Cultura de tecidos e análise do potencial antioxidante de Passiflora alata Curtis

Abstract

Passiflora alata Curtis, commonly known as sweet passion fruit, is one of the commercially cultivated species of the genus Passiflora, being consumed in natura due to its sweet taste. It is also used worldwide as an ornamental and in folk medicine. The goal of this work was the establishment of different strategies for in vitro culture of P.alata and the analysis of the production of antioxidant substances by in vitro materials, in comparison with in vivo-grown plants. Different treatments aiming at seed dormancy breakage were evaluated for in vitro or in vivo germination, in addition to the incubation of seeds under distinct types of light. For the establishment of primary cultures, shoot tips and nodal segments excised from plantlets derived from in vitro germination were cultured on MSM ½. Shoot elongation rate and number of nodes per shoot of the primary cultures were improved by adding coconut water to the medium. Plants derived from these cultures were used as sources of nodal, internodal and leaf explants. The morphogenic potential of decoated seeds was also evaluated. Friable calluses were induced from nodal and leaf segments in the presence of PIC, and those obtained from leaves on medium supplemented with 28.9 μM PIC were selected for the establishment of cell suspension cultures. After the development of different in vitro strategies for P. alata, leaves of in vivo plants were used for the evaluation of the distinct parameters affecting the extraction of antioxidant substances. The antioxidant potential was determined by the DPPH assay and total phenolic content of the extract was determined using the Folin- Ciocalteau method. Following the development of the extraction protocol, the antioxidant activity of the different in vitro materials was also evaluated. The antiradicalar efficiency varied among the culture systems, being directly proportional to the total phenolic content of the extracts. These results indicate that the strategies of in vitro culture of P. alata developed in this study represent an alternative to plant multiplication and production of phenolic substances with antioxidant action.