Soybeans display strategic potential in food security as a source of protein and functional bioactives for human consumption. Polyphenols and other bioactive compounds can be recovered after an aqueous extraction from soybean meal, a byproduct of soy oil refining. The objective of the present study was to compile and quantify compounds from soybean oil refinery by-products, providing information about valuable bioactive phytochemicals, their bioaccessibility and potential bioactivities. Genistin, daidzin, glycitin and malonylgenistin were the predominant isoflavones, and the overall bioaccessibility of their glycosidic forms was of nearly 75%. Sixteen phenolics were identified and caffeic acid, 5-caffeoylquinic chlorogenic acid and hesperidin were the most predominant. Approximately 30% of gallic acid, syringic acid, vanillic acid and myricetin were released and the antioxidant capacity of aqueous extract was enhanced after simulated in vitro gastro intestinal digestion. The ability of aqueous soybean meal extract to inhibit lipid peroxidation was higher than natural and synthetic food antioxidants. Antimicrobial activity against several foodborne pathogens and antitumoral activity towards human glioblastoma cell line were also observed, but the aqueous extract showed no cytotoxicity to healthy murine cells. Compounds derived from the aqueous soybean meal extract have the potential to be used as health promoting agents.

The lectins, a class of proteins that occur widely in animals, plants, fungi, lichens and microorganisms, are known for their ability to specifically bind to carbohydrates. Plant lectins can be classified into 12 families including the Galanthus nivalis agglutinin (GNA)-related lectin superfamily, which is widespread among monocotyledonous plants and binds specifically to mannose, a behavior that confers remarkable anti-tumor, anti-viral and insecticidal properties on these proteins. The present study characterized a mitogenic lectin from this family, called tarin, which was purified from the crude extract from taro (Colocasia esculenta). The results showed that tarin is a glycoprotein with 2-3% carbohydrate content, composed of least 10 isoforms with pIs ranging from 5.5 to 9.5. The intact protein is a heterotetramer of 47kDa composed of two non-identical and non-covalently associated polypeptides, with small subunits of 11.9kDa and large subunits of 12.6kDa. The tarin structure is stable and recovers or maintains its functional structure following treatments at different temperatures and pH. Tarin showed a complex carbohydrate specificity, binding with high affinity to high-mannose and complex N-glycans. Many of these ligands can be found in viruses, tumor cells and insects, as well as in hematopoietic progenitor cells. Chemical modifications confirmed that both conserved and non-conserved amino acids participate in this interaction. This study determined the structural and ligand binding characteristics of a GNA-related lectin that can be exploited for several different purposes, particularly as a proliferative therapeutic molecule that is able to enhance the immunological response.

Lectins are proteins found in a wide range of organisms, with the ability to bind reversibly to specific carbohydrates. They can display important biological activities, such as the activation of the cell cycle in lymphocytes. Storage proteins with lectin activity have been reported in tuberous plant species, such as Colocasia esculenta, popularly known as taro. A simple strategy based on Cibacron Blue chromatography was used to purify a 12 kDa polypeptide 1.3-fold, with a recovery of 30 %. The purified protein was identified as tarin by mass spectrometry, which indicated that it was present in G1a/G1d isoforms. Tarin exhibited both agglutinating activity against hamster erythrocytes and mitogenic activity in vitro and in vivo toward mouse splenocytes. Optimum cellular proliferation in vitro was achieved by 625 ng of the crude extract or 500 ng of the purified tarin. Total mouse splenocyte proliferation measured after 5 days of intraperitoneal inoculation of purified tarin was increased 3.3-fold in comparison to the control group. Half of the proliferating cells were identified as B lymphocytes by flow cytometry. These results show that this is an efficient and simple strategy to purify tarin and aid in establishing this protein as a new therapeutic drug, able to promote cell proliferation in a murine model.

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Significant effort has been made world-wide to boost biofuels with the expectation of a positive contribution to renewable fuel and greenhouse gas reduction. Jatropha curcas L. has proved to be an opportunistic crop in tropical areas, particularly in unfavorable environments. For this reason, analyses of toxicity and allergy caused by its seeds and pollen are necessary. A 12kDa, allergenic 2S albumin, denoted Jat c 1, was isolated from Physic nut (J. curcas) seeds. Jat c 1 binds IgE attached to rat mast cells, inducing histamine release. It also showed strong cross-reactivity with the major allergens from castor bean, Ric c 1 and Ric c 3.

Leprosy is a chronic granulomatous disease caused by Mycobacterium leprae affecting the skin and peripheral nerves. Despite M. leprae invasion of the skin and keratinocytes importance in innate immunity, the interaction of these cells in vitro during M. leprae infection is poorly understood. Conventional and fluorescence optical microscopy, transmission electronic microscopy, flow cytometry and ELISA were used to study the in vitro interaction of M. leprae with the HaCaT human keratinocyte cell line. Keratinocytes uptake of M. leprae is described, and modulation of the surface expression of CD80 and CD209, cathelicidin expression and TNF-α and IL-1β production of human keratinocytes are compared with dendritic cells and macrophages during M. leprae interaction. This study demonstrated that M. leprae interaction with human keratinocytes enhanced expression of cathelicidin and greatly increased TNF-α production. The highest spontaneous expression of cathelicidin was by dendritic cells which are less susceptible to M. leprae infection. In contrast, keratinocytes displayed low spontaneous cathelicidin expression and were more susceptible to M. leprae infection than dendritic cells. The results show, for the first time, an active role for keratinocytes during infection by irradiated whole cells of M. leprae and the effect of vitamin D on this process. They also suggest that therapies which target cathelicidin modulation may provide novel approaches for treatment of leprosy.

We show in this study that long-term tolerance to allogeneic skin grafts can be established in the absence of immunosuppression by the combination of the following elements: 1) augmenting the frequency of regulatory CD4+CD25+ T cells (Treg) and 2) presentation of the allogeneic stimuli through linked recognition of allo- and self-epitopes on semiallogeneic F1 APCs. BALB/c spleen cells enriched for CD4+CD25+ T lymphocytes were transferred either to BALB/c nu/nu mice or to BALB/c nu/nu previously injected with F1(BALB/c × B6.Ba) spleen cells, or else grafted with F1(BALB/c × B6.Ba) skin (chimeric BALB/c nu/nu-F1). Chimeric BALB/c nu/nu-F1 reconstituted with syngeneic CD25+-enriched spleen cells were unable to reject the previously transferred F1(BALB/c × B6.Ba) spleen cells or F1(BALB/c × B6.Ba) skin grafts, and a specific tolerance to a secondary B6 graft was obtained, with rejection of third-party CBA grafts. BALB/c nu/nu mice reconstituted only with syngeneic CD25+-enriched spleen cells rejected both B6 and CBA skin grafts. In contrast, when chimeric BALB/c nu/nu-F1 were reconstituted with spleen populations comprising normal frequencies of Treg cells, the linked recognition of allo and self resulted in breaking of self tolerance and rejection of syngeneic grafts, strongly suggesting that linked recognition works in both directions, either to establish tolerance to allo, or to break tolerance to self, the critical parameter being the relative number of Treg cells.

The search for natural anticancer agents and nanocarrier uses are a part of the current strategies to overcome the side effects caused by chemotherapeutics. Liposomal nanocapsules loaded with purified tarin, a potential immunomodulatory and antitumoral lectin found in taro corms, were produced. Liposomes were composed by 1,2-dioleoyl-sn-glycerol-3-phosphoethanolamine, cholesterylhemisuccinate, and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[folate(polyethylene glycol)-2000 prepared by thin-film hydration. Small unilamellar vesicles were achieved by sonication and extrusion. Scanning electron microscopy evidenced round-shaped nanocapsules presenting a smooth surface, 150 nm diameter and polydispersity index <0.2, estimated by dynamic light scattering. Tarin entrapment rates were over 80% and leakage of ~3% under 40 days of storage at 4 °C. Entrapped tarin exhibited an 83% release after 6 h at pH 4.6–7.4 and 36 °C. Both free and encapsulated tarin exhibited no in vitro toxicity against healthy mice bone marrow and L929 cells but stimulated the production of fibroblast-like and large round-shaped cells. Encapsulated tarin resulted in inhibition of human glioblastoma (U-87 MG) and breast adenocarcinoma (MDA-MB-231) proliferation, with an IC50 of 39.36 and 71.38 µg/mL, respectively. The effectiveness of encapsulated tarin was similar to conventional chemotherapy drugs, such as cisplatin and temozolide. Tarin liposomal nanocapsules exhibited superior pharmacological activity compared to free tarin as a potential chemotherapy adjuvant.