Several species of Passiflora have been employed widely as a folk medicine because of sedative and tranquillizer activities. In this study, we evaluate the effects on anxiety and memory process of two popularly used Passiflora species. To this aim, male Wistar rats (weighing 250-300 g) were intraperitoneally injected with the aqueous extract of Passiflora alata or Passiflora edulis (25, 50, 100, or 150 mg/kg; single injection) 30 minutes prior to the elevated plus-maze test, inhibitory avoidance test, or habituation to an open-field apparatus. The effects of both species of Passiflora were compared with that of diazepam (1 mg/kg), a standard anxiolytic drug. Our findings revealed that, similar to diazepam, the treatment with P. alata (100 and 150 mg/kg) and P. edulis (50, 100, and 150 mg/kg) induced anxiolytic-like effects in rats. Memory was not affected by the treatment with any dose of P. alata or P. edulis, but diazepam disrupted memory process in rats. Phytochemical analysis showed that the content of flavonoids of the aqueous extract of P. edulis is almost twice that of P. alata. These differences in contents of flavonoids could explain the lower active doses of the aqueous extract of P. edulis in inducing anxiolytic-like effects compared to P. alata. In conclusion, our findings suggest that, distinct from diazepam, the aqueous extract of both species of Passiflora induced anxiolytic-like effects in rats without disrupting memory process.

Bauhinia belongs to the Caesalpinaceae, a plant family that comprises approximately 250 species.1) Native peoples from tropical regions use Bauhinia leaves and bark as medicine in infusions and other phytotherapic preparations. 2,3)Some native Bauhinia species in Brazil are known as "patade-vaca" (cow's hoof) and are widely used in folk medicine to treat various ailments, mainly infections and diabetes. Some reports have demonstrated positive effects on factors related to diseases and pathological states.2-5) Bauhinia microstachya (RADDI) MACBR. (Caesalpinaceae) is a creeper plant that occurs naturally in southern Brazil where is popularly known as "escada-de-macaco" (monkey's ladder). B. microstachya is often cultivated in small areas and its leaves are used as herbal antidiabetic medicine. Traditionally the leaf infusion or garrafada (a preparation with cachaça-the popular local sugar cane brandy-and leaves) is drunk after meals to help control blood sugar levels and other diabetic disorders. Phytochemical investigations with B. microstachya leaves have identified compounds such as steroidal glycosides, triterpenes, lactones and phenolic compounds, mainly flavonoids. [6][7][8] Plant phenolics form a large group of natural compounds, ubiquitous in the plant kingdom. It is known that these secondary metabolites display a remarkable array of biochemical interactions, probably due to antioxidant properties. 9)These substances may act as potent metal chelators and/or free radical scavengers, 10) however, it has been reported that the performance of these compounds in oxidative systems depends on activity-structure relationships.11,12) As an unfortunate consequence of aerobic life, free radicals and other reactive oxygen species (ROS) are formed by biological redox reactions.13) The role of free radicals reactions in biology and medicine has become an area of intense interest due to their relationship to chronic diseases.13) It is generally accepted that free radicals play an important role in the development of tissue damage and pathological events in living organisms.13) Lipids containing polyunsaturated fatty acids can be oxidized by free radical-mediated reactions. In addition, when oxygen is supplied in excess or their reduction is insufficient, this generates endogenous ROS imbalance with formation of hydroxyl ( · OH) and superoxide (O 2 · Ϫ ) radicals.13) In inflammation and endothelial damage, NO plays a major role as precursor of peroxynitrite (ONOO Ϫ ).14) If the endogenous response system, such as antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), is inadequate in scavenging ROS, damage to important macromolecules can be established and generate cellular oxidative stress.13) In addition, the non-enzymatic antioxidants (such as vitamin C, vitamin E and phenolic compounds found in a vegetable-rich diet) play a significant role in the physiological redox balance together with enzymatic defenses. 13)Considering the increasing interest in antioxidants, the potential antioxidant effects of pheno...