Coagulant Activity of Water-Soluble Moringa oleifera Lectin Is Linked to Lowering of Electrical Resistance and Inhibited by Monosaccharides and Magnesium Ions

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.

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.

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.

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.

Isolation of active coagulant protein from the seeds of Strychnos potatorum - a potential water treatment agent

The application of natural coagulants for decentralized water treatment is gaining importance as a part of global sustainable initiative. This study focuses on the isolation of active coagulation components responsible for water clarification with respect to Strychnos potatorum seeds. The active coagulant components, protein and polysaccharide, were successfully isolated, dialysed and subjected to gel permeation chromatography. The polysaccharide was isolated with the saline extraction method and characterized using FTIR and NMR spectroscopy. Protein was precipitated with 80% ammonium sulphate solution combined with dialysis and gel permeation chromatography using Sephadex G-50. SDS-PAGE revealed that the isolated protein has a molecular weight of 12 kDa. The small-scale coagulation assay suggests that the protein fraction has superior coagulation activity than the isolated polysaccharide residue. The active coagulant fractions reported in this study would be helpful in deploying cheaper and simple methods in scaling up the coagulant fraction from these seeds acting as a potential water treatment agent.

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.

Plant Lectins and Lectin Receptor-Like Kinases: How Do They Sense the Outside?

Lectins are fundamental to plant life and have important roles in cell-to-cell communication; development and defence strategies. At the cell surface; lectins are present both as soluble proteins (LecPs) and as chimeric proteins: lectins are then the extracellular domains of receptor-like kinases (LecRLKs) and receptor-like proteins (LecRLPs). In this review; we first describe the domain architectures of proteins harbouring G-type; L-type; LysM and malectin carbohydrate-binding domains. We then focus on the functions of LecPs; LecRLKs and LecRLPs referring to the biological processes they are involved in and to the ligands they recognize. Together; LecPs; LecRLKs and LecRLPs constitute versatile recognition systems at the cell surface contributing to the detection of symbionts and pathogens; and/or involved in monitoring of the cell wall structure and cell growth.