Inhibition of some hepatic glycosidases by the diseco nucleoside, 4-amino-3-(D-glucopentitol-1-yl)-5-mercapto-1,2,4-triazole and its 3-methyl analog

The in vivo and in vitro effects of 4-amino-3-(D-glucopentitol-1-yl)-5-mercapto-1,2,4-triazole and its 3-methyl analogue on alpha- and beta-glucosidases, beta-glucuronidase as well as alpha-amylase have been investigated. alpha-Glucosidase is the enzyme that is markedly affected in vivo and in vitro in a dose-dependent manner. The compounds showed a reversible inhibition of a competitive type for alpha-glucosidase. Moreover, they exert a relatively potent inhibition on alpha-glucosidase with a Ki magnitude of 3.6 x 10(-4), 9.5 x 10(-5) M.     

In vivo and in vitro management of Meloidogyne incognita (Tylenchida: Heteroderidae) using rhizosphere bacteria,Pseudomonas spp. and Serratia spp. compared with oxamyl

Biological control using rhizosphere bacteria, Pseudomonas spp. and Serratia spp. is a prospective alternative technique to overcome plant parasitic nematodes infection. So, the current study was conducted in vitro on five egg-masses, 100 free eggs and 100 infective juveniles (IJs) of Meloidogyne incognita as well as greenhouse treatments on Luffa aegyptiaca L. to evaluate the nematicidal potential of six strains belong to Pseudomonas spp. and Serratia spp. as compared to oxamyl.Results showed that the inhibitory effect and juvenile mortality varied according to bacteria species, strains and exposure time. All the tested bacteria significantly (P ≤ 0.05) inhibited egg hatching and increased juvenile mortality in vitro. After 3 days of treatment, Pseudomonas spp. were more effective against eggs (48.31to 55.15%) and IJs (20.98 to 25.30%) than Serratia spp. (44.55 to 49.75% with eggs) and (19.06 to 21.61% with IJs), respectively. In the pot experiment, Luffa aegyptiaca L. treated with Serratia spp. and Pseudomonas spp. displayed significantly higher (P ≤ 0.05) levels of growth (as indicated by root length, fresh roots weight and fresh shoots weight) compared to control plants and significantly (P ≤ 0.05) suppressed galling (number of galls) and reproduction (as indicated by number of egg-masses on roots and number of eggs and juveniles in pot soil). Meanwhile, among the treated plants, Serratia spp. and Pseudomonas spp. gave the best results in shoot weight of pots infected by eggs of M. incognita than those infected with IJs as compared with positive control. While, oxamyl treatment gave the best results in pots infected by eggs and IJs.The lowest galling (gall index), number of eggs and juveniles in soil was observed in the treatment with mixture of Serratia spp. and Pseudomonas spp. as well as, enhanced growth of sponge gourd more than application each of them alone. Pots treated with oxamyl overwhelmed those treated with mixture of Serratia spp. and Pseudomonas spp.     

Anti-hypercholesterolemic impacts of barley and date palm fruits on the ovary of Wistar albino rats and their offspring

A high cholesterol diet is related to ovarian dysfunction and infertility which has been increased among young ages consuming processed food products. The present study was conducted to evaluate the role of a high cholesterol diet on the ovaries of young female rats via assessments of histopathology, immunohistochemistry, oxidative stress and apoptic markers. Also, mating of hypercholesterolemic female rats was carried out to measure the fertility and numbers of their offspring. At the same time, phytotherapy was carried out through supplementing the diet with barley and/ or date palm fruits (10%) during the experiment to assess the phyto-therapeutic impacts in attenuation of drastic hypercholesterolemic effects.Hypercholesterolemic diet-fed rats exhibited damage of the ovarian follicles and increased follicular atresia. Furthermore, expression of cleaved caspase-3 was upregulated, while PCNA was downregulated in granulosa, theca and stroma cells. Hypercholesterolemic female rats showed marked depletion of antioxidative enzymes, increased lipid peroxidation and apoptotic markers. Alterations to the female serum hormones were detected. Offspring maternally fed on hypercholesterolemic diet showed a significant decrease of body weight and altered sex ratio. However, concomitant supplementation of barley and or date fruits to hypercholesterolemic groups revealed marked improvement of ovarian structure and function.On the basis of these evidences, it is believed that the enhanced synergistic effects of barley and/or date palm fruits in the amelioration of ovarian structure and functions were elicited by the potential antioxidant activity of their phytomicronutrients, polyphenols, β-glucan and trace elements. These materials scavenge free radicals from inflamed cells that can be used to establish an effective and novel therapeutic strategy for activating ovarian cell regeneration.     

Biological silicon nanoparticles maximize the efficiency of nematicides against biotic stress induced by Meloidogyne incognita in eggplant

Nemours effective management tactics were used to reduce world crop losses caused by plant-parasitic nematodes. Nowadays the metallic nanoparticles are easily developed with desired size and shape. Nanoparticles (NPs) technology becomes a recognized need for researchers. Ecofriendly and biosafe SiNPs are developed from microorganisms. Recently, silicon nanoparticles (SiNPs) have gained novel pesticide properties against numerous agricultural pests. This study assessed the biosynthesis of SiNPs from Fusarium oxysporum SM5. The obtained SiNPs were spherical with a size of 45 nm and a negative charge of −25.65. The nematocidal effect of SiNPs against egg hatching and second-stage juveniles (J2) of root-knot nematode (RKN) (Meloidogyne incognita) was evaluated on eggplant,Solanum melongena L. plants. In vitro, all tested SiNPs concentrations significantly (p ≤ 0.05) inhibited the percentage of egg hatching at a different time of exposure than control. Meanwhile, after 72 h, the percent mortality of J2 ranged from 87.00 % to 98.50 %, with SiNPs (100 and 200 ppm). The combination between SiNPs and the half-recommended doses (0.5 RD) of commercial nematicides namely,  fenamiphos (Femax 40 % EC)^R, nemathorin (Fosthiazate 10 % WG) ^R, and fosthiazate (krenkel 75 % EC) ^R confirmed the increase of egg hatching inhibition and J2 mortality after exposure to SiNPs (100 ppm) mixed with 0.5 RD of synthetic nematicides. The findings suggest that the combination between SiNPs, and 0.5 RD of nematicides reduced nematode reproduction, gall formation, egg masses on roots and final population of J2 in the soil. Therefore, improving the plant growth parameters by reducing the M. incognita population.     

Synthesis and Evaluation of Antimicrobial Activity of Some Pyrimidine Glycosides

Reaction of ethyl 4-thioxo-3,4-dihydropyrimidine-5-carboxylate derivatives 1a,b and ethyl 4-oxo-3,4-dihydropyrimidine-5-carboxylate 1c with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide in KOH or TEA afforded ethyl 2-aryl-4-(2′,3′,4′,6′-tetra-O-acetyl-β-D-glucopyranosylthio or/ oxy)-6-methylpyrimidine-5-carboxylate 6a-c. The glucosides 6a and 6b were obtained by the reaction of 1a and 1b with peracetylated glucose3 under MW irradiation. Mercuration of 1a followed by reaction with acetobromoglucose gave the same product 6a. The reaction of 1a-c with peracetylated ribose 4 under MW irradiation gave ethyl 2-aryl-4-(2′,3′,5′-tri-O-acetyl-β-D-ribofuranosylthio)-6-methylpyrimidine-5-carboxylate 8a–c. The deprotection of 6a–c and 8a–c in the presence of methanol and TEA/H₂O afforded the deprotected products 7a–c and 9a–c. The structure were confirmed by using ¹H and ¹³CNMR spectra. Selected members of these compounds were screened for antimicrobial activity.     

Hyperactivation of MAPK induces loss of ERalpha expression in breast cancer cells.

ERalpha-negative breast tumors tend to overexpress growth factor receptors such as epidermal growth factor receptor or c-erbB-2. Raf-1 is a key intermediate in the signal transduction pathways of these receptors. High levels of constitutive Raf kinase (Deltaraf) activity imparts ERalpha- positive MCF-7 breast cancer cells with the ability to grow in the absence of estrogen. Deltaraf transfectants maintained in estrogen-depleted media showed greatly diminished responses to 17beta-estradiol or the pure antiestrogen ICI 182,780. Western blotting, ligand binding, and immunohistochemistry assays revealed a loss of ERalpha protein expression, and ribonuclease protection assays indicated that this correlated with loss of ERalpha message. In examining the basal expression of estrogen-induced genes in the stable transfectants or in transient cotransfection assays with an estrogen-response element- reporter construct and Deltaraf or constitutively active MAPK kinase (DeltaMEK), no ligand- independent activation of ERalpha was observed. Transient expression of Deltaraf and double-label immunostaining showed ERalpha was lost in those cells that transiently expressed Deltaraf. Abrogation of Raf signaling via treatment with the MEK inhibitors PD 098059 or U0126 resulted in reexpression of ERalpha. Similar studies performed with MCF-7 cells overexpressing epidermal growth factor receptor or c-erbB-2 confirmed that hyperactivation of MAPK resulted in down-regulation of ERalpha that was reversible by MEK inhibition or transfection with dominant negative ERK1 and ERK2 constructs. These data suggest that the hyperactivation of MAPK in epidermal growth factor receptor- or c-erbB-2-overexpressing breast cancer cells is directly responsible for generation of an ERalpha-negative phenotype and, more importantly, that this process may be abrogated by inhibiting these pathways, thus restoring ERalpha expression.     

Synthesis of mono- and di-hydroxylated prolines and 2-hydroxymethylpyrrolidines from non-carbohydrate precursors

Natural and synthetic imino sugars are biologically important as glycosidase inhibitors. This review includes selected syntheses of 3-hydroxyproline, 4-hydroxyproline, 3,4-dihydroxyproline, 2-hydroxymethyl-3-hydroxypyrrolidine and 2-hydroxymethyl-pyrrolidine-3,4-diol, which exhibit glycosidase inhibitory and various other biological activities.