Aqueous Extract Of Fruit Pulp Of Adansonia digitata (Linn): Phytochemical Screening And In Vitro Antitrypanosomal Effect

Abstract

Chemotherapy is the most widely used means of controlling Trypanosomosis, a major health problem to man and his livestock over much of Tropical Africa. However, effectiveness of the drugs available is limited by a number of factors which include increasing parasite resistance, treatment failures and unacceptable toxicity. This study investigated the phytoconstituents of aqueous extract of fruit pulp of Adansonia digitata and its in vitro anti-trypanosomal effects on Federe strain of Trypansoma brucei brucei. Qualitative phytochemical analysis of the extract was carried out using standard technique. While in the in vitro study, about 3 ×105 T. brucei brucei in 0.3mls of blood suspended in 0.4mls Ringer’s solution were each dispensed into tubes (A-D) containing 0.3mls of the aqueous extract at concentrations of 0.02mg/ml, 0.2mg/ml, 2mg/ml and 20mg/ml respectively. The fifth tube (E) was an untreated control (Ringer’s solution and parasite). The tubes were incubated at 370C and examined for the presence and motility of trypanosomes at 15 minutes intervals for 2hours. After the incubation and motility assessment, 0.2ml of the contents of each tube was inoculated intraperitoneally into group of 3 rats, 3 other rats served as uninfected controls. The inoculated animals were then examined daily for the presence of trypanosomes for a period of 60 days. The phytochemical analysis showed the presence of tannins, saponin, phenol, terpenoid, cardiac active glycoside, anthraquinone, reducing sugar, alkaloids, flavonoids and steroids. The extract demonstrated a concentration and time dependent inhibitory effect on trypanosomal motility. Highest effect was observed at concentration of 20mg/ml, with total ceassation of trypanosome motility from 75 minutes of exposure all through the 120 minutes of the incubation. Also rats inoculated with content of the tubes containing the 20mg/ml of the extract did not show parasitaemia and survived the 60 days infectivity test period. However, all rats inoculated with trypanosomes exposed to lower concentrations of the extract showed high parasitaemia with 100% mortality within 5 days post inoculation.

Keywords: Adansonia digitata, Trypanosomiasis, Phytochemistry, Trypanosoma brucei brucei.