Immune challenge of mating effort:steroid hormone profile,dark ventral patch and parasite burden in relation to intrasexual competition in male Iberian red deer

Testosterone secretion may regulate the reproductive effort and the development of sexual traits,but it may also involve costs at the immunological and metabolic levels.However,the evidence for this trade-off in wild populations is scarce.Cortisol also plays an important role in mediating the reproductive and immune functions.In this study,we analyzed whether the endoparasite burden relates to hormonal levels(fecal testosterone and cortisol metabolites)and/or morphological sexual traits(size of the dark ventral patch,a trait that indicates reproductive effort in males)in male Iberian red deer.For this purpose,we sampled male red deer harvested during hunting actions in 2 types of populations in south western Spain that differed in structure,affecting the level of male–male competition for mates.We used coprological analyses to estimate the parasite burden mainly of gastrointestinal and bronchopulmonary nematodes and of protozoa,and assessed testosterone and cortisol metabolite levels from fecal pellets.We found a positive relationship of host parasitation with both testosterone levels and the size of the dark ventral patch,but these relationships depended on the intensity of male–male competition in the population,being only found under the high-competition scenario.These results are discussed under the hypothesis of the testosterone immunocompetence handicap,suggesting a cost at the immunological level,and,therefore,higher susceptibility to parasite infection in males that make a greater reproductive effort.However,this effect seems to be modulated by the social environment(male–male competition)that might lead to different optima in testosterone production and sexual trait development.

Evaluation of the adjuvanticity of artemisinin with soluble Leishmania major antigens in BALB/c mice

Objective： To determine the adjuvant potential of artemisinin with a soluble leishmanial antigen in vaccinating BALB/c mice. Methods： Seventy two female BALB/c mice were randomly assigned into six groups. The mice were vaccinated with soluble Leishmania antigens （SLA） alone, artemisinin co-administered with SLA, SLA and Bacille Calmette Gu fin （BCG） vaccine, and artemisinin and BCG alone. Unvaccinated mice formed the control group. The induction of cell-mediated immunity following vaccination was determined by measuring in vitro lymphocyte proliferation and the production of interleukin （IL）-4, IL-5 and gamma interferon （IFN-γ） determined by flow cytometry. Protection against L. major was determined by quantifying parasite burdens in L. major infected footpads using a limiting dilution assay and by measuring lesion sizes of the infected footpad compared to the contralateral uninfected footpad. Results： Mice receiving SLA plus artemisinin produced significantly high levels of IL-4 and IL-5 （P 〈 0.05） and low levels of IFN-γ, resulting in exacerbated disease. In addition, subcutaneous administration of SLA ＋ artemisinin, artemisinin alone or SLA alone resulted in the development of large footpad swellings and high parasite loads that were comparable to those of the control unvaccinated mice （P 〉 0.05）, resulting in exacerbated disease. Conclusion： These data suggest that artemisinin is not a suitable adjuvant for Leishmania vaccines. However, since artemisinin has been shown to be effective against Leishmania parasites in vitro and in vivo, further studies ought to be conducted to determine its immunochemotherapeutic potential when co-administered with Leishmania antigens.

Evaluation of the Therapeutic Potential of Warburgia ugandensis,Prunus africana,and Piliostigma thonningii against Leishmania donovani in vitro and in Balb/c Mice

Leishmaniasis is a zoonotic disease caused by protozoan parasites of the genus Leishmania.Conventional chemotherapy remains to be the most preferred measure against leishmaniasis despite being associated with high toxicity and relapse rates.They are also expensive and require hospitalization.Plant-based compounds provide a better treatment alternative because they are effective,cheap,and less associated with toxicity and resistance.This study examined the therapeutic potential of Warburgia ugandensis,Prunus africana,and Piliostigma thonningii against Leishmania donovani infection in BALB/c mice.Anti-promastigote and toxicity studies were evaluated by incubating the test compound with promastigotes and Vero cells,respectively.Serum was obtained from the mice for total immunoglobulin gamma(IgG)quantification.For in vivo studies,the mice were infected with virulent Leishmania donovani then treated with methanolic extracts of Warburgia ugandensis,Prunus africana,and Piliostigma thonningii and control drug,pentostam(sodium stibogluconate).Treatment with the plant extracts and standard drug resulted to significant reduction in parasite burden.Outcomes in the mice treated with plant extracts were comparable to those treated with pentostam(P≥0.05).In the promastigote assay,all the test compounds killed more than half of the promastigotes at the highest concentration(500μg/mL).Warburgia ugandensis,P.thonningii,and P.africana reduced the number of promastigotes from 2.0×10^(6) to 7.7×10^(3),72.0×10^(3),and 5.0×10^(3),respectively.Pentostam had the lowest IC50(210μg/mL),followed by Warburgia ugandensis(IC50 of 270μg/mL).Piliostigma thonningii and P.africana were less toxic with IC50 of 720μg/mL and 500μg/mL,respectively.There was low production of IgG antibodies following treatment with the plant extracts and high levels in the untreated control.