Full Length Research Paper

Effect of falciparum malaria on some plasma proteins in males: With special reference to the levels of testosterone and cortisol

Muawia A. Abdagalil¹* and Nabiela M. ElBagir²

¹Department of Biochemistry, Faculty of science, University of West Kordufan, Sudan.

²Department of Biochemistry, Faculty of veterinary medicine, University of Khartoum, Sudan.

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

Accepted 1 September, 2009

   Abstract

Sex-associated hormones were evidenced to modulate immune responses and consequently directly influence the outcome of infection. Testosterone is known to influence both protein metabolism and the level of cortisol which is the hormone of stress. This work was conducted to explore the influence of the degree of parasitemia in Plasmodium falciparum malaria on the male sex hormone testosterone, plasma proteins and the stress hormone cortisol in male patients. The study targeted male subjects whose ages ranged between 20 and 40 years old. The subjects were divided into three groups: lightly-infected patients (Infected with P. falciparum density 1 - 10 asexual form of the parasite per 100 fields), heavily-infected patients (Infected with P. falciparum density 11 - 99 asexual form of the parasite per 100 fields) and a group of malaria-free individuals who were used as a control group. Blood samples were taken from the median cephalic vein to investigate for malaria parasite, plasma proteins and hormones. The effect of the degree of parasitemia was considered for all parameters studied. The study revealed that low parasitemia in malaria-infected patients resulted in significantly (P < 0.05) higher level of plasma total proteins and it was found to be due to a significant (P < 0.05) increase in the total globulins fraction which reached 5.85 ± 1.03 g/dl compared to 3.44 ± 0.4 g/dl in the control group. The opposite was true for the heavily-infected group as it reported significantly (P < 0.05) lower total plasma proteins value which was found to be due to a significant (P < 0.05) reduction of the total globulins fraction reported only 2.96 ± 0.20 g/dl. The albumin fraction maintained levels similar to that of the control group in both infected groups. The levels of the hormones tested also showed significant changes, manifested as significantly (P < 0.05) lower values in both groups of patients compared to the control group for the testosterone hormone, with significant (P < 0.05) difference between the two groups. Thus, high parasitemia resulted in the least testosterone level in the heavily-infected group of 2.64 ± 0.28 ng/ml, compared to 6.03 ± 0.86 ng/ml in the control group. In contrast, the stress hormone, the cortisol, showed the highest level in the heavily-infected patients of 191.03 ± 18.17 ng/ml, with significant (P < 0.05) difference compared to 166.28 ± 10.63 ng/ml in the control group.

Key words: Malaria, testosterone, cortisol, parasitemia.