Liver function of Streptozotocin- Induced Diabetic Rats Orally Administered Aqueous Root-Bark Extracts of Tetrapleura tetraptera (Taub).

The aqueous root-bark extract of Tetrapleura tetraptera Taub. has been shown to  ameliorate streptozotocin (STZ)-induced hyperglycaemia and dyslipidaemia. This study evaluated the liver status of STZ- induced diabetic rats treated with aqueous root-bark extract of T. tetraptera for 35 days. Twenty-four (24) rats in four groups (normal control, diabetic control, T. tetraptera treated STZ induced diabetic rats at 150 mg/kg b. w. and T. tetraptera treated STZ-diabetic rats at 300 mg/kg b. w.) were used. Serum and liver alanine and aspartate transaminases (ALT and AST), alkaline phosphatase (ALP), gamma glutamyl transferase (γGT) activities and protein concentration were assessed. Also, serum albumins, globulins, total and direct bilirubin concentrations were measured. STZ induced diabetes significantly (P<0.05) increased serum ALT, AST and ALP activities, while treatment of diabetic rats with T. tetraptera reduced the activities of these enzymes. T. tetraptera caused significant (P<0.05) increases in serum γGT, total and direct bilirubin levels, especially at the higher dose (300mg/kg body weight). While the treatment of STZ induced diabetic rats with the extract of T. tetraptera ameliorated hepatocellular damage, at the higher dose of 300mg/kg body weight, T. tetraptera treatment may cause bile duct obstruction. The use of this plant in the treatment of diabetes or other diseases should therefore be monitored with respect to hepato-biliary toxicity.Keywords: Tetrapleura tetraptera, STZ diabetes, Liver function, Toxicity, Medicinal plant

Phosphodiesterase-4 Inhibition Alters Gene Expression and Improves Isoniazid – Mediated Clearance of Mycobacterium tuberculosis in Rabbit Lungs

Tuberculosis (TB) treatment is hampered by the long duration of antibiotic therapy required to achieve cure. This indolent response has been partly attributed to the ability of subpopulations of less metabolically active Mycobacterium tuberculosis (Mtb) to withstand killing by current anti-TB drugs. We have used immune modulation with a phosphodiesterase-4 (PDE4) inhibitor, CC-3052, that reduces tumor necrosis factor alpha (TNF-α) production by increasing intracellular cAMP in macrophages, to examine the crosstalk between host and pathogen in rabbits with pulmonary TB during treatment with isoniazid (INH). Based on DNA microarray, changes in host gene expression during CC-3052 treatment of Mtb infected rabbits support a link between PDE4 inhibition and specific down-regulation of the innate immune response. The overall pattern of host gene expression in the lungs of infected rabbits treated with CC-3052, compared to untreated rabbits, was similar to that described in vitro in resting Mtb infected macrophages, suggesting suboptimal macrophage activation. These alterations in host immunity were associated with corresponding down-regulation of a number of Mtb genes that have been associated with a metabolic shift towards dormancy. Moreover, treatment with CC-3052 and INH resulted in reduced expression of those genes associated with the bacterial response to INH. Importantly, CC-3052 treatment of infected rabbits was associated with reduced ability of Mtb to withstand INH killing, shown by improved bacillary clearance, from the lungs of co-treated animals compared to rabbits treated with INH alone. The results of our study suggest that changes in Mtb gene expression, in response to changes in the host immune response, can alter the responsiveness of the bacteria to antimicrobial agents. These findings provide a basis for exploring the potential use of adjunctive immune modulation with PDE4 inhibitors to enhance the efficacy of existing anti-TB treatment

Effect of aqueous root bark extract of Tetrapleura tetraptera (Taub) on blood glucose and lipid profile of streptozotocin diabetic rats

Background: Tetrapleura tetraptera (Schum. and Thonn) Taub is used in Africa as a spice and in folk medicine. Its documented biological activities include molluscicidal, hypotensive, anti-convulsant, anti-inflammatory, hypoglycaemic and anti-microbial effects.Objective: This study evaluated the potential role of the aqueous root-bark extract of T. tetraptera in the treatment of diabetes and its antihyperlipidemic effect in streptozotozin-induced diabetic rats.Methods: T. tetraptera extract was orally administered to streptozotocin (STZ) diabetic rats at 150 and 300mg/kg body weight (Groups 3 and 4). The effect of the extract on body weight, fasting blood sugar (FBS) and serum lipid profile of the treated diabetic rats were compared with untreated control rats (Group 1) and untreated diabetic control rats (Group 2) after 35 days of treatment.Results: T. tetraptera treatment caused a non-significant improvement of STZ-induced weight loss and significantly (p<0.05) reduced FBS in treated diabetic rats. Serum triacylglycerol, total cholesterol and LDL-cholesterol concentration significantly (p<0.05) reduced in treated diabetic rats while the HDL- cholesterol concentration of the 150mg/kg body weight treated group increased.Conclusion: The antidiabetic effect of the aqueous root bark extract of T. tetraptera validates the folkloric use of this part of the plant as an antidiabetic remedy. The associated anti-hyperlipidaemic effect may be useful in the treatment of chronic diabetic complications.Keywords: Tetrapleura tetraptera, diabetes, Antidiabetic, Antihyperlipidemic, Rat

A pilot external quality assurance study of transfusion screening for HIV, HCV and HBsAG in 12 African countries

Background and Objectives: Serologic screening for the major transfusion transmissible viruses (TTV) is critical to blood safety and has been widely implemented. However, actual performance as measured by proficiency testing has not been well studied in sub-Saharan Africa. Therefore, we conducted an external quality assessment of laboratories engaged in transfusion screening in the region. Materials and Methods: Blinded test panels, each comprising 25 serum samples that were pedigreed for HIV, HBsAg, HCV and negative status, were sent to participating laboratories. The panels were tested using the laboratories' routine donor screening methods and conditions. Sensitivity and specificity were calculated, and multivariable analysis was used to compare performance against mode of testing, country and infrastructure. Results: A total of 12 African countries and 44 laboratories participated in the study. The mean (range) sensitivities for HIV, HBsAg and HCV were 91·9% (14·3-100), 86·7% (42·9-100) and 90·1% (50-100), respectively. Mean specificities for HIV, HBsAg and HCV were 97·7%, 97% and 99·5%, respectively. After adjusting for country and infrastructure, rapid tests had significantly lower sensitivity than enzyme immunoassays for both HBsAg (P < 0·0001) and HCV (P < 0·05). Sensitivity also varied by country and selected infrastructure variables. Conclusion: While specificity was high, sensitivity was more variable and deficient in a substantial number of testing laboratories. These findings underscore the importance of proficiency testing and quality control, particularly in Africa where TTV prevalence is high

A pilot external quality assurance study of transfusion screening for HIV, HCV and HBsAG in 12 African countries

Background and Objectives: Serologic screening for the major transfusion transmissible viruses (TTV) is critical to blood safety and has been widely implemented. However, actual performance as measured by proficiency testing has not been well studied in sub-Saharan Africa. Therefore, we conducted an external quality assessment of laboratories engaged in transfusion screening in the region. Materials and Methods: Blinded test panels, each comprising 25 serum samples that were pedigreed for HIV, HBsAg, HCV and negative status, were sent to participating laboratories. The panels were tested using the laboratories' routine donor screening methods and conditions. Sensitivity and specificity were calculated, and multivariable analysis was used to compare performance against mode of testing, country and infrastructure. Results: A total of 12 African countries and 44 laboratories participated in the study. The mean (range) sensitivities for HIV, HBsAg and HCV were 91·9% (14·3-100), 86·7% (42·9-100) and 90·1% (50-100), respectively. Mean specificities for HIV, HBsAg and HCV were 97·7%, 97% and 99·5%, respectively. After adjusting for country and infrastructure, rapid tests had significantly lower sensitivity than enzyme immunoassays for both HBsAg (P < 0·0001) and HCV (P < 0·05). Sensitivity also varied by country and selected infrastructure variables. Conclusion: While specificity was high, sensitivity was more variable and deficient in a substantial number of testing laboratories. These findings underscore the importance of proficiency testing and quality control, particularly in Africa where TTV prevalence is high