Ameliorative Effect of Palm Oil in Aluminum Lactate Induced Biochemical and Histological Implications in Rat Brain.

α-Tocotrienol is one of the major constituents of palm oil. It is a well-known antioxidant and cholesterol-lowering neuroprotectant. To prevent the initiation of Alzheimer's like symptoms, much attention has been shifted to the major role played by antioxidants. Previous epidemiological reports correlate the increasing incidence of developing Alzheimer's disease (AD), to the aluminum (Al) content in drinking water. Al, being a ubiquitous element, has a long history of being particularly reactive towards multiple aspects of neurobiology. So, the current study examines the effect of Al-induced behavioral, biochemical, and histopathological changes in rat brain; and the ameliorative effect of palm oil in reducing the resulting neurotoxicity. The experimental design consisted of 4 groups: control group which received rodent chow diet and water ad libitum; Al group received aluminum lactate (50 mg/kg bw); Al + palm oil group was administered with Al (50 mg/kg bw) and palm oil (60 mg/kg bw); and palm oil group received palm oil (60 mg/kg bw). Al was given by oral gavage once daily for 6 weeks and palm oil was administered intraperitoneally. After 6 weeks of supplementation, Al + palm oil group showed significantly lower malondialdehyde (MDA) content, but higher superoxide dismutase (SOD), catalase (CAT), GST, and GPx activity as compared to Al group. Al group has significantly higher level of MDA content, but lower SOD, CAT, GST, and GPx activity as compared to control group. In conclusion, this study suggested that palm oil was effective in preventing the Al-induced brain damage in rats.

RIFM fragrance ingredient safety assessment, butyl lactate, CAS registry number 138-22-7.

The existing information supports the use of this material as described in this safety assessment. Butyl lactate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog ethyl (L)-lactate (CAS # 687-47-8) show that butyl lactate is not expected to be genotoxic. Data on read-across materials butyl alcohol (CAS # 71-36-3) and lactic acid (CAS # 50-21-5) provide a calculated margin of exposure (MOE) > 100 for the repeated dose and reproductive toxicity endpoints. The skin sensitization endpoint was completed using the dermal sensitization threshold (DST) for non-reactive materials (900 µg/cm2); exposure is below the DST. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; butyl lactate is not expected to be phototoxic/photoallergenic. Data on butyl lactate provide a calculated MOE >100 for the local respiratory endpoint. The environmental endpoints were evaluated; butyl lactate was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.

RIFM fragrance ingredient safety assessment, ethyl lactate, CAS registry number 97-64-3.

The existing information supports the use of this material as described in this safety assessment. Ethyl lactate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data on ethyl lactate show that ethyl lactate is not genotoxic and provided a calculated Margin of Exposure (MOE) > 100 for the repeated dose toxicity, reproductive toxicity, and local respiratory endpoints. Data from ethyl lactate and additional material ethyl (L)-lactate (CAS # 687-47-8) show that there are no safety concerns for ethyl lactate for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; ethyl lactate is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; ethyl lactate was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.

Ginkgo biloba attenuates aluminum lactate-induced neurotoxicity in reproductive senescent female rats: behavioral, biochemical, and histopathological study.

Extensive use of aluminum (Al) in industry, cooking utensils, and wrapping or freezing the food items, due to its cheapness and abundance in the environment, has become a major concern. Growing evidence supports that environmental pollutant Al promotes the aggregation of amyloid beta (Aß) in the brain, which is the main pathological marker of Alzheimer's disease (AD). Further, AD- and Al-induced neurotoxic effects are more common among women following reproductive senescence due to decline in estrogen. Though clinically Ginkgo biloba extract (GBE) has been exploited as a memory enhancer, its role in Al-induced neurotoxicity in reproductive senescent female rats needs to be evaluated. Animals were exposed to intraperitoneal dose (10 mg/kg b.wt) of Al and oral dose (100 mg/kg b.wt.) of GBE daily for 6 weeks. A significant decline in the Al-induced Aß aggregates was observed in hippocampal and cortical regions of the brain with GBE supplementation, as confirmed by thioflavin (ThT) and Congo red staining. GBE administration significantly decreased the reactive oxygen species, lipid peroxidation, nitric oxide, and citrulline levels in comparison to Al-treated rats. On the contrary, a significant increase in the reduced glutathione, GSH/GSSG ratio as well as in the activities of antioxidant enzymes was observed with GBE administration. Based on the above results, GBE prevented the neuronal loss in the hippocampus and cortex, hence caused significant improvement in the learning and memory of the animals in terms of AChE activity, serotonin levels, Morris water maze, and active and passive avoidance tests. In conclusion, GBE has alleviated the behavioral, biochemical, and histopathological alterations due to Al toxicity in rats. However, molecular studies are going on to better understand the mechanism of GBE protection against the environmental toxicant Al exposure. Graphical abstract .

Oligo(Lactic Acid)8-Rapamycin Prodrug-Loaded Poly(Ethylene Glycol)-block-Poly(Lactic Acid) Micelles for Injection.

PURPOSE: To prepare an oligo(lactic acid)8-rapamycin prodrug (o(LA)8-RAP)-loaded poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA) micelle for injection and characterize its compatibility and performance versus a RAP-loaded PEG-b-PLA micelle for injection in vitro and in vivo. METHODS: Monodisperse o(LA)8 was coupled on RAP at the C-40 via DCC/DMAP chemistry, and conversion of o(LA)8-RAP prodrug into RAP was characterized in vitro. Physicochemical properties of o(LA)8-RAP- and RAP-loaded PEG-b-PLA micelles and their antitumor efficacies in a syngeneic 4 T1 breast tumor model were compared. RESULTS: Synthesis of o(LA)8-RAP prodrug was confirmed by 1H NMR and mass spectroscopy. The o(LA)8-RAP prodrug underwent conversion in PBS and rat plasma by backbiting and esterase-mediated cleavage, respectively. O(LA)8-RAP-loaded PEG-b-PLA micelles increased water solubility of RAP equivalent to 3.3 mg/ml with no signs of precipitation. Further, o(LA)8-RAP was released more slowly than RAP from PEG-b-PLA micelles. With added physical stability, o(LA)8-RAP-loaded PEG-b-PLA micelles significantly inhibited tumor growth relative to RAP-loaded PEG-b-PLA micelles in 4 T1 breast tumor-bearing mice without signs of acute toxicity. CONCLUSIONS: An o(LA)8-RAP-loaded PEG-b-PLA micelle for injection is more stable than a RAP-loaded PEG-b-PLA micelle for injection, and o(LA)8-RAP converts into RAP rapidly in rat plasma (t1/2 = 1 h), resulting in antitumor efficacy in a syngeneic 4 T1 breast tumor model.

A Guardian Angel Phosphatase for Mainline Carbon Metabolism.

It is increasingly clear that many metabolic enzymes mistakenly form minor but toxic side-products that must be eliminated to maintain normal fluxes. Collard et al. show that this is true of two iconic glycolytic enzymes, and that a hitherto somewhat mysterious phosphatase rescues central carbon metabolism from their mistakes.

A conserved phosphatase destroys toxic glycolytic side products in mammals and yeast.

Metabolic enzymes are very specific. However, most of them show weak side activities toward compounds that are structurally related to their physiological substrates, thereby producing side products that may be toxic. In some cases, 'metabolite repair enzymes' eliminating side products have been identified. We show that mammalian glyceraldehyde 3-phosphate dehydrogenase and pyruvate kinase, two core glycolytic enzymes, produce 4-phosphoerythronate and 2-phospho-L-lactate, respectively. 4-Phosphoerythronate strongly inhibits an enzyme of the pentose phosphate pathway, whereas 2-phospho-L-lactate inhibits the enzyme producing the glycolytic activator fructose 2,6-bisphosphate. We discovered that a single, widely conserved enzyme, known as phosphoglycolate phosphatase (PGP) in mammals, dephosphorylates both 4-phosphoerythronate and 2-phospho-L-lactate, thereby preventing a block in the pentose phosphate pathway and glycolysis. Its yeast ortholog, Pho13, similarly dephosphorylates 4-phosphoerythronate and 2-phosphoglycolate, a side product of pyruvate kinase. Our work illustrates how metabolite repair enzymes can make up for the limited specificity of metabolic enzymes and permit high flux in central metabolic pathways.

[The study on the relationship between hippocampus neuronal apoptosis and hippocampus synaptic plasticity in rats exposed to aluminum].

OBJECTIVE: To investigate the effect of aluminum exposure on neuronal apoptosis of rats hippocampus and the correlation of and synaptic plasticity. METHODS: There were 40 SPF grade SD rats which were randomly divided into four groups: the control group, the low dose group, the medium dose group and the high dose group, 10 rats in each group. The rats were daily gavaged with aluminum lactate for 30 days. The hippocampal fEPSPs in rat was measured by electrophysiological grapher and the neuronal apoptosis in hippocampus was detected by Flow cytometer. In addition, the relative expression of gene which includes caspase-3, 8, 9 was measured by Real-time PCR. RESULTS: Compared to the control group, the average of fEPSPs which after HFS 10, 20, 30, 40, 50, 60 min was decreased at different time point in the low dose group, the medium dose group and the high dose group (P < 0.05). Compared with the control group, the rate of apoptosis was significantly increased in the medium dose group and the high dose group (P < 0.05). Compared to the control group, the relative expression of caspase-3 in the medium dose group and the high dose group was significantly increased in Real-time PCR (P < 0.05), and the relative expression of caspase-8 in the high dose group was significantly increased (P < 0.05). CONCLUSION: Aluminum exposure may induced neuronal apoptosis in rats, and then affect hippocampal synaptic plasticity.

Delayed adverse effects of neonatal exposure to polymeric nanoparticle poly(ethylene glycol)-block-polylactide methyl ether on hypothalamic-pituitary-ovarian axis development and function in Wistar rats.

We studied delayed effects of neonatal exposure to polymeric nanoparticle poly(ethylene glycol)-block-polylactide methyl ether (PEG-b-PLA) on the endpoints related to pubertal development and reproductive function in female Wistar rats from postnatal day 4 (PND4) to PND 176. Female pups were injected intraperitoneally, daily, from PND4 to PND7 with PEG-b-PLA (20 or 40mg/kg b.w.). Both doses of PEG-b-PLA accelerated the onset of vaginal opening compared with the control group. In the low-dose PEG-b-PLA-treated group, a significantly reduced number of regular estrous cycles, increased pituitary weight due to hyperemia, vascular dilatation and congestion, altered course of hypothalamic gonadotropin-releasing hormone-stimulated luteinizing hormone secretion, and increased progesterone serum levels were observed. The obtained data indicate that neonatal exposure to PEG-b-PLA might affect the development and function of hypothalamic-pituitary-ovarian axis (HPO), and thereby alter functions of the reproductive system in adult female rats. Our study indicates a possible neuroendocrine disrupting effect of PEG-b-PLA nanoparticles.

Effects of Differently Coated Silver Nanoparticles on the Photosynthesis of Chlamydomonas reinhardtii.

Various factors have been invoked to explain the toxicity of silver nanoparticles (AgNP) to microorganisms including particle size and the nature of stabilizing coatings as well as the amount of dissolved silver occurring in AgNP suspensions. In this study we have assessed the effects of nine differently coated AgNP (chitosan, lactate, polyvinylpyrrolidone, polyethelene glycol, gelatin, sodium dodecylbenzenesulfonate, citrate, dexpanthenol, and carbonate) and AgNO3 on the photosynthesis of the freshwater algae Chlamydomonas reinhardtii. We have thus examined how AgNP effects on algae relate to particle size, measured dissolved silver (Agd), and bioavailable silver (Agbioav). Agbioav was indirectly estimated in toxicity experiments by cysteine-silver complexation at the EC50. The EC50 calculated as a function of measured Agd concentrations showed for some coatings values similar to that of dissolved Ag, whereas other coated AgNP displayed lower EC50 values. In all cases, excess cysteine completely prevented effects on photosynthetic yield, confirming the role of Agd as a cause of the observed effect on the photosynthesis. Toxicity was related neither to particle size nor to the coatings. For all differently coated AgNP suspensions, the EC50 values calculated as a function of Agbioav were comparable to the value of AgNO3. Depending on the coatings Agbioav was comparable to or higher than measured Agd.

Effect of polymeric nanoparticle poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA) on in vitro luteinizing hormone release from anterior pituitary cells of infantile and adult female rats.

OBJECTIVES: Polymeric PEG-b-PLA nanoparticles (NPs) were developed for delivery of poorly water-soluble drugs via blood brain barrier into brain parenchyma. We analyzed neuroendocrine disrupting effects of neonatal exposure of female rats to PEG-b-PLA NPs and diethylstilbestrol (DES) on the function of adenohypophyseal gonadotrophs of infantile or adult rats by examining in vitro luteinizing hormone releasing hormone (LHRH)-induced luteinizing hormone (LH) release. METHODS: Neonatal female Wistar rats were injected intraperitoneally, daily, from postnatal day (PND) 4 to PND7 with PEG-b-PLA NPs (20 mg.kg b.w.(-1)), DES (4 µg.kg b.w.(-1)) or vehicle. At the necropsy day (PND15 in infantile and the first estrus day after PND176 in adult rats), adenohypophyseal cells were isolated by enzymatic digestion, plated in 96-well plates (5×10(4) cells.well(-1)) in serum-supplemented medium and left to recover for 96 h. LHRH (10-7 mol.L(-1)) treatment was performed in serum-free medium for 60 min and LH levels in culture media were determined by radioimmunoassay. RESULTS: In all experimental groups, in vitro LHRH treatment significantly stimulated LH release from pituitary cells of infantile but not adult female rats. Neonatal DES treatment increased basal LH secretion from cultured pituitary cells of adult but not infantile rats. In both, infantile and adult rats, neonatal treatment with PEG-b-PLA significantly increased basal and LHRH-induced LH release from pituitary cells compared to corresponding controls and DES-treated group. CONCLUSIONS: Data indicate that neonatal exposure to PEG-b-PLA NPs may alter pituitary LH release, and thereby modify reproductive system development in infantile female rats leading to reproductive dysfunctions in adult age.

A comparative proteomic analysis of Bacillus coagulans in response to lactate stress during the production of L-lactic acid.

The growth rate and maximum biomass of Bacillus coagulans 2-6 were inhibited by lactate; inhibition by sodium lactate was stronger than by calcium lactate. The differences of protein expressions by B. coagulans 2-6 under the lactate stress were determined using two-dimensional electrophoresis coupled with mass spectrometric identification. Under the non-stress condition, calcium lactate stress and sodium lactate stress, the number of detected protein spots was 1,571 ± 117, 1,281 ± 231 and 904 ± 127, respectively. Four proteins with high expression under lactate stress were identified: lactate dehydrogenase, cysteine synthase A, aldo/keto reductase and ribosomal protein L7/L12. These proteins are thus potential targets for the reconstruction of B. coagulans to promote its resistance to lactate stress.

Antiangiogenic effect of docetaxel and everolimus as individual and dual-drug-loaded micellar nanocarriers.

PURPOSE: The in vitro inhibitory effect of Docetaxel (DTX) and Everolimus (EVR) alone and together in poly(ethylene glycol)-block-poly(D,L-lactic acid) (PEG-b-PLA) nanocarriers on angiogenic processes and acute toxicity in mice was evaluated. METHODS: PEG-b-PLA DTX and/or EVR nanocarriers were characterized for size, drug loading, stability, and drug release. Cell proliferation, tubule formation, and migration studies were performed in Human Umbilical Vein Endothelial Cells (HUVEC) and Maximum Tolerated Doses (MTD) studies were in mice. RESULTS: DTX and EVR loading was 1.93 and 2.00 mg/mL respectively with similar solubilities for dual-drug micelles. All micelles were below 30 nm with diffusion controlled drug release. The IC50 for DTX, EVR micelles were, 6.80 ± 0.67, 18.57 ± 2.86 and 0.65 ± 0.11 nM respectively with a synergistic inhibitory effect for dual-drug nanocarriers. Significant inhibition of tube formation occurred upon treatment with dual-drug nanocarriers as compared to individual micelles. EVR presence in dual-drug nanocarriers was able to significantly increase the inhibition of the migration of HUVEC by DTX. The MTDs for EVR, DTX and dual-drug micelles were 50, 30 and 20 mg/kg for each respectively. CONCLUSIONS: DTX-EVR dual-drug nanocarriers have antiangiogenic effects in vitro mediated through cellular angiogenic process and possess clinically relevant MTD.

Single oral dose toxicity test of polycalcium, a mixed composition of polycan and calcium lactate-gluconate 1:9 (G/G) in SD rat.

The object of this study was to obtain acute oral toxicity information of Polycalcium, a mixed composition of Polycan and Calcium lactate-gluconate 1:9 (g/g), in Sprague-Dawely (SD) rats. In order to investigate the toxicity and identify target organs, Polycalcium were once orally administered to female and male SD rats at dose levels of 2000, 1000, 500 and 0 (control) mg/kg body weights. The mortality, changes on body weight and clinical signs were monitored during 14 days after treatment with gross observation, changes on the organ weights and histopathology of principle organs and treatment sites based on the recommendation of KFDA Guidelines [2009-116, 2009]. As the results of single oral treatment of Polycalcium, no treatment related mortalities were observed within 14 days after end of treatment up to 2000 mg/kg, the limited dosage of rodents in the both genders. In addition, no Polycalcium treatment related changes on the body and organ weights, clinical signs, necropsy and histopathological findings were detected. The results obtained in this study suggest that the Polycalcium is non-toxic in rats. The LD50 and approximate LD in rats after single oral dose of Polycalcium were considered over 2000 mg/kg in both female and male, respectively.

Concanavalin A-conjugated poly(ethylene glycol)-poly(lactic acid) nanoparticles for intranasal drug delivery to the cervical lymph nodes.

Concanavalin A (ConA)-conjugated poly(ethylene glycol)-poly(lactic acid) nanoparticles (ConA-NPs) were prepared for targeted drug delivery to the cervical lymph nodes after intranasal administration. ConA, a lectin specifically binding to α-mannose and α-glucose, was covalently conjugated on NPs without loss of its carbohydrates binding bioactivity. In vitro cellular uptake experiment demonstrated that NPs could be uptaken by Calu-3 cells in a time- and concentration-dependent manner, and conjugation of ConA on NPs could significantly increase the rate and amount of cellular uptake. ConA-NP showed no obvious toxicity to Calu-3 cells in vitro or to the nasal cilia of rats in vivo. Compared with NPs without ConA, ConA-NP is more effective in targeting drugs to the deep cervical lymph nodes, as evidenced by 1.36-2.52 times increase of targeting efficiency, demonstrating that ConA-NP is a potential carrier for targeted drug delivery to the cervical lymph nodes via nasal route.

Biological evaluation of Fe3O4-poly(L-lactide)-poly(ethylene glycol)-poly(L-lactide) magnetic microspheres prepared in supercritical CO2.

The biocompatibility of Fe3O4-poly(L-lactide)-poly(ethylene glycol)-poly(L-lactide) magnetic microspheres (Fe3O4-PLLA-PEG-PLLA MMPs) prepared in a process of suspension-enhanced dispersion by supercritical CO2 (SpEDS) was evaluated at various levels: cellular, molecular, and integrated. At the cellular level, the investigations of cytotoxicity and intracellular reactive oxygen species (ROS) generation indicate that the polymer-coated MMPs (2.0 mg/mL) had a higher toxicity than uncoated Fe3O4 nanoparticles, which led to about 20% loss of cell viability and an increase (0.2 fold) in ROS generation; the differences were not statistically significant (p > 0.05). However, an opposite phenomenon was observed in tests of hemolysis, which showed that the MMPs displayed the weakest hemolytic activity, namely only about 6% at the highest concentration (20 mg/mL). This phenomenon reveals that polymer-coated MMPs created less toxicity in red blood cells than uncoated Fe3O4 nanoparticles. At the molecular level, the MMPs were shown to be less genotoxic than Fe3O4 nanoparticles by measuring the micronucleus (MN) frequency in CHO-K1 cells. Furthermore, the mRNA expression of pro-inflammatory cytokines demonstrates that polymer-coated MMPs elicited a less intense secretion of pro-inflammatory cytokines than uncoated Fe3O4 nanoparticles. Acute toxicity tests of MMPs show quite a low toxicity, with an LD50 > 1575.00 mg/kg. The evidence of low toxicity presented in the results indicates that the Fe3O4-PLLA-PEG-PLLA MMPs from the SpEDS process have great potential for use in biomedical applications.

Recognition memory and ß-amyloid plaques in adult Tg2576 mice are not modified after oral exposure to aluminum.

The role of aluminum (Al) in Alzheimer disease is highly controversial. However, this element has been detected in neuritic plaques and neurofibrillary tangles in patients with Alzheimer disease. Its presence in neuritic plaques in hippocampus is especially relevant, as this is an area closely related to spatial learning and memory. In this study, the diet of wild-type and Tg2576 mice (animals overexpressing the human amyloid precursor protein) was supplemented with Al lactate (1 mg/g). General neurotoxic Al effects were evaluated using a functional observational battery and a novel object recognition task. Four experimental groups were used: Control-wild, Al-wild, Control-Tg, and Al-Tg mice. The results show a decreased home-cage activity and an increase in piloerection in all Al-exposed animals, and an increased sensorimotor reactivity in Tg2576 mice given Al. Neither Al treatment nor genotype had any noticeable effect on corticosterone levels and Al concentrations in frontal cortex and cerebellum of the mice. Recognition memory was impaired in Tg2576 mice, whereas ß-amyloid plaque depositions were observed in all these animals. However, Al did not alter the recognition memory and ß-amyloid plaque loads of Tg2576 mice.

Aluminium effects on thyroid gland function: iodide uptake, hormone biosynthesis and secretion.

The effects of aluminium (Al) on thyroid function were evaluated in adult Wistar rats intraperitoneally (i.p) injected with 7 mg Al (as lactate)/kg body weight (b.w) per day during a six week period. The time-course kinetics of Na(125)I (3 µCi per 100 g b.w, i.p) was analysed by measuring gamma-radioactivity of thyroid, serum, serum protein precipitate and bile, at times ranging from 2 to 96 h post-dosing. In Al-treated group the (125)I(-) thyroid uptake at 24 h (15,840 ± 570 vs. 18,030 ± 630 dpm/mg, P<0.05) as well as the rate of (125)I(-) release from the gland, calculated as the slope of the plot between 24 and 96 h (84 ± 8 vs. 129 ± 11 dpm/mg/h, P<0.05) were significantly reduced as compared to control. The biliary (125)I(-) excretion was not modified at all studied times. The Al content and lipid peroxidation (69.1 ± 8.5 vs. 53.2 ± 7.0 nmol MDA/g wet weight, P<0.05) of thyroid tissue were increased in Al-treated rats. The serum concentrations of total thyroxine (T4, 3.78 ± 0.14 vs. 4.68 ± 0.12 µg/dL, P<0.05) and total triiodothyronine (T3, 47 ± 4 vs. 66 ± 5 ng/dL, P<0.05) were decreased by effect of Al, but free-T4 (1.05 ± 0.05 vs. 1.04 ± 0.04 ng/dL, NS) and thyrotropin (TSH, 2.7 ± 0.4 vs. 2.6 ± 0.5 ng/ml, NS) remain unchanged. In spite of the Al could indirectly affect thyroid iodide uptake and hormones secretion by a mechanism involving the induction of an oxidative stress state, however, these changes could be managed by the hypothalamus-pituitary-thyroid endocrine axis. We can conclude that in adult rats the Al would not act as a thyroid disruptor.