Anti-trypanosome effects of nutritional supplements and vitamin D3: in vitro and in vivo efficacy against Trypanosoma brucei brucei

Abstract

BackgroundPrevious publications suggest that nutritional supplements have anti-trypanosome activity in vitro, although apparent efficacy was not noted in vivo. This study was conducted by experimentally infecting mice with Trypanosoma brucei brucei to assess the anti-trypanosome activity of various nutritional supplements with the hope of finding possible application in the treatment of African trypanosomiasis.MethodsActivities of nutritional supplements were screened in vitro against bloodstream forms of T. b. brucei. To evaluate selectivity, we used two mammalian cells, Jurkat cells and Vero cells. The IC50 values and selectivity index values were calculated, and supplements with promising efficacy in vitro were selected for further testing in vivo. Mice were infected intraperitoneally with 1 × 103T. b. brucei. We observed parameters for disease progression such as parasitemia, red blood cell count, white blood cell count, survivability, and splenomegaly. Morphological profiles after the treatment were analyzed by scanning electron microscopy.ResultsVitamin D3 showed anti-trypanosome efficacies both in vitro and in vivo. It seemed to have suppressive effects on parasitemia, and spleen weight was also significantly lower in vitamin D3-treated mice when compared to non-treated control mice. There was, however, no significant prolonged survivability of infected mice treated with vitamin D3. Among green tea extracts, polyphenon-60 and epigallocatechin gallate had suppressive effects against T. b. brucei in vitro, but in vivo efficacies were marginal.ConclusionsTreatment with nutritional supplements, vitamin D3, and polyphenon-60 seemed to have anti-trypanosome activity in vitro and protective activity to some extent in vivo, respectively, although those supplements themselves did not have curable effects. The exact mechanisms of action are not clear, but the significant efficacy in vitro suggested direct effects of supplements against African trypanosome parasites.

Salvianolic acid B: In vitro and in vivo effects on the immune system

“…SalB is another compound present in oregano extracts at a high concentration. It is frequently found in potentially immunomodulatory substances that are active in vitro, however, its effects do not appear to be translatable to an in vivo system [17]. In the present research, the in vitro anti-inflammatory potential of SalB was mediated by a reduction of TNF from macrophages, which is in accordance with the study of Sun et al (2016), who also showed that SalB downregulated TNF secretion [18].…”

Host-Directed Drug Therapies for Neglected Tropical Diseases Caused by Protozoan Parasites

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Drug Resistance in Animal Trypanosomiases: Epidemiology, Mechanisms and Control Strategies

“…In addition, some studies have shown antitrypanosomal activity of vitamins and their antioxidant property may help ameliorate toxicity, which is a characteristic of many trypanocides. The antitrypanosomal activities of vitamin C, vitamin D3 and vitamin E been demonstrated in vitro with IC5O of 58.6 μM, 4.58 μM and 28.6 μM respectively in T. b. brucei (Jamal et al, 2016). Likewise, in mice infected with T. b. brucei, treatment with 250 and 500 ng/Kg vitamin D3 resulted in significant decrease in parasitaemia, significant suppression of splenomegaly and recovery from declined RBC compared with non-treated control mice, although there was no detectable difference in body weight (Jamal et al, 2016).…”