Evaluation of In vitro and In vivo Protective Efficacy of Bauhinia variegata Against Leishmania donovani in Murine Model

Abstract

Purpose: Visceral leishmaniasis is one of the ignored parasitic infection affecting millions of people globally. Currently, available treatment options are unsatisfactory because of high cost and side effects of the leishmanicidal drugs. Therefore, herbal medicines provide a promising choice for the detection of efficient and novel leishmanicidal therapeutics which can rejuvenate the immune response of the host with less adverse effects. The objective of the present study was to determine the in vitro and in vivo effect of hydroethanolic extract of Bauhinia variegata (HEBV) against Leishmania donovani.

Methods: The in vitro efficacy and cytotoxicity of HEBV was checked against L. donovani and THP1 human macrophages. Further HEBV (500 and 1000 mg/kg b.wt.) were given orally to inbred BALB/c mice infected with L. donovani for 2 weeks and euthanized on 14th post treatment day. Various parameters like parasite load, delayed-type hypersensitivity (DTH) responses, T cells, Th1/Th2 cytokines, histological and biochemical tests were investigated.

Results: HEBV showed marked antileishmanial activity with cell cycle arrest at sub-G0/G1 phase. HEBV was found to be more effective at higher dose in declining parasite concentration in the spleen as compared to the lower dose. Moreover, the extract augmented the DTH reaction and T cell responses in the infected mice. Oral administration of HEBV caused the enhancement of disease-suppressing Th1 cytokines and suppression of disease-progressing Th2 cytokines with no toxicities.

Conclusion: Thus, HEBV showed the antileishmanial efficacy through the generation of pro-inflammatory immunity of the host which further suggests the mechanistic exploration of it as a leishmanicidal therapeutic.

Keywords: Bauhinia variegata; CD8+ T cells; DTH responses; Sub-G0/G1 phase; Th1 cytokines; Visceral leishmaniasis.