Oxidized dietary lipids induce vascular inflammation and atherogenesis in post-menopausal rats: estradiol and selected antihyperlipidemic drugs restore vascular health in vivo.

BACKGROUND: Thermoxidation of edible oil through deep fat frying results in the generation of several oxidized products that promote lipid peroxidation and ROS production when eaten. Consumption of thermoxidized oil in post-menopausal conditions where the estrogen level is low contributes to cardiovascular disease. This study evaluates the role of estradiol and antihyperlipidemic agents (AHD) in restoring the vascular health of ovariectomized (OVX) rats fed with thermoxidized palm oil (TPO) and thermoxidized soya oil (TSO) diets. METHOD: A total of 10 groups of rats (n = 6) were set up for the experiment. Group I (normal control) rats were sham handled while other groups were OVX to bring about estrogen deficient post-menopausal state. Group II (OVX only) was not treated and received normal rat chow. Groups III-X were fed with either TPO or TSO diet for 12 weeks and treated with estradiol (ETD) 0.2 mg/kg/day, atorvastatin (ATV) 10 mg/kg/day, and a fixed-dose combination of ezetimibe and ATV (EZE 3 mg/kg/day + ATV 10 mg/kg/day). RESULTS: Pro-atherogenic lipids levels were significantly elevated in untreated TSO and TPO groups compared to OVX and sham, resulting in increased atherogenic and Coronary-risk indices. Treatment with Estradiol and AHDs significantly reduced the total cholesterol, triglycerides, low-density lipoprotein cholesterol as well as AI and CRI compared to untreated TSO and TPO groups, whereas TSO and TPO groups showed significant elevation in these parameters compared to Group I values. Moreover, aortic TNF-α levels were extremely elevated in the untreated TSO and TPO compared to Group I. TNF-α levels were significantly reduced in rats treated with AHDs and ETD. Localized oxidative stress was indicated in the aortic tissues of TSO and TPO-fed OVX rats by increased malondialdehyde and decreased glutathione, catalase, and superoxide dismutase levels. This contributed to a depletion in aortic nitric oxide. AHDs and ETD replenished the nitric oxide levels significantly. Histological evaluation of the aorta of TSO and TPO rats revealed increased peri-adventitia fat, aortic medial hypertrophy, and aortic recanalization. These pathologic changes were less seen in AHDs and ETD rats. CONCLUSION: This study suggests that ETD and AHDs profoundly attenuate oxidized lipid-induced vascular inflammation and atherogenesis through oxidative-stress reduction and inhibition of TNF-α signaling.

Antidiabetic and antihyperlipidemic effects of aqueous extract of Parquetina nigrescens in streptozotocin-nicotinamide induced type 2 diabetic rats.

BACKGROUND: Parquetina nigrescens is among the evergreen plants native to West Africa. It is used in the management of various ailments including anemia, fever, asthma and diabetes. This study evaluated the antidiabetic and antihyperlipidemic effect of Parquetina nigrescens in streptozotocin-nicotinamide-induced type 2 diabetic rats. METHODS: Type 2 diabetes mellitus was induced in overnight fasted rats with a single intraperitoneal injection of streptozotocin (60 mg/kg), followed by the administration of nicotinamide (120 mg/kg) after an interval of 15 min. Diabetic rats were orally administered with; 200, 400 and 800 mg/kg of aqueous extract of Parquetina nigrescens (AEPN), metformin (180 mg/kg) and glibenclamide (1 mg/kg) for two weeks. The effect of treatments on fasting blood glucose, serum insulin, leptin, adiponectin, homa-ir, lipid profile, body weight, pancreatic antioxidants parameters, hepatic glycogen content, glucose-6-phosphate activity, α-amylase inhibition, α-glucosidase inhibition, lipase inhibition and histology of the organs were evaluated. RESULTS: Data from this study showed that treatment with AEPN produced a significant reduction (p < 0.05) in fasting blood glucose, glucose-6-phosphatase activity, serum lipase, total triglyceride, total cholesterol, low-density lipoproteins, very low-density lipoprotein, atherogenic index, coronary risk index, pancreatic α-amylase, α-glucosidase and lipase activities. Treatment with AEPN also produced a significant (p < 0.05) increase in; glucose tolerance, glycogen content, leptin, adiponectin and pancreatic antioxidants (glutathione, superoxide dismutase, catalase and high-density lipoproteins). The histology of the organ showed regeneration of the pancreatic tissue after treatment with AEPN. CONCLUSIONS: This study showed that AEPN exhibited antidiabetic and antihyperlipidemic activity in streptozotocin-nicotinamide-induced type 2 diabetic rats.

Acute and sub-acute toxicity of aqueous extract of aerial parts of Caralluma dalzielii N. E. Brown in mice and rats.

Caralluma dalzielii N. E. Brown (Asclepiadaceae) is a cactus-like shaped shrub widely used in traditional medicine for the treatment of rheumatoid arthritis, diabetes, infertility and impotence. The present study evaluated the potential toxicity of aqueous extract of aerial parts of Caralluma dalzielii (AECD) through acute and sub-acute oral administration in mice and rats. During acute toxicity study, female mice and rats were orally administered with AECD at single doses of 175, 500 and 2000 mg/kg according to OECD Guidelines 425. Sub-acute toxicity of AECD (150, 300 and 600 mg/kg p.o) was studied by daily dosing of Wistar rats of both sexes for 28 days. The acute toxicity study revealed no lethal effects and behavioural signs of toxicity at the tested doses indicating that LD50 is greater than 2000 mg/kg. In sub-acute study, a significant reduction in the body weight (p < 0.05), feed and water (p < 0.001) intake of the rats were observed. A significant (p < 0.05) increase in lymphocytes, mean platelet volume counts and alanine aminotransferase were also observed. Histopathological analysis showed mild liver cell distortion in female rats treated at 600 mg/kg of AECD. These results show low toxicity of AECD on short-term use and liver toxicity on long-term use.

A Review of Heavy Metal Contamination of Food Crops in Nigeria.

Heavy metal contamination of food crops is an issue of global concern that ultimately results in toxicity and diseases in humans and animals through consumption of contaminated soils and food crops. With a population of 182 million people, Nigeria is regarded as the most populous country in Africa. The people suffer environmental pollution from high levels of heavy metal accumulation in the environment and in food crops. Heavy metals have atomic densities higher than 4 g/cm3, and these include lead (Pb), cadmium (Cd), zinc (Zn), mercury (Hg), arsenic (As), silver (Ag), chromium (Cr), copper (Cu), iron (Fe), and platinum (Pt). The high level of environmental contamination by these metals is dangerous because their uptake by plants and subsequent accumulation in food crops consumed by humans and animals is deleterious to health. There are many known sources of harmful metals, including the earth, which releases them into food, air, and water, and anthropogenic activities, such as the application of fertilizer in agriculture, the use of pesticides and herbicides, and irrigation. Other sources are automobile emissions, paints, cigarette smoking, industries, and sewage and waste disposal. Evidence shows that vegetables and other food crops consumed in Nigeria are contaminated by heavy metals, and this is associated with adverse health issues, such as cancer, which is currently on the rise in Nigeria. It is therefore vital that communities with high levels of heavy metal pollution avoid eating large quantities of these food items. There is also the need for the monitoring of levels of these injurious elements in food crops.

Anticonvulsant effect of the aqueous extract of Xeromphis nilotica in mice

Xeromphis nilotica is used traditionally to treat epilepsy. The freeze dried aqueous extract of the plants' rootbark was tested for anticonvulsant activity against pentylenetetrazol (PTZ) induced seizures and pentobarbital induced sleep in mice. Results showed that the extract significantly (p 0.05) reduced the onset and severity of the PTZ-induced seizure and prolonged the duration of sleep induced by pentobarbital dose dependently. The results show that the extract has depressant effect; supporting the claimed ethno- medical usage in controlling seizure

Testicular toxicity of Nigerian bonny light crude oil in male albino rats.

The purpose of this work was to investigate the testicular effects of Nigerian bonny light crude oil on male albino rats. Male albino rats were administered 200, 400, and 800 mg/kg body weight of bonny light crude oil dissolved in Tween 80 in their drinking water for 7 days, while the control group received Tween 80 in their drinking water only. After 7 days, the rats were sacrificed and testis excised, weighed, and processed for histological examination. Treatment with bonny light crude oil showed a dose-dependent decrease in the absolute weight of the testes, and a significant (P < 0.05) dose-dependent reduction in the epididymal sperm number (ESN). The final body weights of the animals treated with crude oil were also significantly (P < 0.05) decreased. Histological evaluation of the testes showed slight to severe degeneration or even complete absence of seminiferous tubules and necrosis of cells depending on the dose of the crude oil. This study suggests that the Nigerian bonny light crude oil is a testicular toxicant and its use as a folklore medicine may cause infertility.