Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Toxicol ; 38(5): 357-384, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31462100

RESUMO

Potential applications of gold nanoparticles in biomedicine have increasingly been reported on account of the ease of synthesis, bioinert characteristics, optical properties, chemical stability, high biocompatibility, and specificity. The safety of these particles remains a great concern, as there are differences among toxicity study protocols used. This article focuses on integrating results of research on the toxicological behavior of gold nanoparticles. This can be influenced by the physicochemical properties, including size, shape, surface charge, and other factors, such as methods used in the synthesis of gold nanoparticles, models used, dose, in vivo route of administration, and interference of gold nanoparticles with in vitro toxicity assay systems. Several researchers have reported toxicological studies with regard to gold nanoparticles, using various in vitro, in vivo, and in ovo models. The conflicting results concerning the toxicity of gold nanoparticles should thus be addressed to justify the safe use of gold nanoparticles in biomedicine.

2.
Can J Gastroenterol Hepatol ; 2018: 4379673, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30186819

RESUMO

Background: The wnt/APC/ß-catenin pathway is a critical initiator in colorectal carcinogenesis in both hereditary and sporadic colorectal cancer (CRC). The progression of this process remains incompletely understood, although inflammation is pivotal. Drivers of inflammation are elevated in malignant tissue and have been shown to regulate ß-catenin expression. Interleukin-17A (IL-17A) is protumorigenic at elevated levels via COX-2 stimulation. Elevated peroxisome proliferator-activated receptor γ (PPARγ) expression has reduced risk of carcinogenesis and good overall prognosis in established CRC. Activation of PPARγ has inhibitory effect on ß-catenin. Methods: Using qPCR and IHC, we compared ß-catenin, PPARγ, COX-2, and IL-17A in the colonic mucosa of patients with sporadic CRC, inflammatory bowel disease (IBD), and irritable bowel syndrome (IBS), against a normal control population. Results: ß-catenin mRNA and protein expression progressively increased from the Normal group, through IBS and IBD reaching statistical significance in CRC. COX-2 mRNA levels increased similarly with statistical significance in IBD and CRC. However, COX-2 protein expression was inverted with significant expression in the Normal and IBS groups and reduced levels in IBD and CRC. PPARγ mRNA expression was unchanged in IBD and CRC but was significantly elevated in the IBS. IL-17A mRNA was significantly reduced in IBS and CRC but unchanged in IBD. There were no differences in all parameters tested in the Normal and IBS groups. Conclusion: ß-catenin is confirmed as a major driver of colorectal carcinogenesis but is controlled by many more players other than APC. Elevated levels of PPARγ may have an anticarcinogenic effect. The role of COX-2 expression, especially its posttranscriptional regulation in colorectal cancer, needs further elucidation.

3.
Nutrition ; 30(10): 1151-7, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25194614

RESUMO

OBJECTIVES: Irritable bowel syndrome (IBS) is a common diagnosis in gastroenterology. Its etiology is unknown and therapeutic options limited. Trials suggest probiotics may be beneficial. The aim of this study was to assess the symptomatic efficacy of Lactobacillus plantarum 299 v (L. plantarum 299 v) for the relief of abdominal pain in patients with IBS fulfilling Rome II criteria. METHODS: This study was conducted in a referral hospital. Trial participants were randomized to receive either two capsules of L. plantarum 299 v at a dosage of 5 × 10(9) cfu per capsule or placebo daily for 8 wk. Severity of abdominal pain was assessed using a visual analog scale at each visit and a quality-of-life IBS (QoL-IBS) questionnaire was also completed. RESULTS: There was no significant difference in abdominal pain relief between the study and placebo groups (P = 0.800). There was also no difference in QoL- IBS scores between the groups (P = 0.687). Both groups had a significant improvement in abdominal pain scores over the study period, from an average of 251.55 to 197.90 (P < 0.0001) indicating a large placebo effect. CONCLUSION: An 8-wk treatment with L. plantarum 299 v did not provide symptomatic relief, particularly of abdominal pain and bloating, in patients fulfilling the Rome II criteria.


Assuntos
Dor Abdominal , Síndrome do Intestino Irritável , Lactobacillus plantarum , Probióticos , Dor Abdominal/tratamento farmacológico , Adulto , Método Duplo-Cego , Feminino , Humanos , Síndrome do Intestino Irritável/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Probióticos/uso terapêutico , Qualidade de Vida , Resultado do Tratamento
4.
Phytother Res ; 26(12): 1830-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22422585

RESUMO

High fat diet induced insulin resistance correlates with dyslipidaemia and ectopic fat deposits in skeletal muscle and liver. The effects of Sutherlandia frutescens, an antidiabetic medicinal plant, on lipid metabolism were evaluated in an insulin resistant (IR) rat model and in 3 T3-preadipocytes. Wistar rats received normal diet (ND) or high fat diet (HFD). After the onset of IR in the HFD group, the rats were subdivided into two subgroups, which either continued with HFD or were treated with 50 mg S. frutescens/kg BW/day and HFD (HFD + SF). After 4 weeks, the HFD + SF rats had a significantly lower body weight than the HFD rats (p < 0.05). Blood plasma analysis showed a decrease in insulin, free fatty acids and triglycerides. Related changes in lipid parameters were observed in the liver, skeletal muscle and adipose tissue. To investigate the effects of S. frutescens on adipose tissue, 3 T3-L1 cells were used as a model. Treatment with S. frutescens led to a decrease in triglyceride accumulation, whilst glucose consumption and lactate production were increased (p < 0.05). These results indicate that S. frutescens directly affects mitochondrial activity and lipid biosynthesis in adipose tissue and provide a mechanism by which S. frutescens can restore insulin sensitivity by modulating fatty acid biosynthesis.


Assuntos
Adipócitos/metabolismo , Fabaceae/química , Resistência à Insulina , Metabolismo dos Lipídeos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Glicemia/análise , Peso Corporal/efeitos dos fármacos , Dieta Hiperlipídica , Insulina/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Ratos , Ratos Wistar
5.
Phytother Res ; 23(11): 1609-14, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19370539

RESUMO

Intake of high caloric food induces raised plasma free fatty acids, culminating in insulin resistance (IR) and Diabetes mellitus type 2 (DMT2). The present study has shown for the first time that Sutherlandia frutescens reduces plasma free fatty acid levels in rats fed a high fat diet, thereby preventing the development of insulin resistance. A commercially available S. frutescens extract was administered to rats to examine its effects on the progression of high fat diet induced IR. In comparison to rats fed high fat diet only (positive control for IR), levels of plasma free fatty acids (FFA) were significantly reduced after one week (p < 0.025). Twelve weeks of treatment with S. frutescens reduced the level of plasma free fatty acids below that of rats fed a normal diet (negative control) (p < 0.025). QUICKI and HOMA-IR index confirmed that S. frutescens treated rats did not develop IR when fed a high fat diet for twelve weeks. In addition to preventing IR and reducing plasma FFA, chronic medication over twelve weeks decreased total cholesterol levels and the LDL/HDL ratio. We propose that S. frutescens is an effective medicinal remedy to prevent elevated plasma free fatty acids and IR, and therefore DMT2.


Assuntos
Ácidos Graxos não Esterificados/sangue , Resistência à Insulina , Fitoterapia , Extratos Vegetais/farmacologia , Animais , Glicemia , Colesterol/sangue , Diabetes Mellitus Experimental/prevenção & controle , Diabetes Mellitus Tipo 2/prevenção & controle , Gorduras na Dieta/efeitos adversos , Fabaceae , Hipoglicemiantes/farmacologia , Insulina/sangue , Masculino , Ratos , Ratos Wistar
6.
J Ethnopharmacol ; 119(1): 81-6, 2008 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-18588966

RESUMO

AIM: To investigate the traditional antidiabetic uses of indigenous or naturalised South African plants using an optimised screening and scoring method. MATERIALS AND METHODS: Eleven plant species were screened against Chang liver, 3T3-L1 adipose and C2C12 muscle cells measuring glucose utilisation in all three cell lines and toxicity in the hepatocytes and adipocytes only. A scoring system was devised to aid interpretation of results. RESULTS: Catharanthus roseus results correlated with previously reported in vivo results, with best stimulation of glucose utilisation in hepatocytes. Momordica foetida and Momordica balsamina extracts were active in myocytes but only the latter stimulated glucose utilisation in hepatocytes. Brachylaena discolor gave the best overall results, with all plant parts giving high activity scores and negligible toxicity. In vitro toxicity results for Catharanthus roseus, Vinca major, Momordica balsamina and some Sclerocarya birrea extracts raise concern for chronic use. CONCLUSION: This screening system increases the likelihood of identifying drug candidates using in vitro antidiabetic screening of crude plant extracts, whilst the scoring system aids data interpretation. ETHNOPHARMACOLOGICAL RELEVANCE: The multitude of metabolic steps affected by Type II diabetes offer many drug targets but they complicate in vitro screening to validate traditional uses or find new drug leads from plants.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Linhagem Celular , Glucose/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/toxicidade , Medicina Tradicional Africana , Camundongos , Extratos Vegetais/toxicidade , África do Sul , Testes de Toxicidade
7.
J Ethnopharmacol ; 109(1): 121-7, 2007 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-16939705

RESUMO

Sutherlandia frutescens has been marked as a potential hypoglycaemic agent for the treatment of type 2 diabetes. We investigated the effects of Sutherlandia frutescens in bringing about hypoglycaemia and promoting glucose uptake in pre-diabetic rats. Crushed Sutherlandia frutescens leaves in drinking water were administered to rats fed a high fat diet. Positive control rats received only metformin. Glucose uptake experiments were undertaken using [(3)H] deoxy-glucose. Various physiological parameters were also measured. Rats receiving Sutherlandia frutescens displayed normoinsulinaemic levels, after 8 weeks medicational compliance, compared to the fatty controls. There was a significant increase in glucose uptake into muscle and adipose tissue, and a significant decrease in intestinal glucose uptake (p<0.001 at 60min) in rats receiving the plant extract. The Sutherlandia frutescens plant extract shows promise as a type 2 anti-diabetes medication because of its ability to normalize insulin levels and glucose uptake in peripheral tissues and suppress intestinal glucose uptake, with no weight gain noted. The exact mechanism of action and the extract's efficacy in humans need further confirmation.


Assuntos
Hipoglicemiantes/farmacologia , Estado Pré-Diabético/induzido quimicamente , Estado Pré-Diabético/tratamento farmacológico , Anestesia , Animais , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Dieta , Gorduras na Dieta/farmacologia , Glucose/metabolismo , Glicogênio/metabolismo , Hiperinsulinismo/induzido quimicamente , Insulina/sangue , Mucosa Intestinal/metabolismo , Masculino , Metformina/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Ratos , Ratos Wistar
8.
Nutrition ; 21(1): 14-9, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15729777

RESUMO

OBJECTIVE: We explored whether tactile defensive children have picky eating habits because fussy or picky eaters are a general problem to parents and different health professionals. METHODS: Children (n = 62) of both sexes, ages 3 to 10 y, were assigned to an experimental tactile defensive (TD) group (n = 29) or a control non-TD group (n = 33). A questionnaire on eating habits was compiled and given to parents for completion during personal interviews (children were screened with a checklist and evaluated for tactile defensiveness with the Winnie Dunn Caregiver profile questionnaire). RESULTS: This research confirmed that the eating habits and food choices of TD and non-TD children differ significantly. TD children had a fair to poor appetite. They hesitated to eat unfamiliar foods, did not eat other people's houses, and refused certain foods because of the smell and temperature. They also had a problem eating vegetables. They often gagged and/or bit their inner lips and cheeks. The results showed a definite difference in the limited selection of foods that TD children chose and a pronounced aversion toward textures or consistencies, smells, and temperatures of food as compared with integrated children. CONCLUSIONS: Fussy or picky eaters should evaluated more widely than to treat only the feeding problem. Tactile or oral defensiveness can be treated. This report underlines the team approach of health professionals.


Assuntos
Comportamento Infantil , Preferências Alimentares/fisiologia , Transtornos das Sensações/fisiopatologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Limiar Sensorial , Inquéritos e Questionários , Verduras
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA