Effect of Moringa oleifera lectin on development and mortality of Aedes aegypti larvae

Efficacy of maturase K and rpL20 protein extracted from C. procera leaves on Anophelesstephensi

The present work is carried out to protein isolation, purification, and characterization from leaves, stem, and seed of C. procera and to evaluate the larvicidal potential on Anopheles stephensi. The whole protein was isolated using protein extraction buffer and precipitated by ammonium sulphate and larvicidal active protein was purified by the column chromatography. The homogeneity of larvicidal protein was confirmed by the SDS-PAGE. The identification of protein was done by the HPLC and LC-MS/ESI-MS. The crude protein from leaves showed 100% mortality of 3rd instar larvae of An. stephensi at the concentration of 5.5 mg/ml after 24 h of exposure. The crude protein from stem showed 25% mortality and no mortality observed was observed in seed protein. The leaves crude protein was further purified by ion exchange chromatography and eluted fractions were tested for larvicidal potential. The purified single protein fractions L2 and L3 from C. procera leaves showed 100% mortality at concentration of 0.06 mg/ml. The homogeneity of purified protein was confirmed by SDS-PAGE and two bands of 26 kDa and 15 kDa protein were observed. The peptide sequence "R.SQMLENSFLIENVMKR.L" was identified in the trypsin digested homogenous protein fraction L2 and "R.DRGSQKR.N" peptide sequence in L3 fraction by LC-MS/ESI-MS. The CprL2 peptide showed the sequence similarity with the protein maturase K and CprL3 peptide showed the sequence similarity with ribosomal protein L20 of C. procera. The conserved functional domain was also identified in both the CprL2 and CprL3 peptide. The identified proteins showed strong larvicidal efficacy at very low concentration. The identified proteins are novel and natural larvicidal agents against An. stephensi and hence can be used to control the malaria.

Influence of temperature combined with photodynamic inactivation on the development of Aedes aegypti

To reduce the speed of selection of populations resistant to chemical insecticides, photodynamic inactivation (PDI) against Aedes aegypti is a hot-topic and promising alternative technique to vector control. Temperature is an important factor in the survival of Ae. aegypti larvae and mosquitoes as it influences physiology, behavior, and ecology. This work aimed to evaluate parameters of the biological cycle of Ae. aegypti such as: hatching rate, larval development, adult mosquito longevity, sex ratio, weight, and lethal concentration of larval mortality (LC) through the combination of PDI with different temperatures. The number of larvae found after 48 h suggests that temperature affects hatching rate. Additionally, results showed a delay in development of surviving larvae after PDI when compared to control groups, and there was a reduction in the longevity of mosquitoes that undertook photodynamic action. PDI also led to a predominance of male insects, and observed weight indicates that the inactivation method may have also interfered in mosquito size. The results point to a satisfactory performance of PDI at all tested temperatures. Experimental conditions that were not lethal to all larvae implied that PDI impacts the mosquitoes' biological cycle. Though metabolism and development are improved at higher temperatures, so is PDI action, thus maintaining the net benefit. Therefore, it is assumed that the proposed photolarvicide can be useful in reducing arbovirus transmission, and results invite for future research in different abiotic conditions.

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.

Extract from Opuntia ficus-indica cladode delays the Aedes aegypti larval development by inducing an axenic midgut environment

This study evaluated the effects of acute exposure of Aedes aegypti third instar (L₃ ) larvae to the saline extract of Opuntia ficus-indica cladodes on the biological cycle and fertility of the emerging adults. For this, larvae were treated for 24 h with the extract at ¼ LC₅₀ (lethal concentration to kill 50% of larvae), ½ LC₅₀ or LC₅₀ ; the development and reproduction of the emerged adults were evaluated after a recovery period of 9 days. The resistance of proteins in the extract to hydrolysis by L₃ digestive enzymes and histomorphological alterations in the larval midgut were also investigated. The extract contained lectin, flavonoids, cinnamic derivatives, terpenes, steroids, and reducing sugars. It showed a LC₅₀ of 3.71% for 48 h. The data indicated mean survival times similar in control and extract treatments. It was observed development delay in extract-treated groups, with a lower number of adults than in control. However, the females that emerged laid similar number of eggs in control and treatments. Histological evaluation revealed absence of bacterial and fungal microorganisms in the food content in midguts from larvae treated with cladode extract. Electrophoresis revealed that three polypeptides in the extract resisted to hydrolysis by L₃ digestive proteases for 90 min. The lectin activity was not altered even after 24-h incubation with the enzymes. In conclusion, the extract from O. ficus-indica can delay the development of Ae. aegypti larvae, which may be linked to induction of an axenic environment at larval midgut and permanence of lectin activity even after proteolysis.

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.

Proximate Analysis of Moringa oleifera Leaves and the Antimicrobial Activities of Successive Leaf Ethanolic and Aqueous Extracts Compared with Green Chemically Synthesized Ag-NPs and Crude Aqueous Extract against Some Pathogens

Research on the use of different parts of the Moringa oleifera plant as a nutritional and pharmaceutical resource for human and animals has increased in recent years. This study aimed to investigate the chemical composition and the TPCs and TFCs of Moringa leaves, the antimicrobial activities of Moringa successive ethanolic, aqueous, crude aqueous extracts, and green-chemically synthesized characterized Ag-NPs. The results indicated that the ethanolic extract recorded the highest activity against E. coli. On the other side, the aqueous extract showed higher activity, and its effects ranged from 0.03 to 0.33 mg/mL against different strains. The MIC values of Moringa Ag-NPs against different pathogenic bacteria ranged from 0.05 mg/mL to 0.13 mg/mL, and the activity of the crude aqueous extract ranged from 0.15 to 0.83 mg/mL. For the antifungal activity, the ethanolic extract recorded the highest activity at 0.04 mg/mL, and the lowest activity was recorded at 0.42 mg/mL. However, the aqueous extract showed effects ranging from 0.42 to 1.17 mg/mL. Moringa Ag-NPs showed higher activity against the different fungal strains than the crude aqueous extract, and they ranged from 0.25 to 0.83 mg/mL. The MIC values of the Moringa crude aqueous extract ranged from 0.74 to 3.33 mg/mL. Moringa Ag-NPs and their crude aqueous extract may be utilized to boost antimicrobial attributes.

New lectin isolated from the tropical sponge Haliclona (Reniera) implexiformis (Hechtel, 1965) shows antibiofilm effect

A lectin from the marine sponge Haliclona (Reniera) implexiformis (HiL) was isolated by affinity chromatography on Sepharose™ matrix. HiL showed specificity for galactose and its derivatives. The glycoproteins porcine stomach mucin (PSM) and bovine stomach mucin (BSM) were potent inhibitors. Hemagglutinating activity of the lectin was maximal between pH 5.0 and 9.0. The lectin remained active until 60°C. The presence of CaCl2 and EDTA did not affect the hemagglutinating activity. In SDS-PAGE, HiL showed a single band of 20 kDa under reduced conditions, whereas in the non-reducing conditions, it showed a band of 20 kDa and one additional band of 36 kDa. The average molecular mass determined by Electrospray Ionization Mass Spectrometry (ESI-MS) was 35.874 ± 2 Da in native and non-reducing conditions, whereas carboxyamidomethylated-lectin showed 18,111 Da. These data indicated that HiL consists in a dimer formed by identical subunits linked by disulfide bonds. Partial amino acid sequence of HiL was determined by mass spectrometry, and revealed that it is a new type of lectin, which showed no similarity with any protein. Secondary structure consisted of 6% α-helice, 31% β-sheet, 18% β-turn and 45% random coil. HiL showed significant reduction in the number of viable cells of Staphylococcus biofilms.

Anthelmintic effect of a water soluble Moringa oleifera lectin in rodents experimentally infected with Haemonchus contortus

Allied to the problem of gastrointestinal parasites, especially Haemochus contortus, the use of lectins of plant origin has contributed to the research of alternative anthelmintics. The nematicidal effect of a water soluble Moringa oleifera lectin (WSMoL) was investigated in an experimental model with H. contortus infected Wistar rodents. Three concentrations were tested orally: 5 mg/kg, 2.5 mg/kg and 1 mg/kg. The reduction in the number of larvae recovered in the experimental groups was analyzed, as well as biochemical, hematological and histological parameters. Treatments with 5, 2.5 and 1 mg/kg of WSMoL reduced the number of larvae recovered of animals by 74.7%, 72.8% and 66%, respectively. Untreated infected animals had anemia, moderate mononuclear multifocal hepatitis, vascular congestion in the liver and kidneys, white pulp hyperplasia in the spleen, and presence of eosinophils in the intestine. Infected animals treated with 5 mg/kg of WSMoL showed liver with moderate bleeding, kidney with vascular congestion, spleen with white pulp hyperplasia and intestine with moderate presence of mononuclear cells. An increase in the serum level of glutamic pyruvic transaminase and a reduction in the level of hemoglobin (p < 0.001) were also observed in this group when compared to the uninfected group. However, the administered concentrations of 2.5 and 1 mg/kg of WSMoL were both satisfactory in terms of reducing the number of recovered larvae and not promoting negative changes in the biochemical, hematological and histological parameters evaluated. These results indicate an in vivo nematicidal effect of WSMoL on the H. contortus parasite.

Biotechnological Approaches for Host Plant Resistance to Insect Pests

Annually, the cost of insect pest control in agriculture crosses billions of dollars around the world. Until recently, broad-spectrum synthetic pesticides were considered as the most effective means of pest control in agriculture. However, over the years, the overreliance on pesticides has caused adverse effects on beneficial insects, human health and the environment, and has led to the development of pesticide resistant insects. There is a critical need for the development of alternative pest management strategies aiming for minimum use of pesticides and conservation of natural enemies for maintaining the ecological balance of the environment. Host plant resistance plays a vital role in integrated pest management but the development of insect-resistant varieties through conventional ways of host plant resistance takes time, and is challenging as it involves many quantitative traits positioned at various loci. Biotechnological approaches such as gene editing, gene transformation, marker-assisted selection etc. in this direction have recently opened up a new era of insect control options. These could contribute towards about exploring a much wider array of novel insecticidal genes that would otherwise be beyond the scope of conventional breeding. Biotechnological interventions can alter the gene expression level and pattern as well as the development of transgenic varieties with insecticidal genes and can improve pest management by providing access to novel molecules. This review will discuss the emerging biotechnological tools available to develop insect-resistant engineered crop genotypes with a better ability to resist the attack of insect pests.

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.

Acaricidal activity of the hexanic and hydroethanolic extracts of three medicinal plants against southern cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

The southern cattle tick Rhipicephalus microplus is a major problem for the cattle industry in tropical and subtropical areas worldwide. Chemical products are commonly applied to control it; however, their indiscriminate use has resulted in the appearance of resistant lineages. In the last decades, plants have been used as an alternative to conventional acaricidal drugs, as several plant compounds repel activity, decrease the reproductive potential and reduce the survival rate of ticks. For this reason, the in vitro efficacy of hexanic and hydroalcoholic extracts of Randia aculeata, Moringa oleifera and Carica papaya were evaluated against the larvae and engorged females of R. microplus. Larval packet tests and adult immersion tests were performed with seven concentrations of each of the extracts. The extracts obtained with hydroethanolic solution (polar solvent) exhibited a higher acaricidal activity than extracts prepared with n-hexane (non-polar solvent). Hydroethanolic extracts of R. aculeata seed and shell showed the highest larvicidal activity against R. microplus (100 and 91% mortality, respectively) at a concentration of 100 mg/mL. Randia aculeata (seed and shell), M. oleifera and C. papaya treatments at the same concentration (100 mg/mL) also resulted in adult mortality of 85, 75, 66 and 55%, respectively. The adult immersion test showed that hydroethanolic extracts derived from R. aculeata seed significantly reduced the index of egg laying and increased the percentage inhibition of oviposition of female ticks at a concentration of 100 mg/mL. These results indicate that the tested extracts exhibit acaricidal activity and could be considered as potential agents for the development of alternative natural acaricides against R. microplus.

Chemical characterization of billy goat weed extracts Ageratum conyzoides (Asteraceae) and their mosquitocidal activity against three blood-sucking pests and their non-toxicity against aquatic predators

The petroleum ether crude extracts of A. conyzoides (Pe-Ac) were used to treat three medically intimidating pests of Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus, to evaluate their non-target screening against the mosquito predator. The chemical scanning of Pe-Ac through GC-MS analysis revealed a total of nine compounds and the maximum peak area was observed in 1,5-Heptadien-3-yne (22.14%). At the maximum dosage of Pe-Ac (200 ppm), significant larvicidal activity was shown against the fourth instars of Ae. aegypti (96%), An. stephensi (93%), and Cx. quinquefasciatus (92%) respectively. The percentages of oviposition deterrence index (ODI) of all three mosquito vectors are maximum at the highest sub-lethal dosage of Pe-Ac (75 ppm) and minimum at the control dosage. The sub-lethal dosage blocked the activity of carboxylesterase activity and upregulated the detoxifying enzyme activity in a dose-dependent way. The adulticidal activity of Pe-Ac showed that the maximum adult mortality rate (100%) was recorded at the prominent dosage of Pe-Ac 600 ppm against the vectors of all three mosquitos at the maximum adulticidal time of 30 min. Histopathological investigation of fourth instar larvae of all three mosquitos treated with a sub-lethal dosage of Pe-Ac showed that the midgut cells (epithelium, lumen, and peritrophic matrix) are ruptured completely whereas they appear to be normal in control larvae. The non-toxicity evaluation of Pe-Ac compared with the chemical toxin Temephos in aquatic predator Toxorhynchites splendens revealed that the plant extracts are harmless even at the prominent dosage (1000 ppm) as compared to Temephos (1 and 2 ppm) and displayed a higher mortality rate against the mosquito predators. Thus the safety index recommends that the Pe-Ac is more explicit to targets and a suitable auxiliary to chemical pesticides.

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.

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.

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.

Antibacterial Efficacy of Muringa Seed Extract and Potato Peel Extract Against Enterococcus faecalis

BACKGROUND

Elimination of infection and prevention of reinfection should be the main goal in the treatment of apical periodontitis. The most challenging part of endodontics is the complete disinfection of root canal system. Herbal alternatives have emerged as the more biofriendly approach in root canal irrigation and disinfection.

AIM AND OBJECTIVE

The aim of this study was to evaluate the antimicrobial efficacy of natural extracts like muringa seed and potato peel extract against Enterococcus faecalis.

MATERIALS AND METHODS

The antimicrobial activity was determined using agar diffusion test. The solutions were divided into three groups: Group I- Muringa seed extract, Group II- potato peel extract, and Group III-5.25% sodium hypochlorite. The zones of inhibition of growth were recorded. The strain used for this study was Enterococcus faecalis ATCC 29212.

RESULTS AND CONCLUSION

Muringa seed extract (Group I) demonstrated the best result among the tested solutions. Although there was no significant difference between potato peel extract (Group II) and 5.25% sodium hypochlorite (Group III). Within the limitations of this study, herbal extracts tested has shown significant antimicrobial action against Enterococcus faecalis.

Target Activity of Isaria tenuipes (Hypocreales: Clavicipitaceae) Fungal Strains against Dengue Vector Aedes aegypti (Linn.) and Its Non-Target Activity Against Aquatic Predators

The present investigation aimed to determine the fungal toxicity of Isaria tenuipes (My-It) against the dengue mosquito vector Aedes aegypti L. and its non-target impact against the aquatic predator Toxorhynchitessplendens. Lethal concentrations (LC₅₀ and LC₉₀) of My-It were observed in 2.27 and 2.93 log ppm dosages, respectively. The sub-lethal dosage (My-It-1 × 10⁴ conidia/mL) displayed a significant oviposition deterrence index and also blocked the fecundity rate of dengue mosquitos in a dose-dependent manner. The level of major detoxifying enzymes, such as carboxylesterase (α-and β-) and SOD, significantly declined in both third and fourth instar larvae at the maximum dosage of My-It 1 × 10⁵ conidia/mL. However, the level of glutathione S-transferase (GST) and cytochrome P-450 (CYP450) declined steadily when the sub-lethal dosage was increased and attained maximum reduction in the enzyme level at the dosage of My-It (1 × 10⁵ conidia/mL). Correspondingly, the gut-histology and photomicrography results made evident that My-It (1 × 10⁵ conidia/mL) heavily damaged the internal gut cells and external physiology of the dengue larvae compared to the control. Moreover, the non-target toxicity against the beneficial predator revealed that My-It at the maximum dosage (1 × 10²⁰ conidia/mL) was found to be less toxic with <45% larval toxicity against Tx.splendens. Thus, the present toxicological research on Isaria tenuipes showed that it is target-specific and a potential agent for managing medically threatening arthropods.

In vitro effects of Moringa oleifera seed lectins on Haemonchus contortus in larval and adult stages

Haemonchus contortus is a hematophagous parasite causing damage to the production of ruminant animals throughout the world. This study evaluated the in vitro effect of proteins from Moringa oleifera (WSMoL - Water Soluble M. oleifera Lectin and cMoL - coagulant M. oleifera Lectin) on the motility of infective larvae and adult male and female worms of H. contortus. The specific activity of total proteases and the morphology of the worms exposed to the lectins were observed. Both lectins inhibited motility of all parasite stages tested. WSMoL and cMoL at 500 μg mL^-1 interfered in the motility of larvae. Values of 11.1% and 8.1% were the lowest motility indices of larvae with sheath, and 30.6% and 16.4% were the lowest motility indices of exsheathed larvae treated with WSMoL and cMoL, respectively. In 1 mg mL^-1 solutions of WSMoL and of cMoL, the motility index of adult male worms was 23.3% (p < 0.001) and 20% (p < 0.001), while the motility index of adult female worms was 63.3% (p > 0.05) and 26.6% (p < 0.001), respectively. Greater proteolytic activity was detected in extracts obtained from adult worms, male and female, after incubation with the lectins. Morphological changes caused by the lectins were revealed by changes in the crests of the cuticle, in the longitudinal striations and at the vulva.

Ovicidal and Latent Effects of Pulicaria jaubertii (Asteraceae) Leaf Extracts on Aedes aegypti

The control of Aedes aegypti with synthetic pesticides may result in adverse effects on wildlife and the environment. Bioactive plant extracts have been proposed as one of the alternatives to chemical pesticides used against mosquitoes. Here, we report on the ovicidal and latent effects of ethanolic, petroleum ether, and chloroform leaf extracts of Pulicaria jaubertii at 25 to 150 ppm each against the life stages of laboratory stain of Ae. aegypti. At 150 ppm, the ethanolic leaf extract resulted in 100% ovicidal activity, followed by petroleum ether extract (74%), and chloroform extract about 7% mortality. The ethanolic extract produced 100% larval and pupal mortality at both 75 and 50 ppm, while the petroleum ether extract produced 76.5 and 58.3%, respectively. The ethanolic extract recorded the highest percentage of adult mortality (72.7%) at the lowest concentration (25 ppm). At 25 and 50 ppm, the ethanolic extract resulted in 62.2 and 85.2% sterility index of Ae. aegypti females, respectively, as compared with the 0.1 and 3.5% sterility index caused by the chloroform extract at the same concentrations. In conclusion, P. jaubertii appears to have potential to be further evaluated as a mosquito control agent. Additional studies are needed on its mode of action, synergism with other products, and efficacy under actual field conditions.

Investigation of the ability of the oviposition-stimulant lectin from Moringa oleifera seeds (WSMoL) to bind with membrane proteins present in the legs of Aedes aegypti

The mosquito Aedes aegypti L. is a vector transmitting diseases such as dengue, chikungunya and Zika virus fever. The water-soluble lectin from Moringa oleifera Lam. seeds (WSMoL) is larvicidal, ovicidal and can stimulate oviposition in A. aegypti. This study aimed to investigate whether WSMoL could bind to membrane proteins from A. aegypti legs. Initially, proteins from the legs were extracted using sodium deoxycholate, digitonin, dodecyl sodium sulfate (SDS) or Triton X-100. The protein concentration was found to be higher in the extract obtained using Triton X-100, which was applied to a WSMoL-Sepharose column. The adsorbed proteins were evaluated using gel filtration chromatography and polyacrylamide gel electrophoresis (PAGE) in presence of SDS. The similarity in the sequences of adsorbed proteins with those available in databases was determined. The proteins adsorbed on the matrix were eluted forming a single peak. Gel filtration chromatography and SDS-PAGE revealed the presence of proteins with molecular masses of approximately 20 kDa and polypeptide bands of 17.0 and 23.7 kDa, respectively. MS/MS analysis indicated similarity between these proteins and ABC carriers, which are expressed in the legs of mosquitos. WSMoL could bind to membrane proteins in the legs of A. aegypti females and induce oviposition through these interactions.

Evaluation of the Cardiac Effects of a Water-Soluble Lectin (Wsmol) from Moringa Oleifera Seeds

Fundsamento

As sementes de Moringa oleifera , que são utilizadas para clarificação de água, contêm uma lectina chamada WSMoL que tem mostrado atividade antibacteriana e imunomoduladora in vitro . Devido ao seu valor nutritivo e potencial terapêutico, as folhas e as sementes dessa árvore são consumidas em algumas comunidades. Algumas lectinas de plantas não são tóxicas para mamíferos, mas tem sido relatado que outras são prejudiciais quando ingeridas ou administradas por outros meios.

Objetivo

Como um dos passos necessários para determinar a segurança de WSMoL, nós avaliamos os possíveis efeitos cardiotóxicos desta proteína purificada.

Métodos

Durante 21 dias consecutivos, a WSMoL foi administrada a camundongos por gavagem. Foram investigadas as funções eletrofisiológicas, mecânicas e metabólicas in vivo e ex vivo por meio de registros eletrocardiográficos, ressonância magnética nuclear e respirometria de alta resolução.

Resultados

O tratamento com WSMoL não induziu alterações nos níveis de glicose no sangue ou peso corporal em comparação com o grupo controle. Adicionalmente, as relações peso cardíaco/peso corporal e peso cardíaco/comprimento tibial estavam semelhantes em ambos os grupos. A ingestão de lectina também não modificou a tolerância à glicose ou resistência à insulina. Não foram observadas alterações nos parâmetros eletrocardiográficos ou na duração do potencial de ação cardíaco. Os corações dos camundongos dos grupos controle e WSMoL mostraram função ventricular esquerda preservada. Além disso, a WSMoL não induziu alterações na função mitocondrial (em todos os casos, p > 0,05).

Conclusões

A administração de WSMoL demonstrou ter um perfil de segurança cardíaca. Estes resultados contribuem à avaliação de segurança do uso de sementes de M. oleifera para tratar água, visto que essa lectina está presente na preparação empregada por algumas populações com esse fim. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

Ovicidal lectins from Moringa oleifera and Myracrodruon urundeuva cause alterations in chorionic surface and penetrate the embryos of Aedes aegypti eggs

BACKGROUND

Lectins from Moringa oleifera seeds (WSMoL), Myracrodruon urundeuva bark (MuBL), and heartwood (MuHL) are larvicidal agents against Aedes aegypti; in addition, WSMoL is an ovicidal agent against this mosquito. In this work, we evaluated the ovicidal activity of MuBL and MuHL by determining the concentrations that reduce the hatching rates by 50% in 72 h (EC₅₀ ). The effects of WSMoL, MuBL, and MuHL on the ultrastructure of the eggs' surface were assessed by scanning electron microscopy (SEM). In addition, the ability of these lectins to penetrate the eggs was investigated by using conjugates of the lectins with fluorescein isothiocyanate (FITC).

RESULTS

MuBL and MuHL were ovicidal agents with EC₅₀ of 0.26 and 0.80 mg/mL (260 and 800 ppm), respectively. SEM images of eggs treated with WSMoL for 24 h revealed discontinuity of the exochorionic network and the absence of the exochorionic cells and their tubercles. After 48 and 72 h of incubation, strong deformation and degeneration of egg surfaces were observed. In MuBL and MuHL-treated eggs, the presence of lumps on the surface of the eggs, disappearance of the exochorionic network and the decrease and deformation of tubercles were observed. Lastly, fluorescence microscopy revealed that the three lectins were able to enter the eggs and reach the digestive tract of the embryos.

CONCLUSION

WSMoL, MuBL, and MuHL are ovicidal agents on A. aegypti that have differing efficiencies in terms of how they cause alterations in the chorionic surface and in terms of their ability to penetrate the eggs. © 2019 Society of Chemical Industry.

Exposure of mosquito (Aedes aegypti) larvae to the water extract and lectin-rich fraction of Moringa oleifera seeds impairs their development and future fecundity

Aedes aegypti control is a key component of the prophylaxis of dengue fever and other diseases. Moringa oleifera seeds contain a water-soluble lectin (WSMoL) with larvicidal and ovicidal activities against this insect. In this study, A. aegypti individuals were exposed at the third larval instar for 24 h to the water extract (0.1-1.0 mg/mL of protein) or lectin-rich fraction (0.05-0.6 mg/mL of protein) containing WSMoL, and then their survival and development were followed for 9 days post-exposure. The feeding capacity of adult females that developed from the treated larvae and the hatching success of eggs laid by them were also evaluated. Further, any alterations to the midgut histology of treated larvae, pupae, and adults were investigated. The extract and fraction induced the death of A. aegypti larvae along the post-exposure period. Both preparations also delayed the developmental cycle. The midguts of treated larvae and pupae showed disorganization and epithelial vacuolization, while in treated adults, the epithelium was underdeveloped compared to control. Unlike in control mosquitos, proliferating cells were not detected in treated larvae, and appeared in lower numbers in treated pupae than in control pupae. Adult females that developed from larvae treated with the fraction gained less weight after a blood meal compared with control. The amount of eggs laid by females that developed from larvae treated with both the extract and fraction was significantly lower than in control. In addition, the eggs showed lower hatching rates. In conclusion, females that developed from larvae treated with both the water extract and lectin-rich fraction showed reduced engorgement after a blood meal, with the consequent impairment of their fertility and fecundity. These results were probably due to the damage to midgut organization and impairment of the remodeling process during metamorphosis.

Toxic effect of essential oil and its compounds isolated from Sphaeranthus amaranthoides Burm. f. against dengue mosquito vector Aedes aegypti Linn

Aedes aegypti is a major mosquito vector that can transfer many deadly diseases such as dengue, chikungunya, Zika, and yellow fever viruses. Due to the developing resistance among the vector populations by the application of chemical insecticides, alternative eco-friendly vector management strategies are being focused. In this aspect, the present study was carried out to evaluate the mosquitocidal potentials of essential oil of Sphaeranthus amaranthoides (EO-Sa). EO-Sa was found to be effective against Ae. aegypti mosquito vector by exhibiting significant larvicidal, adulticidal and repellent activities. GCMS analysis of EO-Sa revealed the presence of Carvone as the major component (peak area of 89.7%). The larvicidal bioassays performed revealed that the second instar larvae were relatively more susceptible (94.32% mortality) to EO-Sa treatments (75 ppm), LC₅₀, 20.38 ppm.The sub lethal treatment concentration (20 ppm) significantly affected the oviposition, fecundity and morphology of Ae. aegypti. At sub lethal treatment concentration, EO-Sa down regulated α- and β carboxylesterase and up regulated the GST and CYP450 level of third and fourth instar larvae. Thus the present results illustrates that EO-Sa can deliver a durable larvicidal, repellent and adulticidal activity against Ae. aegypti in an effective and eco-friendly manner.

Biological, nutritional, and therapeutic significance of Moringa oleifera Lam

The genus Moringa Adans. comprises 13 species, of which Moringa oleifera Lam. native to India and cultivated across the world owing to its drought and frost resistance habit is widely used in traditional phytomedicine and as rich source of essential nutrients. Wide spectrum of phytochemical ingredients among leaf, flower, fruit, seed, seed oil, bark, and root depend on cultivar, season, and locality. The scientific studies provide insights on the use of M. oleifera with different aqueous, hydroalcoholic, alcoholic, and other organic solvent preparations of different parts for therapeutic activities, that is, antibiocidal, antitumor, antioxidant, anti-inflammatory, cardio-protective, hepato-protective, neuro-protective, tissue-protective, and other biological activities with a high degree of safety. A wide variety of alkaloid and sterol, polyphenols and phenolic acids, fatty acids, flavanoids and flavanol glycosides, glucosinolate and isothiocyanate, terpene, anthocyanins etc. are believed to be responsible for the pragmatic effects. Seeds are used with a view of low-cost biosorbent and coagulant agent for the removal of metals and microbial contamination from waste water. Thus, the present review explores the use of M. oleifera across disciplines for its prominent bioactive ingredients, nutraceutical, therapeutic uses and deals with agricultural, veterinarian, biosorbent, coagulation, biodiesel, and other industrial properties of this "Miracle Tree."

Insect midgut structures and molecules as targets of plant-derived protease inhibitors and lectins

The midgut of insects is involved in digestion, osmoregulation and immunity. Although several defensive strategies are present in this organ, its organization and function may be disturbed by some insecticidal agents, including bioactive proteins like lectins and protease inhibitors (PIs) from plants. PIs interfere with digestion, leading to poor nutrient absorption and decreasing amino acid bioavailability. Intake of PIs can delay development, cause deformities and reduce fertility. Ingestion of PIs may lead to changes in the set of proteases secreted in the insect gut, but this response is often insufficient and results in aggravation of the malnutrition status. Lectins are proteins that are able to interact with glycoconjugates, including those linked to cell surfaces. Their effects on the midgut include disruption of the peritrophic matrix, brush border and secretory cell layer; induction of apoptosis and oxidative stress; interference with nutrient absorption and transport proteins; and damaging effects on symbionts. In addition, lectins can cross the intestinal barrier and reach the hemolymph. The establishment of resistant insect populations due to selective pressure resulting from massive use of a bioactive protein is an actual possibility, but this can be minimized by the multiple mode-of-action of these proteins, mainly the lectins. © 2018 Society of Chemical Industry.

Crystal structure of a novel Kunitz type inhibitor, alocasin with anti-Aedes aegypti activity targeting midgut proteases

BACKGROUND

The pesticidal properties of many Kunitz-type inhibitors have been reported previously; however, the mechanism of action is not well established. In this study, the activity of alocasin against Aedes aegypti is demonstrated and the structure-activity relationship of this Kunitz-type inhibitor is explained through X-ray structure analyses.

RESULTS

Alocasin was purified from mature rhizomes of Alocasia as a single polypeptide chain of ∼ 20 kDa. The structure at 2.5 Å resolution revealed a Kunitz-type fold, but variation in the loop regions makes this structure unique; one loop with a single disulfide bridge is replaced by a long loop with two bridges. Alignment of homologous sequences revealed that this long loop contains a conserved Arg residue and modeling studies showed interaction with the catalytic Ser residue of trypsin-like enzymes. The anti-Aedes aegypti activity of alocasin is examined and discussed in detail. The in vitro activity of alocasin against midgut proteases of Aedes aegypti showed profound inhibition. Further, morphological changes in larvae upon treatment with alocasin revealed its activity against Ae. aegypti. Docking studies of alocasin with trypsin (5G1), a midgut protease involved in the development cycle and blood meal digestion, illustrated its insecticidal activity.

CONCLUSION

The three-dimensional structure of alocasin was determined and its structure-function relationship established for its anti Ae. aegypti activity. © 2018 Society of Chemical Industry.

Evaluation of Eosin-Methylene Blue as a Photosensitizer for Larval Control of Aedes aegypti by a Photodynamic Process

Aedes aegypti (Ae. aegypti) is a competent vector for transmitting important viral diseases such as yellow fever, dengue, chikungunya, and Zika. Several strategies have been applied to avoid Ae. aegypti proliferation by using environmental management, biological, and chemical approaches. However, the development of new methods for effective control of the insect vector population is still needed. Photodynamic control is an alternative way to control the vector population by using a physical approach based on the larval phototoxicity of a photosensitizer. In this context, the present study evaluated the use of eosin-methylene blue (EMB) as a new photosensitizer for photodynamic control of Ae. aegypti larval populations. The photodynamic assays were performed submitting Ae. aegypti third-instar larvae to different EMB concentrations (0.0, 0.5, 1.0, 5.0, 10.0, 50.0, and 100.0 µg mL⁻¹) in combination of three different light doses (24.3, 48.6, and 97.2 J cm⁻²) under either white-light radiation from RGB LEDs or sunlight. The results demonstrated that EMB presented a rapid internalization into the larvae and was phototoxic. The photodynamic action induced 100% of larval mortality after about 40 min of sunlight irradiation even using low EMB concentration (0.5 µg mL⁻¹). The findings reveal EMB as an effective photoactive compound to control larval populations of Ae. aegypti by photodynamic process induced by either sunlight or white-light from RGB LEDs.

Nematicidal activity of a water soluble lectin from seeds of Moringa oleifera

Gastrointestinal nematodes are the major cause of animal diseases, and the indiscriminate use of synthetic anthelmintic contributes to the development of drug resistance. Natural bioproducts are noteworthy since they have proved to be promising for alternative antiparasitic therapies. This study evaluated the in vitro effect of WSMoL (water soluble Moringa oleifera lectin) on hatching of eggs and on the development of early-stage larvae of gastrointestinal nematodes from naturally infected goats. In addition, the interference of WSMoL on activity of proteases was determined and the affinity of the lectin for glycosylated molecules of these parasites was investigated using fluorescein isothiocyanate (FITC)-labeled WSMoL. WSMoL at 250μgmL^-1 interfered on hatching of eggs (40.4% of not hatched eggs; p=0.018), and on larval development (stages L1-L3) (IC₅₀ of 78.22μgmL^-1). The activity of secreted proteases showed a significant increase in the presence of WSMoL (307.14U/mg-1031U/mg). FITC-labeled WSMoL recognized embryonic egg content and larval content after hatching, which suggests that WSMoL interact with intestinal glycoconjugate receptors in the embryo, as well as in cuticle of the larvae.

Ecotoxicity of water-soluble lectin from Moringa oleifera seeds to zebrafish (Danio rerio) embryos and larvae

The evaluation of ecotoxicity of mosquito larvicidal agents (such as the water-soluble lectin from Moringa oleifera seeds, WSMoL) is an essential step to establish the guidelines for their use. In this sense, this work evaluated the toxicity of WSMoL to Danio rerio embryos and larvae. Embryos were exposed to waterborne WSMoL (0.0125-0.2 mg mL^-1) for 96 h and lethal and sub-lethal effects were observed every 24 h. In the bioassays with larvae, the individuals were exposed to the WSMoL (0.025-0.2 mg mL^-1), mortality was recorded daily, and larval swimming velocities were analyzed after 72 h and 168 h of exposure. Additionally, acetylcholinesterase (AChE) activity of larvae was determined after 168 h of exposure. WSMoL LC₅₀ values to embryos were 0.190, 0.133 and 0.049 mg mL^-1 after 48, 72 and 96 h, respectively. No toxic endpoint was observed after exposure for 24 h. In addition, hatching was delayed and larval length at 96 h was reduced compared to the control. WSMoL LC₅₀ to larvae were 0.21 and 0.135 mg mL^-1, after 24 h and 96 h, respectively. Larvae exposed to 0.1 and 0.2 mg mL^-1 showed a decrease in swimming speed and a significant reduction in AChE activity. In conclusion, WSMoL at waterborne concentrations needed for its use as a larvicide to A. aegypti causes lethal and sublethal effects to zebrafish embryos and larvae. Therefore, its use in waterbodies where there are non-target organisms is not recommended.

Bti-based insecticide enhances the predatory abilities of the backswimmer Buenoa tarsalis (Hemiptera: Notonectidae)

The backswimmer Buenoa tarsalis (Hemiptera: Notonectidae) is a naturally occurring predator of immature stages of mosquitoes. These aquatic predators can suffer from non-targeted exposure to insecticides that are commonly used in aquatic environments to control mosquitoes. Here, we evaluated whether insecticide formulations containing the bacterium Bacillus thuringiensis var. israelensis (Bt_i) or the organophosphate pirimiphos-methyl would affect the survival and the predatory abilities of B. tarsalis. First, we conducted survival bioassays to estimate the median survival time (LT₅₀) of B. tarsalis when exposed to Bt_i-based insecticide (at 0.25 and 25 mg a.i./L) and pirimiphos-methyl (at 1, 10 and 1000 mg a.i./L). The highest concentrations of the insecticides were equivalent to the label-recommended field rates. Second, the predatory abilities of B. tarsalis exposed to insecticides were evaluated at three prey densities (3, 6 and 9 mosquito larvae/100 mL water) just after insecticide exposure or after a 24 h recovery time. While the survival of B. tarsalis was significantly reduced with pirimiphos-methyl concentrations ≥10 mg a.i./L, the Bt_i-exposed predators exhibited similar survival as unexposed predators. Interestingly, after a recovery time of 24 h, B. tarsalis sublethally exposed to pirimiphos-methyl or Bt_i-based insecticide consistently killed more A. aegypti larvae (at the intermediate density) than unexposed predators. However, for the without-recovery bioassays, the pirimiphos-methyl-exposed predators exhibited reduced predatory abilities at the lowest prey density. Because they do not reduce the survival or the predatory abilities of B. tarsalis, Bt_i-based insecticides can be considered a safe insecticide to use in the presence of backswimmers.

Comparative role of neem seed extract, moringa leaf extract and imidacloprid in the management of wheat aphids in relation to yield losses in Pakistan

Wheat being staple food of Pakistan is constantly attacked by major wheat aphid species, Schizaphis graminum (R.), Rhopalosiphum padi (L.) and Sitobion avenae (F.). Due to concern on synthetic chemical use in wheat, it is imperative to search for alternative environment- and human- friendly control measures such as botanical pesticides. In the present study, we evaluated the comparative role of neem seed extract (NSE), moringa leaf extract (MLE) and imidacloprid (I) in the management of the aphid as well as the yield losses parameters in late planted wheat fields. Imidacloprid reduced significantly aphids infestation compared to the other treatments, hence resulting in higher yield, particularly when applied with MLE. The percentages of yield increase in I+MLE treated plots over the control were 19.15–81.89% for grains per spike, 5.33–37.62% for thousand grain weight and 27.59–61.12% for yield kg/ha. NSE was the second most effective control measure in suppressing aphid population, but the yield protected by NSE treatment over the control was comparable to that by imidacloprid. Population densities of coccinellids and syrphids in the plots treated with NSE-2 were higher than those treated with imidacloprid in two out of three experiments during 2013–14. Low predator density in imidacloprid-treated plots was attributed to the lower availability of prey aphids. The efficacy of NSE against aphids varied depending on degree of synchronization among the application timing, the activity of aphids, crop variety and environmental conditions. Despite that, we suggested NSE to be a promising alternative botanical insecticide compared to the most commonly recommended imidiacloprid. Further studies should consider the side effects of biopesticides on non-target organisms in order to provide better management practices in the field.

Proteomic Profiles Reveal the Function of Different Vegetative Tissues of Moringa oleifera

Moringa oleifera is a rich source of bioactive compounds and is widely used in traditional medicine and food for its nutritional value; however, the protein and peptide components of different tissues are rarely discussed. Here, we describe the first investigation of M. oleifera proteomes using mass spectrometry and bioinformatics methods. We aimed to elucidate the protein profiles of M. oleifera leaves, stem, bark, and root. Totally 202 proteins were identified from four vegetative organs. We identified 101 proteins from leaves, 51 from stem, 94 from bark and 67 from root, finding that only five proteins existed in both four vegetative parts. The calculated pI of most of the proteins is distributed in 5-10 and the molecular weight distributed below 100 kDa. Functional classification analysis revealed that proteins which are involved in catalytic activities are the most abundant both in leaves, stem, bark and root. Identification of several heat shock proteins in four vegetative tissues might be adaptive for resistance to high temperature environmental stresses of tropical or subtropical areas. Some enzymes involved in antioxidant processes were also identified in M. oleifera leaves, stem, bark and root. Among the four tissues studies here, leaves protein content and molecular diversity were the highest. The identification of the flocculating protein MO2.1 and MO2.2 in the bark and root provides clue to clarify the antimicrobial molecular mechanisms of root and bark. This study provides information on the protein compositions of M. oleifera vegetative tissues that will be beneficial for potential drug and food supplement development and plant physiology research.

Comparative analysis of mosquito (Diptera: Culicidae: Aedes aegypti Liston) responses to the insecticide Temephos and plant derived essential oil derived from Piper betle L

Resistance to treatments with Temephos or plant derived oil, Pb-CVO, between a field collected Wild Strain (WS) and a susceptible Laboratory Strain (LS) of Ae. aegypti were measured. The Temephos (0.1mg/L) showed the greatest percentage of mosquito mortality compared to Pb-CVO (1.5mg/L) in LS Ae. aegypti. However, WS Ae. aegypti was not significantly affected by Temephos (0.1mg/L) treatment compare to the Pb-CVO (1.5mg/L). However, both strains (LS and WS) when treated with Pb-CVO (1.5mg/L) displayed steady larval mortality rate across all instars. The LC₅₀ of Temephos was 0.027mg in LS, but increased in WS to 0.081mg/L. The LC₅₀ of Pb-CVO treatment was observed at concentrations of 0.72 and 0.64mg/L for LS and WS strains respectively. The enzyme level of α- and β-carboxylesterase was reduced significantly in both mosquito strains treated with Pb-CVO. Whereas, there was a prominent deviation in the enzyme ratio observed between LS and WS treated with Temephos. The GST and CYP450 levels were upregulated in the LS, but decreased in WS, after treatment with Temephos. However, treatment with Pb-CVO caused both enzyme levels to increase significantly in both the strains. Visual observations of the midgut revealed cytotoxicity from sub-lethal concentrations of Temephos (0.04mg/L) and Pb-CVO (1.0mg/L) in both strains of Ae. aegypti compared to the control. The damage caused by Temephos was slightly less in WS compared to LS mosquito strains.

Lectins, Interconnecting Proteins with Biotechnological/Pharmacological and Therapeutic Applications

Lectins are proteins extensively used in biomedical applications with property to recognize carbohydrates through carbohydrate-binding sites, which identify glycans attached to cell surfaces, glycoconjugates, or free sugars, detecting abnormal cells and biomarkers related to diseases. These lectin abilities promoted interesting results in experimental treatments of immunological diseases, wounds, and cancer. Lectins obtained from virus, microorganisms, algae, animals, and plants were reported as modulators and tool markers in vivo and in vitro; these molecules also play a role in the induction of mitosis and immune responses, contributing for resolution of infections and inflammations. Lectins revealed healing effect through induction of reepithelialization and cicatrization of wounds. Some lectins have been efficient agents against virus, fungi, bacteria, and helminths at low concentrations. Lectin-mediated bioadhesion has been an interesting characteristic for development of drug delivery systems. Lectin histochemistry and lectin-based biosensors are useful to detect transformed tissues and biomarkers related to disease occurrence; antitumor lectins reported are promising for cancer therapy. Here, we address lectins from distinct sources with some biological effect and biotechnological potential in the diagnosis and therapeutic of diseases, highlighting many advances in this growing field.

Evaluation of using aluminum sulfate and water-soluble Moringa oleifera seed lectin to reduce turbidity and toxicity of polluted stream water

Aluminum salts are used as coagulants in water treatment; however, the exposure to residual aluminum has been associated with human brain lesions. The water-soluble Moringa oleifera lectin (WSMoL), which is extracted with distilled water and isolated by chitin chromatography, has coagulant activity and is able to reduce the concentration of metal ions in aqueous solutions. This study evaluated the potential of using aluminum sulfate and WSMoL to reduce the turbidity and toxicity of water from the Cavouco stream located in Recife, Pernambuco, Brazil. The water sample used (called P1) was collected from the stream source, which was found to be strongly polluted based on physicochemical and water quality analyses, as well as ecotoxicity assays with Artemia salina and seeds of Eruca sativa and Lactuca sativa. The assays combining WSMoL and aluminum sulfate were more efficient than those that used these agents separately. Furthermore, the greatest reduction in turbidity (96.8%) was obtained with the treatment using aluminum sulfate followed by WSMoL, compared to when they were applied simultaneously (91.3%). In addition, aluminum sulfate followed by WSMoL treatment resulted in residual aluminum concentration (0.3 mg/L) that was much lower than that recorded after the treatment using only the salt (35.5 mg/L). The ecotoxicity of P1 was also strongly reduced after the treatments. In summary, the combined use of aluminum sulfate and WSMoL was efficient in promoting a strong reduction of turbidity and ecotoxicity of a polluted water sample, without resulting in a high residual aluminum concentration at the conclusion of the treatment.

Potential mode of action of a novel plumbagin as a mosquito repellent against the malarial vector Anopheles stephensi, (Culicidae: Diptera)

Plumbagin was isolated and characterized from the roots of Plumbago zeylanica using chromatography: TLC, Column chromatogram, HPLC, FTIR and ¹H NMR. The isolated pure compounds were assayed for potency as inhibitors of: acetylcholine esterase (AchE), glutathione S-transferases (GST), superoxide dismutase (SOD), cytochrome P450 and α, β-esterase, and for repellency with Anopheles stephensi at four different concentrations (25, 50, 75 and 100ppm). The enzyme assay against the pure compound reveals that the level of esterase and SOD was decreased significantly in contrast the level of GST and cytochrome P450 was increased significantly. Our results suggests that novel Plumbagin has significantly alters the level of enzyme comparable to the control. Evaluations resulted in Plumbagin producing maximum repellency scores against An. stephensi mosquitoes in dose dependent manner with highest repellence was observed in the 100ppm. Histological examination showed that the midgut, hindgut and muscles are the most affected tissues. These tissues affected with major changes including separation and collapse of epithelial layer and cellular vacuolization. The results support the utility of plant compound Plumbagin for vector control as an alternative to synthetic insecticides, however, more vigorous field trials are needed to determine viability under natural conditions.