Does epigenetic polymorphism contribute to phenotypic variances in <Emphasis Type="Italic">Jatropha curcas</Emphasis> L.?

Background  

There is a growing interest in Jatropha curcas L. (jatropha) as a biodiesel feedstock plant. Variations in its morphology and seed productivity have been well documented. However, there is the lack of systematic comparative evaluation of distinct collections under same climate and agronomic practices. With the several reports on low genetic diversity in jatropha collections, there is uncertainty on genetic contribution to jatropha morphology.     

Coumarin Schiff-bases: as antioxidant and possibly anti-inflammatory agents

Coumarin Schiff-bases (CSB) possessing different substituents on the 4-methyl-2-substituted phenyl imino-2H-chromene-7-ol molecule were evaluated for their in-vitro antioxidant and plausible anti-inflammatory potential. The antioxidant studies of selected CSB were carried out by determining their reducing power, OH* radical scavenging activity, scavenging of stable 2,2-diphenyl-l-picrylhydrazine (DPPH*) radical and inhibition of the polyphenol oxidase (PPO) enzyme. The assessment of possible anti-inflammatory potential was performed by trypsin inhibition assay and inhibition of beta-glucuronidase. All the CSBs under study showed significant reducing effects. The majority of the tested CSB were found to be effective scavengers of DPPH* radical with moderate to low OH* scavenging ability and significantly inhibited the activity of PPO. With few exceptions, results from the inhibition assay of trypsin and beta-glucuronidase were not encouraging, however they may be helpful in defining structure-activity relationships in further optimization of the lead molecules.     

Synthesis,Characterization and In Vitro Study of Biocompatible Cinnamaldehyde Functionalized Magnetite Nanoparticles (CPGF Nps) For Hyperthermia and Drug Delivery Applications in Breast Cancer

Cinnamaldehyde, the bioactive component of the spice cinnamon, and its derivatives have been shown to possess anti-cancer activity against various cancer cell lines. However, its hydrophobic nature invites attention for efficient drug delivery systems that would enhance the bioavailability of cinnamaldehyde without affecting its bioactivity. Here, we report the synthesis of stable aqueous suspension of cinnamaldehyde tagged Fe₃O₄ nanoparticles capped with glycine and pluronic polymer (CPGF NPs) for their potential application in drug delivery and hyperthermia in breast cancer. The monodispersed superparamagnetic NPs had an average particulate size of ∼20 nm. TGA data revealed the drug payload of ∼18%. Compared to the free cinnamaldehyde, CPGF NPs reduced the viability of breast cancer cell lines, MCF7 and MDAMB231, at lower doses of cinnamaldehyde suggesting its increased bioavailability and in turn its therapeutic efficacy in the cells. Interestingly, the NPs were non-toxic to the non-cancerous HEK293 and MCF10A cell lines compared to the free cinnamaldehyde. The novelty of CPGF nanoparticulate system was that it could induce cytotoxicity in both ER/PR positive/Her2 negative (MCF7) and ER/PR negative/Her2 negative (MDAMB231) breast cancer cells, the latter being insensitive to most of the chemotherapeutic drugs. The NPs decreased the growth of the breast cancer cells in a dose-dependent manner and altered their migration through reduction in MMP-2 expression. CPGF NPs also decreased the expression of VEGF, an important oncomarker of tumor angiogenesis. They induced apoptosis in breast cancer cells through loss of mitochondrial membrane potential and activation of caspase-3. Interestingly, upon exposure to the radiofrequency waves, the NPs heated up to 41.6°C within 1 min, suggesting their promise as a magnetic hyperthermia agent. All these findings indicate that CPGF NPs prove to be potential nano-chemotherapeutic agents in breast cancer.     

RuvbL1 and RuvbL2 enhance aggresome formation and disaggregate amyloid fibrils

The aggresome is an organelle that recruits aggregated proteins for storage and degradation. We performed an siRNA screen for proteins involved in aggresome formation and identified novel mammalian AAA+ protein disaggregases RuvbL1 and RuvbL2. Depletion of RuvbL1 or RuvbL2 suppressed aggresome formation and caused buildup of multiple cytoplasmic aggregates. Similarly, downregulation of RuvbL orthologs in yeast suppressed the formation of an aggresome‐like body and enhanced the aggregate toxicity. In contrast, their overproduction enhanced the resistance to proteotoxic stress independently of chaperone Hsp104. Mammalian RuvbL associated with the aggresome, and the aggresome substrate synphilin‐1 interacted directly with the RuvbL1 barrel‐like structure near the opening of the central channel. Importantly, polypeptides with unfolded structures and amyloid fibrils stimulated the ATPase activity of RuvbL. Finally, disassembly of protein aggregates was promoted by RuvbL. These data indicate that RuvbL complexes serve as chaperones in protein disaggregation.     

In-vitro evaluation of selected chalcones for antioxidant activity

Synthetic chalcones (SCs) having different side chains on the 1-(2-Hydroxy-3-(2-hydroxy-cyclohexyl)-4,6 dimethoxy-phenyl(-methanone structure were examined in-vitro for their antioxidant abilities by DPPH (2,2-diphenyl-1-picryl hydrazine) radical scavenging activity, reducing ability, OH radical scavenging activity, inhibition of polyphenol oxidase (PPO) and formation of diene conjugates. Overall, with few exceptions, all the SCs showed moderate biological activity in all the parameters examined. The SCs were found to be reactive towards DPPH radical and had considerable reducing ability. With few exceptions, all the test compounds under study were found to possess moderate to poor OH radical scavenging activity and inhibited PPO significantly and all were found to be effective inhibitors of hydroperoxide formation. These findings suggest that these SCs can be considered as potential antioxidant agents which might be further explored for the design of lead antioxidant drug candidates.     

Cloning, expression, purification, and characterization of the acid alpha-mannosidase from Trypanosoma cruzi

The acid alpha-mannosidase of Trypanosoma cruzi is a broad-specificity hydrolase involved in the catabolism of glycoconjugates, presumably in the digestive vacuole. We have cloned the alpha-mannosidase gene from a T.cruzi epimastigote genomic library. The alpha-mannosidase gene was determined to be single copy by Southern analysis, and similar sequences were not detected in genomic digests of either Trypanosoma brucei or Leishmania donovani. The coding region was subcloned into the Pichia pastoris expression vector pPICZ, and alpha-mannosidase activity was detected in the medium of induced cultures. The recombinant alpha- mannosidase demonstrated a pH optimum, inhibition by swainsonine, Km, and substrate specificity consistent with the characteristics of the alpha-mannosidase previously purified from T.cruzi epimastigotes. The recombinant enzyme was purified 103-fold from the culture medium of Pichia pastoris and had a native molecular mass of 359 kDa by gel filtration. A combination of SDS-PAGE, deglycosylation with endo H, and NH2-terminal sequencing indicates that the enzyme is originally synthesized as a homodimeric polypeptide that is subsequently cleaved to form a heterotetramer composed of 57 and 46 kDa subunits. A polyclonal antibody raised to the recombinant enzyme was shown to immunoprecipitate the alpha-mannosidase from T.cruzi cell extracts and will be used in future immunolocalization studies.