Homocysteine and nitrite levels are modulated by MTHFR 677C>T polymorphism in obese women treated with simvastatin

Higher homocysteine (Hcy) levels are associated with cardiovascular risk. The aim of the present study was to evaluate the effect of simvastatin treatment on circulating Hcy levels in obese women without hypertension, diabetes or dyslipidaemia; and to determine whether the 677C>T polymorphism located in methylenetetrahydrofolate reductase (NAD(P)H) (MTHFR) gene modulates the effects of this treatment on Hcy and nitrite (as a biomarker of nitric oxide (NO) bioavailability). Twenty‐five obese women (body mass index ≥ 30 kg/m²) who had received 20 mg/day simvastatin for 6 weeks were enrolled in the study. Venous blood samples were collected to measure plasma biomarkers and gene polymorphisms. Simvastatin treatment significantly reduced total cholesterol, low‐density lipoprotein–cholesterol, thiobarbituric acid‐reactive substances, high‐sensitivity C‐reactive protein and Hcy, whereas nitrite levels were increased. The reduction in Hcy levels in carriers of the T allele was ?20.3% compared with –9.4% in patients with the CC genotype. Importantly, before treatment, nitrite levels were significantly higher in patients with the CC genotype compared with T allele carriers, whereas after treatment these levels were similar between groups. Our findings demonstrate that obese women without comorbidities and carrying the T variant of the 677C>T polymorphism of MTHFR exhibit benefits with simvastatin treatment, mainly in terms of increased NO levels.     

Canthaxanthin induces apoptosis in human cancer cell lines

To investigate the possibility that canthaxanthin inhibits cancer cell growth by inducing apoptosis, human WiDr colon adenocarcinoma and SK- MEL-2 melanoma cells were treated with two different doses of the carotenoid for 48 h. Canthaxanthin was incorporated and/or associated to cells. The treatment with the carotenoid caused growth inhibition in both cell types. Concomitantly, apoptosis was induced. Increasing time of exposure and carotenoid concentration, this effect was more pronounced. At 48 h, the percentages of apoptotic cells were 13 and 15, using 1 microM canthaxanthin, and 18 and 20, using 10 microM canthaxanthin in WiDr and SK-MEL-2 cells, respectively. This study represents the first demonstration that canthaxanthin is able to induce apoptosis in tumour cells.      

Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting

Elastic recoil of the vessel wall is a common cause of failure of percutaneous transluminal angioplasty in renal arteries. To oppose such recoil, balloon-expandable metal stents were implanted in artificially stenotic renal arteries in pigs and normal renal arteries in dogs and pigs. The stents were then examined angiographically and histologically at regular intervals. All stents were completely covered with endothelialized neointima in 3 weeks. There was no difference in intimal thickness between the stenotic and nonstenotic renal arteries. A large stent diameter and a large open or nonmetal surface may cause less intimal hyperplasia, but nonturbulent, fast arterial flow is probably the most important factor in ensuring long-term patency of the vessel.     

Ethnoecology of traditional leafy vegetables of the Luo people of Bondo district,western Kenya

Diversity of traditional leafy vegetables consumed by the Luo people of Nyang'oma, Bondo District, western Kenya, was evaluated in relation to their ecological habitats. The study generally revealed high species diversity within different ecological areas. A total of 60 leafy vegetable species (domesticated and wild) belonging to 47 genera and 29 families were collected. Most of the vegetable species were gathered from the wild but a few were domesticated on farmlands and kitchen gardens. Plant families that comprised most leafy vegetable species were Fabaceae, Amaranthaceae, Acanthaceae, Asteraceae and Solanaceae.     

Pharmacokinetics of biliary excretion of N-nitrosodimethylamine in rats fed diets containing levels of protein

Albino Wistar rats (Rattus norvegius) fed semi-purified diets containing 3.5%, 8%, 27%, and 64% casein, respectively, as the protein source, were poisoned with an intraperitoneal dose of 20mg N-nitrosodimethylamine (NDMA)/kg, following cannulation of the bile duct, in vitro, under urethane anaesthesia. Bile exudates was collected at designated time intervals and analysed for unchanged NDMA using thin layer chromatography and gas liquid chromatography methods. Rats on 64% high protein diet (HPD) were the highest excretors of NDMA, followed by rats on the 3.5% kwashiorkorigenic diet (KWD), 8% low protein diet (LPD) and 27% normal protein diet (NDP) as the least excretors, in that order. The corresponding values for culmulative excretions of NDMA were 4.38%, 2.74%, 2.96% and 4.11%, and for elimination rate contents they were 54.05Kh⁻¹, 23.01Kh⁻¹, 23.76Kh⁻¹ and 48.88Kh⁻¹, while the respective elimination half-life values were 0.013h, 0.031h, 0.029h and 0.014h. The toxicological and pharmacological implication of the pharmacokinetic findings are discussed.     

Mineral content of traditional leafy vegetables from western Kenya

Socio-economic changes that have taken place in Africa have influenced people's eating habits in both rural and urban set-ups. Most people prefer introduced foods to traditional foods, including plant foods whose consumption is widely regarded as a primitive culture manifesting poor lifestyles. However, recent studies on traditional plant foods have shown that some are highly nutritious; containing high levels of both vitamins and minerals. They also have potential as a remedy to counter food insecurity since most are well adapted to the local environment, enabling them to resist pests, drought and diseases. This paper describes the mineral (calcium, iron and zinc) contents in some 54 traditional vegetable species collected from Nyang'oma area of Bondo district, western Kenya. Atomic absorption spectroscopy was used to determine the mineral content. We found that most traditional leafy vegetables, domesticated and wild, generally contain higher levels of calcium, iron and zinc compared with the introduced varieties such as spinach (Spanacia oleracea), kale (Brassica oleracea var. acephala) and cabbage (Brassica oleracea var. capitata). The results of this study could contribute towards identification, propagation and subsequent domestication and cultivation promotion of nutrient-rich and safe species within the farming systems of the local communities in Kenya, sub-Saharan Africa or elsewhere.     

Snake bites by the jararacucu (Bothrops jararacussu): clinicopathological studies of 29 proven cases in Sao Paulo State, Brazil

The jararacucu, one of the most dreaded snakes of Brazil, southern Bolivia, Paraguay and northeastern Argentina, is a heavily-built pit viper which may grow to a length of 2.2 m. Up to 1000 mg (dry weight) of highly-lethal venom may be milked from its venom glands on a single occasion. It has accounted for 0.8% to 10% of series of snake bites in Sao Paulo State, Brazil. We examined 29 cases of proven jararacucu bites recruited over a 20-year period in two Sao Paulo hospitals. Severe signs of local and systemic envenoming, (local necrosis, shock, spontaneous systemic bleeding, renal failure) were seen only in patients bitten by snakes longer than 50 cm; bites by shorter specimens were more likely to cause incoagulable blood. Fourteen patients developed coagulopathy, six local necrosis (requiring amputation in one) and five local abscesses. Two became shocked and four developed renal failure. Three patients, aged 3, 11 and 65 years, died 18.75, 27.75 and 83 h after being bitten, with respiratory and circulatory failure despite large doses of specific antivenom and intensive-care- unit management. In two patients, autopsies revealed acute renal tubular necrosis, cerebral oedema, haemorrhagic rhabdomyolysis at the site of the bite and disseminated intravascular coagulation. In one survivor with chronic renal failure, renal biopsy showed bilateral cortical necrosis; the patient remains dependent on haemodialysis. Effects of polyspecific Bothrops antivenom were not impressive, and it has been suggested that anti-Bothrops and anti-Crotalus antivenoms should be given in combination.      

Quercetin inhibits the growth of leukemic progenitors and induces the expression of transforming growth factor-beta 1 in these cells

We previously showed that quercetin (3,3',4',5,7 pentahydroxyflavone) inhibits in a dose-dependent manner the growth of acute leukemias and is able to enhance the antiproliferative activity of cytosine arabinoside. We show here that quercetin inhibits the clonogenic activity of 20 of 22 acute leukemias (AL; 4 M1-AML, 3 M2-AML, 2 M3-AML, 3 M4-AML, 3 M5-AML, and 7 ALL). In the present report, we show that the induction of transforming growth factor-beta 1 (TGF-beta 1) in leukemic blasts is one of the growth-inhibitory mechanisms of quercetin in these cells. This observation was supported by the following data. (1) Quercetin-sensitive leukemic blasts, when treated with quercetin, secrete large amounts of TGF-beta 1 in the medium and show positivity for TGF-beta 1-immunoreactive material in the cytoplasm. (2) At a concentration of 8 mumol/L, antisense TGF-beta 1 oligonucleotides prevent the growth-inhibitory action of quercetin. (3) Anti-TGF-beta 1 neutralizing monoclonal antibodies can prevent almost completely the growth-inhibitory activity of quercetin. The analysis of quercetin- resistant cases confirmed as well the central role of TGF-beta 1 in the growth-inhibitory activity of quercetin. In conclusion, quercetin can act as a cytostatic agent for leukemic cells by modulating the production of TGF-beta 1.