RESUMO
Collagen is considered to be an intercellular adhesive that prevents tissue stretching or damage. It is widely utilized in cosmetic skin solutions, drug delivery, vitreous substitutions, 3D cell cultures, and surgery. In this study, we report the development of a green technology for manufacturing collagen peptides from flatfish skin using ultrasound and enzymatic treatment and a subsequent assessment on skin functionality. First, flatfish skin was extracted using ultrasound in distilled water (DW) for 6 h at 80 °C. Molecular weight analysis via high-performance liquid chromatography (HPLC) after treatment with industrial enzymes (alcalase, papain, protamex, and flavourzyme) showed that the smallest molecular weight (3.56 kDa) was achieved by adding papain (0.5% for 2 h). To determine functionality based on peptide molecular weight, two fractions of 1100 Da and 468 Da were obtained through separation using Sephadex™ G-10. We evaluated the effects of these peptides on protection against oxidative stress in human keratinocytes (HaCaT) cells, inhibition of MMP-1 expression in human dermal fibroblast (HDF) cells, reduction in melanin content, and the inhibition of tyrosinase enzyme activity in murine melanoma (B16F10) cells. These results demonstrate that the isolated low-molecular-weight peptides exhibit superior skin anti-oxidant, anti-wrinkle, and whitening properties.
Assuntos
Colágeno , Peptídeos , Pele , Animais , Humanos , Pele/efeitos dos fármacos , Pele/metabolismo , Colágeno/metabolismo , Peptídeos/química , Peptídeos/farmacologia , Camundongos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Ondas Ultrassônicas , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/farmacologia , Antioxidantes/química , Células HaCaT , Peso Molecular , Melaninas , Monofenol Mono-Oxigenase/metabolismoRESUMO
Daphne odora, a blooming shrub, has been traditionally used for various medicinal purposes. However, information on its anti-melanogenic activity and dermal application is limited. In this study, the Daphne odora extract (DOE), with constituents including daphnetin, was used to investigate depigmenting activity and the underlying mechanism of Daphne odora. DOE inhibited in vitro and cellular tyrosinase activity in a dose-dependent manner, and reduced the α-MSH-induced melanin biosynthesis to a control level. The protein expressions of melanin synthesis-related enzymes were also significantly reduced by DOE. Moreover, DOE decreased the phosphorylation of cAMP-response element binding proteins (CREBs) induced by α-MSH in B16F10 cells, while it activated phosphorylated extra-cellular signal-regulated kinases (ERKs) and protein kinase B (AKT) expression. These results suggest that DOE might inhibit the melanogenesis signaling pathways by activating ERK- and AKT-signaling pathways to regulate the expression of CREB and MITF and its downstream pathways. Therefore, DOE could potentially be developed as a depigmenting agent.
RESUMO
Comparative proteomic profiling of human follicular fluid (HFF) from polycystic ovary syndrome (PCOS) and non-PCOS patients who displayed low levels of fertility was carried out via two-dimensional gel electrophoresis (2-DE) combined with mass spectrometry. HFF, an important reproductive fluid, was used for the proteomic analysis of PCOS patients to determine the effect of PCOS on folliculogenesis. HFF was obtained from 10 women (average age, 35 years) undergoing in vitro fertilization at two hospitals. The proteins of HFF were separated using 2-DE analysis and validated by Western blot assay. Approximately 250 protein spots were separated on the 2-DE gel. Among them, the expression levels of seven proteins were found to change at least 1.5-fold in the PCOS patient group. Three protein spots, albumin, uncharacterized protein 1, and uncharacterized protein 2, were downregulated in PCOS patients. However, four protein spots, gelsolin, vitamin D binding protein, serum albumin, and complement factor B, were upregulated in PCOS patient group. These proteins may serve as a panel of potential pathological biomarkers during fertilization and oocyte development.
Assuntos
Síndrome do Ovário Policístico , Adulto , Eletroforese em Gel Bidimensional , Feminino , Fertilização in vitro , Líquido Folicular , Humanos , ProteômicaRESUMO
GHK (Gly-His-Lys), a natural peptide found in human skin and plasma, has been widely used in the cosmeceutical and pharmaceutical fields. The hydrophilic GHK and GHK-Cu are limited in their abilities to penetrate deeply into skin; because of this, various strategies for their skin delivery have been developed. In this investigation, Arg4 was conjugated with GHK to get heptapeptide, GHK-R4, and then in vitro antiwrinkle activity and transdermal delivery were compared between GHK and GHK-R4. Notably, Arg4 conjugation accelerated the cellular penetration of GHK both in vitro and in vivo. Furthermore, higher in vitro antiwrinkle activity and collagen biosynthesis was obtained with GHK-R4 at much lower doses than with control R4-free GHK. The enhanced activity and delivery of GHK-R4 might be due to the cell penetrating ability and matrix metalloproteinase (MMP) inhibitory activity of R4 itself.
Assuntos
Oligopeptídeos/farmacologia , Peptídeos/química , Envelhecimento da Pele/efeitos dos fármacos , Administração Cutânea , Linhagem Celular , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/farmacologia , Colágeno/metabolismo , Humanos , Metaloproteinases da Matriz/metabolismo , Oligopeptídeos/químicaRESUMO
The adverse health effect of nanoparticles is of concern for humans and environment. In the present study, TiO2-nanoparticles (TiO2-NPs)-induced oxidative DNA damage in lymphocytes was measured by comet assay. 80 mg ml-1 TiO2-NPs induced approximately 3-fold increase in DNA damage than in the PBS-control group as measured by olive tail moment. However, on treating vitamin C and N-acetylcysteine, DNA damage was effectively protected in a concentration dependent manner. Moreover, the protective effect of several phytochemicals including berberine, resveratrol, sulforaphane, and curcumin on DNA damage caused by TiO2-NPs was manifested. The increased olive tail moment induced by TiO2-NPs was effectively inhibited by treatment with these phytochemicals. Especially, olive tail moment of 5 mg ml-1 berberine-treated group was significantly reduced down to the level of control group, showing almost complete protection. Taken together, the protective effect of phytochemicals against DNA damage by TiO2-NPs may be applied for the development of antidote for TiO2 toxicity.
Assuntos
Dano ao DNA/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Compostos Fitoquímicos/farmacologia , Titânio/toxicidade , Animais , Ensaio Cometa , Masculino , Nanopartículas Metálicas/química , Ratos Sprague-Dawley , Titânio/químicaRESUMO
The properties of wheat dough according to salt level and type of mixer were investigated, and parameters derived from each analysis were comprehensively compared. Mixolab analysis showed that water absorption decreased with salt level while the dough strength increased. In the Mixolab C2 stage, related with thermal strength, C2 temperature and time had stronger correlation with other dough strength parameters than C2 torque. Thickness increase of gluten strand was dominant in the doughs prepared by vertical mixer (VMD) than in those prepared by Mixolab device (MLD), for the same salt level. In large deformation, increase in resistance to extension by salt level was much greater in VMD than in MLD. In small deformation, relationships of salt level with G', G'' and power-law exponent (n) were linear and non-linear in MLD and VMD, respectively. Since MLD could not perfectly reflect VMD, properties of dough should be considered in multiple ways for its comprehensive understanding.
RESUMO
Photodynamic therapy (PDT) has been used to treat cancers and non-malignant skin diseases. In this study, a chlorin e6-curcumin conjugate (Ce6-PEG-Cur), a combination of chlorin e6 (Ce6) and curcumin via a PEG linker, was used as a photosensitizer. The in vitro and in vivo effects of PDT using Ce6-PEG-Cur were analyzed in UVB-irradiated fibroblasts and hairless mice. The UVB-induced expression of MMPs was reduced in Hs68 fibroblast cells, and procollagen type â expression was enhanced by Ce6-PEG-Cur-mediated PDT on a Western blotting gel. Moreover, UVB-induced collagen levels were restored upon application of Ce6-PEG-Cur-mediated PDT. Ce6-PEG-Cur-mediated PDT inhibited the expression of phosphorylated p38 in the MAPK signaling pathway, and it reduced the expression of phosphorylated NF-κB. In animal models, Ce6-PEG-Cur-mediated PDT inhibited the expression of MMPs, whereas procollagen type â levels were enhanced in the dorsal skin of UVB-irradiated mice. Moreover, UVB-induced dorsal roughness was significantly reduced following Ce6-PEG-Cur-mediated PDT treatment. H&E staining and Masson's trichrome staining showed that the thickness of the epidermal region was reduced, and the density of collagen fibers increased. Taken together, Ce6-PEG-Cur-mediated PDT might delay and improve skin photoaging by ultraviolet light, suggesting its potential for use as a more effective photo-aging treatment.
RESUMO
Retrogradation is the principal cause for bread staling and, therefore, it has attracted a lot of interest from the food industry. In this study, the inhibitory effect of citrus peel hydrolysates (CPH) on retrogradation of wheat starch (WS) in the presence of sucrose was investigated. The pasting properties showed that further addition of CPH caused a lower setback value than the addition of sucrose alone. Hardness of the gel, retrograded at 4 °C for five days, showed a similar tendency, which was reduced more in CPH addition than WS itself or sucrose addition alone. The low retrogradation enthalpy of the CPH including starch gel also indicated the positive effect of CPH on retarding retrogradation. These results suggested that incorporation of CPH in starch-based foods would be effective for inhibiting retrogradation, preventing the deterioration of the quality of food products.
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BACKGROUND: Chlorin e6-mediated photodynamic therapy (Ce6-mediated PDT) is a therapeutic modality that consists of a photosensitizer, source of light at a suitable wavelength, and molecular oxygen. PDT has been widely used for the treatment of cancers and non-neoplastic disorders. However, information on the inhibitory activity of Ce6-mediated PDT on adipogenesis and lipogenesis in 3T3-L1 cells is not available to date. METHODS: MTT assay, Oil Red O staining, and Nile red staining were used to investigate lipid accumulation in 3T3-L1 cells to clarify adipocyte differentiation. The expression levels of various molecular signals associated with adipogenesis and lipogenesis were examined by RT-PCR and western blot analysis. RESULTS: Adipocyte differentiation and lipid accumulation were reduced by Ce6-mediated PDT in 3T3-L1 cells. Inhibition of the expression of PPAR-γ, C/EBPα, ß, δ, SREBP-1, FAS, and LPL and the activation of AMPK, revealed concise modulation of adipogenic and lipogenic molecules by Ce6-mediated PDT. The anti-adipogenic effect of Ce6-mediated PDT was reversed by AMPKα siRNA. CONCLUSION: Ce6-mediated PDT inhibits adipocyte differentiation and lipogenesis via regulating AMPK. Ce6-mediated PDT might serve as a potential therapy for the treatment of obesity and obesity-associated diseases.
Assuntos
Fotoquimioterapia , Células 3T3-L1 , Adipócitos , Animais , Diferenciação Celular , Clorofilídeos , Lipogênese , Camundongos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , PorfirinasRESUMO
Toll-like receptors (TLRs) are a group of pattern-recognition receptors (PRRs) that are at the core of innate and adaptive immune responses. TLRs activation triggers the activation of two downstream signaling pathways, the myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter inducing interferon-ß (TRIF)-dependent pathways. To evaluate the therapeutic potential of DHL, a natural sesquiterpene lactone derived from Inulahelenium L. and Saussurea lappa, we examined its effect on signal transduction via the TLR signaling pathways. DHL inhibited the activation of nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3), the representative transcription factors involved in the inflammatory response, induced by TLR agonists, as well as the expression of cyclooxygenase-2 and interferon inducible protein-10. DHL also inhibited the activation of NF-κB and IRF3 induced by the overexpression of downstream signaling components of the TLRs signaling pathways. All results suggest that DHL might become a new therapeutic drug for a variety of inflammatory diseases.
Assuntos
Anti-Inflamatórios/farmacologia , Inflamação/tratamento farmacológico , Lactonas/farmacologia , Sesquiterpenos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Receptores Toll-Like/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Células HEK293 , Humanos , Inflamação/imunologia , Fator Regulador 3 de Interferon/metabolismo , Inula/química , Lactonas/uso terapêutico , Camundongos , Fator 88 de Diferenciação Mieloide/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Células RAW 264.7 , Saussurea/química , Sesquiterpenos/uso terapêutico , Transdução de Sinais/imunologiaRESUMO
Vibrio parahaemolyticus is the most common pathogen causing seafood-borne illnesses in Korea. The present study evaluated the occurrence, virulence, and antimicrobial resistance of V. parahaemolyticus in seawater and bivalves obtained in 2016 from the southern coast of Korea, an important region for commercial aquaculture industries, especially the Korean raw seafood culture. V. parahaemolyticus was detected in 87 of 160 (54.4%) bivalve samples and in 32 of 130 (24.5%) seawater samples. Especially high levels were detected during summer to early autumn. All the seawater and bivalves contained less than 2 and 5% of the tdh and trh genes of the isolates, respectively, and seawater isolates possessed two fewer genes than the bivalve isolates. Of 23 antimicrobials tested, three agents (ofloxacin, norfloxacin, and trimethoprim/sulfamethoxazole) effectively treated V. parahaemolyticus illness due to the sensitivity of the isolates. The isolates were highly resistant to ampicillin, however, excluding it as a treatment option. More than half of the isolates exhibited resistance to at least three antimicrobials. These findings indicate the importance of an integrated monitoring and surveillance program noting the occurrence, virulence, and antimicrobial resistance patterns of V. parahaemolyticus in various aquatic sources for preventing human health risks from seafood consumption.
Assuntos
Aquicultura/estatística & dados numéricos , Bivalves/microbiologia , Farmacorresistência Bacteriana , Frutos do Mar/microbiologia , Vibrio parahaemolyticus/patogenicidade , Animais , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Humanos , República da Coreia , Estações do Ano , Água do Mar/microbiologia , Vibrio parahaemolyticus/efeitos dos fármacos , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/isolamento & purificação , Virulência/genéticaRESUMO
Cigarette smoke contains more than 4,500 chemicals; most of which are highly reactive free radicals, which induce proinflammatory and carcinogenic reactions. Numerous efforts have focused extensively on the role of cigarette smoking as a cause of many diseases. Extracellular vesicles and exosomes have recently received increasing interest for their diagnostic and therapeutic roles in many diseases. However, research done on the role of extracellular vesicles and exosomes on cigarette smoke-induced chronic disease is still in its infancy. In this review, we summarize the recently addressed roles of extracellular vesicles and exosomes in the pathogenesis of cigarette smoke-related diseases, such as chronic obstructive pulmonary disease, cardiovascular disease, lung cancer, and oral cancer. Moreover, their potential utilization and future prospects as diagnostic biomarkers for cigarette smoke-related diseases are described.
Assuntos
Vesículas Extracelulares/metabolismo , Pneumopatias/etiologia , Estresse Oxidativo , Fumaça/efeitos adversos , Animais , Humanos , Pneumopatias/metabolismo , Pneumopatias/patologiaRESUMO
We determined the abundance and virulence of Vibrio parahaemolyticus in seawater and bivalves from the Gyeongnam coast in Korea, a major area for the seafood industry, during 2004-2016. V. parahaemolyticus is one of the most common pathogen causing seafood-borne illnesses in Korea, and increases during the summer. Its occurrence in seawater and bivalve samples was seasonally dependent, with high levels during the summer to early autumn. There were more strains in the area of sea continually exposed to inland wastewater. Only 5.1% and 3.5% of V. parahaemolyticus isolates from seawater and bivalves, respectively, had the trh gene, and only the bivalve isolates produced the tdh gene at levels below 2%. Continuous monitoring is clearly needed to reduce seafood-borne outbreaks of disease caused by V. parahaemolyticus, and to reveal the occurrence patterns and the presence of toxic genes of the strains in different marine environments.
Assuntos
Bivalves/virologia , Água do Mar/virologia , Frutos do Mar/virologia , Vibrio parahaemolyticus/isolamento & purificação , Animais , Proteínas de Bactérias/genética , Proteínas Hemolisinas/genética , República da Coreia , Estações do Ano , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/patogenicidade , Virulência/genética , Águas ResiduáriasRESUMO
BACKGROUND: Photodynamic therapy (PDT) is a clinically approved therapeutic for cancers and non-neoplastic diseases, based on the use of a photosensitizer activated by light. The feasibility of PDT depends on several factors, such as PDT dose, photosensitizer efficacy, type of light source, and target tissue irradiated. METHODS: In this study, the second generation photosensitizer chlorin e6 (Ce6) and halogen light were used to investigate their PDT effect on the collagen production and MMPs expression of heat killed P. acnes-stimulated HaCaT cells. The mRNA levels of COL1A1, c-Jun, and c-Fos were detected by RT-PCR. The protein levels of MMPs, ERK and JNK were detected by western blot. The transactivation of AP-1 was detected by luciferase assay. RESULTS: Ce6-based PDT markedly upregulated the mRNA level of COL1A1 and type I procollagen level; and at the same time downregulated the expression of MMPs in P. acnes-infected HaCaT cells. Moreover, Ce6-mediated PDT, in a dose dependent manner, inhibited P. acnes-induced phosphorylation of JNK and ERK, as wells as the phosphorylation of their downstream targets c-Jun and c-Fos. P. acnes-induced mRNA expression of c-Jun and c-Fos were also suppressed by Ce6-mediated PDT. The transactivation of AP-1 induced by P. acnes infection was also downregulated. CONCLUSION: These results indicated that Ce6-mediated PDT with halogen light enhanced collagen production, but inhibited the expression of MMPs in P. acnes-infected HaCaT cells, by regulating AP-1 signals. This investigation provided the first molecular basis for the increase in collagen production by Ce6-mediated PDT, suggesting its potential use for scar amelioration and skin rejuvenation in acne treatment.
Assuntos
Colágeno/efeitos dos fármacos , Metaloproteinases da Matriz/efeitos dos fármacos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Clorofilídeos , Colágeno Tipo I/efeitos dos fármacos , Humanos , Proteínas Quinases Ativadas por Mitógeno/efeitos dos fármacos , RNA Mensageiro , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição AP-1/efeitos dos fármacosRESUMO
Photodynamic therapy (PDT), consisting of photosensitizer, light, and oxygen has been used for the treatment of various diseases including cancers, microbial infections and skin disorders. In this study, we examined the anti-inflammatory effect of chlorin e6-mediated PDT in P. acnes-infected HaCaT cells using photosensitizer chlorin e6 (Ce6) and halogen light. The live and heat-killed P. acnes triggered an upregulation of inflammatory molecules such as iNOS, NO, and inflammatory cytokine in HaCaT cells and mouse model. Ce6-mediated PDT notably downregulated the expression of these inflammatory molecules in vitro and in vivo. Similarly, chlorin e6-mediated PDT was capable of regulating inflammatory response in both live and heat killed S. epidermidis exposed HaCaT cells. Moreover, phosphorylation of p38, JNK, and ERK were reduced by Ce6-mediated PDT. Ce6-mediated PDT also reduced the phosphorylation of IKKα/ß, IĸBα and NFκB p65 in P. acnes-stimulated HaCaT cells. In addition, the dramatic increase in the nuclear translocation of NFκB p65 observed upon stimulation with P. acnes was markedly impaired by Ce6-based PDT. This is the first suggestion that Ce6-mediated PDT suppresses P. acnes-induced inflammation through modulating NFκB and MAPKs signaling pathways.
Assuntos
Acne Vulgar/tratamento farmacológico , Citocinas/biossíntese , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Queratinócitos/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , NF-kappa B/metabolismo , Fotoquimioterapia , Porfirinas/uso terapêutico , Propionibacterium acnes/efeitos dos fármacos , Radiossensibilizantes/uso terapêutico , Acne Vulgar/microbiologia , Linhagem Celular , Clorofilídeos , Citocinas/genética , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Temperatura Alta , Humanos , Queratinócitos/metabolismo , Queratinócitos/microbiologia , Queratinócitos/efeitos da radiação , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/biossíntese , Óxido Nítrico Sintase Tipo II/genética , Estresse Oxidativo , Porfirinas/farmacologia , Propionibacterium acnes/patogenicidade , Propionibacterium acnes/efeitos da radiação , Radiossensibilizantes/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/efeitos da radiaçãoRESUMO
Vibrio parahaemolyticus and V. vulnificus are the most common pathogens causing seafood-borne illnesses in Korea. This study determines the abundance and antimicrobial resistance of pathogenic Vibrio species in seawater and zooplankton samples from the Geoje Island coast in Korea, which is an important area for coastal fisheries, the fishing industry, and tourism. The two Vibrio species were detected more in mesozooplankton samples than in seawater samples. V. parahaemolyticus isolates showed greater resistance than those of V. vulnificus for antimicrobials. Of V. parahaemolyticus isolates, 93.3% exhibited resistance to three or more antimicrobial agents. Conversely, more than 80% of V. vulnificus isolates showed susceptibility to all antimicrobials examined, with the exception of rifampicin. Our findings show that strong antimicrobial resistance of V. parahaemolyticus in the surveyed area was exposed to conventionally used antibiotics, therefore necessitating proper surveillance programs for the monitoring of antimicrobial resistance patterns in seawater bodies and aquatic animals.
Assuntos
Antibacterianos , Vibrio parahaemolyticus/isolamento & purificação , Vibrio vulnificus/isolamento & purificação , Zooplâncton/microbiologia , Animais , Anti-Infecciosos , Testes de Sensibilidade Microbiana , República da Coreia , Alimentos Marinhos , Água do Mar , Vibrio parahaemolyticus/patogenicidadeRESUMO
The structural requirements of acetohexamide reductases purified from rabbit liver, kidney, and heart for substrates and inhibitors were examined. Acetohexamide, an oral antidiabetic drug with a ketone group, and analogs of it with various alkyl groups instead of the cyclohexyl group were used as substrates for these three enzymes. The results obtained as to substrate specificity suggested that the nature of the substrate-binding region of the heart enzyme is markedly different from those of the substrate-binding regions of the liver and kidney enzymes. Tolbutamide, which has no ketone group within its chemical structure, strongly inhibited the heart enzyme, whereas it had little ability to inhibit the liver or kidney enzyme. The inhibition of the heart enzyme by tolbutamide was competitive with respect to acetohexamide and uncompetitive with respect to NADPH. Furthermore, tolbutamide analogs with n-pentyl and n-hexyl groups instead of the n-butyl group exhibited very pronounced inhibition of only the heart enzyme. Therefore, it is reasonable to postulate that the heart enzyme, unlike the liver and kidney ones, has a cleft of a strongly hydrophobic nature near its substrate-binding region, and that this hydrophobic cleft plays a critical role in the interaction of the heart enzyme with the cyclohexyl group of acetohexamide.
Assuntos
Oxirredutases do Álcool/antagonistas & inibidores , Oxirredutases do Álcool/metabolismo , Rim/enzimologia , Fígado/enzimologia , Miocárdio/enzimologia , Acetoexamida/análogos & derivados , Acetoexamida/química , Acetoexamida/metabolismo , Animais , Sítios de Ligação , Carbutamida/química , Carbutamida/farmacologia , Clorpropamida/química , Clorpropamida/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Hipoglicemiantes/farmacologia , Cinética , Oxirredução , Coelhos , Relação Estrutura-Atividade , Especificidade por Substrato , Tolbutamida/análogos & derivados , Tolbutamida/metabolismo , Tolbutamida/farmacologia , Triazinas/química , Triazinas/metabolismo , Triazinas/farmacologiaRESUMO
An enzyme catalyzing the metabolic reduction of acetohexamide [4-acetyl-N-(cyclohexyl-carbamoyl)benzenesulfonamide], an oral antidiabetic drug, was purified to homogeneity from the cytosolic fraction of rabbit heart. The molecular mass of the purified enzyme was estimated to be 110 kDa by gel filtration and nondenaturing PAGE and 28 kDa by SDS-PAGE, suggesting that the enzyme is composed of four identical-size subunits. 4-Benzoyl-pyridine and p-nitroacetophenone, typical substrates of carbonyl reductase [EC 1.1.1.184], were not reduced by the enzyme. Of drugs with a ketone group tested, only acetohexamide was a good substrate of the enzyme. the enzyme effectively reduced analogs substituted with various alkyl groups instead of the cyclohexyl group in acetohexamide, although it had little or no ability to reduce analogs substituted with various alkyl groups instead of the methyl group in acetohexamide. The enzyme was inhibited not only by quercetin, a well-known inhibitor of carbonyl reductase, but also by phenobarbital, a potent inhibitor of aldehyde reductase [EC 1.1.1.2]. These results indicate that the enzyme purified from rabbit heart is a novel enzyme responsible for the reduction of acetohexamide and its analogs.
Assuntos
Acetoexamida/metabolismo , Oxirredutases do Álcool/isolamento & purificação , Oxirredutases do Álcool/metabolismo , Miocárdio/enzimologia , Acetoexamida/análogos & derivados , Oxirredutases do Álcool/antagonistas & inibidores , Oxirredutases do Álcool/química , Animais , Catálise , Inibidores Enzimáticos/farmacologia , Masculino , Peso Molecular , Fenobarbital/farmacologia , Quercetina/farmacologia , Coelhos , Especificidade por SubstratoRESUMO
The effects of reactive oxygen species (ROS) on elastin molecules (tropoelastin) were studied in vitro. ROS generated by ultraviolet A and hematoporphyrin rapidly degraded tropoelastin within 5 min. Their degradative activity was inhibited by the addition of NaN3. Treatment of tropoelastin with copper sulfate/ascorbic acid resulted in degradation of tropoelastin producing fragments of molecular weight 45, 30 and 10 kDa within 30 min. The degradation of tropoelastin was partially blocked by the addition of mannitol. ROS induced by the xanthine/xanthine oxidase system also degraded tropoelastin within 6 h. The degradation was blocked by catalase but not by superoxide dismutase (SOD). ROS generated by copper-ascorbate seems to be unique in that it cleaves relatively specific sites of the tropoelastin molecule. Thus ROS may play a degradative role in elastin metabolism which may cause the elastolytic changes or the deposition of fragmented elastic fibers in photoaged skin or age-related elastolytic disorders.
Assuntos
Espécies Reativas de Oxigênio , Tropoelastina/química , Ácido Ascórbico/farmacologia , Sulfato de Cobre/farmacologia , Hematoporfirinas/farmacologia , Tropoelastina/efeitos dos fármacos , Tropoelastina/efeitos da radiação , Raios Ultravioleta , Xantina/farmacologia , Xantina Oxidase/farmacologiaRESUMO
This study was conducted to evaluate the effects of unsaturated fatty acids on ultraviolet-induced hyperpigmentation of the skin. An efficient lightening effect was observed following topical application of linoleic acid or alpha-linolenic acid to UV-stimulated hyperpigmented dorsal skin of brownish guinea pigs. The number of melanocytes in the treated skin was similar to the number in the skin of the pigmented control, indicating that the pigment-lightening effect was not due to depletion of melanocytes. In vitro experiments using cultured murine melanoma cells showed that melanin production was inhibited most effectively by alpha-linolenic acid, followed by linoleic acid and then by oleic acid. Furthermore, the turnover of the stratum corneum, which plays an important role in the removal of melanin pigment from the epidermis, was accelerated by linoleic acid and by alpha-linolenic acid. Taken together, the results suggest that the pigment-lightening effects of linoleic acid and alpha-linolenic acid are, at least in part, due to suppression of melanin production by active melanocytes, and to enhanced desquamation of melanin pigment from the epidermis.