ABSTRACT
Aim: To evaluate the in vitro and in vivo exposure effects of Euphorbia hirta decoction on Baby Hamster Kidney (BHK-21) cells and in albino rats, respectively. Materials and Methods: Extract of the plant was obtained after boiling and the filtrate dried. In vitro cytotoxic effect was evaluated on Baby Hamster Kidney (BHK-21) cells by examination of cell morphology under the microscope after exposure to 25, 50, 100 and 200 µg/ml concentrations of extract while the in vivo toxicity on some biochemical; alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), Total protein, Albumin, Urea, Creatinine and electrolytes), haematological (Full Blood Count) and histological (Liver and Kidney) indices were evaluated after daily oral administration of the extract to four groups (n =8) of albino rats at dose of 0, 300, 600 and 1200 mg/kg body weight, respectively for 14 days. Results: In vitro evaluation showed a concentration dependent increase in cytopathic effect (CPE) in BHK-21 cells ranging from dark single particles indicative of early sign CPE at 25 µg/ml to severe CPE and apoptosis at 200 µg/ml. The in vivo evaluation revealed significant increases (p<0.05) in the activities of ALT, AST and ALP with values ranging from 11-15, 22-35 and 168-308 iu/l respectively in serum when compared to the control group. The concentrations of urea (243.71-270.60 mmol/lit) and creatinine (168.07-280.71 µmol/lit) were significantly higher (p<0.05) in the test groups compared to the control group. Histopathological examination of the liver and kidney revealed varying degrees of alterations (sinusoidal dilatation, congestion, haemorrhage, centrilobular degeneration, tubular necrosis and tubular degeneration). Conclusion: The decoction of Euphorbia hirta is cytotoxic to BHK-21 cells and toxic to the liver and kidney of albino rats at the tested concentrations and dosages respectively. Until safe doses are determined, its uncontrolled consumption should be discouraged.
ABSTRACT
Aims: To determine the presence of rabies virus neutralizing antibodies (rVNA) as well the potency of the rVNA in rabies occupational risk humans in Niger State of Nigeria. Study Design: Cross-sectional study. Place and Duration: Research was conducted at the Department of Veterinary Public Health, Ahmadu Bello University, Zaria, Nigeria and Rabies Unit, Centers for Disease Control and Prevention, CDC, Atlanta, USA, between May, 2012 and March, 2013 Materials and Methods: A total of 185 human volunteers were recruited from rabies risk occupational groups who filled a structured questionnaire on their previous bite history and vaccination status, between May and July, 2012. A 2 ml each of blood from volunteers was collected and centrifuged at 3000 rpm for 10 minutes and sera separated into pre-labeled vacutainers. Standard Rapid fluorescent focus inhibition test (RFFIT) was used to detect the presence of rVNA in the sera. Further end point titration of the rVNA positive human sera was conducted to determine the potency. Results: The results indicated that, detectable titre of rVNA was recorded in 16.4% (23 of 140) viable human sera screened. Although from the questionnaire survey, 21.7% (5 out of the 23 positives) responded to have been vaccinated over ten years prior. At least 3 of the respondents (1 dog butcher and 2 dog meat consumers) who responded not previously vaccinated had some neutralizing antibody titre range of 0.65 – 0.7 IU/ml which is above the minimum protective titre (0.5IU/ml) recommended by WHO. Similarly, 3 respondents (2 veterinarians and 1 animal health personnel) who responded to have been previously vaccinated (> 10 years earlier) yet had a high titre range of 0.5 – 5.4IU/ml. The highest specific rate for rVNA of 25% each was seen amongst the dog butchers and pet owners followed by hunters (20%) and dog meat consumers (14.8%). Up to 125 (67.6%) of the volunteers do consume dog meat with only 12 (9.6%) of them being dog butchers who source dogs for slaughter from households within and outside their territories. Conclusion: Although the WHO minimum protective titre of rVNA is 0.5 IU/ml, the presence of relatively high titres amongst these risk groups in this report is an indication of a serious public health threat. This study recommends the vaccination of rabies high risk groups and further screening of rabies occupational risk and non risk groups in the study area and Nigeria at large.