Trypanosuppressive effects of Kolaviron may be associated with down regulation of Trypanothione reductase in Trypanosoma congolense infection

@#Trypanothione reductase is a key enzyme that upholds the redox balance in hemoflagellate protozoan parasites such as T. congolense. This study aims at unraveling the potency of Kolaviron against trypanothione reductase in T. congolense infection using Chrysin as standard. The experiment was performed using three different approaches; in silico, in vitro and in vivo. Kolaviron and Chrysin were docked against trypanothione reductase, revealing binding energies (-9.3 and -9.0 kcal/mol) and Ki of 0.211μM and 0.151μM at the active site of trypanothione reductase as evident from the observed strong hydrophobic/hydrogen bond interactions. Parasitized blood was used for parasite isolation and trypanothione reductase activity assay using standard protocol. Real-time PCR (qPCR) assay was implored to monitor expression of trypanothione reductase using primers targeting the 177-bp repeat satellite DNA in T. congolense with SYBR Green to monitor product accumulation. Kolaviron showed IC50 values of 2.64μg/ml with % inhibition of 66.78 compared with Chrysin with IC50 values of 1.86μg/ml and % inhibition of 53.80. In vivo studies following the administration of these compounds orally after 7 days post inoculation resulted in % inhibition of Chrysin (57.67) and Kolaviron (46.90). Equally, Kolaviron relative to Chrysin down regulated the expression trypanothione reductase gene by 1.352 as compared to 3.530 of the infected group, in clear agreement with the earlier inhibition observed at the fine type level. Overall, the findings may have unraveled the Kolaviron potency against Trypanosoma congolense infection in rats.

Erythropoietic and bone marrow stimulating activity of terminalia catappa extract: Possible role of nitric oxide signaling.

Aims: We assessed the capacity and mechanism of Terminalia catappa (TC) to induce erythropoiesis in vivo in phenylhydrazine- induced anemic mice. Place and Duration of Study: Sample: This study was carried out at Department of Biochemistry and Center for Biotechnology Research and Training Ahmadu Bello University Zaria, and National Research Institute for Chemical Technology, Zaria. The duration spanned between Jan 2011 and Feb 2012. Methodology: Solvent fractions of Terminalia catappa aqueous extract was used to treat phynylhydrazine-induced anemic mice. Treatment was done for four days, erythropoietic activity of each fraction was assayed by determining the effect of these fractions on intracellular hemoglobin and reticulocyte level from the blood, arginase was also assayed. Bone marrow carbonic anhydrase was assayed to monitor bone marrow erythropoietic stimulation. Results: Terminalia catappa was able to up-regulate the synthesis of intracellular hemoglobin (0.135 ±0.004 μmol/0.1ml) significantly comparable to hydroxyurea (HU) (0.158±0.006 μmol/0.1ml), and normalize the peripheral blood reticulocyte index significantly at P<.05 0.94±0.25% close to the non anemic mice 0.97±0.25% and bone marrow carbonic anhydrase activity. TC inhibited arginase activity significantly (P<.05) comparable to hydroxyurea. Conclusion: The results demonstrate Terminalia catappa extract as an erythropoietic agent that supports normal erythroid differentiation in vivo in phenylhydrazine- induced anemic mice in a synergistic fashion.