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.

Essential oil from leaves of Croton blanchetianus Baill does not present acute oral toxicity, has antigenotoxic action and reduces neurogenic and inflammatory nociception in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Croton blanchetianus Baill., popularly known as "marmeleiro preto", is an endemic plant from Brazil, being found mainly in the Northeast region. In traditional medicine, the use of medicines based on the leaves of this plant has been reported for the treatment of inflammatory processes, pain, urethral pain, gastrointestinal disorders, rheumatism and headache.

AIM OF THE STUDY

The present work describes the chemical characterization, as well as toxicological evaluation and antinociceptive activity of an essential oil of C. blanchetianus leaves (EOCb).

MATERIALS AND METHODS

The chemical constituents of the oil were identified by gas chromatography coupled to mass spectrometry (GC-MS). In vitro hemolytic activity was tested using mouse blood. Acute toxicity in mice was assessed by the oral or intraperitoneal administration of a single dose of 2000 mg/kg b.w. EOCb (1000 and 2000 mg/kg) was also evaluated for genotoxicity and antigenotoxicity in vivo using the micronucleus test. The antinociceptive activity of EOCb (25, 50 and 100 mg/kg) was evaluated through the abdominal writhing, formalin and tail flick tests.

RESULTS

The chemical characterization indicated as major components α-pinene (21.23%), β-phelandrene (13.92%), terpinolene (13.01%) and germacrene D (10.89%). EOCb did not cause hemolysis and was also neither toxic nor genotoxic, while protected the animals' bone marrow cells from damage caused by cyclophosphamide in oral treatment. However, all animals died after 15 min of intraperitoneal treatment. There was a reduction in the number of abdominal contortions (69.43-89.41%) as well as in licks in the first (38.77-84.47%) and second (59.75-90.74%) phases of the formalin test. In the latter case, the effects were reduced by naloxone and glibenclamide, indicating action via the opioid system and blockage of K+ channels. The latency time in the tail flick test also increased significantly.

CONCLUSION

In conclusion, ingestion of EOCb proved to be safe when administered orally; however, it was lethal intraperitoneally. Additionally, EOCb protected mouse blood cell DNA against the action of cyclophosphamide and showed an antinociceptive effect via the opioid system and dependent on K+ channels.

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.

Evaluation of 28-day repeated doses oral toxicity of essential oil from Psidium glaziovianum Kiaersk leaves on various biological parameters in Swiss mice

Only a small number of the many medicinally important species in the genus Psidium L. have had their safety assessed. Psidium glaziovianum, a plant native to Brazil, is reported to exert antinociceptive and anti-inflammatory effects; however, there are no apparent reports of long-term safety following administering of repeated doses. The aim of this study was to examine the effects of 28-day oral of treatment at 250, 500 or 1,000 mg/kg Psidium glaziovianum essential oil (PgEO) on behavioral and physiological parameters in male and female Swiss mice. First, PgEO was chemically characterized by gas chromatography mass spectrometry (GC-MS). The following parameters were examined: motor activity, body temperature, blood glucose, urine, hematology, biochemistry, histology, and oxidative stress. Characterization of PgEO revealed 48 components which were dominated by sesquiterpenes 1,8-cineol (24.29%), α-pinene (19.73%) and β-pinene (17.31%). Data showed that PgEO treatment in mice increased activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) without markedly affecting body weight, hematological or biochemical parameters, as well as water or food consumption. Administration of PgEO in repeated daily dosages over 28 days did not significantly alter exploratory or locomotor activities. Based upon our findings, PgEO administration daily for 28 days, exhibited low toxicity and absence of effects on the nervous system. Data demonstrated that PgEO produced hypoglycemic and antioxidant actions which need to be considered in safety assessment.

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.

Eugenia uniflora: a promising natural alternative against multidrug-resistant bacteria

This work aimed to evaluate the chemical composition, antioxidant and antimicrobial activities from crude extract and fractions from leaves of Eugenia uniflora Linn. The crude extract was obtained by turbo extraction and their fractions by partitioning. Chromatographic analysis were performed, and the antioxidant capacity was verified by two methods (DPPH• and ABTS•+). The Minimal Inhibitory/Bactericidal Concentration were conducted against twenty-two bacteria, selecting five strains susceptible to extract/fractions and resistant to the antibiotics tested. Ampicillin, azithromycin, ciprofloxacin, and gentamicin were associated with Ethyl Acetate Fraction (EAF) against multidrug-resistant strains in modulatory and checkerboard tests. The chromatographic data showed gallic acid, ellagic acid, and myricitrin in crude extract, with enrichment in the EAF. The electron transfer activity demonstrated in the antioxidant tests is related to the presence of flavonoids. The Gram-positive strains were more susceptible to EAF, and their action spectra were improved by association, comprising Gram-negative bacilli. Synergisms were observed to ciprofloxacin and gentamicin against Pseudomonas aeruginosa colistin-resistant. The results demonstrate that the extract and enriched fraction obtained from the leaves of E. uniflora act as a promising natural alternative against multidrug-resistant bacteria.

Chemical composition, antinociceptive and anti-inflammatory effects in mice of the essential oil of Psidium cattleyanum Sabine leaves

ETHNOPHARMACOLOGICAL RELEVANCE

One of the native species of the genus most often mentioned by traditional people is Psidium cattleyanum Sabine, which is used mostly to treat disorders of the respiratory, genitourinary, and digestive systems. These symptoms are mainly treated by the decoction of the leaves. Additionally, there are gaps in the in vivo and toxicity investigations of this species.

AIM OF THE STUDY

The aim of this study was evaluate antinociceptive and anti-inflammatory potential of essential oil from P. cattleyanum leaves in vivo.

MATERIALS AND METHODS

Gas chromatography-mass spectrometry (GC/MS) was used to examine the essential oil of P. cattleyanum. The acute toxicity test was then done with a 2000 mg/kg dosage. The oil at 50, 100, and 200 mg/kg orally, as well as the reference medications Morphine 10.0 mg/kg IP and/or Indomethacin 20.0 mg/kg IP, were tested using nociception (abdominal writhing, formalin, and tail immersion) and inflammatory models (paw edema and peritonitis).

RESULTS

The phytochemical assay showed a high concentration of β-caryophyllene (46.68%) and α-caryophyllene (10.81%). In the in vivo assays, P. cattleyanum essential oil proved to be an important antinociceptive agent, reaching 76.96% inhibition of abdominal writhing with acetic acid and 67.12% in the formalin assay. An increase in latency time in the tail test was also reported. In the test with carrageenan, the oil showed significant inhibition compared to the control. A decrease in the migration of leukocytes was also reported in the group treated with P. cattleyanum, reaching 60.49% at the dose of 200 mg/kg.

CONCLUSIONS

The essential oil from the leaves of P. cattleyanum has anti-inflammatory and antinociceptive action and has potential for application in the pharmaceutical and food industry.

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 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.

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 a potential tool for bacterial characterization based on superficial carbohydrate detection.

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.

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.

The lectin from Schinus terebinthifolia leaf (SteLL) reduces immobility of mice on the tail suspension test dependent on the monoaminergic and nitric oxide signaling

Depression underlies a common psychiatric disorder that has been rising in the diagnosis of long-term disabilities worldwide. Natural products have been studied as an antidepressant and anxiolytic agents aiming to make available new options for the daily basis treatment of those psychological disorders. SteLL is a lectin extracted from Schinus terebinthifolia leaf that has been revealed as an antimicrobial, immunomodulatory, antitumor, and antinociceptive agent. Nonetheless, the efficacy of SteLL in the treatment of depression has not yet been explored. In view of this, the aim of this study was to investigate the effect of SteLL in an acute protocol for symptoms of depression using the tail suspension test (TST) to assess despair. Administration of SteLL (1, 2 e 4 mg/kg) significantly diminished the immobility time of animals in the TST and this anti-immobility action was dependent on the carbohydrate-recognizing domain (CRD) since the prior incubation with casein (an inhibitor of SteLL carbohydrate-binding property) blocked the effect. SteLL effect was also reversed by pre-treatment with pharmacological antagonists of α2-adrenoceptor, 5-HT2A/2C serotonin receptor, and D1 dopamine receptor as well as by a selective inhibitor of iNOS (aminoguanidine). l-arginine, a precursor of NO, potentiated SteLL anti-immobility effect. In a subacute evaluation, the anti-immobility effect of SteLL persisted after seven days of treatment. Our findings suggest a role of SteLL in the modulation of depression mostly through monoaminergic and nitric oxide signaling.

Cytotoxicity, oral toxicity, genotoxicity, and mutagenicity evaluation of essential oil from Psidium glaziovianum Kiaersk leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Members of the Psidium genus have been suggested in ethnobotanical research for the treatment of various human diseases, and some studies have already proven their popular uses through research, such as Psidium glaziovianum, which is found in Brazil's northeast and southeast regions and has antinociceptive and anti-inflammatory properties; however, the safety of use has not yet been evaluated.

AIM OF THE STUDY

This study investigated the safety of using essential oil obtained from P. glaziovianum leaves (PgEO) in vitro and in vivo models.

MATERIALS AND METHODS

Cytotoxicity was evaluated in murine erythrocytes, while acute toxicity, genotoxicity (comet assay) and mutagenicity (micronucleus test) studies were performed using Swiss albino mice.

RESULTS

In the cytotoxicity assay, the hemolysis rate indicated a low capacity of PgEO to cause cell lysis (0.33-1.78%). In the acute oral toxicity study, animals treated with up to up to 5000 mg/kg body weight did not observe mortality or physiological changes. Neither dosage caused behavioral problems or death in mice over 14 days. The control and 2,000 mg/kg groups had higher feed intake and body weight than the 5,000 mg/kg PgEO group. Erythrocyte count, hemoglobin level, mean corpuscular volume, and MCV decreased, but serum alanine and aspartate aminotransferases increased. In the genotoxic evaluation, 5000 mg/kg PgEO enhanced nucleated blood cell DI and DF.

CONCLUSIONS

The present study describes that PgEO can be considered well tolerated in acute exposure at doses up to 2000 mg/kg, however the dose of 5000 mg/kg of PgEO should be used with caution.

Eugenia gracillima essential oil has pharmaceutical applications in pain and inflammation without toxic effects in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia gracillima is widely used by the population in the manufacture of pulps and jellies, with popular reports of its use in the treatment of infections in the urinary system, respiratory and dermatological problems. A previous study reports that EO from E. gracillima leaves proved to be a promising antioxidant agent in combating the promastigote forms of protozoa. Despite this, this species has been little studied due to its pharmacological properties.

STUDY OBJECTIVE

In this study, an essential oil extracted (EO) from Eugenia gracillima leaves was evaluated for its acute toxicity and anti-inflammatory, antinociceptive and behavioral effects in mice.

METHODS

The EO was obtained by hydrodistillation, and the composition analysis was performed by gas chromatography coupled to mass spectrometry. Acute toxicity assessment was performed with observation of hematological parameters and histopathological evaluation, as well as tests to investigate antinociceptive, anti-inflammatory activities and behavioral effects.

RESULTS

Chromatographic analysis showed D-germacrene (16.10%), γ-muurolene-g (15.60%) and bicyclogermacrene (8.53%) as the majority of compounds. In the toxicity evaluation, no death or physiological changes were observed in mice treated with a single oral dose of up to 5000 mg/kg, and it did not lyse erythrocytes in vitro. The hematological parameters evaluated were not changed after treatment; however, 5,000 mg/kg promoted an increase in transaminase levels. In the histopathological evaluation, only the animals that received the dose of 5000 mg/kg showed discrete leukocyte infiltration around the centrilobular vein in the liver. Antinociceptive activity was detected through tests of acetic acid-induced writhing, formalin, and tail flick, promoted in part by the opioid receptor pathway. In the evaluation of anti-inflammatory activity, a reduction in inflammation was observed in the paw edema test and a decrease in the migration of leukocytes and neutrophils in the peritonitis test. The open field and elevated plus maze tests showed that EO did not affect the animals' motor functions or exploratory activity.

CONCLUSION

It was concluded that the essential oil of E. gracillima has potential for the development of pharmaceutical formulations with analgesic and anti-inflammatory actions in non-toxic concentrations.

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.

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.

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.

Safety evaluation of aqueous extract from Eugenia uniflora leaves: Acute and subacute toxicity and genotoxicity in vivo assays

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia uniflora Linn (Myrtaceae) is the native species of Brazil. The leaves of this species are used in folk medicine to treat different inflammatory and gastrointestinal disorders. However, research on the safety of using E. uniflora leaves has been poorly explored.

AIM OF THE STUDY

This approach aims to investigate the phytochemical composition as well as the acute, subacute toxicity, and in vivo genotoxic profile of the aqueous extract of E. uniflora leaves.

MATERIALS AND METHODS

The chemical composition of E. uniflora leaf extract was determined by Fingerprint by High-Performance Thin Layer and High-Performance Liquid Chromatography. The acute toxicity in vivo was evaluated for 14 days after the administration of E. uniflora leaves extract (2000 mg/kg). For the evaluation of subacute toxicity, mice were daily treated for 28 days with E. uniflora extract (250, 500, or 1000 mg/kg). Signs of behavioral toxicity and biochemical and hematological alterations, including the multiple organ toxicities were investigated. In addition, the micronucleus assay was used to evaluate the in vivo genotoxicity of the leaves extract in murine erythrocytes.

RESULTS

The phytochemical analysis showed the majority presence of phenolic compounds (gallic acid, ellagic acid, and myricitrin). Single or repeated doses of the aqueous extract of E. uniflora leaves did not reveal any signs of in vivo toxicity. Daily doses of the extract for 28 days induced a slight reduction in cholesterol and triglyceride levels. Furthermore, E. uniflora leaves extract (1000-2000 mg/kg) showed no genetic damage in the micronucleus assay, indicating the absence of genotoxicity of the herbal species.

CONCLUSION

The aqueous extract of E. uniflora leaves showed a predominance of phenolic compounds, with non-toxic and non-genotoxic action in vivo. This approach sheds light on the chemical composition of the leaves of E. uniflora and suggests a high margin of safety in the popular use of the leaves of this plant species.

Anti-inflammatory, antinociceptive effects and involvement of opioid receptors in the antinociceptive activity of Eugenia uniflora leaves obtained with water, ethanol, and propylene glycol mixture

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia uniflora (Myrtaceae) is a species native to Brazil and has a traditional use in the treatment of inflammation.

AIM OF THE STUDY

To evaluate the anti-inflammatory and antinociceptive effects, and the involvement of opioid receptors in the antinociceptive activity of extract and fractions from Eugenia uniflora leaves.

MATERIALS AND METHODS

TLC and HPLC were used to characterize the spray-dried extract (SDE) and fractions. In the in vivo assays, Swiss (Mus musculus) mice were used. Carrageenan-induced hind-paw edema and carrageenan-induced peritonitis models were used to determine the anti-inflammatory effect of the extract (50, 100, or 200 mg/kg). Acetic acid-induced writhing, tail-flick, and formalin tests were used to determine the antinociceptive effect of the extract (50, 100, or 200 mg/kg). The aqueous (AqF) and ethyl acetate (EAF) fractions (6.25, 12.5, and 25 mg/kg) were then combined with naloxone to evaluate the involvement of opioid receptors in the antinociceptive activity.

RESULTS

In this work, the TLC and HPLC analysis evidenced the enrichment of EAF, which higher concentration of gallic acid (5.29 ± 0.0004 %w/w), and ellagic acid (1.28 ± 0.0002 %w/w) and mainly myricitrin (8.64 ± 0.0002 %w/w). The extract decreased the number of total leukocytes and neutrophils in the peritoneal cavity (p < 0.05), at doses of 100 and 200 mg/kg and showed significant inhibition in the increase of paw edema volume (p < 0.05). The treatment per oral route (doses of 50, 100, and 200 mg/kg) significantly reduced the nociceptive response in acetic acid-induced abdominal writhing (p < 0.05). The effect of the extract on the tail-flick test showed a significant increase in latency time of animals treated at doses of 200 and 100 mg/kg (p < 0.05). The extract and ethyl acetate fraction reduced the nociceptive effect in both phases of formalin at all tested doses. The naloxone reversed the antinociceptive effect of EAF, suggesting that opioid receptors are involved in mediating the antinociceptive activity of EAF of E. uniflora in the formalin test.

CONCLUSION

The current study demonstrates the anti-inflammatory and analgesic activities of water: ethanol: propylene glycol spray-dried extract from E. uniflora leaves using in vivo pharmacological models in mice. Our findings suggest that spray-dried extract and ethyl acetate fraction exhibit peripheral and central antinociceptive activity with the involvement of opioid receptors that may be related to the presence of flavonoids, mainly myricitrin.

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.

Oral administration of essential oil from Psidium glaziovianum Kiaersk leaves alleviates pain and inflammation in mice

Plants of the genus Psidium have been employed in "in natura" consumption and agroindustry, and owing to the diversity of phytochemicals, the development of new pharmaceutical forms has received remarkable research interest. In this study, the essential oil obtained from Psidium glaziovianum (PgEO) leaves were evaluated antinociceptive and anti-inflammatory activities were evaluated in mouse models. Initially, PgEO was characterized by gas chromatography-mass spectrometry and gas chromatography with flame ionization detection, and the profile was dominated by sesquiterpene compounds. In the evaluation of acute antinociceptive activity (abdominal contortions induced by acetic acid, formalin, tail immersion, and hot plate tests), PgEO promoted a reduction in nociception in the chemical and thermal models. Additionally, the potential underlying mechanism was investigated using pain pathway blockers, and the results revealed a combined action of opioidergic and muscarinic pathways. The anti-inflammatory potential was confirmed by anti-edematogenic action, reduced cell migration, pro-inflammatory cytokine production, and granuloma formation in chronic processes. This study provides evidence that PgEO can be effective for the treatment of pain and acute and chronic inflammation.

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.

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.

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 ​μg/mL and minimal bactericidal concentrations from 62.5 to 200 ​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 ​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.

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The rhizome of Microgramma vacciniifolia contains a lectin called MvRL.

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MvRL-rich fraction showed antibacterial activity.

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The fraction was also effective in vivo against bacterial infection.

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MvRL-rich fraction causedn 62.58–75.43% inhibition of Erlich carcinoma.

Quantum dots conjugated to lectins from Schinus terebinthifolia leaves (SteLL) and Punica granatum sarcotesta (PgTeL) as potential fluorescent nanotools for investigating Cryptococcus neoformans

This study reports the development of conjugates based on quantum dots (QD)s and lectins from Schinus terebinthifolia leaves (SteLL) and Punica granatum sarcotesta (PgTeL). Cryptococcus neoformans cells were chosen to evaluate the efficiency of the conjugates. Lectins were conjugated to QDs via adsorption, and the optical parameters (emission and absorption) were monitored. Lectin stability in the conjugates towards denaturing agents was investigated via fluorometry. The conjugation was evaluated using fluorescence microplate (FMA) and hemagglutination (HA) assays. The labeling of the C. neoformans cell surface was quantified using flow cytometry and observed via fluorescence microscopy. The QDs-SteLL and QDs-PgTeL conjugates, obtained at pH 7.0 and 8.0, respectively, showed the maintenance of colloidal and optical properties. FMA confirmed the conjugation, and the HA assay indicated that the lectin carbohydrate-binding ability was preserved after conjugation. SteLL and PgTeL showed stability towards high urea concentrations and heating. Conjugates labeled over 90% of C. neoformans cells as observed via flow cytometry and confirmed through fluorescence microscopy. C. neoformans labeling by conjugates was inhibited by glycoproteins, suggesting specific interactions through the lectin carbohydrate-binding site. Thus, an effective protocol for the conjugation of SteLL or PgTeL with QDs was proposed, yielding new nanoprobes useful for glycobiological studies.

Degradation of the residual textile mixture cetyltrimethylammonium bromide/remazol yellow gold RNL-150%/reactive blue BF-5G: evaluation photo-peroxidation and photo-Fenton processes in LED and UV-C photoreactors

This article presents a study on the degradation of a residual textile mixture composed of cationic surfactant cetyltrimethylammonium bromide (CTAB) and the remazol yellow gold RNL-150% and reactive blue BF-5G textile dyes. This was carried out by employing the photo-peroxidation and photo-Fenton processes in LED and UV-C photoreactors. The photo-Fenton process was the most efficient as regards the degradation of the CTAB and dye mixture, for both types of radiation. In the kinetic study, degradations of 99% were obtained in 180 min for the chromophore groups using both types of radiation. The degradation of the CTAB and aromatic groups was, meanwhile, an average of 25% when employing LED radiation. The behavior of the degradation reaction was pseudo-first-order. Toxicity tests indicated that the solutions were better able to grow seeds and bacteria after treatment with the photo-Fenton process, using both types of radiation. The photo-Fenton processes carried out by employing LED and UV-C photoreactors were able to degrade the CTAB and dye mixture, thus highlighting the efficiency of LED radiation when its power (three times smaller) is compared to that of UV-C radiation. This process, therefore, represents an alternative for use in textile wastewater treatment systems.

Evaluation of Antioxidant, Antibacterial and Enhancement of Antibiotic Action by Punica granatum Leaves Crude Extract and Enriched Fraction against Multidrug-Resistant Bacteria

The aim of this study was to evaluate the phytochemical composition, antioxidant, and antimicrobial potential of crude extract and fractions of Punica granatum leaves. The extract was produced by turbo extraction, after which hexanic, ethyl acetate, and aqueous fractions were obtained by partitioning. The chemical analyses were performed by thin layer chromatography and high-performance liquid chromatography, and the antioxidant activities were assayed by DPPH^. and ABTS^.+ . Minimal inhibitory and bactericidal concentrations (MIC/MBC) were applied to twenty-two bacteria. Most strains susceptible to extract/fractions and resistant to antibiotics were selected, and ampicillin, azithromycin, ciprofloxacin, and gentamicin were associated with the ethyl acetate fraction (EAF) against multidrug-resistant strains in modulatory and checkboard models. The data from chromatographic analyses showed flavonoids and tannins in the extract, as well as the enrichment of EAF in phenols, mainly flavonoids. The flavonoids were connected to the electron transfer activity demonstrated in the DPPH^. and ABTS^.+ assays. Gram-positive strains are more susceptible to EAF. The subinhibitory concentrations of P. granatum enhanced the antimicrobial activity of the agents and reduced the EAF individual MIC, and the combination of EAF and antibiotics demonstrated a synergistic effect. These results present a promising approach for developing a therapy in which antioxidant extracts and fractions can be used in combination with antibiotics.

Effects of a Mixed Limosilactobacillus fermentum Formulation with Claimed Probiotic Properties on Cardiometabolic Variables, Biomarkers of Inflammation and Oxidative Stress in Male Rats Fed a High-Fat Diet

High-fat diet (HFD) consumption has been linked to dyslipidemia, low-grade inflammation and oxidative stress. This study investigated the effects of a mixed formulation with Limosilactobacillusfermentum 139, L. fermentum 263 and L. fermentum 296 on cardiometabolic parameters, fecal short-chain fatty acid (SCFA) contents and biomarkers of inflammation and oxidative stress in colon and heart tissues of male rats fed an HFD. Male Wistar rats were grouped into control diet (CTL, n = 6), HFD (n = 6) and HFD with L. fermentum formulation (HFD-Lf, n = 6) groups. The L.fermentum formulation (1 × 10⁹ CFU/mL of each strain) was administered twice a day for 4 weeks. After a 4-week follow-up, biochemical parameters, fecal SCFA, cytokines and oxidative stress variables were evaluated. HFD consumption caused hyperlipidemia, hyperglycemia, low-grade inflammation, reduced fecal acetate and propionate contents and increased biomarkers of oxidative stress in colon and heart tissues when compared to the CTL group. Rats receiving the L. fermentum formulation had reduced hyperlipidemia and hyperglycemia, but similar SCFA contents in comparison with the HFD group (p < 0.05). Rats receiving the L. fermentum formulation had increased antioxidant capacity throughout the colon and heart tissues when compared with the control group. Administration of a mixed L. fermentum formulation prevented hyperlipidemia, inflammation and oxidative stress in colon and heart tissues induced by HFD consumption.

Insecticidal activity of a chemotype VI essential oil from Lippia alba leaves collected at Caatinga and the major compound (1,8-cineole) against Nasutitermes corniger and Sitophilus zeamais

Lippia alba is an aromatic shrub known to produce a diversity of essential oils, which can be classified into chemotypes. This study reports on the insecticidal activity of essential oil from L. alba leaves collected at Caatinga and its major compound against termite Nasutitermes corniger and maize weevil Sitophilus zeamais. The chromatographic analysis revealed the presence of 19 compounds, with 1,8-cineole being the most common (70.01%). When ingested, the oil promoted the mortality of N. corniger (LC₅₀: 18.25 and 8.4 nL/g for workers and soldiers, respectively). The compound 1,8-cineole was also termiticidal for workers (LC₅₀: 13.7 nL/g). The oil inhibited the activity of N. corniger exoglucanase, xylanase, and proteases. Toxicity by ingestion to S. zeamais was detected for the oil (LC₅₀: 0.297 μL/g) but not for 1,8-cineole; however, both the oil and 1,8-cineole showed anti-nutritional effects. Fumigant effects of the oil and 1,8-cineole against S. zeamais (LC₅₀ of 78.0 and 13.64 μL/L in air, respectively) were detected. This is the first record of a chemotype VI oil from L. alba collected at Caatinga and the first report of the insecticidal activity of a chemotype VI oil. Our study demonstrates that essential oil from L. alba and 1,8 cineole have the potential for the development of natural insecticides.

Water-soluble lectin (WSMoL) from Moringa oleifera seeds treatment recovers glycemic levels and improves left ventricular ejection fraction on Type-2 Diabetes mice model

Moringa oleifera, a plant widely used in traditional medicine as well as for water purification, contains a lectin on its seeds named WSMoL which modulates several immune characteristics and has shown cardiac safe properties. Here, we tested the hypothesis that WSMoL is able to recover fasting glucose levels and to improve the cardiac left ventricular (LV) function in a type 2 diabetes mellitus (T2DM) mice model. T2DM was induced in adult C57BL/6 mice by combining a high fat diet and low doses of Streptozotocin. Mice were randomly divided in two groups: i. received WSMoL for 21 consecutive days by gavage (T2DM + WSMoL) and ii. received saline solution (T2DM). Metabolic parameters and LV function were assessed. WSMoL was able to reduce fasting blood glucose levels in T2DM mice after 2 weeks of treatment, when compared to T2DM untreated group. Regarding to cardiac LV function, the T2DM + WSMoL group depicted ejection fraction values comparable to non-diabetic group. Our results show: i. WSMoL treatment presented a potent hypoglycemic effect decreasing insulin resistance and ii. WSMoL was able to improve cardiac LV ejection fraction. Collectively, the results presented here show WSMoL as a potential hypoglycemic agent to be tested in T2DM patients.

Antinociceptive and Anti-Inflammatory Effects of Saline Extract and Lectin-Rich Fraction from Microgramma vacciniifolia Rhizome in Mice

Previous studies have characterized a saline extract from Microgramma vacciniifolia rhizome and its lectin (MvRL)-rich fraction with low acute toxicity. In the present study, we evaluated these preparations for acute toxicity (1,000 mg/kg) and antinociceptive and anti-inflammatory activities (100-400 mg/kg for the extract and 25-50 mg/kg for the fraction). No signs of toxicity were observed. Both the extract and fraction increased the latency period for nociception in the hot plate assay, decreased writhing induced by acetic acid, and promoted analgesic effects in phases 1 and 2 of the formalin test. The antinociceptive mechanism was attributed to interactions with opioid receptors and K⁺ ATPase channels. The extract and fraction decreased carrageenan-induced paw edema in 46.15 % and 77.22 %, respectively, at the highest doses evaluated. Furthermore, the fraction was shown to act on the bradykinin pathway. The ability to decrease leukocyte migration after treatment was also verified in the peritonitis and air pouch models. In exudates collected from air pouches, decreased tumor necrosis factor (TNF)-α and increased interleukin (IL)-10 levels were noted. Both the extract and fraction also effectively inhibited the development of granulomatous tissue. In conclusion, the substances investigated in this study can be used for the development of novel therapeutic options for pain and inflammatory processes.

Chemical and antibacterial analysis of Cinnamomum verum leaves extract and fractions against multidrug resistant bacteria

The chemical composition, the antioxidant and antimicrobial potential of crude extract from leaves Cinnamomum verum and their enriched fractions was studied. Phytochemical analyses were performed by TLC and HPLC, and the antioxidant capacity was verified by DPPH^• and ABTS^•+. The Minimal Inhibitory/Bactericidal Concentration was conducted against twenty-two bacteria to select five strains susceptible to extracts/fractions and resistant to the antibiotics tested. Interference of Ethyl Acetate Fraction (EAF) in resistance to synthetic antibiotic was assayed by modulatory and checkerboard model. The chromatographic data showed phenolic compounds in crude extract, as well the flavonoid enrichment in the EAF. The combination of EAF and synthetic antibiotics (ampicillin, azithromycin, ciprofloxacin, or gentamicin) provides a synergistic effect against multidrug resistant strains). The results are useful to obtain multi-targeting in a single therapy solution, which on antioxidants molecules plant-derivatives can act synergistically in antimicrobial combinations, a valuable aid as bacterial resistance modifying compounds.

Effects of a solid formulation containing lectin-rich fraction of Moringa oleifera seeds on egg hatching and development of Aedes aegypti larvae

The measures currently used to minimize the spread of arboviruses, comprising dengue, Chikungunya, and Zika virus, involve controlling the size of population of the mosquito Aedes aegypti. However, the search for formulations containing new insecticides is gaining pace due to reports of mosquito populations showing resistance to commonly used compounds. In this study, tablets containing a protein fraction of Moringa oleifera seeds enriched in the WSMoL lectin, known to show larvicidal and ovicidal activities against A. aegypti, were developed. The compatibility between the fraction and the excipients used in obtaining the tablets was evaluated by thermogravimetry (TG), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) absorption spectroscopy. The larvicidal and ovicidal activities of the resulting tablets [5%, 10%, and 15% (w/w) of the fraction] were evaluated, as well as their effect on mosquito oviposition. Assays were also performed using a placebo tablet. According to the TG, DSC, and FTIR results, the protein composition of the fraction did not change when mixed with the components of the formulation. Tablets containing 10% and 15% WSMoL-rich fraction caused mortality of 42.5% and 95% of the larvae after 48 h, respectively, with larvae incubated with these tablets showing reduced acetylcholinesterase activity. All tablets inhibited egg hatching after 72 h (36-74%), and tablets containing 15% fraction were found to exert a repellent effect on oviposition. Our results show that the formulation developed in this study interfered with the life cycle of A. aegypti, and thus show potential for use in the control of this mosquito.

Pilosocereus gounellei (Cactaceae) stem extract decreases insulin resistance, inflammation, oxidative stress, and cardio-metabolic risk in diet-induced obese mice

ETHNOPHARMACOLOGICAL RELEVANCE

Pilosocereus gounellei (xique-xique) is a popular cactus from Caatinga, traditionally used to counter inflammatory processes and indicated as a hypoglycemic agent. Previous studies have shown that mice treated orally with saline extract of P. gounellei stem (containing flavonoids and sugars) showed decreased serum lipid levels.

AIM OF THE STUDY

In this work, we evaluated whether this extract would have beneficial effects against hyperglycemia and inflammatory status related to obesity in mice fed a high-fat diet (HFD).

METHODS

Obese animals were treated daily per os with the extract (EXT; 125, 250, and 500 mg/kg), metformin (MET; 400 mg/kg), or saline solution (diet-induced obese, DIO) for 21 days. A group of non-obese animals served as the control. We evaluated lipid profile, glucose and insulin tolerance, atherogenic indices, histological alterations, cytokine levels, and oxidative stress in liver, muscle, and adipose tissue.

RESULTS

At the end of the experiment, mice from EXT groups showed lower body weight and total cholesterol, LDL-cholesterol, and triglycerides compared with the DIO group; in addition, HDL-cholesterol levels and glucose and insulin tolerance were similar to those of the control group. When compared with the DIO group, the extract-treated mice showed reduction in cardiac risk ratio, atherogenic coefficient, atherogenic index of plasma, and Castelli's Risk Index II; decrease in epididymal fat; reduction in steatosis, collagen deposition, and liver inflammation; lower serum levels of pro-inflammatory cytokines (tumor necrosis factor α, interleukin 6, and monocyte chemoattractant protein-1); inhibited lipid peroxidation; and increased superoxide dismutase levels in liver, muscle, and adipose tissue.

CONCLUSION

The P. gounellei saline extract was able to improve physiological parameters of obese mice, which highlight the potential of this plant as source of compounds with biotechnological relevance for pharmaceutical industry.

Antibacterial effects of the lectin from pomegranate sarcotesta (PgTeL) against Listeria monocytogenes

AIMS

To investigate the effects of the lectin from Punica granatum sarcotesta (PgTeL) on growth, viability, cell structure, biofilm formation and chitinase activity of Listeria monocytogenes. In addition, the effect of PgTeL on the adhesion and invasion of human cells (HeLa) was determined.

METHODS AND RESULTS

PgTeL showed bacteriostatic and bactericidal effects on the strains L. monocytogenes N53-1 and EGD-e, causing morphometric alterations, cell aggregation, strong deformation and cell disruption. PgTeL inhibited biofilm formation by EGD-e and N53-1 and also interfered with the adhesion and invasion processes of EGD-e and N53-1 in HeLa cells. Finally, the chitinase activity of L. monocytogenes EGD-e was reduced in the presence of PgTeL, which can be involved in the inhibition of adhesion process.

CONCLUSION

PgTeL is an antibacterial agent against L. monocytogenes, inhibiting growth and promoting cell death, as well as impairing biofilm formation and bacterial adhesion and invasion into human cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results stimulate future investigations on the potential of PgTeL for protection of contamination in food products.

A new lectin from the floral capitula of Egletes viscosa (EgviL): Biochemical and biophysical characterization and cytotoxicity to human cancer cells

Egletes viscosa is a plant with therapeutic value due to its antibacterial, antinociceptive and gastroprotective properties. This study aimed to purify, characterize, and evaluate the cytotoxicity of a lectin (EgviL) from the floral capitula of E. viscosa. The lectin was isolated from saline extract through precipitation with ammonium sulfate followed by Sephadex G-75 chromatography. The molecular mass and isoelectric point (pI) of EgviL were determined as well as its temperature and pH stability. Physical-chemical parameters of interaction between EgviL and carbohydrates were investigated by fluorescence quenching and ¹H nuclear magnetic resonance (NMR). Cytotoxicity was investigated against human peripheral blood mononuclear cells (PBMCs) and neoplastic cells. EgviL (28.8 kDa, pI 5.4) showed hemagglutinating activity stable towards heating until 60 °C and at the pH range 5.0-7.0. This lectin is able to interact through hydrophobic and electrostatic bonds with galactose and glucose, respectively. EgviL reduced the viability of PBMCs only at the highest concentration tested (100 μg/mL) while was toxic to Jurkat E6-1 cells with IC₅₀ of 24.1 μg/mL,inducing apoptosis. In summary, EgviL is a galactose/glucose-binding protein with acidic character, stable to heating and with cytotoxic effect on leukemic cells.

Anti-Candida activity of the water-soluble lectin from Moringa oleifera seeds (WSMoL)

This work reports the effects of the water-soluble lectin from Moringa oleifera seeds (WSMoL) on growth and survival of Candida species. In addition, cellular alterations linked to the antifungal effect were investigated. The minimal inhibitory (MIC) and fungicidal (MFC) concentrations were determined and 24-h growth curves in absence and presence of lectin were established. Flow cytometry was used to evaluate the induction of apoptosis/necrosis, alterations in mitochondrial membrane potential (ΔΨm), and occurrence of lysosomal damage. WSMoL inhibited the growth of C. albicans, C. glabrata, C. krusei and C. parapsilosis with MIC of 20μg/mL. The lowest MFC (20μg/mL) was detected for C. glabrata and the highest (80μg/mL) for C. albicans and C. parapsilosis. The inhibitory effect started from the ninth to nineteenth hour of incubation depending on the fungal species. Incubation with the lectin at the MIC for 24h increased the number of cells undergoing apoptosis and necrosis. Hyperpolarization of the mitochondrial membrane was detected after 12-h treatment, followed by reduction of ΔΨm or depolarization after 24h. No lysosomal damage was detected in treated cells. In conclusion, WSMoL is a fungistatic and fungicide agent against Candida with differential effects depending on the species.

Antinociceptive activity of Schinus terebinthifolia leaf lectin (SteLL) in sarcoma 180-bearing mice

ETHNOPHARMACOLOGY RELEVANCE

Schinus terebinthifolia Raddi leaves have been used in folk medicine due to several properties, including antitumor and analgesic effects. The variable efficacy and adverse effects of analgesic drugs have motivated the search for novel antinociceptive agents. It has been reported that the S. terebinthifolia leaf lectin (SteLL) has antitumor activity against sarcoma 180 in mice.

AIM OF THE STUDY

This work aimed to evaluate whether SteLL would reduce cancer pain using an orthotopic tumor model.

MATERIALS AND METHODS

A sarcoma 180 cell suspension was inoculated into the right hind paws of mice, and the treatments (150 mM NaCl, negative control; 10 mg/kg morphine, positive control; or SteLL at 1 and 2 mg/kg) were administered intraperitoneally 24 h after cell inoculation up to 14 days. Spontaneous nociception, mechanical hyperalgesia, and hot-plate tests were performed. Further, the volume and weight of the tumor-bearing paws were measured.

RESULTS

SteLL (2 mg/kg) improved limb use during ambulation. The lectin (1 and 2 mg/kg) also inhibited mechanical hyperalgesia and increased the latency time during the hot-plate test. Naloxone was found to reverse this effect, indicating the involvement of opioid receptors. The tumor-bearing paws of mice treated with SteLL exhibited lower volume and weight.

CONCLUSION

SteLL reduced hyperalgesia due to sarcoma 180 in the paws of mice, and this effect can be related to its antitumor action.

Toxicity assessment of saline extract and lectin-rich fraction from Microgramma vacciniifolia rhizome

Microgramma vacciniifolia is broadly used in folk medicine but safety information is unavailable. Therefore, we evaluated the toxicity of a saline extract and a lectin-rich fraction of M. vacciniifolia rhizome. The extract showed hemolytic activity on mice erythrocytes at 1000 μg/mL, whereas the fraction promoted hemolysis (8.57-26.15%) at all tested concentrations (10-1000 μg/mL). Acute toxicity test in mice indicated an LD₅₀ of >5000 mg/kg. Hematological alterations and increased serum alkaline phosphatase level were observed in the treated animals. Transaminases and urea levels increased in the groups treated with the extract or fraction at 5000 mg/kg. Leukocyte infiltration was observed in the liver of extract-treated animals and in the liver and lungs of mice treated with the fraction. The kidneys of animals treated with the fraction at 5000 mg/kg presented hydropic degeneration. The extract and fraction did not induce oxidative stress in the liver and did not show genotoxicity, as examined by micronucleus and comet assays. In conclusion, the preparations were not lethal to mice but caused some signs of toxicity, mainly the fraction. The results indicated the need to evaluate the toxicity of M. vacciniifolia rhizome in other models and in chronic assays.

Antitumor activity of Moringa oleifera (drumstick tree) flower trypsin inhibitor (MoFTI) in sarcoma 180-bearing mice

The plant Moringa oleifera is used as food and medicine. M. oleifera flowers are source of protein, fiber, and antioxidants, and are used to treat inflammation and tumors. This work evaluated the antitumor activity of the M. oleifera flower trypsin inhibitor (MoFTI) in sarcoma 180-bearing mice. Swiss female mice were inoculated with sarcoma 180 cells. Seven days later, the animals were treated intraperitoneally for 1 week with daily doses of PBS (control) or MoFTI (15 or 30 mg/kg). For toxicity assessment, water and food consumption, body and organ weights, histological alterations, and blood hematological and biochemical parameters were measured. Treatment with MoFTI caused pronounced reduction (90.1%-97.9%) in tumor weight. The tumors of treated animals had a reduced number of secondary vessels and lower gauge of the primary vessels compared to the control. No significant changes were observed in water and food consumption or in body and organ weights. Histopathological analysis did not indicate damage to the liver, kidneys, and spleen. In conclusion, MoFTI showed antitumor potential, with no clear evidence of toxicity.

Anti-staphylococcal effects of Myracrodruon urundeuva lectins on nonresistant and multidrug resistant isolates

AIMS

To evaluate the anti-staphylococcal effects of lectins isolated from bark (MuBL), heartwood (MuHL) and leaves (MuLL) of Myracrodruon urundeuva.

METHODS AND RESULTS

The lectins were evaluated for: effects on growth, aggregation, haemolytic activity and biofilm-forming ability of Staphylococcus aureus clinical isolates nonresistant (8325-4) and multidrug resistant (LAC USA300); interference with the expression of virulence genes (hla, rnaIII and spa) of the Agr system of S. aureus; and synergistic effect with the antibiotics cefoxitin and cefotaxime. MuBL, MuHL and MuLL reduced growth (minimal inhibitory concentration (MIC): 12·5-50 µg ml^-1 ) and viability (minimal bactericidal concentration (MBC): 100 µg ml^-1 ) of 8325-4 and LAC USA300 cells. MuLL (at ½MIC and MIC) reduced LAC USA300 agglutination. The lectins did not interfere with haemolytic activity and expression of hla, rnaIII and spa genes. Only MuHL was able to reduce the biofilm production by 8325-4 (50-400 µg ml^-1 ) and LAC USA300 (400 µg ml^-1 ).

CONCLUSION

The M. urundeuva lectins showed antibacterial activity against nonresistant and resistant clinical isolates of S. aureus and synergistic effects with antibiotics in reducing growth and biofilm formation.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work reports bioactive molecules capable of acting as anti-staphylococcal agents, since there are increasing reports of multiresistant isolates of this bacterium.

Polymorphisms in GSTE2 is associated with temephos resistance in Aedes aegypti

The glutathione S-transferases (GSTs) are enzymes involved in several distinct biological processes. In insects, the GSTs, especially delta and epsilon classes, play a key role in the metabolism of xenobiotics used to control insect populations. Here, we investigated its potential role in temephos resistance, examining the GSTE2 gene from susceptible (RecL) and resistant (RecR) strains of the mosquito Aedes aegypti, vector for several pathogenic arboviruses. Total GST enzymatic activity and the GSTE2 gene expression profile were evaluated, with the GSTE2 cDNA and genomic loci sequenced from both strains. Recombinant GSTE2 and mutants were produced in a heterologous expression system and assayed for enzyme kinetic parameters. These proteins also had their 3D structure predicted through molecular modeling. Our results showed that RecR has a profile of total GST enzymatic activity higher than RecL, with the expression of the GSTE2 gene in resistant larvae increasing six folds. Four exclusive RecR mutations were observed (L111S, I150V, E178A and A198E), which were absent in the laboratory susceptible strains. The enzymatic activity of the recombinant GSTE2 showed different kinetic parameters, with the GSTE2 RecR showing an enhanced ability to metabolize its substrate. The I150V mutation was shown to induce significant changes in catalytic parameters and a 3D modeling of GSTE2 mapped two of the RecR changes (L111S and I150V) near the enzyme's catalytic pocket, also implying an impact on its catalytic activity. Our results reinforce a potential role for GSTE2 in the metabolic resistance phenotype while contributing to the understanding of the molecular basis for the resistance mechanism.