Tropical Journal of Pharmaceutical Research, December 2013; 12(6): 1003-1010

Purpose: To investigate the antibacterial and antitumor activities of the aerial parts of 8 different Turkish endemic plants (Phlomis russeliana, Phlomis armeniaca, Astragalus brachypterus, Astrantia maxima, Ptilostemon afer, Senecio castagneanus, Echium orientale and Arum euxinum).

Methods: Two different bioassays were performed to evaluate the antibacterial and antitumor activities of the endemic plants. For each plant, 3 types of extracts (aqueous, methanol and ethanol) were prepared, giving a total of 24 extracts tested. The disc diffusion assay was used to screen for antibacterial activity against 10 bacteria including Streptococcus pyogenes, Staphylococcus aureus, Staphylococcus epidermidis, Escheria coli, Pseudomonas aeruginosa, Salmonella typhimurium, Serratia marcescens, Proteus vulgaris, Enterobacter cloacea, and Klebsiella pneumoniae. Five different antibiotics (ampicillin, carbenicillin, chloramphenicol, erythromycin and tetracycline) were used as positive controls. Antitumor activity was evaluated using potato disc diffusion bioassay with camptothecin as positive control. 

Results: The highest antibacterial activity was observed for all extracts of A. brachypterus against S. pyogenes (15.0 - 16.3 mm inhibition zone). The aqueous extract of S. castagneanus showed the strongest antibacterial activity against S. pyogenes (14.3 mm). Furthermore, alcohol extracts (ethanol and methanol) of P.  russeliana exhibited moderate activity against S. epidermidis (9 and 8.5 mm, respectively) and S. pyogenes (9.5 mm). High antitumor activity was observed for all extracts of A. brachypterus (91.7 - 100 % tumor inhibition). In addition, ethanol extract of P. russeliana (75 % inhibition) exhibited strong antitumor activity.

Conclusion: The present study reveals the strong antibacterial and antitumor activities of A. brachypterus. However, the active components of the plant extracts needs to be identified in future studies.