RESUMO
Present study concerns the radiological character of Malaysian honey. A total of 18 samples (representative of the various most common types) were obtained from various honey bee farms throughout the country. Using a high-purity germanium γ-ray spectroscopic system, the samples were analysed for the naturally occurring radionuclides 226Ra, 228Ra and 40K. The respective range of activities (in Bq/kg) was: 3.49 ± 0.35 to 4.51 ± 0.39, 0.99 ± 0.37 to 1.74 ± 0.39 and 41.37 ± 3.26 to 105.02 ± 6.91. The estimated associated committed effective doses were derived from prevailing data on national consumption of honey, the annual dose being found low compared with the UNSCEAR reference dose limit of 290 µSv y-1. The estimated threshold consumption rate for honey indicates a maximum intake of 339 g/d, which poses an insignificant radiological risk to public health; however, the total dietary exposure may not, the guidance level of 290 µSv y-1 being applicable to dietary intake of all foodstuffs. The study is in support of the cultivation of a healthy lifestyle, acknowledging prevailing radioactivity within the environment.
Assuntos
Monitoramento de Radiação , Rádio (Elemento) , Animais , Rádio (Elemento)/análise , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Malásia , Doses de Radiação , Tório/análiseRESUMO
Dihydroorotate dehydrogenase (DHODH) is the key enzyme in de novo biosynthesis of pyrimidine in both prokaryotes and eukaryotes. The de novo pathway of pyrimidine biosynthesis is essential in cancer cells proliferation. Leflunomide is an approved DHODH inhibitor that has been widely used for the treatment of arthritis. Similarly, brequinar sodium is another DHODH inhibitor that showed anti-tumour effect in MC38 colon carcinoma cells when used in combination with fluorouracil. Despite the potential role of DHODH inhibitors in cancer therapy, their mechanisms of action remain obscure and await further elucidation. Here, we evaluated the effect of DHODH inhibitors on the production of ATP and ROS in sensitive and non-sensitive breast cancer cells. Subsequently, the effects of DHODH inhibitors on cell cycle as well as on signalling molecules such as p53, p65 and STAT6 were evaluated in sensitive T-47D and non-sensitive MDAMB-436 cells. The correlations between DHODH protein expression, proliferation speed and sensitivity to DHODH inhibitors were also investigated in a panel of cancer cell lines. DHODH inhibitors-sensitive T-47D and MDAMB-231 cells appeared to preserve ROS production closely to endogenous ROS level whereas the opposite was observed in non-sensitive MDAMB-436 and W3.006 cells. In addition, we observed approximately 90% of intracellular ATP depletion in highly sensitive T-47D and MDAMB-231 cells compared to non-sensitive MDAMB-436 cells. There was significant over-expression of p53, p65 and STAT6 signalling molecules in sensitive cells which may be involved in mediating the S-phase arrest in cell cycle progression. The current study suggests that DHODH inhibitors are most effective in cells that express high levels of DHODH enzyme. The inhibition of cell proliferation by these inhibitors appears to be accompanied by ROS production as well as ATP depletion. The increase in expression of signalling molecules observed may be due to pyrimidine depletion which subsequently leads to cell cycle arrest at S-phase.
Assuntos
Trifosfato de Adenosina/metabolismo , Neoplasias da Mama/enzimologia , Neoplasias da Mama/metabolismo , Inibidores Enzimáticos/farmacologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Di-Hidro-Orotato Desidrogenase , Feminino , Humanos , Espécies Reativas de Oxigênio/metabolismoRESUMO
OBJECTIVES: A study was done to investigate the effect of palm oil (Elaeis guineensis) tocotrienols on (1) rats mesenteric adipose tissue deposition (2) and 11ß-HSD1 enzyme expression in mesenteric adipocyte. There is a necessity to find an inhibitor for the 11ß-HSD1 enzyme which enhances the proliferation of mesenteric adipocyte tissue therefore curbing the onset of metabolic syndrome. MATERIAL AND METHODS: A total of 35 male Spraque Dawley rats were divided into 5 different groups, i.e., a baseline control group (n=7), a sham operated group (n=7) and three experimental adrenalectomised groups (ADR) (n=21). Each of the experimental ADR group was given intramuscular dexamethasone (Dexa) with a dose of 120 µg/kg after 2 weeks post adrenalectomy and were divided into adrenalectomised control (n=7), Glycyrrhizic acid (GCA) treated (dose=120 mg/kg/day; n=7) and Palm Tocotrienol treated (dose=60 mg/kg/day; n=7) groups. These various treatments were given 6 days a week for 8 weeks via gastric gavage (following 2 weeks of adrenalectomy). Data is expressed as mean ± standard error mean (SEM), compared to each other using one-way analysis-of-variance (ANOVA) followed by Tukey's post hoc test and then a t-test. RESULTS: The results show that palm tocotrienol tend to slightly increase mesenteric adipose tissue deposition in rats. However, palm tocotrienol was also found to have potential in inhibiting the expression of 11ß-HSD1 enzyme in mesenteric adipocytes. CONCLUSIONS: This study suggests palm tocotrienol inhibits 11ß-HSD1 enzyme expression and activity.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Tecido Adiposo/efeitos dos fármacos , Óleos de Plantas/farmacologia , Tocotrienóis/farmacologia , Adipócitos/metabolismo , Adrenalectomia , Animais , Ácido Glicirrízico/farmacologia , Masculino , Síndrome Metabólica , Óleo de Palmeira , Óleos de Plantas/farmacocinética , Ratos , Ratos Sprague-Dawley , Tocotrienóis/farmacocinéticaRESUMO
BACKGROUND AND OBJECTIVES: Tibial nerve is a branch of the sciatic nerve and it is the main nerve innervating the muscles of the back of the leg. The tibial nerve divides into medial and lateral plantar nerves. The level of division may be important for surgical purpose. The main aim of the present study was to observe the exact level of division of the tibial nerve and discuss its clinical implications. MATERIALS AND METHODS: A total of 20 cadaveric limbs (irrespective of left or right side) were taken randomly. The posterior compartment of the thigh and leg was dissected to trace the tibial nerve and its branches. The specimens were subjected to measurements with respect to an arbitrary horizontal line passing through tip of medial malleolus and the calcaneum. All the specimens were photographed. RESULTS: In 5 cases (25%), the tibial nerve divided deep to the flexor retinaculum. In 15 cases (75%) cases, the tibial nerve divided at a distance of 3.5 cm - 6.5 cm (average 5 cm) above the medial malleolus. CONCLUSION: The tibial nerve and its divisions are important for performing successful nerve blocks and insertion of plates while treating fractures. Variations may account for the various discrepancies between the electromyographic tests and clinical tests.
Assuntos
Pé/inervação , Perna (Membro)/inervação , Músculo Esquelético/inervação , Nervo Tibial/anatomia & histologia , Cadáver , Humanos , Bloqueio Nervoso/métodos , Fraturas da Tíbia/cirurgia , Nervo Tibial/patologiaRESUMO
OBJECTIVES: Visceral obesity may be due to the dysregulation of cortisol production or metabolism that lead to metabolic disease. In adipose tissue, the enzyme 11beta-hydroxysteroid dehydrogenase type 1 regulates cortisol metabolism (11beta-HSD1). A previous study showed an increase in the visceral fat deposition in adrenalectomised rats given intramuscular dexamethasone. Glycyrrhizic acid (GCA) has been shown to reduce fat deposition because it is a known potent inhibitor of the 11beta-HSD1 enzyme. Piper sarmentosum (PS) is an edible medicinal plant commonly used in Asia as traditional medicine for treating diabetes, hypertension and joint pains. In this study, we determined the effects of PS extract on the disposition and morphology of perirenal adipocytes of adrenalectomised rats given intramuscular dexamethasone. MATERIALS AND METHODS: A total of 21 male Spraque Dawley rats were adrenalectomised and given intramuscular dexamethasone, 120 µg/kg/day. These rats were further divided into three groups: adrenalectomised control (ADR+Dexa; n=7), GCA-treated (ADR+Dexa+GCA; dose=240 mg/kg/day; n=7) and PS-treated (ADR+Dexa+PS; dose=125 mg/kg/day; n=7) groups. The various treatments were given via gastric gavage following 2 weeks of adrenalectomy. RESULTS: Treatment with PS extract for 8 weeks showed decreased deposition of perirenal adipocytes which was similar to the GCA-treated group. However, PS-treated rats had thinner adipocyte membrane compared with that of the GCA-treated group. CONCLUSION: In conclusion, PS extract decreased perirenal fat deposition and reduced the diameter of the adipocyte membrane. However, the mechanisms of action needed further study.
Assuntos
Fármacos Antiobesidade/farmacologia , Ácido Glicirrízico/farmacologia , Gordura Intra-Abdominal/efeitos dos fármacos , Obesidade/tratamento farmacológico , Fitoterapia/métodos , Piper , Extratos Vegetais/uso terapêutico , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/efeitos dos fármacos , Adrenalectomia , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Resultado do TratamentoRESUMO
Long term glucocorticoids administration induces oxidative stress which leads to alteration of bone structure and strength. Palm oil is rich in tocotrienol, an antioxidant. It can be used for the prevention of oxidative stress related diseases. The main objective of this study was to determine the mechanism of palm tocotrienol in maintaining the bone structure and strength in glucocorticoid-induced osteoporosis. Thirty two adult male Sprague-Dawley rats, aged 3 months, weighing 300-320 g rats were used in this study. Sixteen rats undergone adrenalectomy and were administered with 120μg/kg/day intramuscular injection of dexamethasone. Eight rats were supplemented with oral palm tocotrienol 60 mg/kg/day (Adrx+Dex+PTT) and the other eight rats were given oral vehicle palm olein 0.1 ml/kg/day (Adrx+Dex). Eight rats underwent sham procedure and were given vehicle palm olein 0.05 ml/kg/day by intramuscularly and oral 0.1 ml/kg/day (Sham). The rats were euthanized after two months of treatments. Eight rats were euthanized after acclimatic action without receiving any treatment (Baseline). The right femurs were used for bone biomechanical strength and histomorphometry analysis while the left for gene expression and oxidative stress enzymes activities. The results indicated that long-term glucocorticoid treatment significantly increased bone resorption marker, CTX (6060.7 ± 410 pg/ml) and decreased bone structure and strength. Osteoblast and osteoclast related genes expressions indicated an increase in bone turnover. Supplementation of palm tocotrienol had maintained serum resorption (2619.4 + 209 pg/ml) marker level and preserved bone structure and strength. Gene expression analysis showed decrease in bone resorption. The findings suggested that palm tocotrienol has potential benefits against glucocorticoid-induced osteoporosis by regulating osteoblast and osteoclast related gene expression
RESUMO
Long term glucocorticoids administration induces oxidative stress which leads to alteration of bone structure and strength. Palm oil is rich in tocotrienol, an antioxidant. It can be used for the prevention of oxidative stress related diseases. The main objective of this study was to determine the mechanism of palm tocotrienol in maintaining the bone structure and strength in glucocorticoid-induced osteoporosis. Thirty two adult male Sprague-Dawley rats, aged 3 months, weighing 300-320 g rats were used in this study. Sixteen rats undergone adrenalectomy and were administered with 120μg/kg/day intramuscular injection of dexamethasone. Eight rats were supplemented with oral palm tocotrienol 60 mg/kg/day (Adrx+Dex+PTT) and the other eight rats were given oral vehicle palm olein 0.1 ml/kg/day (Adrx+Dex). Eight rats underwent sham procedure and were given vehicle palm olein 0.05 ml/kg/day by intramuscularly and oral 0.1 ml/kg/day (Sham). The rats were euthanized after two months of treatments. Eight rats were euthanized after acclimatic action without receiving any treatment (Baseline). The right femurs were used for bone biomechanical strength and histomorphometry analysis while the left for gene expression and oxidative stress enzymes activities. The results indicated that long-term glucocorticoid treatment significantly increased bone resorption marker, CTX (6060.7 ± 410 pg/ml) and decreased bone structure and strength. Osteoblast and osteoclast related genes expressions indicated an increase in bone turnover. Supplementation of palm tocotrienol had maintained serum resorption (2619.4 + 209 pg/ml) marker level and preserved bone structure and strength. Gene expression analysis showed decrease in bone resorption. The findings suggested that palm tocotrienol has potential benefits against glucocorticoid-induced osteoporosis by regulating osteoblast and osteoclast related gene expression