Effects of dietary selenium supplementation on parasitemia, anemia and serum proteins of Trypanosoma brucei brucei infected rats.

Trypanosomosis has been associated with immunosuppression, anemia and oxidative damage while selenium possesses both immunostimulatory and antioxidative effects. This study was designed to assess the effect of dietary selenium supplementation on parasitemia, anemia, survival pattern and serum protein profiles of trypanosome-infected rats. Twenty five rats, divided into five groups (A-E) of 5 each, were treated as follows: 4, 8 and 16 ppm (ppm) of selenium in their feed, respectively throughout the experimental period and were infected with Trypanosoma brucei brucei on day 14 post supplementation, infected not supplemented and the negative control. Supplementation at 4 and 8 ppm increased the packed cell volume (PCV) and hemoglobin (Hb) concentration on day 7 of supplementation (PS) when compared with the unsupplemented groups. Following infection on day 14 PS, the PCV, Hb of 16 ppm and infected not supplemented groups were significantly (P < 0.05) lower than other groups on days 28 and 35 PS. Supplementation did not lead to significant (P > 0.05) changes on the total protein, albumin and globulin by day 14 PS. Infection, however, caused significant (P > 0.05) decrease in the total protein and albumin from day 28. The supplementation did not significantly (P > 0.05) increase the pre-patent period but caused a significant reduction in the parasitemia levels and increased survival intervals. Dietary selenium supplementation, from the results, may show promise in the management of African trypanosomosis as the supplementation was able to: reduce anemia and parasitemia and increase survival intervals of trypanosome infected rats.

Antagonistic antimalarial properties of pawpaw leaf aqueous extract in combination with artesunic acid in Plasmodium berghei-infected mice.

BACKGROUND & OBJECTIVES: Artemisinins, the main stay in the treatment of malaria are used in combinations with other antimalarials to forestall resistance, as artemisinin-combination therapies (ACTs). However, ACTs are expensive and some of the non-artemisinin components are not well-tolerated by patients. There are several folkloric and scientific proofs of the efficacy of herbal remedies for malaria. Mature leaves of Carica papaya is widely used to treat malaria in several African countries. An ACT involving a medicinal herb extract or its active constituent(s) will provide an indigenous alternative/herbal ACT. METHODS: Mature fresh leaves of Carica papaya were grounded and macerated in cold distilled water for 24 h and the extract (PCE) was stored in the refrigerator for seven days. Fresh extracts were made as needed. The antiplasmodial activity of PCE and/or artesunic acid were determined by using the Peter's 4-day suppressive test in Plasmodium berghei-infected mice. The ED50 and ED90 were calculated from the dose-response relationships. RESULTS: The combination of 50 mg/kg of PCE and 15 mg/kg of artesunic acid produced a significant reduction of parasitemia (81.25%), compared to 50 mg/kg PCE alone (37.7%). The mean survival time of the combinations of PCE and 15 mg/kg of artesunic acid, and PCE alone followed a dose-dependent manner. The ED50 of PCE showed that it has a very good activity. The isobolar equivalent (IE) calculated from the ED90 of PCE in combination with artesunic acid showed that the interaction was antagonistic. INTERPRETATION & CONCLUSION: Although pawpaw alone was found to have a very good activity, its combination with artesunic acid is antagonistic. Combinations of artemisinins and pawpaw show little promise for combination therapy development.

In vivo evaluation of the antiviral activity of Cajanus cajan on measles virus.

Cajanus cajan, a tropical shrub, serves as source of food and traditional medicines. The evaluation of aqueous and ethanol extracts for activity against measles virus and toxicity to embryonated chicken eggs was carried out in this study. In vivo and in vitro assay techniques using embryonated chicken eggs and tissue culture (Hep-2 cell lines) as media for both virus cultivation and anti-virus assay showed that a hot-water extract yielded higher activity against measles virus. The hot-water extract of the stem yielded a Log(2) titre of 0.1 for the in vivo assay and an inhibition of cytopathic effect (CPE) in Hep-2 cells by 100% for the in vitro assay. At all concentrations of the extracts, there was a lowering of virus concentration (p = 0.05), indicated by hemagglutination (HA) titration, which is the advantage of HA titration over the tissue culture technique using CPE. This study validates embryonated chicken eggs as suitable media for anti-virus assay and the use of C. cajan in the treatment of some diseases of viral origin.

The impact of dietary protein on the pathophysiology of porcine trypanosome infection.

The influence of protein nutrition on porcine trypanosomosis was investigated in this study. Thirty six landrace/large white cross weanling pigs were used. Upon purchase, these were divided into two groups of 18 pigs each and these were housed separately to enable them adapt to our animal house management regimen. Post-adaptation, the pigs were divided into 6 groups A(1) and A(2), B(1), and B(2), and C(1) and C(2) (n=6). A(1) and A(2) were fed diet A(1), B(1) and B(2) diet B while C(1) and C(2) were fed diet C with 28%, 20% and 16% crude protein, respectively. Two-week post-adaptation groups A(1), B(1), and C(1) were infected with 3×10(6)Trypanosoma brucei brucei organisms intraperitoneally. Body weight, temperature and Packed Cell Volume of all group members were determined a week prior to infection, on the day of infection and weekly thereafter till end of the study. Serum biochemistry was also concurrently determined. Three days post-infection, blood was collected from all the members of A(1), B(1) and C(1) and thoroughly screened microscopically for the presence of trypanosome organisms. This was repeated on subsequent days till all the infected animals developed patency by showing parasitaemia under wet mount. The result of this study showed that infection did not have any significant effect on the rate of weight gain except in group C (p≤0.05). Moreover, infections caused significant hyperthermia in all the infection groups (p≤0.05) with diet A showing the least response and C the most severe. Furthermore, diet did not have any effect on parasite establishment or parasitaemia as the prepatent period was similar in all the infection groups. There was also significant reduction in PCV whose severity also correlated with reduction in the protein dietary quality. Similar observation was also made on the total serum protein where significant hyperproteinaemia correlated with increasing dietary protein and the uninfected controls having higher serum protein relative to the infected. There was in addition parasite induced hypoalbuminaemia whose severity was also graduated in favour of increasing protein level. The study demonstrated the protective influence of dietary protein on some of the pathophysiological features of porcine trypanosomosis.

Persistent detection of peste de petits ruminants antigen in the faeces of recovered goats.

Peste des petits ruminants (PPR) disease was confirmed in West African Dwarf goats. They were managed symptomatically with antibiotics and antidarrhoeics. Following clinical recovery, faeces were collected every week from 40 recovered goats to monitor excretion of the PPR virus haemagglutinins in their faeces. All the 40 recovered goats shed the PPR virus haemagglutinins for 11 weeks post recovery. Nine goats (22.5%) continued shedding the viral antigen 12 weeks post recovery. There was correlation between weekly mean haemagglutination titre of the PPR virus and time post recovery with r = -0.7504 (p < 0.01).