The effects of combination of methanolic leaf extract of Azadirachta indica and diminazene diaceturate in the treatment of experimental Trypanosoma brucei brucei infection in rats.

OBJECTIVE: To investigate the effects of combination therapy of methanolic leaf extract of Azadirachta indica (A. indica) and diminazene diaceturate (DDA) in the treatment of experimental Trypanosoma brucei brucei (T. brucei brucei) infection in rats. METHODS: Acute toxicity study of the drug and extract combinations were done. Selection of the best drug and extract combinations was carried out using fifty four rats of both sexes separated into 9 groups. Three dose combinations were derived from selection of the best drug and extract combinations used for the final study viz: 7 mg/kg bw DDA plus 125 mg/kg bw extract (group B), 3.5 mg/kg bw DDA plus 250 mg/kg bw extract (group C), and 1.8 mg/kg bw DDA plus 500 mg/kg bw extract (group D). The final study had in addition to the three groups derived from the dose response study, four other groups viz: uninfected untreated negative control (group F), infected and treated with 3 000 mg/kg bw extract alone (group E), infected and treated with 7 mg/kg bw DDA alone (group A), and infected untreated positive control (group G). The parameters assessed were onset of parasitaemia (OP), level of parasitaemia (LOP), clearance of parasites post treatment (COPPT), relapse infection period (RIP), post infection survival period (PIST). RESULTS: There was no significant difference in OP between the groups (P < 0.05). One day post treatment, the mean LOP of groups A, B, and C were found to be significantly lower than that of group D which in turn was lower than that of group E and G respectively. The mean LOP of group E was significantly lower than group G two days post treatment and this trend continued throughout the experimental period. Mean COPPT of group D was significantly longer than that of groups A, C and B. There was no significant difference in the mean COPPT among groups B, C and A. The mean RIP of group D was significantly shorter than group C, and that of group C was significantly shorter than that of group A. There was no relapse of infection in group B. The PIST of group E did not differ significantly from group G. CONCLUSIONS: This experiment stands to conclude that combination of 125 mg/kg bw extract and 7 mg/kg bw DDA is very effective in the treatment of trypanosomosis, caused by T. brucei. This combination therapy proved to be better than single therapy of DDA.

Effect of iodine supplementation on thyroid and testicular morphology and function in euthyroid rats.

Seventy-five male weaner euthyroid rats, randomly divided into three equal groups were used to evaluate the effect of iodine supplementation in the diet on growth and spermatogenesis. From the age of six weeks, the rat groups were fed normal diet containing 0.05 mg iodine/Kg diet (A); normal diet supplemented with 0.5 mg/Kg iodine (B) and normal diet supplemented with 3.0 mg/Kg iodine for a period of 90 days. Thereafter, all three groups were fed the normal diet for another 60 days. Body weight and feed consumption were determined; morphomeric studies of thyroid glands, testes and epididymes were carried out. Spermatogenesis was evaluated with epididymal (ESC) and testicular sperm counts (TSC). Increasing iodine intake significantly (p < 0.05) decreased mean body weight from day 30 of supplementation. Iodine supplementation influenced feed conversion ratio and efficiency in feed utilization in an inconsistent pattern. Supplementation did not significantly (p > 0.05) alter the size of thyroid glands, but increased the mean weights of the testes and epididymes to levels significantly (p < 0.05) higher than values for non-supplemented rats at specific stages of the study, especially at the highest (3 ppm) level of iodine supplementation. However, supplementation resulted generally in lower sperm counts, which was significant (p < 0.05) in the case of the epididymes. The results of the study show that iodine supplementation to weaner, non-iodine deficient euthyroid rats at 3ppm not only retard weight gain but could also reduce fertility by lowering epididymal sperm counts.