Banca de QUALIFICAÇÃO: RICARDO BEZERRA COSTA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : RICARDO BEZERRA COSTA
DATE: 30/09/2022
TIME: 14:00
LOCAL: por videoconferência
TITLE:

PURIFICATION, CHARACTERIZATION AND EVALUATION OF ANTITUMORAL, ANTIMICROBIAL ACTIVITIES AND ON HEMOSTATIC PARAMETERS OF LECTINS FROM Genipa americana L. (JENIPAPO), Rhizophora mangle L. (RED MANGROVE) AND RED PROPOLIS FROM ALAGOAS

KEY WORDS:

cancer; anticoagulant; antifungal; protein; chromatography.

PAGES: 190
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUBÁREA: Química de Macromoléculas
SPECIALTY: Proteínas
SUMMARY:

The use of plant-derived products has great economic and pharmacological potential and this is due to the presence of bioactive compounds. Among these, lectins have been intensively explored due to the various biotechnological actions they may have, highlighting the antifungal, anticoagulant and antitumor activities. Thus, the present work aimed to purify, characterize and evaluate the antitumor, antimicrobial activity and on hemostatic parameters of lectins from Genipa americana L. (jenipapo), Rhizophora mangle L. (red mangrove) and red propolis from Alagoas. The lectins were initially isolated by extraction in Tris-Hcl 50mM pH 8.0, for seeds and husks of G. americana), NaCl 0.15M, for seeds of R. mangle, and 0.15M NaCl with 30% ethanol for red propolis. Then, saline fractionations were performed with ammonium sulfate. and the fractions that showed better activity were submitted to molecular exclusion chromatography (Sephacryl S-100), for isolation of lectins from G. americana bark (GaBL); molecular exclusion chromatography (Sephacryl S-100) followed by a cation exchanger (DEAE Sepharose) for G. americana seed lectin (GaSL); or chitin column chromatography to isolate R. mangle and red propolis lectins. Through a single chromatographic step, a lectin (GaBL) was isolated and by means of SDS-PAGE (10%) it was observed that GaBL has a molecular mass approximately 242.5 kDa. In the cytotoxic test GaBL was not toxic to 3T3 fibroblast cell lines at concentrations below 50μg/mL. The antitumor activity evaluated used human skin cancer cell lines (A431), melanoma (B16) and squamous cell carcinoma of the tongue (SCC9).Cell proliferation and cell migration were decreased in all strains evaluated in contact with 10 μg/ml of GaBL decreased the invasion of SCC9 cells. Apoptosis was higher in lectin-treated B16 and SCC9 cells. GaBL upregulation of E-cadherin and suppression of Col1A1 in all strains tested indicated a lower development of cancer. The G. americana seed lectin, GaSL, had its hemagglutinating activity (HA) strongly inhibited by rhamnose, but it was not affected by divalent ions or EDTA. GaSL is classified as a thermostable lectin, with best activity at a temperature below 80°C and in the pH range 5.0 to 6.0. The lectin from R. mangle seeds is also thermostable, but, unlike the others, it was more intensely inhibited by arabinose and casein, had better activity at pH 8.0 and 9, 0 and had its HA reduced in the presence of Mn2+, Mg2+ and Ca2+ ions, not altered by EDTA and stimulated in the presence of Zn2+. The propolis lectin was also strongly inhibited by casein, is thermostable, showed better HA in the pH range 5.0 to 6.0 and was reduced in the presence of Mn2+, Mg2+, slightly stimulated by Zn2+ and unaffected by EDTA and Ca2+. Thus, we can highlight that GaBL has high antitumor potential against head cancer. The other lectins have structural characteristics that favor the biotechnological study involving human health. slightly stimulated by Zn2+ and unaffected by EDTA and Ca2+. Thus, we can highlight that GaBL has high antitumor potential against head cancer. The other lectins have structural characteristics that favor the biotechnological study involving human health. slightly stimulated by Zn2+ and unaffected by EDTA and Ca2+. Thus, we can highlight that GaBL has high antitumor potential against head cancer. The other lectins have structural characteristics that favor the biotechnological study involving human health.

BANKING MEMBERS:
Externa ao Programa - 1120583 - EDMA CARVALHO DE MIRANDA
Presidente - 2089586 - FRANCIS SOARES GOMES
Interno - 3061390 - LEONARDO BROETTO
Interno - 1653558 - LUCIANO APARECIDO MEIRELES GRILLO
Externa ao Programa - 166.228.474-87 - SONIA SALGUEIRO MACHADO - UFAL