Synergistic activity of methanolic extract of Thespesia populnea (Malvaceae) flowers with oxytetracycline

Thespesia populnea (Malvaceae) is a large tree found in tropical regions and coastal forests of India. The bark, leaves, and flowers are useful in cutaneous infections such as scabies, psoriasis, eczema, ringworm, guinea worm and the leaves of this plant used as antiinflammatory for poultice as a folk medicine (Chang et al., 2002). Various parts of T. populnea are found to possess useful medicinal properties, such as antifertility, antimicrobial, anti-inflammatory, antioxidant, purgative and hepatoprotective activity (Shirwaikarkumar et al., 1995). Since the majority of bacteria were resistant to many antibiotics, only ampicillin and/or chloramphenicol and /or oxytetracycline were used in the synergism assays. This was because the resistance to at least one of these drugs was common in all the bacteria tested (Nascimento et al., 2000). The synergistic effect from the association of antibiotic with plant extracts against resistant bacteria leads to new choices for the treatment of infectious diseases. This effect enables the use of the respective antibiotic when it is no longer effective by itself during therapeutic treatment. Therefore, the present study was undertaken for the first time to investigate synergistic activity of methanol extract of T. populnea with oxytetracycline.