Vol. 14 No. 25-40 (2023): EVALUATION OF THE in vitro ANTI-TRYPANOSOMAL ACTIVITIES OF ETHYL ACETATE AND AQUEOUS EXTRACTS OF ENDOPHYTIC FUNGI ISOLATED FROM Psidium guajava LEAVES AND STEMS

Endophytic fungi which reside in the tissues of higher plants without causing overt symptoms on

the plants in which they live – are reported to produce bioactive compounds which can be used in

agriculture, pharmaceuticals and the food industries. This study aim to evaluate the anti-

trypanosomal activities of endophytic fungi isolated from the leaves and stems of Psidium

guajava. Following surface sterilization, the plant parts were placed in potato dextrose agar (PDA)

to initiate fungal growth. Hyphae and spores of distinct fungal growth were further sub-cultured in

sabouraud dextrose broth to isolate pure fungal isolates. Each isolated fungal species was

subsequently grown in a 500ml Erlenmeyer’ s flask containing 100ml of liquid broth (pH 5.6) for

7 days at 28°C at 220 rpm in an incubator shaker. The respective fungal growths were filtered from

the broth, air dried, weighed and stored in well labelled airtight containers. Ethyl acetate and

distilled water were used for extraction, and the respective extracts were evaluated for their in vitro

anti-trypanosomal activities. Three endophytic fungi were isolated namely Penicillium sp.,

Aspergillus niger, and Mucor racemosus. The phytochemical analyses revealed the presence of

alkaloids, flavonoids, phenols, tannins, steroids, terpenoids, anthraquinone, cardiac glycoside, and

phlobatannins. The in vitro results indicated that the extracts of the ethyl acetate and aqueous

extracts of the endophytic fungi exhibited concentration dependent effect against Trypanosoma

brucei brucei between 0.15 and 10.0 mg/ml; the median lethal concentration (LC50) of the extracts

showed that ethyl acetate extract of Penicillium sp was the most active with an LC50 of 0.303

mg/ml.