. Though numerous reasons contribute to the low bioavailability of curcumin, one of the important reasons is associated with biotransformation of curcumin through either conjugation or reduction depending on curcumin administration route. The orally administered curcumin (CUR) is metabolised into curcumin glucuronidase (CUR-GLR) and curcumin sulphate by conjugation, whereas dihydroxycurcumin, tetrahydrocurcumin, and hexahydrocurcumin (HHC) are formed by reduction after intraperitoneal administration of curcumin. The main aim of the current study was to investigate the pharmacological properties of curcumin and its biotransformed molecules and its inhibitory potential against CagA (cytotoxic-associated gene A) oncoprotein of Helicobacter pylori. All lead molecules followed the Lipinski’s five rules for biological activities, except CUR-GLR, whereas druglikeness scores were obtained for all molecules. Subsequently, molecular docking was employed to analyse the binding affinity of molecules with CagA. The docking studies revealed that CUR-GLR has highest binding affinity with CagA, whereas less interactive affinity was observed in HHC. From the virtual screening and docking studies, the current study suggests that the biotransformation of curcumin through conjugation has more potential for inhibition of oncogenic activities of CagA+ H. pylori than reduction.

Population authentication of the traditional medicinal plant Cassia tora L. based on ISSR markers and FTIR analysis

Cassia tora is a plant of medicinal importance. Medicinal plants from different localities are believed to differ in their therapeutic potency. In this study, six populations of C. tora with different eco-geographical origins were investigated genotypically (ISSR) and phytochemically (FTIR) to establish an integrated approach for population discrimination and authentication of the origin of this medicinal herb. CHS gene expression analysis and determination of flavonoid content were carried out to substantiate the study. A total of 19 population-specific authentication bands were observed in 11 ISSR fingerprints. Authentication codes were generated using six highly polymorphic bands, including three authentication bands. FTIR spectra revealed that the peaks at wavenumber 1623 cm−1 (carbonyl group) and 1034 cm−1 (>CO- group) were powerful in separating the populations. These peaks are assigned to flavonoids and carbohydrates, respectively, were more intense for Ranchi (highland) population. Variation in the transcript level of CHS gene was observed. The findings of FTIR and RT-PCR analyses were in agreement with the TFC analysis, where, the lowest amount of flavonoids observed for Lucknow (lowland) population. All the populations of C. tora have been authenticated accurately by ISSR analyses and FTIR fingerprinting, and the Ranchi site was observed to be more suitable for the potential harvesting of therapeutic bioactive compounds.

Insights from the molecular docking of curcumin to the virulent factors of Helicobacter pylori

The domains of virulent (Ureα/β, VacA-p55, and CagA) factors of Helicobacter pylori play a pivotal role in developmental processes of numerous diseases including gastric cancer. The pharmacological role of curcumin indicates that it could regulate the signaling of virulent factors by interacting with active domains. However, the controlling mechanism of the curcumin interactions and the binding diversity on structural basis of virulent (Ureα/β, VacA-p55, and CagA) factors are unknown. Curcumin as therapeutic agent was filtered by using Lipinski rule׳s five and the druglikeness property for assessment of pharmacological properties. Here outcome of molecular docking presented the 3-D structure of curcumin complex, that interacted with especially conserved residues of target domains. The structure revealed that the curcumin complexation with domains of these proteins provided structural insight into the diverse nature of proteins (Ureα/β, VacA-p55, and CagA) recognition. In silico study elucidated that the broad specificity of curcumin was achieved by multiple binding mode mechanisms such as distinct hydrogen and hydrophobic interactions with involvement of binding energy. The higher score of curcumin in complexation with both subunits Ureα/β showed the stable binding, and less stability with VacA-p55 complexation with lower score. Curcumin exhibited good interaction with these targeted virulent factors, although extensive interactions of curcumin with Ureα/β subunits could have an important implication to prevent survival and colonisation of H. pylori in stomach.