Abstract: In the present study, 36 plant extracts, belonging to 6 families from Burkina Faso were used to evaluate their glutathione-S-transferase (GST), acetylcholinesterase (AChE), carboxylesterase (CES) and xanthine oxidase (XO) inhibitory activities and their phenolic, tannin and flavonoids contents by using spectrophotometrical methods. At 100 μg mL-1, Lippia chevalieri, Eclipta prostrata, Lantana camara and Indigofera pulchra extracts showed the best percentage of inhibition by regulating GST, AChE, CES and XO activities, respectively. The phytochemical investigations showed that all plant extracts were rich in biological compounds, namely phenolic, tannin and flavonoids. Particularly Cassia mimosoides extract presented the best phenolic, tannin and flavonoid contents. This result indicated that phenolic from Ceasalpiniaceae, flavonoids from Combretaceae and tannin from Verbenaceae contribute significantly to the inactivation of CES, AchE and GST, respectively. However, no significant correlation was found between polyphenolic compounds content and XO inhibitory activity. Present findings could partially justify the traditional uses of these plants in the treatment of mental disorders, gout, painful inflammations and cardiovascular diseases.