Banca de QUALIFICAÇÃO: VERONICA GIULIANI DE QUEIROZ AQUINO MARTINS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : VERONICA GIULIANI DE QUEIROZ AQUINO MARTINS
DATA : 21/03/2019
HORA: 08:30
LOCAL: Sala Carl Peter von Dietrich - Departamento de Bioquímica
TÍTULO:

Chemical characterization and Biologic activities from the extracts of Melocactus zehntneri (Britton & Rose)

PALAVRAS-CHAVES:

Crown-of-friar, extracts, antioxidant activity, antibiofilm, SPF

PÁGINAS: 95
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

In order to correlate the popular use of some species and to encourage the discovery of new active principles, cacti become objects for phytochemical and pharmacological studies. In this context, in the present work, six extracts were obtained from the cactus pulp from Melocactus zehntneri and the antioxidant and biological potentials were evaluated using in vitro and in vivo approaches. The extraction process was done serially from the lyophilized pulp, thus producing six extracts: hexane (HE), chloroform (CE), ethanol (EE), methanol (ME), final water (FWE) and one with water (WE). Then, sugar, protein and phenolic compounds were measured. The phytochemical screening suggested the presence of flavonoids, coumarins and steroid triterpenes like saponins. The presence of terpenes: ursolic and oleanolic acids, saponins, sugars (raffinose, fructose, sucrose and galactose), glycoproteins were observed in thin layer chromatography (CCD). In high performance liquid chromatography (HPLC) the presence of the classes of phenylpropanoids such as coumaric acids, benzoic acid, luteolin hesperidin and ellagic acid were suggested. Among the antioxidant assays were: Total Antioxidant Capacity (CAT), DPPH, Reducing Power Test, Iron and Copper Ion Chelation, Superoxide Ion Scavenging Test, Hydroxyl Radical Scavenging Activity. These assays allowed to verify that the extracts had an antioxidant activity in different concentrations (25, 50, 100, 250 and 500 μg / mL). The antioxidant activities were identified at the Iron Ion Chelation, DPPH, Superoxide Ion Scavenging and Radical Hydroxyl Scavenging assays. Furthermore, the antibiofilm activity against the bacterium Staphylococcus epidermidis 70D MRSE was evaluated. It was observed an inhibitory action on the formation of the biofilm in formation, where almost all extracts except chloroform (CE) promoted the biofilm inhibition. It is important to observe that the aqueous extract (WE) presented the best percentage of biofilm inhibition with approximately 90%. Another approach used was to verify the cytotoxicity of these extracts against the 3T3 cell line. It was not observed any significant cytotoxicity effect. Based on these results, it was analyzed the potential effect of protective activity from these extracts in the presence of hydrogen peroxide in the 3T3 cell line. It was observed in these experiments that the extracts presented a curative activity. Furthermore, it was also analyzed the potential photoprotective activity. The extracts HE and CE presented, respectively, the best values of sun protection factor (2,4 and 3,2). Therefore, the results showed the potential of these extracts to act as antioxidants, antibiofilm, curative activity and as additives in sunscreens.

MEMBROS DA BANCA:
Externa à Instituição - JAILMA ALMEIDA DE LIMA - CRI
Externa à Instituição - KATIA CRISTINA BORGES - UFRN
Presidente - 1720860 - VANESSA DE PAULA SOARES RACHETTI