Sex- and organ-specific toxicity in normal and malnourished rats fed thermoxidized palm oil.

The effects of free radical toxicity as induced by chronic consumption of thermoxidized palm oil (TPO) diet on organ size of normal animals, their first filial offspring and malnourished rats, were studied. Tissue- and sex-specific toxicity was revealed. The TPO diet significantly (P<0.01) reduced lung and kidney mass in normal male rats but female rats remained unaffected. Hearts of first filial offspring of both male and female rats were, however, enlarged while lung, liver and kidneys of first filial female offspring were additionally reduced in size (P<0.01). This information suggests that the observed toxicities could be cumulative for female offspring. Malnutrition protected against toxic injury because none of the kwashiorkoric animals rehabilitated on the toxic diet showed any overt symptoms of toxicity.

Influence of palm oil (Elaesis guineensis) on health.

In recent times there has been a growing research interest in palm oil, one of the major edible plant oils in the tropical countries, because of the link between dietary fats and coronary heart disease. Obtained from a tropical plant, Elaesis guineensis, it has a polyunsaturated fatty acid/saturated fatty acid ratio close to unity and a high amount of antioxidant vitamin A precursors and vitamin E. Palm oil is consumed in the fresh state and/or at various levels of oxidation. Feeding experiments in various animal species and humans have highlighted the beneficial role of fresh palm oil to health. These benefits include reduction in the risk of arterial thrombosis and atherosclerosis, inhibition of cholesterol biosynthesis and platelet aggregation, and reduction in blood pressure. However, a considerable amount of the commonly used palm oil is in the oxidized state which possesses potential dangers to the physiological and biochemical functions of the body. Oxidation is as a result of processing the oil for various culinary purposes. Studies have revealed that relative to fresh palm oil, oxidized palm oil induces an adverse plasma lipid profile, free fatty acids, phospholipids and cerebrosides. Additionally, oxidized palm oil induces reproductive toxicity and organotoxicity particularly of the kidneys, lungs, liver and heart. Available evidence suggests that at least part of the oxidized oil impact on health reflects generation of toxicants due to oxidation. The reduction of the dietary level of oxidized oil and/or the level of oxidation may reduce the health risk associated with consumption of oxidized fats.

Thermoxidized palm oil induces reproductive toxicity in healthy and malnourished rats.

Repeatedly thermoxidized palm oil (TPO), simulating local culinary practice, was fed for eight weeks at 15% of a balanced basal diet to two sets of male and female weanling albino rats of Wistar strain. The first set of animals were normal and healthy while the second set were kwashiorkoric. Primary controls (PC) of all rats were fed a balanced basal diet of commercial rat pellets while secondary controls (SC) were fed the balanced basal diet supplemented with 15% untreated palm oil. The findings indicate that fertility, as expressed by the pregnancy rate of healthy test rats, was 78% when compared with 80% in PC (p < 0.05). Fetotoxicity was additionally observed in that neonatal birth weights and litter size in test rats (4.92 g and 6.70, respectively) were inferior (p < 0.05) to both SC and PC (4.96 g and 8.40; 5.38 g and 9.25, respectively). Protein energy malnutrition worsened the observed TPO-induced reproductive toxicities in that reproductive capacities of the rehabilitated animals were inferior to that of the healthy animals. Pregnancy rates in test animals were reduced by as much as 55% (p < 0.01) while fetotoxicities were also more pronounced (p < 0.05).

Ecological variation in essential elements and trace elemental composition of some Nigerian fruits.

Identical species of various fruits were harvested just ripe from two different ecological regions in Southern Nigeria and assayed for trace elemental composition. There was significant variation in observed results. Trace elemental quantities (Fe, Zn, Cu, Cd, Cr, Pb, P) in fruits obtained from locations in South-western Nigeria were generally higher than those obtained from fruits harvested in South-eastern Nigeria (P <0.1), except for calcium and magnesium which showed converse trend. Furthermore the study highlighted some of these locally available fruits as good sources of various trace elements essential to man. The need for conditioned awareness that guards against possible micronutrient malnutrition in deficient areas is emphasised.

Comparative studies on the nutritional and toxic composition of three varieties of Lesianthera africana.

The research presents analytical data on three varieties of a commonly consumed vegetable, Lesianthera africana, in southern Nigeria. The Etoi (bitter) variety seemed to possess the best (p < or = 0.01) nutritional value (highest lipid, protein, calories, iron, calcium, phosphorus, least fiber) but highest toxic components (mg/100 g: 1.62 HCN; 17.6 oxalate; 1630 glucosinolates), which are far below toxic limits. The Ikot Abasi (riverine) variety was found to be highly (p < or = 0.01) fibrous (18.1 mg/100 g dry matter) but low in micronutrient minerals. The Etinan (flavorful) variety was found to be moderately nutritious. The findings are discussed in relation to nutrient interactions and recommendations are made regarding dietetic use.

Nutrient and antinutrient composition of three varieties of Piper species.

The proximate composition of three varieties of Piper guineense (Odusa-Ibibio/Efik) viz. 'Uyat Odusa' (cultivated and peppery), 'Eting-keni Ikot' (wild forest variety) and 'Eting-keni mben inyang' (wild, riverine variety), were determined using available standard methods. Also determined were mineral, antinutrient and ascorbate levels. The cultivated pepperic variety had the highest content of crude protein and moisture (18.9% and 97% respectively) while the wild, riverine variety had the highest content of ether extract, carbohydrate and calories (7.79%, 63.38% and 398 cals respectively). The cultivated variety had appreciable amounts of phosphorus (1.12 mg/100 g), potassium (1.2 mg/100 g), sodium (0.24 mg/100 g), zinc (0.18 mg/100 g), and copper (0.18 mg/100 g) while the forest variety contained more of calcium (12.38 mg/100 g), magnesium (1.21 mg/100 g) and iron (0.85 mg/100 g). The wild riverine variety appeared to have the least mineral content but had the highest ascorbate level of 173.4 mg/100 g. Of four antinutrients assayed, the cultivated pepperic one had the least quantities while the forest variety was highest in hydrocyanic acid (85.8 mg/100 g) and glucosinolates (0.20 mg/100 g). The wild riverine variety had the highest level of total oxalate (165.0 mg/100 g). These quantities are however far below documented toxic levels.