Evaluation of the antileishmanial potency, toxicity and phytochemical constituents of methanol bark extract of Sterculia villosa.
BACKGROUND
Visceral leishmaniasis is a protozoan disease caused by Leishmania donovani parasite. The genus Sterculia (Malvaceae) possesses ethnobotanical potential against this protozoan infection.


OBJECTIVE
Determining the potential role of methanol bark extracts from Sterculia villosa Roxb (SVE) and its phytoconstituents against Leishmania donovani promastigotes.


METHODS
SVE was analysed by TLC, UV-Vis, IR spectroscopy and biochemical assays. Antileishmanial potential of SVE (0.5-130 μg/mL for 72 h) was characterized by MTT assay. Fluorescent microscopy was performed to validate the IC50dose. To determine the effect of SVE on promastigotes, reactive oxygen species (ROS) and superoxide generation, lipid peroxidation and DNA fragmentation assays were performed. Molecular aggregation of compounds was determined by atomic force microscopy (AFM). Extent of cytotoxicity of SVE at IC50dose was determined against RAW 264.7 macrophages, peritoneal macrophages and murine RBCs. In vivo cytotoxicity of SVE was evaluated in BALB/c mice.


RESULTS
SVE exhibited reverse dose dependent antileishmanial activity when 130-0 μg/mL doses were tested against promastigotes. The IC50and IC70values were found to be 17.5 and 10 μg/mL, respectively. SVE at IC50dose demonstrated elevated level of ROS, superoxide, lipid peroxidation and DNA fragmentation against promastigotes with no cytotoxicity. AFM analysis suggested increasing size of molecular aggregation (31.3 nm < 35.2 nm < 2.93 μm) with increase in concentration (10 μg < 17.5 μg < 130 μg).


CONCLUSIONS
The study elucidates the antileishmanial potential of SVE against Leishmania donovani promastigotes by exerting oxidative stress and DNA damage. In sum, SVE can be explored as an immunotherapeutic candidate against leishmaniasis and other infectious diseases.
a Department of Molecular Biology & Bioinformatics , Tripura University (A Central University) , Suryamaninagar , India.
Antu
A
Das
a Department of Molecular Biology & Bioinformatics , Tripura University (A Central University) , Suryamaninagar , India.
Manash C
MC
Das
b Department of Chemistry , Netaji Shubhas Mahavidyalaya , Udaipur , India.
Niranjan
N
Das
a Department of Molecular Biology & Bioinformatics , Tripura University (A Central University) , Suryamaninagar , India.
Surajit
S
Bhattacharjee
D000818:Animals; D000981:Antiprotozoal Agents / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D002855:Chromatography, Thin Layer; D053938:DNA Fragmentation; D004305:Dose-Response Relationship, Drug; D007893:Leishmania donovani / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D007898:Leishmaniasis, Visceral / Q000188:drug therapy* / Q000378:metabolism / Q000469:parasitology; D007928:Lethal Dose 50; D015227:Lipid Peroxidation / Q000187:drug effects; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000473:pathology; D000432:Methanol / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D018384:Oxidative Stress / Q000187:drug effects; D021261:Parasitic Sensitivity Tests; D064209:Phytochemicals / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D008517:Phytotherapy; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D010946:Plants, Medicinal; D000067996:RAW 264.7 Cells; D012997:Solvents / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D032361:Sterculia / Q000737:chemistry*; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors
D000981:Antiprotozoal Agents; D064209:Phytochemicals; D010936:Plant Extracts; D012997:Solvents; D013481:Superoxides; D000432:Methanol
DNA fragmentation; Leishmanicidal; free radicals; lipid peroxidation