Toxicity assessment of sub-acute and sub-chronic oral administration and diuretic potential of aqueous extract of Hibiscus sabdariffa calyces.

BACKGROUND: Food and herbal usage of Hibiscus sabdariffa (HS) is attaining improved global relevance and acceptance without recourse to its potential toxic effects. This study investigated the safety profile of acute, sub-acute, sub-chronic administrations and diuretic potential of aqueous extract of Hibiscus sabdariffa calyces (AEHSC). METHOD: Acute oral toxicity, sub-acute and sub-chronic toxicity as well as diuretic studies were carried out on HS. A total of 20 Wistar rats were used for each toxicity study and assigned into four groups of five rats. The extract was administered as a single daily dose of 125, 250 and 500 mg/kg body weight (bwt) for 28 and 90 days respectively. To evaluate diuretic activity, 25 rats were divided into five groups of five rats and administered normal saline, hydrochlorothiazide 10 mg/kg, AEHSC 67.5, 125 and 250 mg/kg via the oral route. Urine sample was collected after 18 h, volume measured and concentration of electrolytes analyzed. The hematological and biochemical parameters were evaluated as well as the histopathology of kidney and liver. RESULTS: The acute oral toxicity was found to be >2000 mg/kg. AEHSC did not alter concentration of WBC, MCV, MCHC, lymphocyte as well as total and direct bilirubin in the sub-acute study. However, AEHSC significantly (p < 0.05) increased total protein, albumin, globulin, Na+, Cl-, HCO3 - and platelet levels, while levels of uric acid, creatinine, K+, RBC, Hb, total cholesterol, triglycerides, LDL-C, HDL-C and atherogenic index were decreased significantly (p < 0.05). In the sub-chronic study, AEHSC significantly (p < 0.05) increased the levels of globulin, urea, creatinine, MCH and atherogenic index. The concentrations of uric acid, WBC, platelets and HDL-C were significantly (p < 0.05) decreased. In both the sub-acute and sub-chronic studies, activities of ALP, ALT, AST, GGT and LDH in selected organs were altered without significant increase (P < 0.05) in activity of these enzymes in the serum. The AEHSC at all the doses showed remarkable diuretic activity during 18 h period comparable to hydrochlorothiazide. The extract also showed a non-dose-dependent increase in excretion of electrolytes. Histological analysis of sections of the liver and kidney for both sub-acute and sub-chronic studies showed normal histology comparable to the control group. CONCLUSION: This study revealed AEHSC has some toxic effects in rats on sub-chronic administration. In addition, the extracts produced a significant diuretic activity. Hence, prolonged oral consumption of the extract may not be recommended.

Vitamin E attenuates nicotine- and noise-induced reproductive impairment in male albino Wistar rats.

Previous studies showed that exposure to stress or nicotine induced reproductive impairment in male rats. Here, we assessed the effect of an antioxidant (vitamin E) on nicotine-, stress- and nicotine + stress-induced reproductive impairment in male rats. Forty-eight male albino Wistar rats were divided into eight groups as follows; control, stress (generator noise 90-120 dB, 8 hr/day), nicotine (1.5 mg kg-1 day-1 ), nicotine + stress, vitamin E (100 mg kg-1 day-1 ), stress + vitamin E, nicotine + vitamin E and stress + nicotine + vitamin E. Sperm count, viability, motility and rapid progressive forward movement decreased significantly (p < 0.05), while percentage of nonmotile spermatozoa increased significantly (p < 0.05) in stress, nicotine and nicotine + stress groups, compared with control. Serum testosterone and follicle-stimulating hormone decreased significantly (p < 0.05) in stress, nicotine and nicotine + stress groups, compared with control. Serum luteinising hormone decreased (p < 0.05) significantly in stress and nicotine + stress groups, compared with the control. Histology of the testes showed loss of germ cells in numerous seminiferous tubules, and epididymal histology showed decreased sperm density in stress, nicotine and nicotine + stress groups compared with the control. These negative changes were more severe in the nicotine + stress group. Vitamin E ameliorated the negative changes in the above parameters. This may be attributable to its antioxidant property.

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/m(3)/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.

Hypoglycaemic activity of ethyl acetate fraction of the leaf extract of Telfairia occidentalis.

The leaf of Telfairia occidentalis has been found to possess hypoglycemic or antihyperglycemic effect. The hypoglycemic principle of the leaf is yet to be isolated. The aim of this study is to evaluate the hypoglycemic activity of some fractions of ethanolic leaf extract of Telfairia occidentalis in rat as a step toward activity directed isolation of the hypoglycemic component. Ethanolic leaf extract was successively extracted with ethyl acetate, butanol and ethanol to obtain ethyl acetate, butanol and ethanol fractions (I-III). The residue was taken as fraction IV. 250 mg/kg of the various extracts were orally administered to normoglycaemic and alloxan-induced diabetic albino rats. Blood glucose concentration was evaluated at 0, 1, 2 and 4 hours after treatment with One Touch glucometer. None of the fractions reduced glucose concentration in the normoglycaemic rats, while only ethyl acetate fraction lowered glucose concentration significantly at 2 and 4 hours (49.7 and 39.0%) compared to control value of 74.9 and 69.7%, respectively, in the diabetic rats. The results showed that the hypoglycemic component of the ethanolic leaf extract of the plant is contained in the ethyl acetate fraction.

Serum protein and enzyme levels in rats following administration of antioxidant vitamins during caffeinated and non-caffeinated paracetamol induced hepatotoxicity.

The effects of caffeinated and non-caffeinated paracetamol administration, with or without vitamins A and E supplementation on the protein and enzyme levels in Wistar albino rats were investigated using caffeinated paracetamol and paracetamol as caffeinated and non-caffeinated paracetamol respectively, and water soluble acetic acid derivatives of vitamins A and E. Serum AST, ALT and ALP levels (u/l) significantly increased [P < 0.05] following paracetamol administration. Caffeination as well as administration of vitamins A and E caused significant decreases[P < 0.05] in AST and ALP levels in all test groups when co-administered with paracetamol and in ALT level except in the caffeinated paracetamol + Vitamin E group in which ALT and ALP level except in the caffeinated paracetamol + vitamin E group in which ALT and ALP levels significantly increased [P < 0.05]. Total serum protein level (g/100ml) significantly increased following caffeination as well as during co-administration of caffeinated paracetamol and Vitamin E; and significantly decreased during co-administration of paracetamol and vitamin A. Paracetamol administration without caffeination or supplementation with vitamin A and E can therefore cause increases in serum liver enzymes that is suggestive of liver necrosis which can be ameliorated to varying degrees by caffeine, vitamin A and E.

Haematoxic Effects Following Ingestion Of Nigerian Crude Oil And Crude Oil Polluted Shellfish By Rats

The haematological effects following ingestion of shellfish exposed to crude oil polluted water or the pollutant perse were investigated in albino Wistar rats. Feeding of four groups of rats for 28 days duration with two reference casein or shellfish protein control diets (Group A and B); and two test diets (Group C and D) supplemented at varying levels with shellfish which had been previously exposed to crude oil polluted water and the oral gavaging with crude oil at the rate of 3; 6 and 9 ml/kg body weight per day to three groups (groups II; III and IV respectively) of rats for 7 days duration resulted in changes in packed cell volume (PCV); red blood cell (RBC) and white blood cell (WBC) counts; and haemoglobin concentration (Hb) of rats. Group C and D respectively fed 10 and 20 polluted shellfish diets recorded significant (P 0.05) decreases in PCV and RBC counts while Hb concentration and WBC counts increased. Groups II; III and IV gavaged with varying doses of crude oil recorded significant (P 0.05 - 0.01) dose dependent decrease in PCV and RBC counts when compared to controls (group 1). Hb and WBC counts also increased for these groups but the increase was only significant for WBC counts (P 0.05) when compared with controls. The results suggest that the ingestion of shellfish exposed to crude oil polluted water or the polluted perse results in haematotoxicity

Storage beyond three hours at ambient temperature alters the biochemical and nutritional qualities of breast milk.

The effect of storage on stability of human breast milk was investigated in 30 lactating mothers. Samples stored for 3, 6 and 24 hours at ambient temperature of 302K (29 degrees) were analysed for protein, lactose, pH, and microbial content. There were significant (p < 0.01) decreases in protein, lactose and pH upon storage for 6 and 24 hours, compared with storage for 3 hours as control. The mean +/- SEM values for protein for 6 and 24 hours were 15.56 +/- 0.48 and 13.27 +/- 0.50, compared with 17.26 +/- 0.41 for 3 hours. For lactose, corresponding values for 6 and 24 hours were 0.08 +/- 0.005 and 0.07 +/- 0.006, compared with 3 hours (0.09 +/- 0.005). The pH values were 6.1 +/- 0.09, 5.9 +/- 0.07 in 3, 6 and 24 hour samples rspectively. The skin floras investigated were Streptococcus viridians, Straphylococcus aureus and Staphylococcus albus. The microbial content increased with increase in storage time from 3 to 24 hours. The predominant bacterial specie was S. Albus, followed by S.viridians and S. aureus. A positive correlation (r = 0.453, p < 0.01) between lactose level and pH were obtained. These results suggest that breast milk is stable for 3 hours, beyond which significant changes occur in its biochemical composition and nutritional quality. The implications of these findings are discussed with respect to its consequences on their child's survival.

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.

Caffeine and theobromine levels in selected Nigerian beverages.

Caffeine and theobromine contents (mg/g) were determined in samples of selected Nigerian beverage products. The beverages were cocoa (Milo, Bournvita, Rosevita and Enervita), coffee (Nescafe, Bongo, and Maxwell House decaffeinated) and tea (Lipton). The theobromine contents of samples of Milo, Bournvita, Rosevita, Enervita, Nescafe, Bongo, Maxwell House decaffeinated coffee and Lipton were 62.10+/-5.21, 64.80+/-6.72, 82.80+/-4.43, 80.37+/-6.80, 27.00+/-4.31, 14.67+/-2.90, 23.46+/-3.13 and 12.60+/-1.52, respectively. The corresponding caffeine contents of these samples were 2.78+/-0.43 (Milo), 3.17+/-0.36 (Bournvita), 0.92+/-0.51 (Rosevita), 1.05+/-0.68 (Enervita), 93.66+/-8.91 (Nescafe), 6.47+/-2.42 (Bongo), 37.22+/-5.34 (Lipton), and 0.21+/-0.11 (Maxwell House decaffeinated coffee). Semi-processed cocoa beverages (Rosevita and Enervita) had significantly (p < 0.05) higher levels of theobromine compared with the finished cocoas (Milo and Bournvita). Similarly, Nescafe contained significantly (p < 0.05) higher levels of caffeine compared to Maxwell House (decaffeinated coffee) and Bongo. Levels of caffeine in Lipton tea were moderate.

Serum liver enzymes profile of Wistar rats following chronic consumption of fresh or oxidized palm oil diets.

The effect of chronic consumption of palm oil diets on serum levels of some liver enzymes in rat was investigated. Two groups of rats were fed on either fresh or thermally oxidized palm oil, mixed at 15% level for 18 weeks and their effects on serum levels of alkaline phosphatase (EC 3.1.3.1), aspartate aminotransferase (EC 2.6.1.1) and alanine aminotransferase (EC 2.6.1.2) enzymes were compared with a control group receiving normal rat feed. The levels of alkaline phosphatase (ALP) in the two groups were significantly higher (P < 0.05-0.01) than control. Mean ALP levels were significantly different in the two test groups (P < 0.05). Similarly, there was significant elevation (P < 0.05-0.01) of aspartate aminotransferase (AST) levels in oxidized oil-fed and fresh oil-fed groups when compared with the control. The mean alanine aminotransferase (ALT) level was significantly higher (P < 0.01) in the oxidized oil-fed group than the control and fresh oil-fed groups. The results indicate that chronic consumption of thermoxidized palm oil, with its accompanying hazardous free radicals, may be more injurious to liver cell integrity than fresh palm oil.

Effects of aspirin (acetylsalicylic acid) and Cataflam (potassium diclofenac) on some biochemical parameters in rats.

The effects of graded doses of aspirin (acetylsalicylic acid) and cataflam (potassium diclofenac) on serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, 5'Nucleotidase, methaemoglobin, total and conjaged bilirubin were investigated in wistar rats. Results showed a significant increase (P < 0.05) in the levels of alanine animotransferase, aspartate amino transferase, methaemoglobin, total and conjugated bilirubin upon treatment of animals with both drugs. Aspirin significantly decreased (P < 0.05, P < 0.00) the activity of alkaline phsophatase but increased the activity of 5'ucleotidase while cataflam significantly increased the activity of alkaline phosphatase (P < 0.001) and 5'nucletodase (P < 0.05). These effects were however dose dependent and the biochemical implications of these results are discussed.

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).

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.

Milk macronutrient levels during the first month of term and preterm Nigerian mothers.

The lactose levels of the transition milk of term mothers were significantly higher compared with preterm mothers (5.87 versus 5.32 g/100 ml). The same trends were found in colostrum and mature milk. These differences were not significant. The protein contents of the colostrum in term mothers were significantly lower than in their preterm counterparts (1.80 versus 2.20 g/100 ml). Again the same trend (not significant) was showed in transition and mature milk. A significantly lower level of fat in milk of term mothers than of preterm mothers was found in all 3 types of milk (1.84 versus 2.26; 2.16 versus 2.95; 2.72 versus 3.32 in colostrum, transition milk and mature milk respectively). This study showed differences in the macronutrients measured in the different types of milk, hence term babies in Baby care units should be fed term milk and preterm babies with preterm milk.

Effects of fenfluramine on the metabolism of calcium and phosphorus in the rat: fenfluramine effects on Ca and P metabolism.

Daily administration of 2, 5, 10, 15 and 20mg of fenfluramine/kg body weight to adult rats for four weeks resulted in dose dependent decrease in calcium and phosphorus absorption with an inverse correlation of r = -0.94 for calcium and r = -0.93 for phosphorus. Significant (P less than 0.05) increase in the total faecal lipids and moderate decline in plasma calcium levels were also observed in the rats. Adult rats made obese by dietary methods when treated with 10mg and 15 mg of fenfluramine/kg body weight/day for 10 weeks showed a significant reduction (p less than 0.001) in the intestinal absorption of both calcium and phosphorus. The reduction at 15mg/kg drug dose was 10.7 pc for calcium and 9.5 pc for phosphorus. Analyses of the long bones as well as carcasses of the obese rats showed significant decrease (p less than 0.001) in the content of these minerals. Plasma calcium and phosphorus levels were also significantly (p less than 0.001) reduced in the obese-treated rats. However, fenfluramine treatment significantly reduced the plasma calcium but not the phosphorus levels in the non-obese rats. These studies have demonstrated that chronic administration of fenfluramine (greater than or equal to 10mg/kg body weight) to rats, obese or non-obese, impairs calcium and phosphorus metabolism in the body.

The effect of prolonged exposure of rats to sub-lethal dose of acetaminophen.

In this report, we studied the effect of sub-lethal doses (20mg, 30mg, 100mg, 200mg and 300mg/Kg body weight) and duration of acetaminophen given intraperitoneally (i.p) to male albino rats; on the level of pc methaemoglobin and some liver function tests: Alkaline phosphatase, free and conjugated bilirubin. The study showed that the increase in pc methaemoglobin, free and conjugated bilirubin in rats treated with acetaminophen are significantly (P less than 0.05) greater than those for the control rats and that the measured parameters increase with acetaminophen concentrations. The results also show that the free bilirubin is probably displaced from plasma albumin.

Influence of 5 alpha-reduced androgens on oestradiol secretion by granulosa cells of pregnant mare serum gonadotrophin treated immature rats.

The effect of aromatizable androgens (testosterone and androstenedione) and naturally occurring 5 alpha-androstane, 3 alpha 17 beta-diol and 5 alpha-androstane, -3 beta, 17 beta-diol on oestradiol secretion by granulosa cells isolated from preovulatory follicles of PMSG-primed immature rats was investigated. The amount of oestradiol secreted by granulosa cells in the absence of exogenous aromatizable androgen in a 4h incubation was negligible. However, the addition of testosterone or androstenedione resulted in concentration dependent increases in oestradiol secretion. The 5 alpha-reduced androgens inhibit oestradiol and oFSH-stimulated oestradiol secretion by the granulosa cells in the presence of exogenous testosterone. The least potent of the androgens tested in causing this effect being the 5 alpha-androstane-3 alpha, 17 beta-diol. This result suggests that the naturally occurring 5 alpha-reduced androgens have a direct effect on androgen-aromatizing enzymes. The effect of these androgens may have an important connotation with respect to the control of the onset of puberty and regulation of ovarian oestradiol secretion within the microenvironment of an ovarian follicle.

Electrolytes (Na+ and K+) translocation in erythrocytes during iron deficiency in rats and humans.

During iron deficiency a significant (p less than 0.01) increase in erythrocyte Na+ in vivo was observed in both rats and humans. Erythrocyte K+ was down, but the effect was only significant (p less than 0.05) in rats, under this condition. However, erythrocyte Na+/K+ ratio was significantly (p less than 0.001) higher in iron deficiency when compared to normal values in both rats and humans. Although there was no significant (p greater than 0.05) correlation between Haemoglobin (Hb), Packed cell volume (PCV), Plasma Fe, and Total Iron Binding capacity (TIBC), and erythrocyte Na+ or K+ levels during iron deficiency, analysis of variance showed that Hb, PCV, Plasma Fe and TIBC in concert significantly (p less than 0.05) affected erythrocyte Na+ in iron-deficient rats and humans, whereas K+ was significantly (p less than 0.05) affected only in rats. These studies suggest a defect in erythrocyte membrane function during iron deficiency and imply a concerted potentiating effect of Hb, PCV, Plasma Fe and TIBC on erythrocyte membrane malfunction during iron deficiency. Species difference is also demonstrated in erythrocyte (Na+ and K+) translocation in iron deficiency.

Hepatoxicity evaluation in rats given a single overdose of Acetaminophen (Paracetamol).

Of the various parameters measured in the Serum of rats given a single overdose of acetaminophen (APAP), methaemoglobin (M-Hb) free and conjugated bilirubin seem to be better diagnostic indicators of APAP poisoning than alkaline phosphatase (ALP).