Eugenia uniflora (pitanga) juice as a new alternative vehicle for Limosilactobacillus fermentum ATCC 23271: evaluation of antioxidant and anti-infective effects.

Probiotic-containing foods are among the most appreciated functional foods; however, probiotic-based dairy products cannot be consumed by people who are lactose intolerant, allergic to milk, or vegetarian or vegan individuals. Thus, new non-dairy matrices have been tested for probiotics delivery. This study evaluated the growth and viability of Limosilactobacillus fermentum ATCC 23271 and Lacticaseibacillus rhamnosus ATCC 9595 in Pitanga juice (Eugenia uniflora L.). The effects of the fermentation on the antioxidant and anti-infective properties of the juice were also analyzed. The E. uniflora juice allowed lactobacilli growth without supplementation, reaching rates around 8.4 Log CFU/mL and producing organic acids (pH values < 4) after 72 h of fermentation. The strain remained viable after 35 days of refrigerated storage. Fermentation by these bacteria increases the antioxidant capacity of the juice. The central composite rotational design was employed to evaluate the effects of bacterial inoculum and pulp concentration on growth and organic acids production by L. fermentum ATCC 23271. The strain was viable and produced organic acids in all tested combinations. L. fermentum-fermented juice and its cell-free supernatant significantly increased the survival of Tenebrio molitor larvae infected by enteroaggregative Escherichia coli 042. The results obtained in this study provide more insights into the potential of Pitanga juice to develop a functional non-dairy probiotic beverage with antioxidant and anti-infective properties.

Development of gel containing Psidium glaziovianum essential oil has in vitro antimicrobial activity and improves healing of excisional wounds in mice.

Wounds encompass physical, chemical, biological, induced damages to the skin or mucous membranes. In wound treatment, combating infections is a critical challenge due to their potential to impede recovery and inflict systemic harm on patients. Previously, the essential oil extracted from Psidium glaziovianum (PgEO) demonstrated antinociceptive and anti-inflammatory attributes, along with negligible oral toxicity. Hence, our study aimed to assess the effects of topically applying a gel formulation containing PgEO to excisional wounds in mice. Additionally, an in vitro antimicrobial assessment was conducted. The formulated gel underwent characterization and toxicological evaluation on erythrocytes, as well as a dermal irritation test. Its antimicrobial activity was tested against both gram-positive and gram-negative bacteria, as well as fungi. Subsequently, an assessment of its efficacy in excisional wound healing was conducted in mice. The findings of this investigation highlight the gel's efficacy against both gram-positive and gram-negative bacteria, as well as fungi. Moreover, this study underscores that the PgEO-gel treatment enhances skin wound healing, potentially due to its capacity to trigger antioxidant enzymes and suppress pro-inflammatory cytokines. Furthermore, the gel exhibited minimal toxicity to erythrocytes and skin irritation. These findings hold promise for prospective preclinical and clinical trials across diverse wound types. In conclusion, this study sheds light on the potential therapeutic applications of the gel formulation containing essential oil from P. glaziovianum in the context of wound healing.

Water-soluble Moringa oleifera Seed Lectin Exhibits Monoaminergic Pathway-linked Anti-depressive-like Effects in Mice.

OBJECTIVES: The present study investigated the anti-depressive-like (anti-immobility) effect of a lectin from Moringa oleifera seeds (WSMoL) in mice. METHODS: To evaluate an acute effect, the animals were treated with WSMoL (1, 2, and 4 mg/kg, i.p.) 30 min before the tail suspension test (TST). To investigate the involvement of monoaminergic and nitrergic signaling, the mice were pre-treated with selective antagonists. The role of the WSMoL carbohydrate-recognizing domain (CRD) was verified using previous blockage with casein (0.5 mg/mL). The subacute anti-immobility effect was also evaluated by administering WSMoL (1, 2, and 4 mg/kg, i.p.) once a day for 7 d. Finally, an open field test (OFT) was performed to identify possible interferences of WSMoL on animal locomotory behavior. RESULTS: WSMoL reduced the immobility time of mice in the TST at all doses, and combined treatment with fluoxetine (5 mg/kg, i.p.) and WSMoL (1 mg/kg) was also effective. The CRD appeared to be involved in the anti-immobility effect since the solution of WSMoL (4 mg/kg) pre-incubated with casein showed no activity. The lectin effect was prevented by the pre-treatment of mice with ketanserin, yohimbine, and SCH 23390, thereby demonstrating the involvement of monoaminergic pathways. In contrast, pre-treatment with L-NAME, aminoguanidine, and L-arginine did not interfere with lectin action. WSMoL exhibited a subacute effect in the TST, thereby reducing immobility time and increasing agitation time even on the seventh day. OFT data revealed that the anti-immobility effect was not caused by interference with locomotor behavior. CONCLUSION: WSMoL elicits an anti-depressant-like effect that is dependent on monoaminergic signaling.

Microgramma vacciniifolia Frond Lectin: In Vitro Anti-leishmanial Activity and Immunomodulatory Effects Against Internalized Amastigote Forms of Leishmania amazonensis.

PURPOSE: The treatment of leishmaniasis, an anthropozoonosis caused by Leishmania protozoa, is limited by factors, such as adverse effects, toxicity, and excessive cost, which has highlighted the importance of novel drugs. In this context, natural products have been considered as sources of antileishmanial agents. This study investigated the leishmanicidal activity of Microgramma vacciniifolia frond lectin (MvFL) on promastigotes and amastigotes of Leishmania amazonensis. METHODS: The effects of MvFL on promastigote proliferation and macrophage infection by amastigotes were evaluated and mean inhibitory concentrations (IC50) were calculated. As a safety assessment, the hemolytic capacity of MvFL (6.25-200 µg/mL) against mouse and human erythrocytes was determined. Additionally, the ability of MvFL (6.25-100 µg/mL) to modulate lysosomal and phagocytic activities and the nitric oxide (NO) production by murine peritoneal macrophages was also investigated. RESULTS: After 24 h, MvFL inhibited the proliferation of L. amazonensis promastigotes, with an IC50 of 88 µg/mL; however, hemolytic activity was not observed. MvFL also reduced macrophage infection by amastigotes with an IC50 of 52 µg/mL. Furthermore, treatment with MvFL reduced the number of amastigotes internalized by infected murine peritoneal macrophages by up to 68.9% within 48 h. At a concentration of 25 µg/mL, MvFL stimulated lysosomal activity of macrophages within 72 h, but did not alter phagocytic activity or induce NO production at any of the tested concentrations. CONCLUSION: MvFL exerts antileishmanial activity and further studies are needed to assess its therapeutic potential in in vivo experimental models of leishmaniasis.

Toxicity and antitumor activity of the water-soluble lectin from Moringa oleifera Lam. Seeds (WSMoL) in sarcoma 180-bearing mice.

WSMoL, a water-soluble lectin from the seeds of Moringa oleifera, present several biological activities. This work aimed to evaluated the toxicity and antitumor activity of WSMoL. To analyze toxicity, it was determined hematological, biochemical and histological parameters; consumption of water and feed as well as the weight of the animals. Antitumor analysis included evaluation of tumor weight, histology and cytokine levels. Acute toxicity assay revealed 60% mortality of animals treated with lectin at 200 mg/kg i. p. At 100 mg/kg i. p., the animals showed a decreased food and water consumption as well weight gain in comparison with control. However, no animal died and there were no alterations in blood parameters or histological analysis. Antitumor activity evaluated at safe doses (2.5, 5 and 10 mg/kg) showed a significant reduction in tumor weight. Tumor photomicrographs evidenced that WSMoL treatment reduced dissemination of tumor cells. WSMoL (5 and 10 mg/kg) significantly enhance the immune function in the tumor environment as showed by increased the levels of pro-inflammatory (TNF-α, IFN-γ, IL-2, IL-6, and IL-17) and anti-inflammatory (IL-4 and IL-10) cytokines. In conclusion, WSMoL showed in vivo antitumor activity in mice bearing sarcoma 180 tumor, probably by increase the immune response against the tumor.

Pomegranate sarcotesta lectin (PgTeL) inhibits planktonic growth and disrupts biofilm formed by Cryptococcus neoformans.

AIMS: We investigated the putative fungistatic and fungicidal activities of pomegranate sarcotesta lectin (PgTeL) against Cryptococcus neoformans B3501 (serotype D), specifically the ability of PgTeL to inhibit yeast capsule and biofilm formation in this strain. METHODS AND RESULTS: PgTeL showed a minimum inhibitory concentration of 172.0 µg ml-1, at which it did not exhibit a fungicidal effect. PgTeL concentrations of 4.0-256.0 µg ml-1 reduced biofilm biomass by 31.0%-64.0%. Furthermore, 32.0-256.0 µg ml-1 PgTeL decreased the metabolic activity of the biofilm by 32.0%-93.0%. Scanning electron microscopy images clearly revealed disruption of the biofilm matrix. Moreover, PgTeL disrupted preformed biofilms. At concentrations of 8.0-256.0 µg ml-1, PgTeL reduced metabolic activity in C. neoformans by 36.0%-92.0%. However, PgTeL did not inhibit the ability of B3501 cells to form capsules under stress conditions. CONCLUSIONS: PgTeL inhibited biofilm formation and disrupted preformed biofilms, demonstrating its potential for use as an anticryptococcal agent.

Impairment of SK-MEL-28 Development-A Human Melanoma Cell Line-By the Crataeva tapia Bark Lectin and Its Sequence-Derived Peptides.

Melanoma is difficult to treat with chemotherapy, prompting the need for new treatments. Protease inhibitors have emerged as promising candidates as tumor cell proteases promote metastasis. Researchers have developed a chimeric form of the Bauhinia bauhinioides kallikrein inhibitor, rBbKIm, which has shown negative effects on prostate tumor cell lines DU145 and PC3. Crataeva tapia bark lectin, CrataBL, targets sulfated oligosaccharides in glycosylated proteins and has also demonstrated deleterious effects on prostate and glioblastoma tumor cells. However, neither rBbKIm nor its derived peptides affected the viability of SK-MEL-28, a melanoma cell line, while CrataBL decreased viability by over 60%. Two peptides, Pep. 26 (Ac-Q-N-S-S-L-K-V-V-P-L-NH2) and Pep. 27 (Ac-L-P-V-V-K-L-S-S-N-Q-NH2), were also tested. Pep. 27 suppressed cell migration and induced apoptosis when combined with vemurafenib, while Pep. 26 inhibited cell migration and reduced nitric oxide and the number of viable cells. Vemurafenib, a chemotherapy drug used to treat melanoma, was found to decrease the release of interleukin 8 and PDGF-AB/BB cytokines and potentiated the effects of proteins and peptides in reducing these cytokines. These findings suggest that protease inhibitors may be effective in blocking melanoma cells and highlight the potential of CrataBL and its derived peptides.

Electrochemical Characterization Using Biosensors with the Coagulant Moringa oleifera Seed Lectin (cMoL).

Triturated Moringa oleifera seeds have components that adsorb recalcitrant indigo carmine dye. Coagulating proteins known as lectins (carbohydrate-binding proteins) have already been purified from the powder of these seeds, in milligram amounts. The coagulant lectin from M. oleifera seeds (cMoL) was characterized by potentiometry and scanning electron microscopy (SEM) using MOFs, or metal-organic frameworks, of [Cu3(BTC)2(H2O)3]n to immobilize cMoL and construct biosensors. The potentiometric biosensor revealed an increase in the electrochemical potential resulting from the Pt/MOF/cMoL interaction with different concentrations of galactose in the electrolytic medium. The developed aluminum batteries constructed with recycled cans degraded an indigo carmine dye solution; the oxide reduction reactions of the batteries generated Al(OH)3, promoting dye electrocoagulation. Biosensors were used to investigate cMoL interactions with a specific galactose concentration and monitored residual dye. SEM revealed the components of the electrode assembly steps. Cyclic voltammetry showed differentiated redox peaks related to dye residue quantification by cMoL. Electrochemical systems were used to evaluate cMoL interactions with galactose ligands and efficiently degraded dye. Biosensors could be used for lectin characterization and monitoring dye residues in environmental effluents of the textile industry.

Fluorescent nanoprobes based on quantum dots conjugated to Cramoll to assess surface carbohydrates of Aeromonas spp.

The association of quantum dots (QDs) to carbohydrate-binding proteins - lectins - has revealed novel biotechnological strategies for glycobiology studies. Herein, carboxyl-coated QDs were conjugated by adsorption to Cramoll, a glucose/mannose lectin obtained from Cratylia mollis seeds. Then, the conjugates were optically characterized and used to evaluate the surface carbohydrate profiles of four Aeromonas species isolated from the tambaqui fish (Colossoma macropomum). All the Aeromonas cells were labeled by the conjugate. Inhibition assays with methyl-α-D-mannopyranoside and mannan were performed to confirm the labeling specificity. Cramoll-QDs conjugates presented high brightness and showed similar absorption and emission profiles compared to bare QDs. According to the labeling pattern of Aeromonas spp. by the conjugate, results suggested that A. jandaei and A. dhakensis strains may harbor a higher content of more complex glucose/mannose surface glycans, with more available sites for Cramoll-QDs interaction, than A. hydrophila and A. caviae. Noteworthy, the Cramoll-QDs conjugates demonstrated to be potential tools for bacterial characterization based on superficial carbohydrate detection.

Saline extract of Portulaca elatior leaves with photoprotective and antioxidant activities does not show acute oral and dermal toxicity in mice.

The present study aimed to evaluate saline extracts from the leaves (LE) and stem (SE) of Portulaca elatior in relation to their phytochemical composition and photoprotective and antioxidant effects, as well as to evaluate the toxicity of the leaf extract. The extracts were characterized for protein concentration and phenol and flavonoid contents, as well as for thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) profiles. Total antioxidant capacity and DPPH and ABTS+ scavenging activities were determined. In the photoprotective activity assay, the sun protection factor (SPF) was calculated. The toxicity evaluation of LE included in vitro hemolytic assay and in vivo oral and dermal acute toxicity assays in Swiss mice. LE showed the highest protein, phenol, and flavonoid (8.79 mg/mL, 323.46 mg GAE/g, and 101.96 QE/g, respectively). TLC revealed the presence of flavonoids, reducing sugars, terpenes, and steroids in both extracts. In HPLC profiles, LE contained flavonoids, while SE contained flavonoids and ellagic tannins. The antioxidant activity assays showed the lowest IC50 values ​(34.15-413.3 µg/mL) for LE, which presented relevant SPF (> 6) at 50 and 100 µg/mL. LE demonstrated low hemolytic capacity, and no signs of intoxication were observed in mice treated orally or topically at 1000 mg/kg. However, at 2000 mg/kg, an increase in the mean corpuscular volume of erythrocytes and a reduction in lymphocytes were observed; animals treated topically with 2000 mg/kg displayed scratching behavior during the first hour of observation and showed edema and erythema that regressed after six days. In conclusion, LE did not present acute oral or dermal toxicity in Swiss mice at a dose of 1000 mg/kg and showed slight toxicity in animals treated with 2000 mg/kg. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-022-00160-2.

Purification, Characterization, and Assessment of Antimicrobial Activity and Toxicity of Portulaca elatior Leaf Lectin (PeLL).

Lectins are carbohydrate-binding proteins with several bioactivities, including antimicrobial properties. Portulaca elatior is a species found at Brazilian Caatinga and data on the biochemical composition of this plant are scarce. The present work describes the purification of P. elatior leaf lectin (PeLL) as well as the assessment of its antimicrobial activity and toxicity. PeLL, isolated by chromatography on a chitin column, had native liquid charge and subunit composition evaluated by electrophoresis. Hemagglutinating activity (HA) of PeLL was determined in the presence of carbohydrates or divalent cations, as well as after heating and incubation at different pH values. Changes in the lectin conformation were monitored by evaluating intrinsic tryptophan fluorescence and using the extrinsic probe bis-ANS. Antimicrobial activity was evaluated against Pectobacterium strains and Candida species. The minimal inhibitory (MIC), bactericidal (MBC), and fungicidal (MFC) concentrations were determined. Finally, PeLL was evaluated for in vitro hemolytic activity in human erythrocytes and in vivo acute toxicity in mice (5 and 10 mg/kg b.w. per os). PeLL (pI 5.4; 20 kDa) had its HA was inhibited by mannose, galactose, Ca2+, Mg2+, and Mn2+. PeLL HA was resistant to heating at 100 °C, although conformational changes were detected. PeLL was more active in the acidic pH range, in which no conformational changes were observed. The lectin presented MIC and MBC of 0.185 and 0.74 µg/mL for all Pectobacterium strains, respectively; MIC of 1.48 µg/mL for C. albicans, C. tropicalis, and C. krusei; MIC and MFC of 0.74 and 2.96 µg/mL for C. parapsilosis. No hemolytic activity or signs of acute toxicity were observed in the mice. In conclusion, a new, low-toxic, and thermostable lectin was isolated from P. elatior leaves, being the first plant compound to show antibacterial activity against Pectobacterium.

Schinus terebinthifolia leaf lectin has central and peripheral antinociceptive action mediated by its carbohydrate-recognition domain and delta-opioid receptors.

ETHNOPHARMACOLOGICAL RELEVANCE: Preparations from the bark and leaves of Schinus terebinthifolia Raddi are commonly used to treat toothaches and sore throats. The use of medications based on leaves of this plant has also been reported for pain of arthritis, toothache, and sore throat. Some evidence indicated that the lectin SteLL is an antinociceptive agent from leaves. AIM OF THE STUDY: This study evaluated the antinociceptive activity of S. terebinthifolia leaf lectin (SteLL) using mouse models of peripheral and central nociception. MATERIALS AND METHODS: Animals were treated intraperitoneally with SteLL at 1, 5, and 10 mg/kg. An acetic acid-induced abdominal writhing test was performed to screen for the antinociceptive effect of the lectin. Next, the formalin test was used to assess the effects of SteLL on neurogenic (first phase) and inflammatory (second phase) pain, as well as to investigate the involvement of the carbohydrate-recognition domain (CRD) of SteLL and opioid receptors in the antinociceptive effect. The tail immersion test was performed to assess the central antinociception. Additionally, a rotarod test was performed to evaluate the effects of lectin on motor coordination in mice. RESULTS: SteLL reduced the number of acetic acid-induced writhes by 83.5-100.0%. In the first phase of the formalin test, SteLL reduced paw licking time by 49.4-50.5%, while in the second phase, SteLL reduced paw licking time by 80.5-82.6%. This antinociceptive effect was reversed by the previous incubation of the lectin with ovalbumin (indicating the possible involvement of the CRD) and by the administration of naloxone, a nonselective opioid receptor antagonist. When testing selective antagonists of opioid receptors (µ, δ, and κ), only naltrindole, a selective δ receptor antagonist, blocked the antinociceptive action of SteLL during the second phase of the formalin test. In the tail immersion test, SteLL (1, 5, and 10 mg/kg) administration reduced sensitivity to thermal stimulus, which was observed even after 2 h. SteLL (10 mg/kg) did not affect animal motor coordination in rotarod test when compared to the control group. CONCLUSION: SteLL has peripheral and central analgesic action involving opioid receptor modulation without affecting the motor coordination of animals. These results provide new perspectives for developing analgesic agents using lectins.

The Anxiolytic Activity of Schinus terebinthifolia Leaf Lectin (SteLL) Is Dependent on Monoaminergic Signaling although Independent of the Carbohydrate-Binding Domain of the Lectin.

The potential of plant lectins (carbohydrate-binding proteins) for the treatment of neurological disorders such as anxiety and depression has started to be reported in the last few years. Schinus terebinthifolia leaves contain a lectin called SteLL, which has displayed antimicrobial, immunomodulatory, antitumor, and analgesic activities. However, the effects of SteLL on the Central Nervous System (CNS) have not yet been determined. In this study, we investigated the in vivo anxiolytic effect of SteLL in mice using the open field (OF) and elevated plus maze (EPM) tests. In the OF, SteLL (1, 2, and 4 mg/kg, i.p.) did not interfere with the number of crossings but significantly reduced the number of rearings. In the EPM, SteLL 4 mg/kg and the combination SteLL (1 mg/kg) plus diazepam (1 mg/kg) significantly increased the time spent in the open arms while reducing the time spent in the closed arms. The anxiolytic effect of SteLL did not seem to be dependent on the carbohydrate-binding domain of the lectin. Nevertheless, the SteLL effect in the EPM was reversed by the pretreatment with the pharmacological antagonists of the α2-adrenoceptor, 5-HT2A/2C serotonin receptor, and the D1 dopamine receptor. Overall, our results suggest that the anxiolytic effect of SteLL is dependent on the monoaminergic signaling cascade.

Schinus terebinthifolius Leaf Lectin (SteLL) Reduces the Bacterial and Inflammatory Burden of Wounds Infected by Staphylococcus aureus Promoting Skin Repair.

Staphylococcus aureus is commonly found in wound infections where this pathogen impairs skin repair. The lectin isolated from leaves of Schinus terebinthifolius (named SteLL) has antimicrobial and antivirulence action against S. aureus. This study evaluated the effects of topical administration of SteLL on mice wounds infected by S. aureus. Seventy-two C57/BL6 mice (6−8 weeks old) were allocated into four groups: (i) uninfected wounds; (ii) infected wounds, (iii) infected wounds treated with 32 µg/mL SteLL solution; (iv) infected wounds treated with 64 µg/mL SteLL solution. The excisional wounds (64 mm2) were induced on the dorsum and infected by S. aureus 432170 (4.0 × 106 CFU/wound). The daily treatment started 1-day post-infection (dpi). The topical application of both SteLL concentrations significantly accelerated the healing of S. aureus-infected wounds until the 7th dpi, when compared to untreated infected lesions (reductions of 1.95−4.55-fold and 1.79−2.90-fold for SteLL at 32 µg/mL and 64 µg/mL, respectively). The SteLL-based treatment also amended the severity of wound infection and reduced the bacterial load (12-fold to 72-fold for 32 µg/mL, and 14-fold to 282-fold for 64 µg/mL). SteLL-treated wounds show higher collagen deposition and restoration of skin structure than other groups. The bacterial load and the levels of inflammatory markers (IL-6, MCP-1, TNF-α, and VEGF) were also reduced by both SteLL concentrations. These results corroborate the reported anti-infective properties of SteLL, making this lectin a lead candidate for developing alternative agents for the treatment of S. aureus-infected skin lesions.

Evaluation of acute toxicity, 28-day repeated dose toxicity, and genotoxicity of Moringa oleifera leaves infusion and powder.

ETHNOPHARMACOLOGICAL RELEVANCE: Moringa oleifera Lam. leaves infusion and powder are widely used by population due the nutritional and medicinal potentials, however data regarding safety of use are still inconclusive, leading to prohibition of this plant in some countries. AIM OF THE STUDY: The present work investigated the nutritional and phytochemical composition, acute and 28-day repeated dose toxicity, and genotoxicity of M. oleifera leaves infusion and powder. MATERIALS AND METHODS: For nutritional characterization of leaf powder, it was determined: humidity; mineral residue (ash); total lipid, protein, carbohydrate, and crude fiber contents; and total caloric value. Phytochemical composition was determined by high performance liquid chromatography (HPLC). The acute toxicity assay used Swiss female albino mice and oral administration in a single dose at 2000 and 5000 mg/kg of infusion or powder. The 28-day repeated dose toxicity assay employed female and male mice, with oral administration of infusion or powder at the doses 250, 500 and 1000 mg/kg. The animals were evaluated for body weight, water and feed consumption, biochemical and hematological parameters, and histology of the liver, spleen, and kidneys. In vivo genotoxicity and mutagenicity (2000 mg/kg) were evaluated by the comet assay and the micronucleus test, respectively. RESULTS: Nutritional characterization confirmed that M. oleifera leaves are rich in proteins, carbohydrates, lipids, minerals, and fiber. HPLC indicated the presence of flavonoids and cinnamic derivatives as major polyphenols. Acute toxicity did not reveal alterations in weight gain and water and feed consumptions and no change in biochemical, hematological, and histological parameters. Behavior alterations was observed in the first 2 h after administration at 5000 mg/kg in both treatments. Infusion did not present toxicity when administered for 28 days. Conversely, the powder at 500 and 1000 mg/kg promoted liver and kidney damages observed through biochemical parameters and histopathology. Genotoxicity and mutagenicity were not detected at 2000 mg/kg. CONCLUSIONS: The present study reveals that M. oleifera leaves are an important source of polyphenols and nutrients. Indiscriminate use of both infusion and crude leaf powder above 2000 mg/kg and powder at 500 and 1000 mg/kg are not recommended. Chronic toxicological studies and establishment of preparation protocols are suggested aiming to guarantee the safety in the use of M. oleifera leaves as nutraceutical by population.

Myracrodruon urundeuva leaf lectin damages exochorionic cells and binds to the serosal cuticle of Aedes aegypti eggs.

In recent years, lectins have been identified as alternative agents against Aedes aegypti during the aquatic phases of its life cycle. For example, chitin-binding lectin from Myracrodruon urundeuva leaf (MuLL) can function as a larvicide. In this study, we investigated whether MuLL can also act as an ovicide against this insect. Aedes aegypti eggs were incubated with MuLL for 72 h to determine the concentration at which the hatching rate reduces by 50% (EC50). The effects of MuLL on the egg surface structure were evaluated using scanning electron microscopy (SEM), and the possible interaction of MuLL with the internal structures of eggs and embryos was investigated using MuLL-fluorescein isothiocyanate (FITC) conjugate. MuLL acted as an ovicidal agent with an EC50 of 0.88 mg/mL. The SEM analysis revealed that eggs treated with MuLL for 24 and 48 h no longer had tubercles and did not show a well-defined exochorionic network. In addition, deformation and degeneration of the surface were observed after 72 h. Fluorescence microscopy showed that MuLL penetrated the eggs 48 h after incubation and was detected in the upper portion of the embryo's gut. After 72 h, MuLL was observed in the serosal cuticle and digestive tract. In conclusion, MuLL can function as an ovicidal agent against A. aegypti through damage to the surface and internal structures of the eggs.

Inhibition of Carrageenan-Induced Acute Inflammation in Mice by the Microgramma vacciniifolia Frond Lectin (MvFL).

Most anti-inflammatory drugs used nowadays have an excessive cost and their prolonged use has been connected with several injurious effects. Thus, the search for new anti-inflammatory agents is increasing. Lectins are carbohydrate-interacting proteins that can modulate immune response and the release of inflammation mediators. The Microgramma vacciniifolia frond lectin (MvFL) was previously reported to be an immunomodulatory agent in vitro. This work aimed to evaluate the effects of MvFL on the in vivo inflammatory status in the carrageenan-induced peritonitis and paw edema, using female Swiss mice. The animals were pretreated intraperitoneally with MvFL (5 and 10 mg/kg). In the peritonitis assay, the total and differential migration of white blood cells was evaluated, as well as the levels of cytokines, nitric oxide (NO), and total proteins in the peritoneal fluid. In the paw edema evaluation, the paw volume was measured in the early (from 30 min-2 h) and late (3-4 h) phases of edema formation. MvFL (5 and 10 mg/kg) was efficient in reducing neutrophil infiltration, pro-inflammatory cytokines (IL-6, IL-17, and TNF-α), NO, and protein content in the peritoneal fluid. It also repressed the edema formation in the late phase of the assay. In conclusion, MvFL showed inhibitory effects in in vivo acute inflammation, which encouraged future studies exploiting its immunomodulatory ability.

Antibacterial and antitumor activities of a lectin-rich preparation from Microgramma vacciniifolia rhizome.

The rhizome of Microgramma vacciniifolia contains a lectin (carbohydrate-binding protein) called MvRL. Studies demonstrated that a MvRL-rich fraction did not show in vivo genotoxicity and acute toxicity in mice. This study aimed to evaluate the MvRL-rich fraction from M. vacciniifolia rhizome for antibacterial activity in vitro and in vivo as well as antitumor effect in vivo using the Ehrlich carcinoma model in mice. The fraction showed antibacterial activity against Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus with minimal inhibitory concentrations ranging from 31.2 to 125.0 â€‹µg/mL and minimal bactericidal concentrations from 62.5 to 200 â€‹µg/mL. The fraction was also effective in vivo against infection caused by these bacteria on Tenebrio molitor larvae considering the parameters evaluated. In regard to the antitumor activity, the treatments of Ehrlich carcinoma-bearing mice with the fraction at 100 and 200 â€‹mg/kg per os resulted in 62.58% and 75.43% of tumor inhibition, respectively. In conclusion, the MvRL-rich fraction showed in vivo antibacterial and antitumor activities and thus can be considered as an alternative of natural origin for the development of candidates for therapy.

Flavonoid-Rich Fraction from Croton blanchetianus (Euphorbiaceae) Leaves Exerts Peripheral and Central Analgesic Effects by Acting via the Opioid and Cholinergic Systems.

The ethanolic extract from Croton blanchetianus leaves has been shown to have antinociceptive activity in mice. Here, we investigated the antinociceptive activity of an ethyl acetate fraction (EAF) from this extract in mice and the possible pathways involved in the analgesic effect. Adverse effects on behavior and motor coordination were also evaluated. The EAF was characterized by liquid chromatography coupled with mass spectrometry and evaluated (12.5, 25, and 50 mg/kg per os) in the acetic acid-induced abdominal writhing, formalin, hot plate, and tail immersion assays. Naloxone, atropine, glibenclamide, prazosin, or yohimbine was pre-administered to mice to investigate the involved pathways in the formalin test. The open-field, rotarod, and elevated plus-maze tests were used to assess behavior and locomotion. The main components of the EAF were quercetin-3-O-(2-rhamnosyl) rutinoside, hyperoside, quercetin rutinoside pentoside, and quercetin hexoside deoxyhexoside. EAF showed antinociceptive effects in all models and was effective against both neurogenic and inflammatory pain. The reversion of the effects in the formalin test by naloxone and atropine revealed that the EAF acted via the opioid and cholinergic systems. In the open-field test, the behavior of the animals treated with the EAF was like that of control, except at the highest dose, when hypnosis, eyelid ptosis, decreased walking, hygiene, and rearing behaviors were observed. No muscle relaxant effect was observed, but an anxiogenic effect was observed at all doses. This study provides new scientific evidence on the pharmacological properties of C. blanchetianus leaves and their potential for the development of phytomedicines with analgesic properties.

Insecticidal activity of the essential oil of Piper corcovadensis leaves and its major compound (1-butyl-3,4-methylenedioxybenzene) against the maize weevil, Sitophilus zeamais.

BACKGROUND: Sitophilus zeamais is one of the most economically impactful pests, attacking various grains and processed foods. Control of this insect has been achieved using synthetic insecticides, exacerbated and careless use of which has led to the development of resistant insect populations, toxicity to non-target organisms and environmental contamination. In this study, Piper corcovadensis leaf essential oil (PcLEO) and its major compound, 1-butyl-3,4-methylenedioxybenzene (BMDB), were investigated as alternative insecticidal agents against S. zeamais. RESULTS: Characterization of PcLEO showed the presence of 40 compounds. The major components were the phenylpropanoid BMDB (35.77%) and the monoterpenes α-pinene (14.95%) and terpinolene (6.23%). PcLEO and BMDB were toxic by fumigation (half-maximal lethal concentration [LC50 ]: 9.46 and 0.85 µl L-1 of air, respectively), by contact (half-maximal lethal dose [LD50 ]: 9.38 and 6.16 µg g-1 of insect, respectively) and ingestion (LC50 : 16.04 and 14.30 mg g-1 , respectively). In the ingestion test, both PcLEO and BMDB promoted the loss of insect biomass and had a strong deterrent effect. In addition, both were able to inhibit trypsin and α-amylase activities. CONCLUSION: PcLEO and BMDB exhibited insecticidal activity against S. zeamais, with a toxic effect by fumigation, contact and ingestion, in addition to food deterrence and inhibiting trypsin and α-amylase activities, suggesting their potential for use in the control of this pest.