Phytoremediation potential of Portulaca grandiflora Hook. (Moss-Rose) in degrading a sulfonated diazo reactive dye Navy Blue HE2R (Reactive Blue 172)

Wild and tissue cultured plants of Portulaca grandiflora Hook. have shown to be able to decolorize a sulfonated diazo dye Navy Blue HE2R (NBHE2R) up to 98% in 40 h. A significant induction in the activities of lignin peroxidase, tyrosinase and DCIP reductase was observed in the roots during dye decolorization. The wild plants and tissue cultures could independently decolorize and degrade NBHE2R into metabolites viz. N-benzylacetamide and 6-diazenyl-4-hydroxynaphthalene-2-sulfonic acid. A dye mixture and a textile effluent were also decolorized efficiently by P. grandiflora. The phytotoxicity study revealed reduction in the toxicity due to metabolites formed after dye degradation.     

Dendrimer versus linear conjugate: Influence of polymeric architecture on the delivery and anticancer effect of paclitaxel

The relative difference in polymeric architectures of dendrimer and linear bis(poly(ethylene glycol)) (PEG) polymer in conjugation with paclitaxel has been described. Paclitaxel, a poorly soluble anticancer drug, was covalently conjugated with PAMAM G4 hydroxyl-terminated dendrimer and bis(PEG) polymer for the potential enhancement of drug solubility and cytotoxicity. Both conjugates were characterized by 1NMR, HPLC, and MALDI/TOF. In addition, molecular conformations of dendrimer, bis(PEG), paclitaxel, and its polymeric conjugates were studied by molecular modeling. Hydrolysis of the ester bond in the conjugate was analyzed by HPLC using esterase hydrolyzing enzyme. In vitro cytotoxicity of dendrimer, bis(PEG), paclitaxel, and polymeric conjugates containing paclitaxel was evaluated using A2780 human ovarian carcinoma cells. Cytotoxicity increased by 10-fold with PAMAM dendrimer-succinic acid-paclitaxel conjugate when compared with free nonconjugated drug. Data obtained indicate that the nanosized dendritic polymer conjugates can be used with good success as anticancer drug carriers.     

Chloroplasts alter their morphology and accumulate at the pathogen interface during infection by Phytophthora infestans

Upon immune activation, chloroplasts switch off photosynthesis, produce antimicrobial compounds and associate with the nucleus through tubular extensions called stromules. Although it is well established that chloroplasts alter their position in response to light, little is known about the dynamics of chloroplast movement in response to pathogen attack. Here, we report that during infection with the Irish potato famine pathogen Phytophthora infestans, chloroplasts accumulate at the pathogen interface, associating with the specialized membrane that engulfs the pathogen haustorium. The chemical inhibition of actin polymerization reduces the accumulation of chloroplasts at pathogen haustoria, suggesting that this process is partially dependent on the actin cytoskeleton. However, chloroplast accumulation at haustoria does not necessarily rely on movement of the nucleus to this interface and is not affected by light conditions. Stromules are typically induced during infection, embracing haustoria and facilitating chloroplast interactions, to form dynamic organelle clusters. We found that infection-triggered stromule formation relies on BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1 (BAK1)-mediated surface immune signaling, whereas chloroplast repositioning towards haustoria does not. Consistent with the defense-related induction of stromules, effector-mediated suppression of BAK1-mediated immune signaling reduced stromule formation during infection. On the other hand, immune recognition of the same effector stimulated stromules, presumably via a different pathway. These findings implicate chloroplasts in a polarized response upon pathogen attack and point to more complex functions of these organelles in plant–pathogen interactions.     

Synthesis and antitumor activity of new retinobenzoic acids

New retinobenzoic acid derivatives have been synthesized starting from 1,2,3,4-tetrahydro-1,1,2,4,4,6-hexamethylnaphthalene and 1,1,2,3,3-pentamethylindane. Four of the synthetic compounds displayed potent cytotoxic activities in vitro against human breast cancer and leukemic cell lines. Thus, these molecules can be further evaluated for the treatment of human leukemia and breast cancer.     

Activity of dendrimer-methotrexate conjugates on methotrexate-sensitive and -resistant cell lines

Dendritic nanostructures can play a key role in drug delivery, due to the high density and variety of surface functional groups that can facilitate and modulate the delivery process. We have investigated the effect of dendrimer end-functionality on the activity of polyamido amine (PAMAM) dendrimer-methotrexate (MTX) conjugates in MTX-sensitive and MTX-resistant human acute lymphoblastoid leukemia (CCRF-CEM) and Chinese hamster ovary (CHO) cell lines. Two amide-bonded PAMAM dendrimer-MTX conjugates were prepared using a dicyclohexylcarbodiimide (DCC) coupling reaction: one between a carboxylic acid-terminated G2.5 dendrimer and the amine groups of the MTX (conjugate A) and another between an amine-terminated G3 dendrimer and the carboxylic acid group of the MTX (conjugate B). Our studies suggest that conjugate A showed an increased drug activity compared to an equimolar amount of free MTX toward both sensitive and resistant cell lines, whereas conjugate B did not show significant activity on any of the cell lines. Despite substantially impaired MTX transport by MTX-resistant CEM/MTX and RII cells, conjugate A showed sensitivity increases of approximately 8- and 24-fold (based on IC50 values), respectively, compared to free MTX. Co-incubation of the cells with adenosine and thymidine along with either conjugate A or MTX resulted in almost complete protection, suggesting that the conjugate achieves its effect on dihyrofolate reductase (DHFR) enzyme through the same mechanism as that of MTX. The differences in cytotoxicity of these amide-bonded conjugates may be indicative of differences in the intracellular drug release from the cationic dendrimer (conjugate B) versus the anionic dendrimer (conjugate A), perhaps due to the differences in lysosomal residence times dictated by the surface functionality. These findings demonstrate the feasibility of using dendrimers as drug delivery vehicles for achieving higher therapeutic effects in chemotherapy, especially in drug-resistant cells.     

Development of a low-cost, phyto-tunnel system using Portulaca grandiflora and its application for the treatment of dye-containing wastewaters

A phyto-tunnel was developed using a drilled PVC pipe. It was planted with Portulaca grandiflora and used for the treatment of a textile effluent and a dye mixture. COD, BOD, TOC, conductivity, turbidity, total suspended solids and total dissolved solids of the textile effluent, and dye mixture were decreased by 57, 45, 43, 52, 76, 77 and 24 % within 96 h, and 49, 62, 41, 63, 58, 71 and 33 %, within 60 h, respectively, after treatment. The effluent and dye mixture were decolorized up to 87 and 90 % within 96 and 60 h, respectively. Significant induction in activities of lignin peroxidase, tyrosinase and DCIP reductase was observed in root tissues of the plants. FTIR, HPLC and HPTLC of untreated and treated samples showed the formation of new metabolites and preferential dye removal. Phytotoxicity studies revealed the non-toxic nature of the metabolites.     

A sequential aerobic/microaerophilic decolorization of sulfonated mono azo dye Golden Yellow HER by microbial consortium GG-BL

This study is a part of efforts to develop new batch method with the help of prepared consortium GG-BL using two microbial cultures viz. Galactomyces geotrichum MTCC 1360 and Brevibacillus laterosporus NCIM 2298, varying oxidation conditions for the bio-treatment processes to produce reusable water by decolorization of Golden Yellow HER (GYHER) to less toxic metabolites. Consortium was found to be much faster for decolorization and degradation of GYHER as compared to the individual strains. The intensive metabolic activity of these strains led to 100% decolorization of GYHER (50 mg l⁻¹) within 24 h with significant reduction in chemical oxygen demand (84%) and total organic carbon (63%). The presence of veratryl alcohol oxidase, NADH-DCIP reductase and induction in laccase, tyrosinase, azo reductase and riboflavin reductase during decolorization suggests their role in decolorization process. Substrate staining of nondenaturing polyacrylamide electrophoresis gel (PAGE) also confirms induction of oxidative enzymes during GYHER degradation. The degradation of the GYHER into different metabolites by individual organism and in consortium was confirmed using High Performance Thin Layer Chromatography (HPTLC), High Performance Liquid Chromatography (HPLC), Fourier Transform Infra Red Spectroscopy (FTIR), Gas Chromatography Mass Spectroscopy (GC–MS) analysis. Phytotoxicity studies revealed nontoxic nature of the metabolites of GYHER.     

Fluoride Alters Serum Elemental (Calcium,Magnesium, Copper,and Zinc) Homeostasis Along with Erythrocyte Carbonic Anhydrase Activity in Fluorosis Endemic Villages and Restores on Supply of Safe Drinking Water in School-Going Children of Nalgonda District,India

The present study aimed to determine the serum trace elements (copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg)) along with erythrocyte carbonic anhydrase (CA) activity and effect of intervention with safe drinking water for 5 years in the school children of fluorosis endemic area. For this purpose, three categories of villages were selected based on drinking water fluoride (F): Category I (control, F?=?1.68 mg/L), category II (affected F?=?3.77 mg/L), and category III (intervention village) where initial drinking water F was 4.51 mg/L, and since the last 5 years, they were drinking water containing <?1.0 mg/L F. The results revealed that urinary F was significantly (P?<?0.05) higher in category II compared to categories I and III. A significant (P?<?0.05) increase in serum Cu and Mg was observed in category II compared to category I. Serum Zn and Ca was significantly (P?<?0.05) decreased in categories II and III compared to category I. The erythrocyte CA activity was decreased in the category II compared to category I. However, in the category III, erythrocyte CA activity was comparable to the control group. In conclusion, F exposure altered elemental homeostasis which has restored to some extent on intervention by safe drinking water for 5 years in school-going children.     

Synthesis, cellular transport, and activity of polyamidoamine dendrimer-methylprednisolone conjugates

Dendrimers have emerged as promising multifunctional nanomaterials for drug delivery due to their well-defined size and tailorability. We compare two schemes to obtain methylprednisolone (MP)-polyamidoamine dendrimer (PAMAM-G4-OH) conjugate. Glutaric acid (GA) was used as a spacer to facilitate the conjugation. In scheme A, PAMAM-G4-OH was first coupled to GA and then further conjugated with MP to obtain PAMAM-G4-GA-MP conjugates. This scheme yields a lower conjugation ratio of MP, presumably because of lower reactivity and steric hindrance for the steroid at the crowded dendrimer periphery. In scheme B, this steric hindrance was overcome by first preparing the MP-GA conjugate, which was then coupled to the PAMAM-G4-OH dendrimer. The (1)H NMR spectrum of the conjugate from scheme B indicates a conjugation of 12 molecules of MP with the dendrimer, corresponding to a payload of 32 wt %. In addition, conjugates were further fluorescent-labeled with fluoroisothiocynate (FITC) to evaluate the dynamics of cellular entry. Flow cytometry and UV/visible spectroscopic analysis showed that the conjugate is rapidly taken up inside the cell. Fluorescence and confocal microscopy images on A549 human lung epithelial carcinoma cells treated with conjugates show that the conjugate is mostly localized in cytosol. MP-GA-dendrimer conjugate showed comparable pharmacological activity to free MP, as measured by inhibition of prostaglandin secretion. These conjugates can potentially be further conjugated with a targeting moiety to deliver the drugs to specific cells in vivo.     

Mineral content of water and food in fluorotic villages and prevalence of dental fluorosis

The fluoride (F), calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), and phosphorus (P) content in potable water and food samples (cereals, pulses, and vegetables) from endemic and nonendemic villages for fluorosis were analyzed. It was found that the F content in water was significantly higher (p<0.01) in endemic villages (4.20±1.6 ppm) than control villages (0.63±0.15 ppm), whereas the Ca, Cu, and Mg contents were found to be significantly lower (p<0.05) in endemic villages compared to control villages. However, there was no significant difference in Zn and P contents between the villages. Foods (cereals, pulses, and vegetables) grown in endemic villages contained significantly higher (p<0.01) fluoride content as compared to control villages. There was no significant difference in Ca, Mg, P, and Zn contents in food grown in endemic and control villages. Copper content in cereals (p<0.05), pulses (p<0.01), and vegetables (p<0.01) in endemic villages was found significantly higher as compared to control villages. The overall prevalence of dental fluorosis in six endemic villages was 97.4% in boys and 96% in girls, which was significantly higher (p<0.01) than that of control villages, where it was 10.5% in boys and 8.3% in girls. The prevalence of dental fluorosis was positively correlated (r=0.125, p<0.01) to fluoride and negatively correlated to Ca and Cu content in drinking water in endemic villages.