RESUMO
As they manifest specifically and reversibly, lectins are proteins or glycoproteins with the characteristic of agglutinating erythrocytes. Given that grain legume lectins can represent 10% of protein content and can have various biological functions, they are extensively studied. The objective of this work was to purify and partially characterize the lectins of Phaseolus vulgaris black, var surco and vara (LBBS and LBBV). Both lectin types were purified by affinity chromatography on stroma matrix, which agglutinated human erythrocytes type A, B, and O, as well as rabbit, hamster, pig, and chicken erythrocytes. Native-PAGE was employed for molecular mass determination, yielding 109.36 and 112.68 kDa for BBS and BBV, respectively. Further analyses revealed that these lectins are tetrameric glycoproteins that require Ca+2, Mn+2 and Mg+2 ions for exhibiting their hemagglutinating function, which can be inhibited by fetuin. Moreover, optimal pH was established for both lectins (10.5 for LBBS and 7-9 for LBBV), while their activity was temperature-dependent and ceased above 70 °C. Finally, the observed differences in the biochemical characteristics and bioactive functions were ascribed to the different physiological characteristics of each seed, as well as the protein itself.
Assuntos
Phaseolus , Humanos , Coelhos , Suínos , Animais , Phaseolus/química , Lectinas/química , Sementes/química , Cromatografia de Afinidade , Eritrócitos/metabolismo , Glicoproteínas/análise , Lectinas de Plantas/farmacologiaRESUMO
According to the available ethnobotanical data, the Bouvardia ternifolia plant has long been used in Mexican traditional medicine to relieve the symptoms of inflammation. In the present study, the cytotoxic effect of extracts obtained from the flowers, leaves and stems of B. ternifolia using hexane, ethyl acetate (AcOEt) and methanol (MeOH) was evaluated by applying them to the SiHa and MDA-MB-231 cancer cell lines. An MTT reduction assay was carried out along with = biological activity assessments, and the content of total phenols, tannins, anthocyanins, betalains and saponins was quantified. According to the obtained results, nine extracts exhibited a cytotoxic effect against both the SiHa and MDA lines. The highest cytotoxicity was measured for leaves treated with the AcOEt (ID50 of 75 µg/mL was obtained for MDA and 58.75 µg/mL for SiHa) as well as inhibition on ABTSâ¢+ against DPPH⢠radical, while MeOH treatment of stems and AcOEt of flowers yielded the most significant antioxidant capacity (90.29% and 90.11% ABTSâ¢+ radical trapping). Moreover, the highest phenolic compound content was measured in the stems (134.971 ± 0.294 mg EAG/g), while tannins were more abundant in the leaves (257.646 mg eq cat/g) and saponins were most prevalent in the flowers (20 ± 0 HU/mg). Screening tests indicated the presence of flavonoids, steroids, terpenes and coumarins, as well as ursolic acid, in all the studied extracts. These results demonstrate the biological potential of B. ternifolia.
RESUMO
Amaranth seeds, although a valuable food in Mexico, contain anti-nutritional compounds that can affect food quality. As a part of this work, the proximate composition, fatty acid profile, protein digestibility, and the effect of germination and popping of Amaranthus hypochondriacus seeds was analyzed with the aim of eliminating anti-nutritional compounds. Untreated seeds comprised of 11.35-18.8% protein and 0.27-13.39% lipids, including omega 3, 6, and 9 fatty acids such as oleic, linoleic, linolenic, and arachidonic acid. The main minerals detected were Ca+2, K+1, and Mg+2. Nevertheless in vitro studies indicate that germination significantly improved digestibility, whereby treatments aimed at reducing anti-nutritional compounds decreased lectin concentration, while significantly increasing tannins and completely eliminating trypsins and saponins.
RESUMO
Bauhinia forficata L. is a tree used in alternative medicine as an anti-diabetic agent, with little scientific information about its pharmacological properties. The hypoglycemic, antioxidant, and genoprotective activities of a methanolic extract of B. forficata leaves and stems combined were investigated in mice treated with streptozotocin (STZ). Secondary metabolites were determined by qualitative phytochemistry. In vitro antioxidant activity was determined by the DPPH method at four concentrations of the extract. The genoprotective activity was evaluated in 3 groups of mice: control, anthracene (10 mg/kg), and anthracene + B. forficata (500 mg/kg) and the presence of micronuclei in peripheral blood was measured for 2 weeks. To determine the hypoglycemic activity, the crude extract was prepared in a suspension and administered (500 mg/kg, i.g.) in previously diabetic mice with STZ (120 mg/kg, i.p.), measuring blood glucose levels every week as well as the animals' body weight for six weeks. The extract showed good antioxidant activity and caused a decrease in the number of micronuclei. The diabetic mice + B. forficata presented hypoglycemic effects in the third week of treatment, perhaps due to its secondary metabolites. Therefore, B. forficata is a candidate for continued use at the ethnomedical level as an adjuvant to allopathic therapy.