ANTIOXIDANT ACTIVITY OF THREE SPECIES OF Arrabidaea

SÁNCHEZ, CYNTHIA NOELIA; TORRES, CAROLA ANALÍA; NUÑEZ, MARÍA BEATRIZ

Rosario

Encuentro; II Reunión Internacional de Ciencias Farmacéuticas; 2012

Facultad de Ciencias Bioquímicas y Farmacéuticas-Universidad Nacional de Rosario

The genus Arrabidaea belongs to the Bignoniaceae family, a large and morphologically diverse clade of neotropical lianas. The genus contains about 70 species, spread from Mexico to Argentina. The most of these species are used as ornamental for its size and its flowers. Some species from the genus have been used in traditional medicine for astringent, antioxidant, anti-inflammatory, antimicrobial, antitumor and healing purposes. The Brazilian indians use the leaves of Arrabidaea chica to treat symptoms of inflammations and skin affections, the tincture of leaves of this plant also is used as natural dye by guaranís of Misiones. However, there are no reports on the biological activity of many of these species growing in the northern region of Argentina. For this reason, we consider it important to take them as objects of study. Our research group has analyzed the polyphenol contents and antimicrobial activity of the selectioned species in previous studies, these reports have been submitted for publication. Sources of natural antioxidants are primarily, plant phenolics that may occur in all parts of plants such as fruits, vegetables, nuts, seeds, leaves, roots and barks. Many of these antioxidant compounds possess antiinflammatory, antiatherosclerotic, antitumor, antimutagenic, anticarcinogenic, antibacterial or antiviral activities to a greater or lesser extent. The aim of this work was to determine the antioxidant activity and free radical scavenging capacity of three species of Arrabidaea. The three plants selectioned were Arrabidaea caudigera (S. Moore) A.H. Gentry, A. chica (Humb. & Bonpl.) B. Verl y A. selloi (Spreng.) Sandwith. The plant material was collectioned from Misiones province, then was dried and pulverized. The extraction process was by maceration with ethanol 80° to obtain hydroalcoholic extract (tincture) and it was stored at -20 ° C. The total antioxidant activity of the samples was measured by ABTS radical cation decolorization assay according to the method of Re et al., 1999 described by Siddhuraju and Manian, 2007. Triplicate determinations were made at each dilution of the standard solution or the sample dilution. The percentage inhibition was calculated of the blank absorbance at 734 nm and then was plotted as a function of Trolox concentration. The unit of total antioxidant activity was defined as the concentration of Trolox equivalent antioxidant activity expressed as μM/ml of tincture. A. chica exhibited the highest antioxidant activity (30.67 ± 2.96 μM Trolox/mL extract), followed by A. caudigera (17.92 ± 2.63 μM Trolox/ml extract) and A. selloi (12.07 ± 1.88 μM Trolox/ml extract). These results would be relationed with the phenolic content already studied for these species. Also, it is known that many of these compounds with antioxidant capacity may have anti-inflammatory properties which would justify the popular use of A. chica. These results could indicate the promising antioxidant properties and provide also the first data of biological activity the A. caudigera and A. selloi.