Abiotic Stress-Mediated Sensing and Signaling in Plants: An Omics Perspective, 2018
The growth and development of plant are adversely affected due to various abiotic stresses such a... more The growth and development of plant are adversely affected due to various abiotic stresses such as cold, heat, drought, salinity, heavy metal, hypoxia, etc. Plant adaptation to the stress conditions is brought out by changes in its physiological parameters which have underlying molecular basis. Multiple signalling pathways are activated in response to particular stress which are often complex and work through a network of trans-and cis-regulatory factors. In the following chapter, we summarize the current understanding of cis-regulatory factors, viz. promoters and transcription factor binding motifs, which are responsible for relaying signals during anabiotic signalling cascade ultimately preventing and mitigating the ill effect of climatic conditions on plant growth and survival.
Wheat is an important Rabi Crop, which is grown between October and December and harvested betwee... more Wheat is an important Rabi Crop, which is grown between October and December and harvested between April and May. Globally, wheat is the leading source of protein than maize or rice. A study was undertaken to examine the genetic diversity of 20 wheat (Triticum aestivum L.) using designed EST-SSR markers. The similarity coefficient value for all the 20 genotypes ranged from 0.23 to 0.63. The minimum similarity exhibited by genotype PBW550 and DBW17. Whereas, the maximum similarity was shown by genotype DBW16 and RAJ4246. The pair wise genetic similarities among all pairs of samples were estimated and subjected to cluster analysis. The UPGMA based clusters shows that all the genotypes are interlinked with each other and exhibited high genetic similarity. The UPGMA based clustering of 20 wheat genotypes grouped the wheat genotypes into three distinct clusters at 70% similarity coefficient.
Key message Extensive regulatory divergence during development, abiotic stress and ABA regime obs... more Key message Extensive regulatory divergence during development, abiotic stress and ABA regime observed amongst promoter homologs and homeologs of MIR319 from Brassica juncea . Abstract Gene duplication followed by sub-functionalization, neo-functionalization, and pseudogenization are routes to functional and adaptive diversification. The influence of polyploidy on protein-coding genes is well investigated but little is known about their impact on transcriptional regulation of MIRNA gene family. The present study was therefore performed with an aim to uncover regulatory diversification of MIR319 homologs and homeologs in Brassica juncea. We employed comparative genomics to identify and isolate six promoter homologs of MIR319 from B. juncea . Regulatory diversification was studied using analysis of reporter activity driven by BjMIR319 promoters in a heterologous system employing promoter–reporter fusion constructs. MIR319 is known to play important roles in leaf and flower development, and multiple stress responses. Reporter activity was therefore monitored during development, hormonal and stress regimes. In-silico analyses revealed differential distribution of cis -regulatory motifs and functional analysis revealed distinct spatiotemporal expression patterns. The significance of presence of selected cis -regulatory motifs corresponding to heat, cold, salt and ABA stress were further functionally validated. It was observed that promoter of Bj -MIR319a-A01 was upregulated in response to cold and salt stress, while promoter of Bj -MIR319c-A04 (D1) and Bj -MIR319c-A05 (FL) were downregulated in response to high temperature. In summary, comparative analysis of homologous promoters from Brassica juncea , an allopolyploid revealed extensive sequence and functional diversity. Spatiotemporal activity of reporter gene driven by BjMIR319 promoter was distinct, and partially overlapping with from those reported previously for A. thaliana . The present study clearly demonstrates regulatory divergence amongst promoter homologs of MIR319 in Brassica juncea during development and stress response, and underlines the urgent need for dissection of promoter function and detailed characterization including identification of interacting trans- factors. Genbank accession numbers : MT379853-MT379858.
Identification and functional analysis of promoters is critical towards gaining insights into tra... more Identification and functional analysis of promoters is critical towards gaining insights into transcriptional regulation, and helps in identifying interacting trans-factors. Analysis of MIRNA promoter can differentiate the function of paralogs and homeologs where identifying the role of members of MIRNA family is difficult based on small RNA blots due to near-identical mature sequences. The role of miRNA as regulators of development and adaptation in polyploid species-Brassica, and the impact of polyploidy on divergence among paralogs and homeologs especially with reference to transcriptional regulation remains unexplored. We identified homologs of MIR159 from 137 species across plants based on their homology to pre-MIR159A, MIR159B, and MIR159C from Arabidopsis and retrieved their promoter sequences. Promoter sequence analysis revealed high level of divergence; albeit clades of closely related taxonomic units were obtained. We detected biased, but no lineagespecific distribution of transcription factor binding motifs (TFBS) in families. Phylogenetic reconstruction in Brassicaceae revealed genome-and sub-genome specific clades. We isolated three homeologs of MIR159A, and one of MIR159C from the A-genome of B. juncea. Functional characterization involved transgenic lines in A. thaliana Col-0 with promoter::reporter transcriptional fusions (p-MIR159::GUS::ter) and monitoring of reporter activity during development, abiotic stresses, and after administering hormones. Comparison of reporter activity of full-length promoters across homeologs and paralogs reveal extensive functional diversification. Comparative analysis of reporter activity of nested deletions, and with distribution of TFBS did not yield a clear correlation. In summary, analysis of GUS during development, hormone treatment and abiotic stresses reveal complex transcriptional regulation of MIR159 expression.
The availability of a large number of whole-genome sequences allows comparative genomic analysis ... more The availability of a large number of whole-genome sequences allows comparative genomic analysis to reveal and understand evolution of regulatory regions and elements. The role played by events such as whole-genome and segmental duplications followed by genome fractionation in shaping genomic landscape and in expansion of gene families is crucial toward developing insights into evolutionary trends and consequences such as sequence and functional diversification. Members of Brassicaceae are known to have experienced several rounds of whole-genome duplication (WGD) that have been termed as paleopolyploidy, mesopolyploidy, and neopolyploidy. Such repeated events led to the creation and expansion of a large number of gene families. MIR319 is reported to be one of the most ancient and conserved plant MIRNA families and plays a role in growth and development including leaf development, seedling development, and embryo patterning. We have previously reported functional diversification of members of miR319 in Brassica oleracea affecting leaf architecture; however, the evolutionary history of the MIR319 gene family across Brassicaceae remains unknown and requires investigation. We therefore identified homologous and homeologous segments of ca. 100 kb, with or without MIR319, performed comparative synteny analysis and genome fractionation studies. We detected variable rates of gene retention across members of Brassicaceae when genomic blocks of MIR319a, MIR319b, and MIR319c were compared either between themselves or against Arabidopsis thaliana genome which was taken as the base genome. The highest levels of shared genes were found between A. thaliana and Capsella rubella in both MIR319b-and MIR319c-containing genomic segments, and with the closest species of A. thaliana, A. lyrata, only in MIR319a-containing segment. Synteny analysis across 12 genomes (with 30 sub-genomes) revealed MIR319c to be the most conserved MIRNA loci (present in 27 genomes/sub-genomes) followed by MIR319a (present in 23 genomes/sub-genomes); MIR319b was found to be frequently lost (present in 20 genomes/sub-genomes) and thus is under least selection pressure for retention. Genome fractionation revealed extensive and differential loss of MIRNA homeologous loci and flanking genes from various sub-genomes of Brassica species that is in accordance with their older history of polyploidy when compared to Camelina sativa, a recent neopolyploid, where the effect of genome fractionation was least. Finally, estimation of phylogenetic relationship using precursor sequences of MIR319 reveals MIR319a and MIR319b form sister clades, with MIR319c forming a separate clade. An intraspecies synteny analysis between MIR319a-, MIR319b-, and MIR319c-containing genomic segments suggests segmental duplications at the base of Brassicaceae to be responsible for the origin of MIR319a and MIR319b.
We present here a modified, sonication-assisted transient transformation assay for rapid analysis... more We present here a modified, sonication-assisted transient transformation assay for rapid analysis of cis-regulatory elements. We tested promoter elements from locus of by generating stable transgenic lines and compared the transcriptional activity of GUS reporter with that of the transient assay method. To obtain reliable and repeatable results, and to omit false-positive data, we optimized several parameters including sonication duration and cycle and concentration of measured as optical density (O.D.) at 600 nm. To the best of our knowledge, this is the first report of promoter characterization of MIR159B from , and comparative analysis of stable and transient lines. Our analysis shows that the protocol described herein allows understanding promoter activity/transcriptional control in tissues other than leaf or protoplast which have remained the mainstay for transient analysis thus far. We tested reporter gene GUS under the control of constitutive promoter, CaMV 35S, and from . We...
Formation of urinary stone is a serious and debilitating problem throughout the world. In the pre... more Formation of urinary stone is a serious and debilitating problem throughout the world. In the present study, the inhibitory effect of aqueous extract of root of Rotula aquatica was investigated against struvite crystals (one of the components of urinary stone) grown in vitro using single diffusion gel growth technique. For setting the gel, sodium metasilicate solution (specific gravity 1.05) and 0.5 M aqueous solution of ammonium dihydrogen phosphate were mixed, so that the pH of the mixture could be set at 7.0. Equal amounts of supernatant solution of magnesium acetate (1.0 M) prepared with 0.0%, 0.5% and 1% concentrations of the extract were gently poured on the set gels. It was observed that the number, dimension, total mass, total volume, growth rate and depth of growth of struvite crystals decreased with the increasing extract concentrations in the supernatant solutions. The enhancement of dissolution rate and fragmentation of struvite crystals suggested potential application o...
Journal of Environmental Pathology, Toxicology and Oncology, 2012
The objective of this study was to investigate the chemopreventive potential of (+)-catechin-rich... more The objective of this study was to investigate the chemopreventive potential of (+)-catechin-rich extract of Acacia catechu heartwood (AQCE) against 7,12-dimethylbenz[a]anthracene (DMBA)-induced hepatocellular carcinoma in Balb/c mice. The levels of liver injury markers, tumor markers, and oxidative stress were measured in serum and liver tissues. Furthermore, the levels of transcription factors were measured by ELISA. Tumor incidence was found to be 100% in DMBA-treated animals (group 2), whereas, in AQCE-treated animals (group 3), it was 37.5%. AQCE treatment reduced liver injury and restored tumor-marker levels. AQCE also significantly reduced elevated levels of nitrite and hepatic malondialdehyde (MDA) in DMBA-treated animals. Additionally, AQCE modulated the activity of different antioxidant enzymes in liver tissues. Eventually, AQCE also significantly improved body weight, prevented the increase of relative liver weight, and maintained the liver cellular architecture within the normal range of the control. A significant increase in the protein levels of p53, c-jun, and NF-κB (p65) were observed in DMBA-treated mice, whereas low levels of these markers were observed in DMBA+AQCE-treated animals. These findings strongly suggest (1) that (+)-catechin-rich AQCE exerts a chemopreventive effect by modulating the levels of lipid peroxidation and by promoting the enzymatic and non-enzymatic antioxidant defense system and (2) that this effect is linked to the expression of transcription factors during hepatocarcinogenesis.
Objectives Acacia catechu heartwood contains significant amounts of polyphenolic compounds that e... more Objectives Acacia catechu heartwood contains significant amounts of polyphenolic compounds that exhibit powerful antioxidant activity. The purpose of this study was to evaluate the cytotoxicity of A. catechu heartwood extracts in a human epithelial carcinoma cell line (A431) and antitumour activity against DMBA/TPA induced squamous cell carcinoma in Balb/c mice. Methods Various extracts, including aqueous, ethyl acetate, chloroform and n-hexane, were tested for cytotoxic properties on a human epithelial carcinoma cell line (A431) by using MTT, sulforhodamine B and lactate dehydrogenase leakage assays. The standardized A. catechu heartwood aqueous extract (AQCE) was further evaluated for antitumour activity against 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) induced skin carcinoma in Balb/c mice. Key findings The results showed that administration of AQCE showed a dose-dependent growth inhibition response, with an IC50 value of 78.56 µg/ml. Tumour...
The objective of the present study was to prepare nanofibers of Lornoxicam by Electro spinning te... more The objective of the present study was to prepare nanofibers of Lornoxicam by Electro spinning technique and to increase the drug bioavailability using different polymers such as PMMA, Ethyl Cellulose, Polyethylene oxide, Gelatin. Totally 15 different formulations of Lornoxicam were prepared by Electro spinning technique and prepared nanofibers are evaluated for various characteristics like drug content, in-vitro release studies, DSC, XRD and SEM studies. The dissolution profile of optimized formulation was compared with that of the API and the marketed product (Lofecam) and the Optimized formulation (F15) exhibited similar dissolution profiles as that of innovator brand. The drug release from the optimized formulation (F15) was slow and extended over a period of 8hrs and these nanofibers were found to be suitable for the oral controlled release formulation. The Optimized formulation (F15) followed First-order release kinetics as it showed highest linearity (r 2 =0.952).
Objective. The chemopreventive potential of (+)-catechin-rich extract of Acacia catechu (L.f.) Wi... more Objective. The chemopreventive potential of (+)-catechin-rich extract of Acacia catechu (L.f.) Willd. heartwood (AQCE) was evaluated against human breast adenocarcinoma cell line (MCF-7) and 7,12-dimethylbenz[ a]anthracene (DMBA)–induced mammary carcinoma in Balb/c mice. Methods. Cell cytotoxicity was investigated using different colorimetric assays. Apoptosis was observed using diphenylamine assay and fluorescent microscopy. AQCE was further evaluated for antitumor activity against DMBA-induced mammary carcinoma. The levels of tumor markers and oxidative stress were measured. Furthermore, level of transcription factors was measured by enzyme-linked immunosorbent assay. Results. The results showed that administration of AQCE showed a dose-dependent growth inhibition response and DNA fragmentation in MCF-7 cells. Tumor multiplicity was significantly decreased to 42.91% with AQCE when compared with DMBA-treated animals. The levels of tumor markers such as total sialic acid and lipid-a...
Pterocarnin A, isolated from the bark of Pterocarya stenoptera (Juylandaceae), was investigated f... more Pterocarnin A, isolated from the bark of Pterocarya stenoptera (Juylandaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. To identify the anticancer mechanism of pterocarnin A, we assayed its effects on apoptosis, cell cycle distribution, and levels of p53, p21/WAF1, Fas/APO-1 receptor and Fas ligand. The results showed that pterocarnin A induced apoptosis of MCF-7 cells without mediation of p53 and p21/WAF1. We suggest that the Fas/Fas ligand apoptotic system is the main pathway of pterocarnin A-mediated apoptosis of MCF-7 cells. Our study reports here for the first time that the activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of pterocarnin A in MCF-7 cells.
We investigated the antifungal potential of short lipopeptides against clinical fungal isolates w... more We investigated the antifungal potential of short lipopeptides against clinical fungal isolates with an objective to evaluate their clinical feasibility. All tested lipopeptides exhibit good antifungal activity with negligible difference between the MICs against susceptible and drug resistant clinical fungal isolates. The MTT assay results revealed the lower cytotoxicity of lipopeptides towards mammalian cells (NRK-52E). In particular, LP24 displayed highest potency against most of the tested fungal isolates with MICs in the range of 1.5-4.5 μg/mL. Calcein dye leakage experiments with model membrane suggested the membrane active mode of action for LP24. Extending our work from model membranes to intact Aspergillus fumigatus in scanning electron micrographs we could visualize surface perturbation caused by LP24. LP24 (5 mg/kg), significantly reduces the A. fumigatus burden among the various organs of infected animals and 70% of the infected mice were survive when observed for 28 days. This study underscores the potential of small cationic abiotic lipopeptides to develop into the next generation antimicrobial therapy. This article is protected by copyright. All rights reserved.
Abiotic Stress-Mediated Sensing and Signaling in Plants: An Omics Perspective, 2018
The growth and development of plant are adversely affected due to various abiotic stresses such a... more The growth and development of plant are adversely affected due to various abiotic stresses such as cold, heat, drought, salinity, heavy metal, hypoxia, etc. Plant adaptation to the stress conditions is brought out by changes in its physiological parameters which have underlying molecular basis. Multiple signalling pathways are activated in response to particular stress which are often complex and work through a network of trans-and cis-regulatory factors. In the following chapter, we summarize the current understanding of cis-regulatory factors, viz. promoters and transcription factor binding motifs, which are responsible for relaying signals during anabiotic signalling cascade ultimately preventing and mitigating the ill effect of climatic conditions on plant growth and survival.
Wheat is an important Rabi Crop, which is grown between October and December and harvested betwee... more Wheat is an important Rabi Crop, which is grown between October and December and harvested between April and May. Globally, wheat is the leading source of protein than maize or rice. A study was undertaken to examine the genetic diversity of 20 wheat (Triticum aestivum L.) using designed EST-SSR markers. The similarity coefficient value for all the 20 genotypes ranged from 0.23 to 0.63. The minimum similarity exhibited by genotype PBW550 and DBW17. Whereas, the maximum similarity was shown by genotype DBW16 and RAJ4246. The pair wise genetic similarities among all pairs of samples were estimated and subjected to cluster analysis. The UPGMA based clusters shows that all the genotypes are interlinked with each other and exhibited high genetic similarity. The UPGMA based clustering of 20 wheat genotypes grouped the wheat genotypes into three distinct clusters at 70% similarity coefficient.
Key message Extensive regulatory divergence during development, abiotic stress and ABA regime obs... more Key message Extensive regulatory divergence during development, abiotic stress and ABA regime observed amongst promoter homologs and homeologs of MIR319 from Brassica juncea . Abstract Gene duplication followed by sub-functionalization, neo-functionalization, and pseudogenization are routes to functional and adaptive diversification. The influence of polyploidy on protein-coding genes is well investigated but little is known about their impact on transcriptional regulation of MIRNA gene family. The present study was therefore performed with an aim to uncover regulatory diversification of MIR319 homologs and homeologs in Brassica juncea. We employed comparative genomics to identify and isolate six promoter homologs of MIR319 from B. juncea . Regulatory diversification was studied using analysis of reporter activity driven by BjMIR319 promoters in a heterologous system employing promoter–reporter fusion constructs. MIR319 is known to play important roles in leaf and flower development, and multiple stress responses. Reporter activity was therefore monitored during development, hormonal and stress regimes. In-silico analyses revealed differential distribution of cis -regulatory motifs and functional analysis revealed distinct spatiotemporal expression patterns. The significance of presence of selected cis -regulatory motifs corresponding to heat, cold, salt and ABA stress were further functionally validated. It was observed that promoter of Bj -MIR319a-A01 was upregulated in response to cold and salt stress, while promoter of Bj -MIR319c-A04 (D1) and Bj -MIR319c-A05 (FL) were downregulated in response to high temperature. In summary, comparative analysis of homologous promoters from Brassica juncea , an allopolyploid revealed extensive sequence and functional diversity. Spatiotemporal activity of reporter gene driven by BjMIR319 promoter was distinct, and partially overlapping with from those reported previously for A. thaliana . The present study clearly demonstrates regulatory divergence amongst promoter homologs of MIR319 in Brassica juncea during development and stress response, and underlines the urgent need for dissection of promoter function and detailed characterization including identification of interacting trans- factors. Genbank accession numbers : MT379853-MT379858.
Identification and functional analysis of promoters is critical towards gaining insights into tra... more Identification and functional analysis of promoters is critical towards gaining insights into transcriptional regulation, and helps in identifying interacting trans-factors. Analysis of MIRNA promoter can differentiate the function of paralogs and homeologs where identifying the role of members of MIRNA family is difficult based on small RNA blots due to near-identical mature sequences. The role of miRNA as regulators of development and adaptation in polyploid species-Brassica, and the impact of polyploidy on divergence among paralogs and homeologs especially with reference to transcriptional regulation remains unexplored. We identified homologs of MIR159 from 137 species across plants based on their homology to pre-MIR159A, MIR159B, and MIR159C from Arabidopsis and retrieved their promoter sequences. Promoter sequence analysis revealed high level of divergence; albeit clades of closely related taxonomic units were obtained. We detected biased, but no lineagespecific distribution of transcription factor binding motifs (TFBS) in families. Phylogenetic reconstruction in Brassicaceae revealed genome-and sub-genome specific clades. We isolated three homeologs of MIR159A, and one of MIR159C from the A-genome of B. juncea. Functional characterization involved transgenic lines in A. thaliana Col-0 with promoter::reporter transcriptional fusions (p-MIR159::GUS::ter) and monitoring of reporter activity during development, abiotic stresses, and after administering hormones. Comparison of reporter activity of full-length promoters across homeologs and paralogs reveal extensive functional diversification. Comparative analysis of reporter activity of nested deletions, and with distribution of TFBS did not yield a clear correlation. In summary, analysis of GUS during development, hormone treatment and abiotic stresses reveal complex transcriptional regulation of MIR159 expression.
The availability of a large number of whole-genome sequences allows comparative genomic analysis ... more The availability of a large number of whole-genome sequences allows comparative genomic analysis to reveal and understand evolution of regulatory regions and elements. The role played by events such as whole-genome and segmental duplications followed by genome fractionation in shaping genomic landscape and in expansion of gene families is crucial toward developing insights into evolutionary trends and consequences such as sequence and functional diversification. Members of Brassicaceae are known to have experienced several rounds of whole-genome duplication (WGD) that have been termed as paleopolyploidy, mesopolyploidy, and neopolyploidy. Such repeated events led to the creation and expansion of a large number of gene families. MIR319 is reported to be one of the most ancient and conserved plant MIRNA families and plays a role in growth and development including leaf development, seedling development, and embryo patterning. We have previously reported functional diversification of members of miR319 in Brassica oleracea affecting leaf architecture; however, the evolutionary history of the MIR319 gene family across Brassicaceae remains unknown and requires investigation. We therefore identified homologous and homeologous segments of ca. 100 kb, with or without MIR319, performed comparative synteny analysis and genome fractionation studies. We detected variable rates of gene retention across members of Brassicaceae when genomic blocks of MIR319a, MIR319b, and MIR319c were compared either between themselves or against Arabidopsis thaliana genome which was taken as the base genome. The highest levels of shared genes were found between A. thaliana and Capsella rubella in both MIR319b-and MIR319c-containing genomic segments, and with the closest species of A. thaliana, A. lyrata, only in MIR319a-containing segment. Synteny analysis across 12 genomes (with 30 sub-genomes) revealed MIR319c to be the most conserved MIRNA loci (present in 27 genomes/sub-genomes) followed by MIR319a (present in 23 genomes/sub-genomes); MIR319b was found to be frequently lost (present in 20 genomes/sub-genomes) and thus is under least selection pressure for retention. Genome fractionation revealed extensive and differential loss of MIRNA homeologous loci and flanking genes from various sub-genomes of Brassica species that is in accordance with their older history of polyploidy when compared to Camelina sativa, a recent neopolyploid, where the effect of genome fractionation was least. Finally, estimation of phylogenetic relationship using precursor sequences of MIR319 reveals MIR319a and MIR319b form sister clades, with MIR319c forming a separate clade. An intraspecies synteny analysis between MIR319a-, MIR319b-, and MIR319c-containing genomic segments suggests segmental duplications at the base of Brassicaceae to be responsible for the origin of MIR319a and MIR319b.
We present here a modified, sonication-assisted transient transformation assay for rapid analysis... more We present here a modified, sonication-assisted transient transformation assay for rapid analysis of cis-regulatory elements. We tested promoter elements from locus of by generating stable transgenic lines and compared the transcriptional activity of GUS reporter with that of the transient assay method. To obtain reliable and repeatable results, and to omit false-positive data, we optimized several parameters including sonication duration and cycle and concentration of measured as optical density (O.D.) at 600 nm. To the best of our knowledge, this is the first report of promoter characterization of MIR159B from , and comparative analysis of stable and transient lines. Our analysis shows that the protocol described herein allows understanding promoter activity/transcriptional control in tissues other than leaf or protoplast which have remained the mainstay for transient analysis thus far. We tested reporter gene GUS under the control of constitutive promoter, CaMV 35S, and from . We...
Formation of urinary stone is a serious and debilitating problem throughout the world. In the pre... more Formation of urinary stone is a serious and debilitating problem throughout the world. In the present study, the inhibitory effect of aqueous extract of root of Rotula aquatica was investigated against struvite crystals (one of the components of urinary stone) grown in vitro using single diffusion gel growth technique. For setting the gel, sodium metasilicate solution (specific gravity 1.05) and 0.5 M aqueous solution of ammonium dihydrogen phosphate were mixed, so that the pH of the mixture could be set at 7.0. Equal amounts of supernatant solution of magnesium acetate (1.0 M) prepared with 0.0%, 0.5% and 1% concentrations of the extract were gently poured on the set gels. It was observed that the number, dimension, total mass, total volume, growth rate and depth of growth of struvite crystals decreased with the increasing extract concentrations in the supernatant solutions. The enhancement of dissolution rate and fragmentation of struvite crystals suggested potential application o...
Journal of Environmental Pathology, Toxicology and Oncology, 2012
The objective of this study was to investigate the chemopreventive potential of (+)-catechin-rich... more The objective of this study was to investigate the chemopreventive potential of (+)-catechin-rich extract of Acacia catechu heartwood (AQCE) against 7,12-dimethylbenz[a]anthracene (DMBA)-induced hepatocellular carcinoma in Balb/c mice. The levels of liver injury markers, tumor markers, and oxidative stress were measured in serum and liver tissues. Furthermore, the levels of transcription factors were measured by ELISA. Tumor incidence was found to be 100% in DMBA-treated animals (group 2), whereas, in AQCE-treated animals (group 3), it was 37.5%. AQCE treatment reduced liver injury and restored tumor-marker levels. AQCE also significantly reduced elevated levels of nitrite and hepatic malondialdehyde (MDA) in DMBA-treated animals. Additionally, AQCE modulated the activity of different antioxidant enzymes in liver tissues. Eventually, AQCE also significantly improved body weight, prevented the increase of relative liver weight, and maintained the liver cellular architecture within the normal range of the control. A significant increase in the protein levels of p53, c-jun, and NF-κB (p65) were observed in DMBA-treated mice, whereas low levels of these markers were observed in DMBA+AQCE-treated animals. These findings strongly suggest (1) that (+)-catechin-rich AQCE exerts a chemopreventive effect by modulating the levels of lipid peroxidation and by promoting the enzymatic and non-enzymatic antioxidant defense system and (2) that this effect is linked to the expression of transcription factors during hepatocarcinogenesis.
Objectives Acacia catechu heartwood contains significant amounts of polyphenolic compounds that e... more Objectives Acacia catechu heartwood contains significant amounts of polyphenolic compounds that exhibit powerful antioxidant activity. The purpose of this study was to evaluate the cytotoxicity of A. catechu heartwood extracts in a human epithelial carcinoma cell line (A431) and antitumour activity against DMBA/TPA induced squamous cell carcinoma in Balb/c mice. Methods Various extracts, including aqueous, ethyl acetate, chloroform and n-hexane, were tested for cytotoxic properties on a human epithelial carcinoma cell line (A431) by using MTT, sulforhodamine B and lactate dehydrogenase leakage assays. The standardized A. catechu heartwood aqueous extract (AQCE) was further evaluated for antitumour activity against 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) induced skin carcinoma in Balb/c mice. Key findings The results showed that administration of AQCE showed a dose-dependent growth inhibition response, with an IC50 value of 78.56 µg/ml. Tumour...
The objective of the present study was to prepare nanofibers of Lornoxicam by Electro spinning te... more The objective of the present study was to prepare nanofibers of Lornoxicam by Electro spinning technique and to increase the drug bioavailability using different polymers such as PMMA, Ethyl Cellulose, Polyethylene oxide, Gelatin. Totally 15 different formulations of Lornoxicam were prepared by Electro spinning technique and prepared nanofibers are evaluated for various characteristics like drug content, in-vitro release studies, DSC, XRD and SEM studies. The dissolution profile of optimized formulation was compared with that of the API and the marketed product (Lofecam) and the Optimized formulation (F15) exhibited similar dissolution profiles as that of innovator brand. The drug release from the optimized formulation (F15) was slow and extended over a period of 8hrs and these nanofibers were found to be suitable for the oral controlled release formulation. The Optimized formulation (F15) followed First-order release kinetics as it showed highest linearity (r 2 =0.952).
Objective. The chemopreventive potential of (+)-catechin-rich extract of Acacia catechu (L.f.) Wi... more Objective. The chemopreventive potential of (+)-catechin-rich extract of Acacia catechu (L.f.) Willd. heartwood (AQCE) was evaluated against human breast adenocarcinoma cell line (MCF-7) and 7,12-dimethylbenz[ a]anthracene (DMBA)–induced mammary carcinoma in Balb/c mice. Methods. Cell cytotoxicity was investigated using different colorimetric assays. Apoptosis was observed using diphenylamine assay and fluorescent microscopy. AQCE was further evaluated for antitumor activity against DMBA-induced mammary carcinoma. The levels of tumor markers and oxidative stress were measured. Furthermore, level of transcription factors was measured by enzyme-linked immunosorbent assay. Results. The results showed that administration of AQCE showed a dose-dependent growth inhibition response and DNA fragmentation in MCF-7 cells. Tumor multiplicity was significantly decreased to 42.91% with AQCE when compared with DMBA-treated animals. The levels of tumor markers such as total sialic acid and lipid-a...
Pterocarnin A, isolated from the bark of Pterocarya stenoptera (Juylandaceae), was investigated f... more Pterocarnin A, isolated from the bark of Pterocarya stenoptera (Juylandaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. To identify the anticancer mechanism of pterocarnin A, we assayed its effects on apoptosis, cell cycle distribution, and levels of p53, p21/WAF1, Fas/APO-1 receptor and Fas ligand. The results showed that pterocarnin A induced apoptosis of MCF-7 cells without mediation of p53 and p21/WAF1. We suggest that the Fas/Fas ligand apoptotic system is the main pathway of pterocarnin A-mediated apoptosis of MCF-7 cells. Our study reports here for the first time that the activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of pterocarnin A in MCF-7 cells.
We investigated the antifungal potential of short lipopeptides against clinical fungal isolates w... more We investigated the antifungal potential of short lipopeptides against clinical fungal isolates with an objective to evaluate their clinical feasibility. All tested lipopeptides exhibit good antifungal activity with negligible difference between the MICs against susceptible and drug resistant clinical fungal isolates. The MTT assay results revealed the lower cytotoxicity of lipopeptides towards mammalian cells (NRK-52E). In particular, LP24 displayed highest potency against most of the tested fungal isolates with MICs in the range of 1.5-4.5 μg/mL. Calcein dye leakage experiments with model membrane suggested the membrane active mode of action for LP24. Extending our work from model membranes to intact Aspergillus fumigatus in scanning electron micrographs we could visualize surface perturbation caused by LP24. LP24 (5 mg/kg), significantly reduces the A. fumigatus burden among the various organs of infected animals and 70% of the infected mice were survive when observed for 28 days. This study underscores the potential of small cationic abiotic lipopeptides to develop into the next generation antimicrobial therapy. This article is protected by copyright. All rights reserved.
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