Full Length Research Paper

Scoparia dulcis protects against Trypanosoma brucei-induced immunosuppression in experimentally infected rabbits

N. E. J. Orhue¹*, E. A. C. Nwanze¹ and A. Okafor²

¹Department of Biochemistry, Faculty of Life Sciences, University of Benin, P. M. B 1154, Benin City Nigeria.

²Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, 405 Hilgard Avenue, P. O. Box 951361, Los Angeles, CA. 900095-1361.

*Corresponding author.  E-mail: jerryorhue@yahoo.com.

Accepted 30 March, 2009

 Abstract

The present paper summarizes our findings on the effect of Scoparia dulcis on the population of immune cells during a 28 day experimental Trypanosoma brucei infection in rabbits. The result obtained showed that infection resulted in an initial rise in both total white blood cells (WBC) and the absolute number of circulating lymphocytes followed by a progressive decrease in total WBC and all WBC subtypes namely; lymphocytes, monocytes and granulocytes, although the % lymphocytes (lymphocytes expressed as % of total WBC) remained consistently higher than normal throughout the study period. These changes are consistent with the development of trypanosome-induced immunosuppression in their mammalian host. Treatment with S. dulcis at a daily oral dose of 25 mg/Kg body weight significantly reduced the severity of the observed lesions (p < 0.05) when compared with untreated infected animals. Thus the herb demonstrates significant potency in protecting against the parasite induced decrease in the population of immunologically active cells.

Key words: Trypanosoma brucei, Immunosuppresion, Scoparia dulcis, rabbit.