In-vitro and In-vivo Anti-trypanosomal Activity of Terminalia chebula Retz Dried Fruits

Abstract

African trypanosomosis had caused lots of havocs to both humans and animals over a century with successes and failure in curtailing it. This study was aimed at screening medicinal plant, Terminalia chebula dried fruits against Trypanosoma evansi for trypanocidal activity. Twenty grams of powdered Terminalia chebula dried fruits was cold extracted with methanol. Obtained MPE(methanolic plant extract) was in vitro tested against trypanosoma brucei (1 × 106 trypanosomes/mL of the medium in each ELISA plate wells) at concentrations (250~1,000 µg/mL) on Vero cells grown in DMEM (Debecco’s Modified Eagle Medium) in appropriate conditions for trypanocidal activity. In-vitro cytotoxicity test of MPE of Terminalia chebula was conducted on Vero cells grown in DMEM. In-vivo assay for trypanocidal activity, each mouse was inoculated with 1 × 104 /mL of trypanosomes and treated (48 h post inoculation) with MPE of Terminalia chebula at concentrations (12.5, 25, 50, 100 and 200 mg/kg body weight) were administered at dose rate of 100 µL per mouse via intraperitoneal route to different groups of mice, 6 mice per concentration. In-vitro cytotoxicity test was done on Vero cells at concentrations (1.58~100 µg/mL) of MPE of Terminalia chebula. Results of in-vitro trypanocidal activity varied from immobilization, reduction and to the killing of the trypanosomes. At 250 µg/mL of MPE of Terminalia chebula dried fruits, there was significant trypanocidal activity at 4 h of incubation and trypanosomes were not detected in corresponding ELISA plate wells at 5 h of incubation, which was statistically equivalent to reference drug, diminazine aceturate (50 µL/mL) at 4 h of incubation. Results of in-vivo trypanocidal activity revealed that at concentrations (12.5~25 mg/kg body weight) of MPE of Terminalia chebula, mice in these groups survived for 6 days. While at 50 and 100 to 200 mg/kg body weight, mice in these groups survived up to 7 and 8 days, respectively. In-vitro cytotoxicity test showed that all concentrations of MPE of Terminalia chenula and diminazine aceturate were cytotoxic to cells except at 1.56 µL/mL and 6.25 µL/mL. In conclusion, MPE of Terminalia chebula dried fruits possessed trypanocidal compounds. Further study (bioassay-guided purification) is required to know the full potential of Terminalia chebula as future trypanocide candidate