In vitro Studies on the Trypanocidal activities of various Phytochemical fractions obtained from Garcinia kola seed
Background: There is an urgent need for the development of new, cheap, safe and highly effective drugs against African trypanosomiasis a fatal disease which affects both man and livestock in sub- Saharan Africa. Garcinia kola is a medicinal plant with anti-inflammatory, antimicrobial and antiviral properties. In this study, we have investigated the in vitro trypanocidal activity of the various solvent extracts of Garcinia kola seed. Methodology: The extraction of Garcinia kola seed was carried out using 70% ethanol followed by subsequent fractionation using different organic solvents. Assessment of the in vitro trypanocidal activity of each sample was performed in 5 test tubes, each of which contained 0.1ml of fraction and 0.3ml of infected blood and incubated at room temperature. 0.1ml of fraction was replaced with PSG in the control. The number of motile parasites in each sample was monitored by direct microscopic examination and the parasites in virtually 50 fields were counted under a light microscope at x40 magnification. Results: The crude extract of Garcinia kola seed and the four phytochemical fractions showed varying degrees of trypanocidal activity. The alkaloid fraction showed the highest trypanocidal activity as the parasites were found dead within 5 minutes at 5mg/ml. The saponin fraction, the crude extract and the cardiac glycoside fraction also reduced motility at 5mg/ml after 15, 25 and 55 minutes respectively. The flavonoid fraction showed the lowest activity since reduction in motility was observed at 25mg/ml after 55 minutes. Conclusion: Garcinia kola seed extract contains phytochemicals that exhibited in vitro trypanocidal activity, hence has potential of leading to the development of cheap, safe and effective drugs for the treatment or management of African trypanosomiasis. However it would be necessary to establish whether the in vitro activity may translate into therapeutic benefit in vivo.
Key Words African trypanosomiasis, Garcinia kola, alkaloids, flavonoids, saponins, cardiac glycosides