This study was designed to evaluate the antimycobacterial, anti-reverse transcriptase, radical scavenging and antitumor activities of themethanol extracts of the twigs and leaves of three plants of the genus Treculia, namely Treculia obovoidea, Treculia africana and Treculia acuminata. The DPPH radical scavenging assay was used for the antioxidant test while the crown gall tumor assay was used for antitumor evaluation. The INT colorimetry and microplate
Alamar blue assay (MABA)were used for antimycobacterial investigations. The results of the antimycobacterial assays, showed that the leaf crude extract of the three Treculia species as well as that from the twigs of T. africana were able to prevent the growth of Mycobacterium smegmatis and Mycobacterium tuberculosis. The lowest MIC value (19.53 μg/ml) was recorded with extract of the leaves of T. africana on M. smegmatis, and those of T. africana and T. acuminata against M. tuberculosis. All studied extracts inhibited at various extents the anti-reverse transcriptase activity at 200 μg/ml. The best IC50 values, 31.1 μg/ml, 29.5 μg/ml and 21.1 μg/ml were recorded respectively with the extracts of the leaves of T. obovoidea, T. acuminata and T. africana. Results of the antioxidant activity indicate a dose-dependent ability of sample to scavenge the DPPH radical. The lowest IC50 values were obtained with
extracts of the leaves of T. acuminata (56.3 μg/ml) and T. obovoidea (55.9 μg/ml). Pronounced tumor-reducing activity was observed with the extracts of the leaves of T. africana (89.67%), T. acuminata (92.16%), T. obovoidea (96.67%) and that of the twigs of T. acuminata (87.18%). The overall results provide evidence that plants of the genus Treculia might be potential sources of antitubercular, anti-HIV and antitumor compounds.