Setting: Department of Clinical Analysis and Biomedicine, State University of Maringa, Maringa, Parana, Brazil.
Objective: To evaluate the in vitro interaction between eupomatenoid-5 (EUP-5), extracted from Piper solmsianum C. DC. var. solmsianum, and first-line anti-tuberculosis drugs against Mycobacterium tuberculosis H₃₇Rv and 20 clinical isolates.
Design: Resazurin drugs combination microtiter assay (REDCA) was performed to determine the interaction between EUP-5 and isoniazid, rifampicin (RMP) and ethambutol (EMB).
Results: Synergism was observed in M. tuberculosis H₃₇Rv and eight clinical isolates with EUP-5+RMP, and in M. tuberculosis H₃₇Rv and 17 clinical isolates with EUP-5+EMB combinations.
Conclusion: EUP-5 is a promising compound for further studies on the development of anti-tuberculosis drugs.