P. E. Ebong

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.

Synergistic antidiabetic activity of Vernonia amygdalina and Azadirachta indica: biochemical effects and possible mechanism.

ETHNOPHARMACOLOGICAL RELEVANCE A decoction from a combination of herbs is commonly used in Traditional African Medicine for the management of chronic ailments. In Nigeria, the leaves of Vernonia amygdalina Del. (VA) and Azadirachta indica A. Juss (AI) are used traditionally as a remedy against diabetes mellitus for which empirical evidence attests to its efficacy. AIM OF THE STUDY To evaluate the synergistic antidiabetic action of VA and AI, the biochemical effects and possible mechanism in streptozotocin-induced diabetic rat (SDR) models. MATERIALS AND METHODS Ethanolic extracts of VA and AI were co-administered (200 mg/kg, 50:50) to non-diabetic rats (NDRs) and SDRs for 28 days. Blood glucose and body weight were monitored during this period, and at end of treatment, serum glucose, insulin, triiodothyronine (T3), tetraiodothyronine (T4) and α-amylase activity were studied. Glucose and activities of antioxidant enzymes, e.g., catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), were estimated in hepatocytes, along with the impact on the histology of the liver and pancreas. Medium acting insulin, HU (5 IU/kg, s.c.) was used as a positive control. RESULTS The study reveals that compared with single extracts, the combined extract (VA/AI) promptly lowered blood glucose and maintained a relatively steady level over the study period, in tandem with HU. During this period, body weight gain successively increased. In SDRs, fasting blood glucose at days 0 and 28 was raised by 4.33 and 3.16 fold, respectively, and the serum glucose was raised by 7.70 fold vs. normal control (P<0.05). The discrepancies in the individual effects of VA and AI on hepatic glucose and α-amylase activity were also restored. In NDRs, VA/AI lowered blood and serum glucose (1.14 and 1.94 fold, respectively), although to a lesser extent when compared with HU. Furthermore, VA/AI was found to lower serum insulin, T3 and T4 by 1.66, 1.57 and 2.16 fold, respectively, in SDR (P<0.05). This was similar to HU, which demonstrated 1.79 and 1.68 fold reduction of insulin and T3, respectively (P<0.05), but had no effect on T4. Conversely, in NDRs, VA/AI caused 1.32, 4.93 and 1.04 fold increase in insulin, T3 and T4, respectively, reciprocal to its effect on blood and serum glucose. Oxidative stress in SDR, characterised by decreased GPx and CAT activities, was ameliorated, as the activities of the enzymes and SOD increased following a 28-day treatment with VA/AI (P<0.05). The features of diabetic pathology, indicated in the histology of the liver and pancreas, were reversed. However, the extent of recovery was partial with VA, better with AI, and distinct and total with VA/AI, compared with a null effect by HU. CONCLUSION Taken together, our results contribute towards validation of enhanced antidiabetic efficacy of VA and AI when combined. This synergy may be exerted by oxidative stress attenuation, insulin mimetic action and β-cell regeneration.

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).

A Safety Assessment of the Antimalarial Herb Artemisia annua During Pregnancy in Wistar Rats

Artemisia annua is a Chinese antimalarial herb that has been used for more than 2000 years. The maternal and foetal safety of the ethanolic leaf extract of therapeutically active Artemisia annua (EAA), with previously determined artemisinin yield of 1.098% was evaluated in Wistar rats. Twenty pregnant rats, divided into four study groups of saline treated (control), and test groups administered orally with 100, 200 and 300 mg/kg body weights of EAA, respectively, from gestation days (GD) 8 to 19. Following overnight fast, animals were sacrificed on GD 20, and maternal blood was collected to evaluate biochemical and haematological markers. Foetuses were carefully removed, weighed, and observed for any possible malformation. Biochemical and haematological studies revealed that EAA did not result in maternal hepatotoxicity, haematotoxicity, and hyperlipidemia. While litter size significantly decreased (p < 0.05) at 100 mg/kg EAA, maternal estrogen levels decreased in all the EAA‐treated groups. Non‐viable (21%) and malformed (31%) foetuses were observed at the 300 mg/kg dose of EAA, which implies that although consumption of the leaf extract may not predispose users to hepatotoxicity, haematotoxicity, and hyperlipidemia, it should be taken with caution during pregnancy due to possible risk of embryotoxicity at concentrations higher than the therapeutic dose. Copyright

Vitamins A and E reverse gasoline vapors-induced hematotoxicity and weight loss in female rats

In this study, gasoline vapors-induced hematotoxicity, growth-depression and weight-loss reversal effect of vitamins A (retinol) and E (α-tocopherol) was assessed in female Wistar albino rats. The rats were exposed to gasoline vapors (17.8 2.6 cm 3/h/m3/day), 6 hours/day, 6 days/week, for 20 weeks. Vitamins A and E at prophylactic dosage (400 and 200 IU/kg/day, respectively) were orally administered to the rats, separately, in the last 2 weeks of exposure. The levels of hemoglobin (Hb), hematocrit or packed cell volume (PCV), red blood cells (RBC), growth rate and weight gain in the rats exposed to the vapors were significantly lower (p < 0.05) compared, respectively, to the levels obtained for control rats. On the other hand, the levels of white blood cells (WBCs) in the test rats were significantly higher (p < 0.05) compared, respectively, with the level obtained for female control rats. These observations indicated that exposure to gasoline vapors may cause hematotoxicity, growth depression and weight loss in female rats. However, administration of vitamins A and E was observed to produce a significant recovery (p < 0.05) in hematotoxicity, growth depression and weight loss observed to be associated with exposure to gasoline vapors, although the rats administered with vitamin E were noted to respond more favorably than those administered with vitamin A. This suggests that although retinol and α-tocopherol may be used to reverse or prevent hematotoxicity, growth depression and weight loss in subjects exposed to gasoline vapors, the reversal potency of α-tocopherol is higher than that of retinol.

Comparative Hepatoprotective Effect of Vitamins A and E Against Gasoline Vapor Toxicity in Male and Female Rats

Background Plasma alanine transferase(ALT), aspartate transferase(AST), α-glutamyl transferase(GGT), and alkaline phosphatase(ALP) activities are known biomarkers in assessing hepatic functional integrity. A remarkable rise in the activities of these enzymes normally signifies hepatotoxicity of chemical agent(s) in the biological system. Exposure to 17.8 cm3h-1m-3 of PMS blend unleaded gasoline vapors (UGV) for 6 hr/day, 5 days/week for 20 weeks have been reported to cause hepatotoxicity in rats. Methods In this study, the comparative hepatoprotective effect of vitamins A (retinol) and E (α-tocopherol) against UGV-induced toxicity was assessed in male and female rats. Retinol and α-tocopherol at prophylactic dosage (400 and 200 IU/kg/day, respectively) were separately administered orally to the test rats concomitant with exposure to UGV in the last two weeks of the experiment. Results The results of this study indicated that exposure to UGV caused significant increase (P < 0.05) in the activities of serum ALT, AST, ALP, GGT and bilirubin in male and female rats. Oral administration of prophylactic doses of retinol and α-tocopherol produced a significant decrease (P < 0.05) in the activities of these parameters in male and female test rats, compared with the non-treated test rats; but insignificant increase(P ≥ 0.05), compared with the control. However, the hepatoprotective effect of α-tocopherol was observed to be more potent than that of retinol. Conclusions The result of this study demonstrated that the hepatoprotective potency of α-tocopherol against gasoline vapors toxicity was higher than that of retinol in male and female rats, although the female gender of the animal model responded to treatment with both vitamins better than the males. Hence, the work suggested the beneficial effects of both vitamins against hepatotoxicity in individuals frequently exposed to gasoline vapors.

Biochemical and haematological evaluation of repeated dose exposure of male Wistar rats to an ethanolic extract of Artemisia annua.

Artemisia annua is widely used for the treatment of malaria and other disorders. In a previous study, the artemisinin concentration in the dry leaves of A. annua grown under humid tropical conditions was determined to be 1.098% using reversed phase high performance liquid chromatography. In the current study, biochemical and haematological evaluations of ethanolic leaf extracts derived from such plants (EAA) were carried out in 20 male Wistar rats. Rats were divided into four study groups of saline‐treated (control) and test groups exposed orally to graded doses of EAA for 28 days. The results showed that the liver function and haematological indices, and testosterone levels were not adversely affected. High density lipoprotein ‐cholesterol was reduced at 100 mg/kg of EAA, atherogenic index as well as low density lipoprotein ‐cholesterol was raised, and glucose concentration was reduced significantly at the 100 and 200 mg/kg of EAA (p < 0.05). In addition to serving as a possible antidiabetic agent, EAA may not predispose users to hepatotoxicity, haematotoxicity and testicular toxicity. However, due to the possible risk of atherosclerosis, we advise that the plant extract should be taken with caution in people with atherosclerotic condition. Copyright

Abnormalities in Adenosine Triphosphatase of the Erythrocyte Membrane in Iron Deficiency Anaemia

During iron deficiency rat and human erythrocyte membrane enzyme activities (Total ATPase and Ouabainsensitive Na+.K+ ATPase) showed significant (P < 0.001) decrease. The influence of iron deficiency on erythrocyte Na+ and K+ was also studied in rats and humans. The former parameter showed a significant (P < 0.01) increase while the latter showed a downward trend. Plasma Fe and Total Iron Binding capacity (TIBC) in iron deficiency varied significantly (P < 0.05) from normal values. These results suggest a defect in erythrocyte membrane function and a possible potentiating effect of intracellular Na+, plasma Fe and TIBC on ATPase activity in iron deficiency. Values obtained for rats and humans showed differences in the activities of membrane ATPase in iron deficiency anaemia.

Artemisia annua as a possible contraceptive agent: a clue from mammalian rat model

In a previous study, we evaluated the maternal and fetal safety of antimalarial herb Artemisia annua with artemisinin yield of 1.09%. Here, we attempted to ascertain the contraceptive claim of A. annua. Sexually matured female Wistar rats (180–220 g) were allotted into four study groups of six rats each. The control group received normal saline, while the A. annua-treated groups received 100, 200 and 300 mg/kg of A. annua for 2 weeks, followed by mating with proven fertile males (1:1). The rats were allowed to carry the pregnancy to term. At birth and weaning periods, selected reproductive outcome and fertility indices were determined. The results showed that A. annua significantly reduced litter size, reproductive outcome and fertility indices compared with the control (p < 0.05). These results imply that A. annua could serve as a prospective contraceptive agent in addition to its antimalarial activity.

Influence of Chronic Administration of Chloroquine on Leydig Cell Integrity and Testosterone Profile of Albino Wistar Rats

The effect of chronic administration of chloroquine on leydig cells and plasma testosterone level was examined. Twenty-five albino Wistar rats were divided into five groups –– A, B, C, D and E. Group A animals received a normal dose of 0.57mg per kg body weight of chloroquine for 3 days. Groups B, C and D received chronic doses of 0.57 mg per kg body weight of chloroquine for 4, 5 and 6 days respectively. Group E animals, which served as control, were administered normal saline. Historical examination of the process sections of groups B, C and D indicated numerical reduction of the leydig cells when compared with the control group. Group A appeared normal. The basement membrane of the seminiferous epithelium in groups C, C and D were disrupted, leading to the detachment of many spermatocytes. Groups B, C and D recorded reduced level of plasma testosterone when compared with the control group. However, the concentration of plasma testosterone in group A (2.15 1.63g/ml) and control (2.40 ± 1.48g/ml) were similar. Chromic administration of chloroquine reduced the number of leydig cells with concomitant reduction of testosterone production. It also disrupted seminiferous epithelium, leading to the detachment of spermotocytes. (Afr J Reprod Health 1999; 3 [2]: 97-101) Key Words: Chloroquine, leydig cells, testosterone, seminiferous epithelium