Development of chitosan based microencapsulated spray dried powder of tuna fish oil: oil load impact and oxidative stability

Abstract The impact of fish oil concentration on the oxidative stability of microcapsules through the spray drying process using chitosan and maltodextrin as wall material was studied. Emulsions were prepared with different Tuna fish oil (TFO) content (TFO-10%, TFO20%, TF030% TF0-40%) while wall material concentration was kept constant. Microencapsulated powder resulting from emulsion prepared with high fish oil load have high moisture content, wettability, total oil and low encapsulation efficiency, hygroscopicity and bulk tapped density. Oxidative stability was evaluated periodically by placing microcapsules at room temperature. Microcapsules prepared with TFO-10% presented high oxidative stability in terms of peroxide value (2.94±0.04) and anisidine value (1.54±0.02) after 30 days of storage. It was concluded that optimal amounts of fish oil for microencapsulation are 10% and 20% using chitosan and maltodextrin that extended its shelf life during study period.

Resumo Foi estudado o impacto da concentração de óleo de peixe na estabilidade oxidativa de microcápsulas por meio do processo de secagem por atomização, utilizando quitosana e maltodextrina como material de parede. As emulsões foram preparadas com diferentes teores de óleo de atum (TFO) (TFO-10%, TFO20%, TF030% TF0-40%), enquanto a concentração de material de parede foi mantida constante. O pó microencapsulado resultante da emulsão preparada com alta carga de óleo de peixe tem alto teor de umidade, molhabilidade e óleo total e baixa eficiência de encapsulação, higroscopicidade e densidade extraída a granel. A estabilidade oxidativa foi avaliada periodicamente colocando microcápsulas à temperatura ambiente. As microcápsulas preparadas com TFO-10% apresentaram alta estabilidade oxidativa em termos de valor de peróxido (2,94 ± 0,04) e valor de anisidina (1,54 ± 0,02) após 30 dias de armazenamento. Concluiu-se que as quantidades ideais de óleo de peixe para microencapsulação são de 10% e 20% usando quitosana e maltodextrina que prolongaram sua vida útil durante o período de estudo.

Development of chitosan based microencapsulated spray dried powder of tuna fish oil: oil load impact and oxidative stability / Desenvolvimento de pó microencapsulado por pulverização de óleo de atum à base de quitosana: impacto da carga de óleo e estabilidade oxidativa

Abstract The impact of fish oil concentration on the oxidative stability of microcapsules through the spray drying process using chitosan and maltodextrin as wall material was studied. Emulsions were prepared with different Tuna fish oil (TFO) content (TFO-10%, TFO20%, TF030% TF0-40%) while wall material concentration was kept constant. Microencapsulated powder resulting from emulsion prepared with high fish oil load have high moisture content, wettability, total oil and low encapsulation efficiency, hygroscopicity and bulk tapped density. Oxidative stability was evaluated periodically by placing microcapsules at room temperature. Microcapsules prepared with TFO-10% presented high oxidative stability in terms of peroxide value (2.94±0.04) and anisidine value (1.54±0.02) after 30 days of storage. It was concluded that optimal amounts of fish oil for microencapsulation are 10% and 20% using chitosan and maltodextrin that extended its shelf life during study period.

Resumo Foi estudado o impacto da concentração de óleo de peixe na estabilidade oxidativa de microcápsulas por meio do processo de secagem por atomização, utilizando quitosana e maltodextrina como material de parede. As emulsões foram preparadas com diferentes teores de óleo de atum (TFO) (TFO-10%, TFO20%, TF030% TF0-40%), enquanto a concentração de material de parede foi mantida constante. O pó microencapsulado resultante da emulsão preparada com alta carga de óleo de peixe tem alto teor de umidade, molhabilidade e óleo total e baixa eficiência de encapsulação, higroscopicidade e densidade extraída a granel. A estabilidade oxidativa foi avaliada periodicamente colocando microcápsulas à temperatura ambiente. As microcápsulas preparadas com TFO-10% apresentaram alta estabilidade oxidativa em termos de valor de peróxido (2,94 ± 0,04) e valor de anisidina (1,54 ± 0,02) após 30 dias de armazenamento. Concluiu-se que as quantidades ideais de óleo de peixe para microencapsulação são de 10% e 20% usando quitosana e maltodextrina que prolongaram sua vida útil durante o período de estudo.

Amelioration potential of Moringa oleifera extracts against sodium arsenate induced embryotoxicity and genotoxicity in mouse (Mus musculus) / Potencial de melhoria de extratos de Moringa oleifera contra embriotoxicidade e genotoxicidade induzida por arseniato de sódio em camundongos (Mus musculus)

Previous studies have suggested that arsenic crosses the placenta and affects the fetus development. The study under consideration aims to show comparative ameliorative effect of Moringa oleifera leaf and flower extracts against sodium arsenate induced fetus toxicity of mice. Pregnant mice (N=44) were kept in lab and divided into eleven group from (A to K) and were orally administered the doses 6 mg/kg, 12 mg/kg for sodium arsenate, 150 mg/kg and 300 mg/kg for Moringa oleifera leaf extracts (MOLE) and 150 mg/kg and 300 mg/kg for Moringa oleifera flower extracts (MOFE) comparing with control. The investigation revealed evident reduction in the fetuses weight, hind limb, fore limb, tail and snout length, crown rump and head circumferences well as malformations in tail, feet, arms, legs, skin and eyes in the negative control group (only administered with sodium arsenate). Co-administration of sodium arsenate with MOLE and MOFE ameliorate the reversed effect of sodium arsenate on the shape, length, body weight and DNA damage of fetus significantly at 95% confidence interval. However, Moringa oleifera leaf extract showed more significant results in comparison to Moringa oleifera flower extract. Hence concluded that Moringa oleifera leaf extract ameliorated the embryo toxic effects of sodium arsenate and can be used against environmental teratogens.

Estudos anteriores sugeriram que o arsênio atravessa a placenta e afeta o desenvolvimento do feto. O estudo em consideração visa mostrar o efeito melhorador comparativo de extratos de folhas e flores de Moringa oleifera contra a toxicidade fetal induzida por arseniato de sódio em camundongos. Camundongos grávidas (N = 44) foram mantidos em laboratório e divididos em 11 grupos (de A a K) e foram administrados por via oral nas doses de 6 mg/kg, 12 mg/kg para arseniato de sódio, 150 mg/kg e 300 mg/kg para extratos de folhas de Moringa oleifera (MOLE) e 150 mg/kg e 300 mg/kg para extratos de flores de Moringa oleifera (MOFE) em comparação com o controle. A investigação revelou redução evidente no peso do feto, membro posterior, membro anterior, comprimento da cauda e focinho, coroa, nádega e circunferência da cabeça, bem como malformações na cauda, pés, braços, pernas, pele e olhos no grupo de controle negativo (apenas administrado com arseniato de sódio). A coadministração de arseniato de sódio com MOLE e MOFE melhora significativamente o efeito reverso do arseniato de sódio na forma, comprimento, peso corporal e dano ao DNA do feto, com intervalo de confiança de 95%. No entanto, o extrato da folha da Moringa oleifera apresentou resultados mais significativos em comparação ao extrato da flor da Moringa oleifera. Portanto, concluiu que o extrato da folha de Moringa oleifera melhorou os efeitos tóxicos do arseniato de sódio para o embrião e pode ser usado contra teratógenos ambientais.

Amelioration potential of Moringa oleifera extracts against sodium arsenate induced embryotoxicity and genotoxicity in mouse (Mus musculus)

Abstract Previous studies have suggested that arsenic crosses the placenta and affects the fetus development. The study under consideration aims to show comparative ameliorative effect of Moringa oleifera leaf and flower extracts against sodium arsenate induced fetus toxicity of mice. Pregnant mice (N=44) were kept in lab and divided into eleven group from (A to K) and were orally administered the doses 6 mg/kg, 12 mg/kg for sodium arsenate, 150 mg/kg and 300 mg/kg for Moringa oleifera leaf extracts (MOLE) and 150 mg/kg and 300 mg/kg for Moringa oleifera flower extracts (MOFE) comparing with control. The investigation revealed evident reduction in the fetuses weight, hind limb, fore limb, tail and snout length, crown rump and head circumferences well as malformations in tail, feet, arms, legs, skin and eyes in the negative control group (only administered with sodium arsenate). Co-administration of sodium arsenate with MOLE and MOFE ameliorate the reversed effect of sodium arsenate on the shape, length, body weight and DNA damage of fetus significantly at 95% confidence interval. However, Moringa oleifera leaf extract showed more significant results in comparison to Moringa oleifera flower extract. Hence concluded that Moringa oleifera leaf extract ameliorated the embryo toxic effects of sodium arsenate and can be used against environmental teratogens.

Resumo Estudos anteriores sugeriram que o arsênio atravessa a placenta e afeta o desenvolvimento do feto. O estudo em consideração visa mostrar o efeito melhorador comparativo de extratos de folhas e flores de Moringa oleifera contra a toxicidade fetal induzida por arseniato de sódio em camundongos. Camundongos grávidas (N = 44) foram mantidos em laboratório e divididos em 11 grupos (de A a K) e foram administrados por via oral nas doses de 6 mg/kg, 12 mg/kg para arseniato de sódio, 150 mg/kg e 300 mg/kg para extratos de folhas de Moringa oleifera (MOLE) e 150 mg/kg e 300 mg/kg para extratos de flores de Moringa oleifera (MOFE) em comparação com o controle. A investigação revelou redução evidente no peso do feto, membro posterior, membro anterior, comprimento da cauda e focinho, coroa, nádega e circunferência da cabeça, bem como malformações na cauda, pés, braços, pernas, pele e olhos no grupo de controle negativo (apenas administrado com arseniato de sódio). A coadministração de arseniato de sódio com MOLE e MOFE melhora significativamente o efeito reverso do arseniato de sódio na forma, comprimento, peso corporal e dano ao DNA do feto, com intervalo de confiança de 95%. No entanto, o extrato da folha da Moringa oleifera apresentou resultados mais significativos em comparação ao extrato da flor da Moringa oleifera. Portanto, concluiu que o extrato da folha de Moringa oleifera melhorou os efeitos tóxicos do arseniato de sódio para o embrião e pode ser usado contra teratógenos ambientais.

Development of chitosan based microencapsulated spray dried powder of tuna fish oil: oil load impact and oxidative stability.

The impact of fish oil concentration on the oxidative stability of microcapsules through the spray drying process using chitosan and maltodextrin as wall material was studied. Emulsions were prepared with different Tuna fish oil (TFO) content (TFO-10%, TFO20%, TF030% TF0-40%) while wall material concentration was kept constant. Microencapsulated powder resulting from emulsion prepared with high fish oil load have high moisture content, wettability, total oil and low encapsulation efficiency, hygroscopicity and bulk tapped density. Oxidative stability was evaluated periodically by placing microcapsules at room temperature. Microcapsules prepared with TFO-10% presented high oxidative stability in terms of peroxide value (2.94±0.04) and anisidine value (1.54±0.02) after 30 days of storage. It was concluded that optimal amounts of fish oil for microencapsulation are 10% and 20% using chitosan and maltodextrin that extended its shelf life during study period.

Novel finding of atrophic extraocular muscles in Loeys-Dietz syndrome: a case report and review of the literature.

A 19-year-old man with Loeys-Dietz syndrome and right exotropic Duane syndrome after bilateral lateral rectus recessions at age 22 months presented with recurrent progressive exotropia 17 years after his initial surgery. Surgical correction was aborted intraoperatively when extreme atrophy of the right medial rectus, lateral rectus, and superior rectus muscles was observed, later corroborated by orbital magnetic resonance imaging.

How sesquiterpenes modulate signaling cascades in cancers.

Data obtained from high-throughput technologies has started to shed light on the interplay between signal transduction cascades and chromatin modifications thus adding another layer of complexity to the already complex regulation of the protein network. Based on the insights gleaned from almost a decade of research, it has now been convincingly revealed that sesquiterpenes effectively modulated different intracellular signaling cascades in different cancers. In this review we summarize how sesquiterpenes mediated Wnt, Shh, Notch and TRAIL induced signaling cascades.

Site-specific protein transamination using N-methylpyridinium-4-carboxaldehyde.

The controlled attachment of synthetic groups to proteins is important for a number of fields, including therapeutics, where antibody-drug conjugates are an emerging area of biologic medicines. We have previously reported a site-specific protein modification method using a transamination reaction that chemoselectively oxidizes the N-terminal amine of a polypeptide chain to a ketone or an aldehyde group. The newly introduced carbonyl can be used for conjugation to a synthetic group in one location through the formation of an oxime or a hydrazone linkage. To expand the scope of this reaction, we have used a combinatorial peptide library screening platform as a method to explore new transamination reagents while simultaneously identifying their optimal N-terminal sequences. N-Methylpyridinium-4-carboxaldehyde benzenesulfonate salt (Rapoport's salt, RS) was identified as a highly effective transamination reagent when paired with glutamate-terminal peptides and proteins. This finding establishes RS as a transamination reagent that is particularly well suited for antibody modification. Using a known therapeutic antibody, herceptin, it was demonstrated that RS can be used to modify the heavy chains of the wild-type antibody or to modify both the heavy and the light chains after N-terminal sequence mutation to add additional glutamate residues.

Distinct melanization pathways in the mosquito Aedes aegypti.

Serine protease cascades are involved in blood coagulation and immunity. In arthropods, they regulate melanization, which plays an important role in immune defense and wound healing. However, the mechanisms underlying melanization pathways are not completely characterized. We found that in the mosquito Aedes aegypti, there are two distinct melanization activation pathways carried out by different modules of serine proteases and their specific inhibitors serpins. Immune melanization proteases (IMP-1 and IMP-2) and Serpin-1 mediate hemolymph prophenoloxidase cleavage and immune response against the malaria parasite. Tissue melanization, exemplified by the formation of melanotic tumors, is controlled by tissue melanization protease (CLIPB8), IMP-1, and Serpin-2. In addition, serine proteases CLIPB5 and CLIPB29 are involved in activation of Toll pathway by fungal infection or by infection-independent manner, respectively. Serpin-2 is implicated in the latter activation of Toll pathway. This study revealed the complexity underlying melanization and Toll pathway in mosquitoes.

Mosquito RUNX4 in the immune regulation of PPO gene expression and its effect on avian malaria parasite infection.

Prophenoloxidases (PPOs) are key enzymes of the melanization reaction, which is a prominent defense mechanism of arthropods. The mosquito Aedes aegypti has ten PPO genes in the genome, four of which (PPO1, PPO3, PPO5, and PPO8) were expressed in response to microbial infection. Cactus depletion resulted in transcriptional activation of these four genes, suggesting this up-regulation to be under the control of the Toll pathway. The silencing of Cactus also led to developmental arrest and death of the avian malaria parasite, Plasmodium gallinaceum. We discovered that RUNT-related transcription factor 4 (RUNX4), the orthologue of Drosophila Lozenge, bound to the RUNT binding motif in the promoter of mosquito PPO genes and stimulated the expression of Drosophila PPO-A1 and PPO3 in S2 cell line. The immune effects caused by Cactus depletion were eliminated by double knockdown of Cactus/RUNX4. These findings suggest that RUNX4 regulates PPO gene expression under the control of the Toll pathway and plays a critical role in restricting parasite development.

c-jun is essential for sympathetic neuronal death induced by NGF withdrawal but not by p75 activation.

Sympathetic neurons depend on NGF binding to TrkA for their survival during vertebrate development. NGF deprivation initiates a transcription-dependent apoptotic response, which is suggested to require activation of the transcription factor c-Jun. Similarly, apoptosis can also be induced by selective activation of the p75 neurotrophin receptor. The transcriptional dependency of p75-mediated cell death has not been determined; however, c-Jun NH2-terminal kinase has been implicated as an essential component. Because the c-jun-null mutation is early embryonic lethal, thereby hindering a genetic analysis, we used the Cre-lox system to conditionally delete this gene. Sympathetic neurons isolated from postnatal day 1 c-jun-floxed mice were infected with an adenovirus expressing Cre recombinase or GFP and analyzed for their dependence on NGF for survival. Cre immunopositive neurons survived NGF withdrawal, whereas those expressing GFP or those uninfected underwent apoptosis within 48 h, as determined by DAPI staining. In contrast, brain-derived neurotrophic factor (BDNF) binding to p75 resulted in an equivalent level of apoptosis in neurons expressing Cre, GFP, and uninfected cells. Nevertheless, cycloheximide treatment prevented BDNF-mediated apoptosis. These results indicate that whereas c-jun is required for apoptosis in sympathetic neurons on NGF withdrawal, an alternate signaling pathway must be induced on p75 activation.

Intracellular fragments of the natriuretic peptide receptor-C (NPR-C) attenuate dopamine efflux.

Natriuretic peptides suppress adrenergic neurotransmission by a mechanism apparently involving the natriuretic peptide receptor-C (NPR-C) rather than particulate guanylyl cyclase receptors. The bulk of evidence implicating the NPR-C in neuromodulatory effects relies on the pharmacological specificity of peptides believed to be specific for the NPR-C. This study tests for NPR-C effects on neurotransmitter release by examining fragments of the receptor for biological activity in pheochromocytoma (PC12) cells permeabilized with digitonin. A pentadecapeptide segment of the cytoplasmic portion of the NPR-C mimicked the effect of natriuretic peptides to suppress dopamine efflux evoked by calcium approximately 40%. Furthermore, an antibody generated against the pentadecapeptide fragment abolished the neuromodulatory effect of C-type natriuretic peptide in permeabilized cells. In contrast, the carboxy terminal nonadecapeptide portion of the NPR-C failed to attenuate dopamine efflux. These data are consistent with the proposed role of the NPR-C in transducing the biological activity of natriuretic peptides in adrenergic tissue. The most novel aspect of these observations involves the potency of the small cytosolic region of the NPR-C with the region closest to the membrane accounting for neuromodulatory effects.

Atrial natriuretic peptide inhibits evoked catecholamine release by altering sensitivity to calcium.

Natriuretic peptides are cyclized peptides produced by cardiovascular and neural tissues. These peptides inhibit various secretory responses such as the release of renin, aldosterone and autonomic neurotransmitters. This report tests the hypothesis that atrial natriuretic peptide reduces dopamine efflux from an adrenergic cell line, rat pheochromocytoma cells, by suppressing intracellular calcium concentrations. The L-type calcium channel inhibitor, nifedipine, markedly suppressed dopamine release from depolarized PC12 cells, suggesting that calcium entering through this channel was the predominant stimulus for dopamine efflux. Atrial natriuretic peptide maximally reduced depolarization-evoked dopamine release 20 +/- 3% at a concentration of 100 nM and this effect was abolished by nifedipine, but not by pretreatment with the N-type calcium channel inhibitor, omega-conotoxin, or an inhibitor of calcium-induced calcium release, ryanodine. In cells loaded with Fura-2, atrial natriuretic peptide both augmented depolarization-induced increases of intracellular free calcium concentrations and accelerated the depolarization-induced quenching of the Fura-2 signal by manganese, findings consistent with enhanced conductivity of calcium channels. Dopamine efflux induced by either the calcium ionophore, A23187, or staphylococcal alpha toxin was attenuated by atrial natriuretic peptide. Additionally, a natriuretic peptide interacting solely with the natriuretic peptide C receptor in these cells, C-type natriuretic peptide, also suppressed calcium-induced dopamine efflux in permeabilized cells. These data are consistent with natriuretic peptides attenuating catecholamine exocytosis in response to calcium but inconsistent with the neuromodulatory effect resulting from a reduction in intracellular calcium concentrations within pheochromocytoma cells.

C-type natriuretic peptide neuromodulates via "clearance" receptors.

A recently discovered endogenous autacoid, C-type natriuretic peptide, was tested in a pheochromocytoma (PC12) cell line for effects on 1) catecholamine release induced by a depolarizing stimulus, 2) guanylyl and adenylyl cyclase activities, and 3) specific 125I-labeled atrial natriuretic peptide (ANP) binding. C-type natriuretic peptide suppressed evoked neurotransmitter release in the absence of guanylyl cyclase activation or adenylyl cyclase inhibition; however, both a "clearance" (ANP-C) receptor binding agent, des-[Gln18Ser19Gly20Leu21Gly22]-ANF-(4-23)-NH2 (cANF), and pertussis toxin prevented this neuromodulatory effect. The C-type natriuretic peptide preferentially bound to receptors that also bound cANF. The results suggest that C-type natriuretic peptide suppressed evoked neurotransmitter efflux by binding to ANP-C receptors coupled to a pertussis toxin-sensitive process; furthermore, the neuromodulatory effect of C-type natriuretic peptide occurred independently of guanylyl cyclase activation or adenylyl cyclase inhibition. The novel aspects of these findings are 1) neuromodulatory effects of C-type natriuretic peptide, 2) guanylyl cyclase-independent actions of C-type natriuretic peptide, and 3) ANP-C receptors mediating C-type natriuretic peptide actions.

Potassium channel inhibitors attenuate neuromodulatory effects of atrial natriuretic factor in the rabbit isolated vas deferens.

This study tested the hypothesis that neuromodulatory effects of atrial natriuretic factor (ANF) are mediated by an activation of potassium channels in the rabbit isolated vas deferens. The neuromodulatory effects of ANF were tested in the presence of the potassium channel inhibitors, tetraethylammonium, 4-aminopyridine, glibenclamide and charybdotoxin. The effects of the first three were ascertained by their prevention of neuromodulatory effects of a cromokalim enantiomer (BRL 38227), which opens ATP-sensitive potassium channels. The nonspecific potassium channel inhibitors, tetraethylammonium (2 mM) and 4-aminopyridine (2 mM) blocked inhibitory effects of both ANF and BRL 38227 on the electrically-induced adrenergic contraction in the rabbit vas deferens. Glibenclamide (10 microM), an inhibitor of ATP-sensitive potassium channels, failed to antagonize ANF effects, but blocked the actions of BRL 38227. Charybdotoxin (100 nM) is known to block large conductance calcium-activated potassium channels, and it attenuated the neuromodulatory effects of ANF; however, the effects of BRL 38227 were sustained in the presence of charybdotoxin. These results are consistent with the hypothesis that the neuromodulatory action of ANF is mediated by the activation of potassium conductances. The potassium channel involved is not an ATP-sensitive channel, because glibenclamide failed to alter the neuromodulatory activity of ANF. We hypothesize that ANF effects could be mediated by an activation of either calcium-activated or outward rectifying potassium channels.