Search

This study investigated toxicological effects of 5 and/or 10 mg/kg artemether (ART5 or ART10) and nevirapine (NVP) co-administration on serum biochemistry and some organs of Wistar rats. Drugs were administered intraperitoneally to 6 groups (n=6) for 21 days. On day 22, rats were sacrificed, sera obtained to determine electrolyte and antioxidant levels. Liver, kidney, lung and spleen were harvested and weighed for histological studies. Data analysed using oneway ANOVA, Dunnett’s post-hoc test and were considered significant at p≤0.05. There was no difference in superoxide, catalase, Na+ , K+ , Ca2+ and HCO3- levels in the treated groups. Cl- decreased (p≤0.05) in NVP + T80 and NVP + ART10 administered groups. MDA increased (p≤0.05) in NVP + ART10 group while GPx decreased. No pathological changes were observed in the liver of all treated groups but relative weight increased (p≤0.05) in NVPART10 treated group. The kidney of NVP-ART5 and NVP-ART10 treated groups did not differ in relative weight but showed some renal necrosis. The spleen and lung of ART10 treated group showed some pathological changes. The changes in relative liver weight, kidney tissue, Cl-, MDA and GPx levels of ART-NVP administered rats suggest the need for precautionary measures during drug treatment combination. Keywords: Artemether; Nevirapine; Toxicology; Liver; Kidney; Spleen; Lung, Biochemical parameters

Background: Leonotis nepetifolia Linn (Lamiaceae) is used in traditional medicine for its calming (tranquilizing) effects. The aim of this study was to determine whether there is any scientific justification for this use. To achieve this purpose, we investigated the behavioural effects of the methanol extract of Leonotis nepetifolia stem (37.5, 75 and 150 mg/kg) in mice. Methods: Acute toxicity studies were carried out on the methanol stem extract of Leonotis nepetifolia to determine the LD50. The behavioural tests employed were diazepam-induced sleep onset and duration, hole board assay for exploratory activity, mouse beam walk assay for motor coordination, and the staircase test for the detection of anxiolytic compounds. Preliminary phytochemical screening was also carried out on the extract. Results: The intraperitoneal LD50 value was found to be 3.8 g/kg. The results showed that the extract significantly prolonged the duration of diazepam-induced sleep at the highest dose (150 mg/kg). There was no observable effect on exploratory activity and motor coordination at the doses tested (37.5, 75 and 150 mg/kg). The extract, however, at 150 mg/kg elicited a significant decrease in the number of rearings in the staircase test, an effect also observed in the group of mice injected with an anxiolytic dose of diazepam. The preliminary phytochemical screening revealed the presence of alkaloids, saponins, glycosides and triterpenoids. Conclusion: The results obtained suggest that the crude methanol extract of Leonotis nepetifolia stem possesses some biologically active constituents with potential anxiolytic activity and thus may justify its traditional use as a tranquilizer

Background: Lamivudine and artesunate are sometimes co administered in HIV-malaria co morbidity. Both drugs are used concurrently in presumptive malaria treatment and simultaneous HIV post exposure prophylaxis. Aim: The aim of this study was to investigate the effect of lamivudine-artesunate co administration on the histology of the liver of diseased adult Wistar rats. Materials and Methods: Five groups of rats of both sexes were used for the study and placed on feed and water ad libitum . Disease state consisted of immunosuppression with cyclophosphamide, and infection with Plasmodium berghei . Group 1 animals served as vehicle control, while group 2 were the diseased controls. Group 3 animals received 20 mg/kg lamivudine for three weeks, while group 4 similarly received 20 mg/kg Lamivudine but also received 10 mg/kg artesunate from day 12. Animals in group 5 received 10 mg/kg artesunate from day 12. All drugs were administered intraperitoneally. The animals were treated for twenty-one days, at the end of which they were sacrificed and their livers fixed in 10% formalin for histological studies. Result: Results from the study show the presence of regions of focal necrosis and perivascular cuffing with animals that received artesunate. Hemosiderosis was a common feature in all the parasitized groups, while fatty degeneration was observed in the group that received artesunate alone. Conclusion: Concurrent lamivudine-artesunate administration resulted in some histopathological changes in the liver. This study suggests there may be considerable histological changes with repeated occurrence of malaria and immunosuppression that may warrant intermittent lamivudine-artesunate administration, and may require evaluation as well as monitoring of liver function during such therapeutic interventions.

Tapinanthus globiferus is mistletoe that is used in folklore for the management of sleep disorders and epilepsy, amongst others. This study was designed to evaluate the sedative and anticonvulsant properties of the ethanol extract of T. globiferus in mice and chicks. The extract was screened for its sedative activity and effect on motor coordination using diazepam-induced sleep and beam-walk assay respectively; while anticonvulsant property was screened, using maximal electroshock (MES), pentylenetetrazole (PTZ)- and strychnine (STN)-induced seizure test models. Experiments were conducted in mice except MES which was conducted in day old cockerels, with all drug administered by intraperitoneal route. Data was analysed using ANOVA followed by Dunnett’s post-hoc test. The extract produced a significant (p ≤ 0.05) and dose-dependent decreased in the onset and increased in the duration of diazepam-induced sleep at doses of 87.5, 175 and 350 mg/kg and also produced significant (p ≤ 0.05) increase in number of foot slips and the time spent on beam at the highest dose of 350 mg/kg, compared to control. However, the extract had no effect on the onset of seizure compared to the control in both PTZ and STN-induced seizures and offered no protection against STN and MES-induced seizure. The results indicated that the ethanol extract of T. globiferus possesses sedative effects in mice and minimum or no anticonvulsant properties in mice and chicks. Keywords: Tapinanthus globiferus , Electroshock, Pentylenetetrazole, Strychnine

Preliminary investigation of the in vitro and in vivo efficacies of different extracts from the leaves of Vernonia amygdalina (VA), a plant widely used in Nigeria was evaluated in Balb/C mice infected with a laboratory strain of Leishmania major (L. major). The ability of the methanol, hexane and aqueous extracts of the plant to suppress the infection rate and its cytotoxicity on macrophages and L929 cells were determined in the in vitro study. The in vivo study evaluated time course of infection, lesion progression and the histopathology of cutaneous lesions, liver and spleen after inoculation with metacyclic promastigotes. Methanolic extract of VA containing high levels of flavanoids, was the most potent extract as it showed the highest suppression on infectivity and viability of intracellular amastigotes at a concentration lower than that which elicited cytotoxicity on macrophages. Treatment of infected mice with methanolic extract of VA showed delayed onset of disease with a significant reduction in lesion size and attenuation of the histopathological outcome characterised by intact epidermis and less tissue destruction in skin, spleen and liver. In conclusion, these results demonstrate that VA has potent antileishmanial properties which warrants further investigation into the immunological mechanism.

The effect of intravenous infusion of a solution of lactose-in-normal saline on the course of Trypanosoma vivax induced anaemia in Zebu yearlings was investigated. The animals were infected with 11 x 106 trypanosomes by jugular venipuncture and lactose-in-normal saline infusion started on day 6, post-infection (p.i). Three four-hourly doses of 0.5 g lactose/kg body weight were administered to each infected yearling in the experimental group daily for five days, while the infected control yearlings received no lactose-infusion. The experiment was terminated on day 13, p.i. Parasitaemia in the lactoseinfusedyearlings was scorable throughout the duration of experiment while parasites could not be detected in the blood of the infected control yearlings between days 7 and 9, p.i. Serum free sialic acids(FSA) concentration was also consistently higher in the lactose-infused yearlings than in the lactosefree ones. In the before lactose infusion (BL) period the PCV of the lactose-infused group dropped at asignificantly (P < 0.05) faster rate than in the lactose-free one. In the DL (during lactose infusion) period, the rate and magnitude of decline in PCV was significantly lower in the lactose-infused yearlings than inthe lactose-free animals. When lactose infusion was stopped (AL) the rate and magnitude of PCV decline became greater in the lactose-infused yearlings than in the lactose-free ones. It was thusconcluded that lactose ameliorated anaemia, by inhibiting the sequestration of desialylated erythrocytes from the blood stream of T. vivax-infected yearlings. This manifested in the reducedmagnitude and rate of decrease in PCV in the lactose-infused infected yearlings.

In a bid to establish a scientific rationale for the folkloric use of Khaya senegalensis the aim of this study was to determine the effect of the methanolic root bark extract of the plant on the rat uterus. With respect to uterine effects, the rat is the most appropriate animal model which can be extrapolated to man. Contractile response of isolated rat uterine preparations (approximately 2 cm strips) mounted in De-Jalon solution (in 25 ml organ bath) gassed with 95% oxygen / 5% carbon dioxide mixture at 32oC, were recorded using a microdynamometer. Both non-pregnant and pregnant isolated rat uterine tissues were challenged with oxytocin and acetylcholine as standard as well as with different concentrations of the extract followed by interaction studies. The results obtained from the experiments showed that the extract at concentrations between 0.3-3mg/ml (final organ bath concentrations) did not elicit any significant contractile properties but rather antagonized the contractile effects of oxytocin and acetylcholine. The antagonism was rapidly reversed in the non-pregnant uterine tissue while it was sustained in the pregnant uterine tissues. The present data therefore does not provide contractile basis for the purported use of K. senegalensis in abortions. Further studies are in progress to ascertain other possible mechanisms of abortions by the plant. Keywords : Khaya senegalensis , Oxytocin; Rat uterus Journal of Pharmacy and Bioresources Vol. 3 (1) 2006: pp. 30-35

Artemether, highly effective in multi-drug-resistant malaria is not routinely available for use in pregnancy due to the lack of adequate research data in animals and man. This study was therefore aimed at investigating some pregnancy-related effects of artemether. Artemether (1.5, 7.5 and 15 mg/kg i.p. daily for 7 days) did not produce changes in rat oestrous cycle. The drug did not prevent or prolong the rate of conception or parturition, cause pre-term delivery and affect litter size. Birth weight and growth rate of pups from artemether-pretreated dams were within the normal range. Artemether (48–480 µg/ml) had no agonist effect on the isolated uterine smooth muscles of both non-pregnant and pregnant rats and guinea pigs. However, the drug (24– 240 µg/ml) reduced oxytocin-induced contraction of uterine tissues concentration-dependently, particularly in pregnant uteri.

The leaves of Cassia tora Linn. (Family: Caesalpiniaceae) were soxhlet extracted with methanol. The spasmogenic effects of the extract were evaluated on guinea pig ileum, rabbit jejunum and mice intestinal transit. Antinociceptive activity of the extract was also evaluated in the mice. The LD(50) values of the extract in mice were >2000 mg/kg i.p. and p.o. The extract contracted smooth muscles of guinea pig ileum and rabbit jejunum in a concentration-dependent manner. Atropine reversibly blocked this activity. Mepyramine also reduced the contractile amplitude due to the extract in a concentration-dependent manner. The extract increased intestinal transit in mice dose dependently. C. tora extract significantly (P

Dietary association with chemical carcinogens is a well recognized occurence the world over. This paper reviews the presence of some compounds which have been detected and measured in foods and drinks that are indigenous to Nigeria. Diverse staple food items are known to be heavily contaminated with mycotoxins, particularly those producing the aflatoxin series. Poly-cyclic aromatic hydrocarbons such as benzpyrenes and anthracenes are present in smoked fish and meat. Several locally brewed alcoholic beverages have also been shown to contain nitrosatable amines. The widespread use of pesticides for agricultural and disease control purposes ensures a generous level of residues in foodstuffs. The presence of these and other chemical carcinogens in Nigerian foods and drinks may be associated with environmental factors, processing and handling practices and may account for the prevalence of certain types of cancers in the population.