Ethanolic leaf extract of Psidium guajava: phyto-chemical and trypanocidal activity in rats infected with Trypanosoma brucei brucei.

Abstract

The Phyto-chemical composition and trypanocidal activity of the ethanolic leaf extract of Psidium guajava (guava) was investigated in rats infected withTrypanosoma brucei brucei. Results showed that the extract contained a higher amount of flavonoids compared to tannins which is moderately present. Other phyto-chemicals present but in minute amounts included saponins, steroids, and terpenoids amongst others. The result of the test for trypanocidal effects showed that there was low to absolute zero parasitaemia in the treated rats compared to the infected and untreated control. Besides the attainment of low parasitaemia by the leaf extract, there was also an appreciable extension of life span of all infected and treated rats. The life span extension ranged from 30 days to 32 days post infection. The infected and untreated control animals died on the 8th day post infection. We have been able to show that P. guajava leaf extract has trypanocidal properties which could be attributed in parts to the broad antimicrobial and iron chelating activity of flavonoids and tannins respectively. Iron chelation has been suggested by several reports as an effective way of killing trypanosomes. The prime target is the enzyme, ribonucleotide reductase whose activity is central to DNA synthesis prior to cell division as obtained in trypanosomiasis infection. This result thus makes P. guajava leaf extract a probable agent for managing African sleeping sickness. Key words: Psidium guajava, phytochemical, trypanosomes, antimicrobial, iron-chelation, ribonucleotide reductase.