Post traumatic stress disorder (PTSD) is characterized by an inability to extinguish fear memories. If left untreated, PTSD typically follows a chronic, unremitting course culminating in significant impairments of psychological and emotional functioning. Current treatment approaches for PTSD generally yield only symptomatic improvement, thus other avenues must be explored. This thesis was aimed at investigating the use of a blend extract of a 1:1 Souroubea sympetala and Platanus occidentalis (Sycamore tree) as a potential novel treatment for PTSD, which may act by blocking the reconsolidation of fear memories. During reconsolidation, formed memories are rendered labile during reactivation, providing a window of opportunity for pharmacologically manipulating formed fear memories. In the present thesis, the efficacy of reconsolidation blockade of short-term (4h) as well as long term (24h and 9 days) fear memories through treatment with the blend extract (7mg/kg), diazepam (1mg/kg) and vehicle was measured through the Fear Potentiated Startle paradigm.