International Science Community Association International Research Journal of Biological Sciences 14 1 2025 02 10 The in -vitro activity of an extract derived from selected Endophytic fungal species isolated from Psidium guajava against Trypanosoma Brucei Brucei 1 7 EN Baba Hussaina Sani 1 Department of Biological Science, College of Natural and Pharmaceutical Sciences, Bayero University, P.M.B. 3011, Kano, Kano State Nas Faruk Sani 2 Department of Biological Science, College of Natural and Pharmaceutical Sciences, Bayero University, P.M.B. 3011, Kano, Kano State Maigari Ahmad Kabir 3 Department of Biological Science, College of Natural and Pharmaceutical Sciences, Bayero University, P.M.B. 3011, Kano, Kano State Abubakar Salisu 4 Department of Biological Science, College of Natural and Pharmaceutical Sciences, Bayero University, P.M.B. 3011, Kano, Kano State and Biotechnology Advanced Research Centre, Sheda Science and Technology Complex, P.M.B. 186, Garki, Abuja, Nigeria > Research Paper 2024 1 20 2025 02 10 The research focused on the isolation and identification of endophytic fungi, as well as the assessment of the potency of secondary metabolites produced by the isolates from Psidium guajava L. (leaves and stems) against Trypanosoma brucei brucei. A range of endophytic fungal species were isolated using modified surface sterilisation techniques. A random selection of three isolates was made in order to analyse their produced secondary metabolites. Phytochemical screening was carried out using standard procedures on ethylacetate and methanolic extract (50:50v/v). The extracts were also subjected to in vitro anti-trypanosomal activity against Trypanosoma brucei brucei at different doses ranging from 10 mg/ml to 0.15625 mg/ml.In addition the brine shrimp fatality assay was used to assess the extracts' toxicity tests. The presence of steroids, tannins, saponins, flavonoids, phenols, terpenoid, and alkaloids was shown by the phytochemical data. The results of the in vitro antitrypanosomal activity showed that the extracts significantly reduced the concentrations of surviving trypanosomes six hours after incubation when compared to the number in the negative control wells. The Aspergillus nidulan extract had the maximum activity among the studied extracts, with no surviving parasites at 10 mg/ml, 5 mg/ml, 2.5, and 1.25 mg/ml. In comparison to the reference standard, potassium dichromate (LC50 0.80µg/ml), the Brine Shrimp lethality assay showed that extracts of A. nidulan, Fusarium moniliforme, and Rhizoctonia sp. were less toxic to brine shrimp (LC50 206µg/mL, 173.5µg/mL, and 110µg/mL). The statistical package for social science (SPSS) version 2.0 was used to analyse the mean survival rate using two-way Analysis of Variance (p<0.05). This discovery offered empirical evidence that endophytic fungus of Psidium guajava generate a profusion of non-toxic medicinal chemicals, much like their host plants. Copyright@ International Science Community Association