Machaerium acutifolium lectin inhibits inflammatory responses through cytokine modulation

Helja lectin inhibits Candida albicans phagocytosis and induces pro-inflammatory responses in dendritic cells

BACKGROUND

Plant lectins have gained attention for their antimicrobial and immunomodulatory properties and potential therapeutic applications in controlling infectious diseases and inflammatory disorders.

PURPOSE

This study focused on the effect of the sunflower lectin Helja on Candida albicans phagocytosis and its immunomodulatory effects on dendritic cells, to explore alternative immunotherapeutic strategies to control infectious diseases.

RESULTS

Here, we showed that Helja lectin opsonizes and inhibits C. albicans phagocytosis by bone marrow-derived dendritic cells, induces dendritic cell maturation by upregulating co-stimulatory molecules, such as CD86 and MHC class II, promotes reactive oxygen species and nitric oxide generation and increases the production of the pro-inflammatory cytokines TNF-α, IL-12, and TGF-β. This cytokine profile was also observed in peripheral blood mononuclear cells, where Helja and C. albicans pre-incubated with the lectin promoted the release of TNF-α and IL-1β.

CONCLUSION

These findings suggest that Helja lectin has the potential to modulate dendritic cells and cytokine responses, indicating its role in immune regulation and underscoring the significance of this plant lectin as a potential therapeutic agent.

Novel LacdiNAc-specific lectin from Dioclea reflexa seeds exhibits inflammatory and hypernociceptive properties

Diocleinae lectins are well known for their prevalent affinity for glycomannosides. However, a rare subset displays specificity towards galactosides. This study describes the characterization of DrfL II, a novel lectin from Dioclea relexa seeds with specificity for N,N'-diacetyl-lactosamine (LacdiNAc). Isolated by lactose-affinity chromatography, DrfL II exists as a homotetramer formed by associations of a 29 kDa chainis a tetrameric lectin composed of identical 29 kDa subunits and strongly agglutinates rabbit erythrocytes, an activity inhibited by α-lactose. DrfL II binds preferentially to LacdiNAc (GalNAcβ1-4GlcNAc) over N-acetyl-lactosamine (LacNAc, Galβ1-4GlcNAc), functioning optimally between pH 6-8 and retaining stability up to 60 °C. Partial protein sequencing revealed homology with other legume lectins. Beyond its distinct carbohydrate specificity, DrfL II induced significant inflammatory and hypernociceptive responses in mice, as shown by paw edema and von Frey assays, while remaining non-toxic to Artemia nauplii. This finding expand our understanding of the galactoside-specific lectins within the Diocleinae subtribe, suggesting potential roles in physiological processes yet to be fully elucidated and potential biological application within the inflammation field.

From inflammation to immune regulation: The dual nature of dietary lectins in health and disease

Beans, vegetables, fruits, and mushrooms offer a delightful array of fragrances and an abundance of nutrients, including essential vitamins, minerals, protein rich in vital amino acids, and omega-3 fatty acids. However, they may also contain lectins, carbohydrate-binding proteins with potential health risks. While some lectins exhibit stability and resistance to digestion, posing threats to gastrointestinal integrity and immune function, others, such as those from butterfly peas and pink bauhinia, show immunomodulatory properties that could bolster immune responses. While some lectins, such as phytohemagglutinin, have been associated with inflammatory responses and autoimmune disorders, others, such as wheat lectin, have shown potential benefits in nutrient absorption. Additionally, mushroom lectins, while generally nontoxic, exhibit immunomodulatory properties with implications for immune health. Despite their potential benefits, challenges remain in understanding lectin dosages, administration routes, and mechanisms of action. Further research is needed to elucidate the intricate roles of dietary lectins in immune function and autoimmune disorders. This review surveys the immunomodulatory effects of dietary lectins from plants and mushrooms, shedding light on their mechanisms of action. From inflammation modulation to potential autoimmune implications, the diverse roles of dietary lectins have been explored, highlighting avenues for future investigations and therapeutic exploration.

Assessment of acute toxicity, genotoxicity, and anti-inflammatory activity of SteLL, a lectin from Schinus terebinthifolia Raddi. Leaves, in mice

ETHNOPHARMACOLOGY RELEVANCE

Schinus terebinthifolia Raddi (Anacardiaceae), known as Brazilian pepper tree, stands out as a medicinal plant widely used in traditional medicine. The leaves are popularly used as anti-inflammatory agent and to relieve inflammatory conditions such as bronchitis, ulcers, and wounds, for example.

AIM OF THE STUDY

The present study evaluated the acute toxicity, genotoxicity, and anti-inflammatory activity of S. terebinthifolia leaf lectin (SteLL) in mice (Mus musculus).

MATERIALS AND METHODS

In the acute toxicity assay, the animals were treated intraperitoneally (i.p.) or orally (per os) with a single dose of 100 mg/kg. Genotoxicity was assessed by the comet and micronucleus assays. Carrageenan-induced peritonitis and paw edema models were used to evaluate the anti-inflammatory effects of SteLL (1, 5 and 10 mg/kg, i.p.).

RESULTS

No animal died and no signs of intoxication or histopathological damage were observed in the acute toxicity assay. Genotoxic effect was not detected. In peritonitis assay, SteLL reduced in 56-69% leukocyte migration to the peritoneal cavity; neutrophil count decreased by 25-32%, while mononuclear cell count increased by 67-74%. SteLL promoted a notable reduction of paw edema after 4 h (61.1-63.4%). Morphometric analysis showed that SteLL also decreased the thickness of epidermal edema (30.2-40.7%). Furthermore, SteLL decreased MPO activity, plasma leakage, NO release, and modulated cytokines in both peritoneal fluid and paw homogenate.

CONCLUSION

SteLL did not induce acute toxicity or genotoxicity in mice and stands out as a promising candidate in the development of new phytopharmaceuticals with anti-inflammatory action.

In vitro antiproliferative effects of Vatairea macrocarpa (Benth.) Ducke lectin on human tumor cell lines and in vivo evaluation of its toxicity in Drosophila melanogaster

Tumor cells may develop alterations in glycosylation patterns during the initial phase of carcinogenesis. These alterations may be important therapeutic targets for lectins with antitumor action. This work aimed to evaluate the in vitro cytotoxicity of VML on tumor and non-tumor cells (concentration of 25 μg/mL and then microdiluted) and evaluate its in vivo toxicity at different concentrations (1.8, 3.5 and 7.0 μg/mL), using Drosophila melanogaster. Toxicity in D. melanogaster evaluated mortality rate, as well as oxidative stress markers (TBARS, iron levels, nitric oxide levels, protein and non-protein thiols). The cytotoxicity assay showed that VML had cytotoxic effect on leukemic lines HL-60 (IC50 = 3.5 μg/mL), KG1 (IC50 = 18.6 μg/mL) and K562 (102.0 μg/mL). In the toxicity assay, VML showed no reduction in survival at concentrations of 3.5 and 7.0 μg/mL and did not alter oxidative stress markers at any concentrations tested. Cytotoxicity of VML from HL-60, KG1 and K562 cells could arise from the interaction between the lectin and specific carbohydrates of tumor cells. In contrast, effective concentrations of VML against no-tumor cells human keratinocyte - HaCat and in the D. melanogaster model did not show toxicity, suggesting that VML is a promising molecule in vivo studies involving leukemic cells.

Lectin Purification through Affinity Chromatography Exploiting Macroporous Monolithic Adsorbents

Growing medical, engineering, biochemical, and biological interest has led to a steady pace of research and development into polymeric monolithic structures with densely interconnected pores for purifying bio compounds. Cryogels, which are generated by freezing a reactive polymerization mixture, are highlighted due to their versatility and low relative cost as macroporous, polymeric, monolithic adsorbents. The conversion of cryogels into affinity adsorbents is one possible alternative to their optimal application. Some of the most often utilized supports for immobilizing particular ligands are monolithic columns manufactured with epoxy radicals on their surfaces. The purification of biomolecules with a high degree of specificity, such as lectins and glycoproteins with an affinity for glycosylated groups, has garnered interest in the use of fixed non-traditional beds functionalized with ligands of particular interest. The interaction is both robust enough to permit the adsorption of glycoproteins and reversible enough to permit the dissociation of molecules in response to changes in the solution’s pH. When compared to other protein A-based approaches, this one has been shown to be more advantageous than its counterparts in terms of specificity, ease of use, and cost-effectiveness. Information on polymeric, macroporous, monolithic adsorbents used in the affinity chromatographic purification of lectins has been published and explored.

Ethyl Acetate Fraction of Bixa orellana and Its Component Ellagic Acid Exert Antibacterial and Anti-Inflammatory Properties against Mycobacterium abscessus subsp. massiliense

Mycobacterium abscessus subsp. massiliense (Mabs) causes chronic infections, which has led to the need for new antimycobacterial agents. In this study, we investigated the antimycobacterial and anti-inflammatory activities of the ethyl acetate fraction of Bixa orellana leaves (BoEA) and ellagic acid (ElAc). In silico analysis predicted that ElAc had low toxicity, was not mutagenic or carcinogenic, and had antimicrobial and anti-inflammatory activities. Apparently, ElAc can interact with COX2 and Dihydrofolate reductase (DHFR) enzymes, which could explain both activities. In vitro analysis showed that BoEA and ElAc exerted antimicrobial activity against Mabs (minimum inhibitory concentration of 1.56, 1.56 mg/mL and bactericidal concentration of 6.25, 3.12 mg/mL, respectively. Clarithromycin showed MIC and MBC of 1 and 6 µg/mL). Treatment with BoEA or ElAc increased survival of Tenebrio molitor larvae after lethal infection with Mabs and reduced carrageenan-induced paw edema in mice, around 40% of edema volume after the fourth hour, similarly to diclofenac. In conclusion, BoEA and ElAc exert antimicrobial effects against Mabs and have anti-inflammatory effects, making them potential sources of antimycobacterial drugs. The biological activities of ElAc may be due to its high binding affinities predicted for COX2 and DHFR enzymes.