Antibacterial, antiprotozoal and antioxidant activity of five plants used in Izabal for infectious diseases.

Methanol and aqueous extracts from fi ve plant species, used in traditional medicine in Guatemala for the treatment of microbial infections, were tested in vitro for their ability to scavenge DPPH, OH(.) and O(2) (-) radicals and to inhibit lipoperoxidation (LPO) in order to establish a relationship between their antioxidant activities and their effects against infectious agents. Acalypha guatemalensis, Ocimum micranthum and Smilax spinosa possessed a significant activity against both the three free radicals assayed and LPO; Guazuma ulmifolia showed effects against DPPH and OH(.). Piper auritum showed no activity. These extracts were also evaluated for antibacterial and antiprotozoal activities. A. guatemalensis showed activity against Pseudomonas aeruginosa; S. spinosa was active against Salmonella typhi, and A. guatemalensis, and S. spinosa against Trypanosoma cruzi or Leishmania spp.