Antinociceptive and anti-inflammatory effects of a lectin-like substance from Clitoria fairchildiana R. Howard seeds.

Lectins are proteins that have the ability to bind specifically and reversibly to carbohydrates and glycoconjugates, without altering the structure of the glycosyl ligand. They are found in organisms such as viruses, plants and humans, and they have been shown to possess important biological activities. The objective of this study was to purify and characterize lectins in the seeds of Clitoria fairchildiana, as well as to verify their biological activities. The results indicated the presence of a lectin (CFAL) in the glutelin acid protein fraction, which agglutinated native rabbit erythrocytes. CFAL was purified by column chromatography ion-exchange, DEAE-Sephacel, which was obtained from a peak of protein retained in the matrix by applying 0.5 M NaCl using the step-wise method. Electrophoretic analysis of this lectin in SDS-PAGE indicated a two band pattern protein molecular mass of approximately 100 and 116 kDa. CFAL proved to be unspecific to all carbohydrates/glycoconjugates in common use for the sugar inhibition test. This lectin showed no significant cytotoxicity to human red blood cells. It was observed that CFAL has anti-inflammatory activity in the paw edema induced by carrageenan model, in which a 64% diminution in edema was observed. Antinociceptive effects were observed for CFAL in the abdominal writhing test (induced by acetic acid), in which increasing doses of the lectin caused reduction in the number of contortions by up to 72%. It was concluded that the purified and characterized lectin from the seeds of Clitoria fairchildiana has anti-inflammatory and antinociceptive activity, and is not cytotoxic to human erythrocytes.

Nutritional value and antinutritional factors of foliaceous vegetable Talinum fruticosum

Talinum fruticosum Juss (L.) is an unconventional plant belonging to the family Portulacaceae; it is a herbaceous perennial plant that grows in tropical regions as a foliaceous vegetable. T.fruticosum leaves area source of fiber and minerals and they contribute to assemble the micronutrients for daily nutritional requirements. These plants supply the essential nutrients to the human organism; however, these plants contain antinutritinal factors such as lectins and tannins which may compromise their bioavailability. In the present study, the T. fruticosum leaves samples were investigated on proximate composition and anti nutritional factors. Samples were exposed to heat treatment for washing and for cooking for 10 min. These procedures neither signifcantly changed the carbohydrates and lipids contents, nor eliminated the hemagglutinating activity which is inactivated at 70 °C, although no effective reduction of tannin from the leaves was observed.