Biochemistry

Petroleum exploration and production activities pose great threat worldwide in the marine environment with numerous occurrences of spills every year. Ubeji Creek in Nigeria suffers environmental pollution attributable to petroleum exploration. The hydrocarbons in petroleum encompass a large number of toxicants such as BTEX, which are frequently discharged into water bodies during spillage. In terms of scope, this study assessed for the first time BTEX levels in surface water, sediment, and biota of the Ubeji Creek. Environmental samples were collected at designated sampling locations along the Ubeji Creek quarterly for 2 years. Water quality was determined in situ, while BTEX levels in water, sediment, and biota were assessed in the laboratory using GC-FID. The physico-chemical characteristics of water were within the acceptable WHO limits with the exception of DO of 3.01 ± 0.25 mg/L. Organic pollution load could have contributed to the depression of DO level below the limit. BTEX of 5.57 ± 0.62 mg/kg in sediment samples was higher than the level in control sample. The BTEX levels in fish, shrimps, pawpaw fruit, pineapple tissue, bitter leaf, and cassava were 0.37 ± 0.05, 0.39 ± 0.01, 0.56 ± 0.02, 1.35 ± 0.04, 0.46 ± 0.06, and 0.22 ± 0.01 mg/kg, respectively. Accumulation of BTEX in this biota can affect their nutritive quality and consequently pose threat to humans who daily consume them.

ABSTRACT Ubeji Creek in Niger Delta Region of Nigeria suffers environmental pollution attributable to petroleum exploration. Therefore, this study was undertaken to investigate BTEX (benzene, toluene, ethylbenzene, and xylene) levels in locally sourced staple foods and dietary BTEX exposure of residents of the Creek from consumption of these foods. Fish, shrimps, pawpaw, cassava, pineapple, and bitter leaf were collected quarterly in a year at designated sampling locations along the creek. The food samples were collected, processed and analysed for BTEX using gas chromatography-flame ionisation detection. Dietary exposure assessment for the Ubeji Creek residents due to BTEX in the foods was conducted based on food consumption data from a food frequency questionnaire survey completed by 530 residents. Mean, maximum, and percentiles BTEX dietary exposures were estimated by both probabilistic and deterministic analyses methods using the @RISK® software through a first-order Monte Carlo simulation at 50,000 iterations. The food samples contained BTEX levels with pineapple tissue having the highest concentration (1.35 ± 0.11 mg/kg). Fish and shrimps have the highest consumption rates of about 120 g/person/day and 90 g/person/day, respectively. The deterministic and probabilistic assessments indicated that fish and shrimps were the highest contributors to the intakes of total BTEX compared to other foods. The deterministic and probabilistic analyses of dietary intakes of benzene revealed that total dietary intakes of benzene exceeded benzene oral reference dose (RfDo), minimum risk level (MRL), and maximum permissible risk (MPR) level. This indicates that the residents who consume the studied foods are potentially at risk of BTEX dietary exposure.

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 © 2012 John Wiley & Sons, Ltd.

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 © 2012 John Wiley & Sons, Ltd.

Among the artemisinin-based combination therapy (ACT) regimens, artemisinin derivative, artemether in combination with lumefantrine (artemether-lumefantrine, AL) has achieved excellent results in the fight against malarial scourge. In this study, we evaluated the toxic potential of these drugs at the therapeutic doses in female Wistar rats. Animals were randomly divided into four groups: those administered 1% Tween 80 (control), those administered artemether (4 mg/kg body weight), those administered lumefantrine (24 mg/kg body weight), and those coadministered artemether (4 mg/kg body weight) and lumefantrine (24 mg/kg body weight). The drugs were orally administered twice daily for 3 days by gastric intubation after which selected plasma biochemical indices, and erythrocytes antioxidant defence and lipid peroxidation markers were evaluated. Coadministration of artemether and lumefantrine raised liver and renal function markers and increased atherogenic index. While reduced glutathione, glucose-6-phosphate dehydrogenase (G6PD) and catalase activities were reduced, glutathione peroxidase and glutathione-s-transferase activities increased in all the treated groups compared to the control group. The drugs caused significant (p &amp;lt; 0.05) elevation of malondialdehyde (MDA) levels compared to the control group. These results imply that coadministration of artemether and lumefantrine may increase the risks of atherosclerosis as well as liver and renal function impairments in the users. In addition, the drugs may also promote oxidative stress in the erythrocytes.

Artesunate–amodiaquine is among the most widely available artemisinin combination therapy used as treatment regimen for uncomplicated Plasmodium falciparum malaria. Our aim was to evaluate clinical routine markers of liver and renal functions, lipid profile levels and lipid peroxidation status in a female mammalian rat model. This was an attempt to simulate a scenario where the drugs are taken without malarial parasite infection, which is a common practice in settings where drug misuse is a common practice. Twenty female Wistar rats were randomly divided into four study groups of five animals each. Group 1 (control) received distilled water, group 2 was exposed to artesunate [2 mg/kg body weight (b.w.)], group 3 was administered with amodiaquine (6.12 mg/kg b.w.) and group 4 was co-administered with artesunate (2 mg/kg b.w.) and amodiaquine (6.12 mg/kg b.w.) for 3 days. At the end of the treatment period, animals were fasted overnight and sacrificed. Markers of liver and renal functions and lipid profile indices were evaluated in the plasma, whereas lipid peroxidation status, GSH concentration and G6PD activity were assessed in the erythrocytes. The results showed that the co-administration of artesunate and amodiaquine altered liver function markers and lipid profile indices. The drugs also induced lipid peroxidation as evidenced by the elevated level of oxidative stress marker malondialdehyde (p < 0.05). We recommend therefore that the drugs should be taken with prescription only with clinical evidence of malarial parasite infection. Copyright © 2013 John Wiley & Sons, Ltd.

The indiscriminate use, abuse and patients’ noncompliance to normal prescription of artemisinin and its derivatives are a common practice during the treatment for drug-resistant malaria parasites in most developing countries. This study investigated the influence of artemisinin on the testicular and epididymal sperm antioxidant systems as well as on the plasma levels of hormones from the pituitary and thyroid components of the brain–pituitary–testicular axis. Oral exposure of rats to 0, 7 and 35 mg kg−1 artemisinin for 7 days showed that the testicular antioxidant status at both therapeutic dose (7 mg kg−1) and overdose (35 mg kg−1), and the sperm antioxidant status at therapeutic dose of artemisinin remained unaffected compared with control. However, increased hydrogen peroxide and lipid peroxidation levels were accompanied by a concomitant decrease in glutathione peroxidase and glutathione-S-transferase activities as well as glutathione level in spermatozoon of rats administered with overdose of artemisinin. While plasma levels of all the hormones investigated remained unaffected, severe epididymal degeneration with concomitant decrease in sperm quantity and quality was observed in rats treated with overdose of artemisinin compared with control. Overall, induction of oxidative stress in the epididymis, but not in the testes, could cause reproductive deficits in individuals unduly undergoing artemisinin therapy.