Biofilms are complex microbial communities embedded in a self-produced extracellular polymeric matrix. These structures confer increased resistance/tolerance to antimicrobial agents and immune responses, posing a serious challenge in both clinical and industrial contexts. In response to these challenges, increasing attention has been given to the development of novel antibiofilm strategies. Among the promising alternatives are lectins—carbohydrate-binding proteins. This review explores the structural and functional features of biofilms and critically discusses recent studies reporting the antibiofilm effects of lectins. Additionally, it addresses the main challenges and limitations surrounding the practical application of lectins to combat biofilms. Lectins from plants, animals, and microorganisms have shown potential to inhibit biofilm formation by disrupting the extracellular matrix, modulating quorum sensing, and affecting bacterial motility and metabolism. Additionally, they can eradicate established biofilms by degrading the matrix, killing or removing microbial cells, and/or preventing biofilm reformation. Together, the findings reviewed here support the continued investigation of lectins as potential agents against biofilm-associated infections as well as highlight the need to address existing gaps, such as the lack of in vivo studies and limited research on the structure–function relationships of lectins and their antibiofilm activity.

The lesser mealworm, Alphitobius diaperinus, is a widespread pest in poultry farming, causing economic losses and facilitating the spread of pathogens. Current control methods rely heavily on synthetic insecticides, which raise environmental concerns and contribute to resistance. This study investigated the insecticidal potential of Moringa oleifera seed preparations, including an aqueous extract (AE), a protein-enriched fraction (PF), and an isolated lectin (WSMoL), against A. diaperinus. Contact assays demonstrated that AE and PF reduced adult survival by up to 90% and 100%, respectively, while WSMoL was effective only against larvae, causing 48% mortality. Ingestion assays showed that AE and PF reduced adult survival by 60% and 30%, respectively; impaired diet utilization; and caused significant weight loss. WSMoL exhibited antinutritional effects, including a 94% reduction in trypsin-like activity, but did not cause lethality, although it may impair long-term survival. Midgut histological analysis revealed epithelial disorganization, vacuolization, and nuclear condensation in the treated insects. These findings suggest that M. oleifera seed preparations are promising candidates for sustainable pest control, offering both lethal and sublethal effects on A. diaperinus. Future research should focus on the development of formulations and long-term impact assessments on pest populations and non-target organisms, paving the way for eco-friendly alternatives in integrated pest management.

Diseases associated with yeast pathogens have become an increasingly serious global health issue. The range of virulence factors and the development of mechanisms of resistance have posed a significant challenge in the fight against these types of infections. Lectins, proteins capable of reversibly binding to carbohydrates and glycoconjugates, have been assessed as antifungal agents. This review shows that lectins have demonstrated versatility and significant potential as therapeutic agents against Candida, Nakaseomyces and Cryptococcus. These molecules act through diverse mechanisms, including disruption of fungal cell membranes, induction of oxidative stress, inhibition of ergosterol biosynthesis, and interference with mitochondrial and lysosomal functions. Some lectins have been shown to inhibit yeast-to-hyphae morphological transitions and biofilm formation, which are critical virulence factors for pathogenic yeasts. Moreover, some lectins have shown potential to enhance the efficacy of conventional antifungal drugs through synergistic interactions, though these effects can depend on the fungal isolate. Beyond in vitro activity, translational considerations remain underdeveloped in the context of antifungal applications of lectins. Some lectins exhibit minimal toxicity, while others require careful dosing due to potential toxicity or undesired immunogenicity. Delivery and stability also present challenges, though strategies such as chemical modifications and topical, mucosal, or nanoparticle-based formulations show promise. Overall, the multifaceted antifungal activities of lectins highlight their promising role as innovative candidates in the development of novel therapies to address the growing challenge of yeast pathogen resistance. However, significant knowledge gaps persist, highlighting the urgent need for coordinated research that bridges in vitro findings with practical pharmacological applications.

Schinus terebinthifolia Raddi. leaf lectin (SteLL) has been investigated for its neuromodulatory effects. Given the etiological diversity of depression, this study evaluated the effects of SteLL in a pharmacological model induced by reserpine. Mice were administered reserpine intraperitoneally for 10 days to induce anxiety- and depression-like symptoms. Before reserpine administration, animals also received SteLL (2 or 4 mg/kg, i.p.) or fluoxetine (10 mg/kg, i.p.) for 10 days. Behavioral assessments included the open field test, elevated plus maze, and tail suspension test. Body weight variation and brain levels of cytokines, noradrenaline, dopamine, and serotonin were also analyzed. In reserpine-treated mice, SteLL administration (2 and 4 mg/kg) produced anxiolytic-like effects in the open field (reduced number of rearings) and elevated plus maze (increased time spent in open arms) and significantly reduced immobility time in the tail suspension test. Additionally, SteLL prevented the body weight loss typically induced by reserpine. SteLL treatment modulated neuroinflammation by reducing IL-2 and increasing IL-10 levels in the brain. SteLL treatment restored dopaminergic and noradrenergic levels, with no effect on serotonin. In conclusion, SteLL was effective in reserpine-induced monoaminergic depletion, reversing behavioral and biochemical alterations characteristic of depression, likely through dopaminergic, noradrenergic, and anti-inflammatory mechanisms.