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

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.

Protective efficacy of Chlorophytum borivilianum root extract against murine visceral leishmaniasis by immunomodulating the host responses.

BACKGROUND: The available drugs for treating visceral leishmaniasis are limited. Moreover, the disease is associated with suppression of immune function. Therefore, therapies with effective immunomodulatory agents are needed which can decrease parasitic burden and enhance adaptive immunity. OBJECTIVES: The present study was planned to evaluate the antileishmanial efficacy of crude ethanolic extract of roots of Chlorophytum borivilianum (CBREE) against murine visceral leishmaniasis through immunomodulation. MATERIALS AND METHODS: The in vitro studies were carried out to check leishmanicidal activity against promastigote form and cytotoxicity against HeLa cells. The parasite load in liver smears, immunological and biochemical changes induced by 500 and 1000 mg/kg b.wt. of CBREE were assessed on 1, 7, 14 and 21 post treatment days in infected and treated BALB/c mice. RESULTS: CBREE showed inhibitory effect on growth of promastigotes with IC50 of 28.25 µg/mL and negligible cytotoxicity. The extract was toxicologically safe in BALB/c mice when administered orally with 5 g/kg b.wt. of extract. A significant reduction in parasite load was observed along with active immunomodulation through enhanced Th1 type of immune responses and suppressed Th2 type of immune responses. CONCLUSION: The treatment with both doses showed no toxic effect as evidenced by normal liver and kidney function tests and normal histological observations of liver and kidney. Therefore, it should be further explored for its active components in pursuit of the new effective antileishmanial agents in the plant kingdom.