Antiulcer and Antioxidant Activity of a Lectin from Mucuna pruriens Seeds on Ethanol- induced Gastropathy: Involvement of Alpha-2 Adrenoceptors and Prostaglandins

Glycosylated SARs Cov 2 interaction with plant lectins

Lectins are non-immune carbohydrate-binding proteins/glycoproteins that are found everywhere in nature, from bacteria to human cells. They have also been a valuable biological tool for the purification and subsequent characterisation of glycoproteins due to their carbohydrate binding recognition capacity. Antinociceptive, antiulcer, anti-inflammatory activities and immune modulatory properties have been discovered in several plant lectins, with these qualities varying depending on the lectin carbohydrate-binding site. The Coronavirus of 2019 (COVID-19) is a respiratory disease that has swept the globe, killing millions and infecting millions more. Despite the availability of COVID-19 vaccinations and the vaccination of a huge portion of the world's population, viral infection rates continue to rise, causing major concern. Part of the reason for the vaccine's ineffectiveness has been attributed to repeated mutations in the virus's epitope determinant elements. The surface of the Coronavirus envelope is heavily glycosylated, with approximately sixty N-linked oligomannose, composite, and hybrid glycans covering the core of Man3GlcNAc2Asn. Some O-linked glycans have also been discovered. Many of these glyco-chains have also been subjected to multiple mutations, with only a few remaining conserved. As a result, numerous plant lectins with specificity for these viral envelope sugars have been discovered to interact preferentially with them and are being investigated as a potential future tool to combat coronaviruses such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by preventing viral attachment to the host. The review will discuss the possible applications of plant lectins as anti-coronaviruses including SARS-CoV-2, antinociceptive, anti-inflammation and its immune modulating effect.

Gastroprotective activity and physicochemical analysis of carboxymethylated gum from Anadenanthera colubrina

Biotechnological advancements require the physicochemical alteration of molecules to enhance their biological efficacy for the effective treatment of gastric ulcers. The study aimed to produce a polyelectrolytic compound from red angico gum (AG) by carboxymethylation, evaluate its physicochemical characteristics and investigate gastric protection against ethanol-induced ulcers. AG and carboxymethylated angico gum (CAG) were characterized by Fourier transform infrared spectroscopy, determination of the degree of substitution and gel permeation chromatography (GPC) and 13C NMR techniques. The results demonstrated that the modification of the polymer was satisfactory, presenting conformational changes e improving the interaction with the gastric mucosa. AG and CAG reduced macroscopic and microscopic damage such as edema, hemorrhage and cell loss caused by exposure of the mucosa to alcohol. Both demonstrated antioxidant activity in vitro, and in vivo, pretreatment with gums led to the restoration of superoxide dismutase and glutathione levels compared to the injured group. Concurrently, the levels of malondialdehyde and nitrite decreased. Atomic force microscopy showed that CAG presented better conformational properties of affinity and protection with the gastric mucosa compared to AG in the acidic pH. Based on our findings, it is suggested that this compound holds promise as a prospective product for future biotechnological applications.

Antimicrobial, antioxidant and antiproliferative activities of a galactose-binding seed lectin from Manilkara zapota

A seed lectin from Manilkara zapota (MZSL) was purified using ammonium sulphate precipitation and affinity chromatography. Hemagglutination activity, neutral sugar content and physicochemical properties of the lectin were determined and toxicity was checked by brine shrimp toxicity assay. Antimicrobial, antioxidant as well as in vitro anticancer activities of MZSL were also evaluated. Our findings showed the molecular weight of MZSL to be 33.0 ± 1 kDa. Minimum hemagglutination concentration of the lectin was 15.625 μg/ml. With a neutral sugar content of 6.32 %, the lectin was fully active at a temperature range of 30-50 °C and pH 7.0-8.0 and it was mildly toxic with an LC50 value of 107.93 μg/ml. The lectin demonstrated bacteriostatic activity against gram-positive bacteria in contrast to gram-negative bacteria at a concentration of 31.25 μg/ml, agglutinated Staphylococcus aureus and Shigella dysenteriae and exerted fungistatic activity against Aspergillus niger. MZSL dose-dependently reduced the formation of biofilm by E. coli. DPPH assay confirmed its antioxidant activity with an IC50 value of 96.42 μg/ml. MZSL showed 21.64 % growth inhibition against Ehrlich ascites carcinoma (EAC) cells at 80 μg/ml whereas its antiproliferative potential against MCF-7 and A-549 cancer cell lines became evident with IC50 values of 70.66 μg/ml and 107.64 μg/ml, respectively.

Intraspecific Variability in Proteomic Profiles and Biological Activities of the Honey Bee Hemolymph

Pollinator declines have raised major concerns for the maintenance of biodiversity and food security, calling for a better understanding of environmental factors that affect their health. Here we used hemolymph analysis to monitor the health status of Western honey bees Apis mellifera. We evaluated the intraspecific proteomic variations and key biological activities of the hemolymph of bees collected from four Egyptian localities characterized by different food diversities and abundances. Overall, the lowest protein concentrations and the weakest biological activities (cytotoxicity, antimicrobial and antioxidant properties) were recorded in the hemolymph of bees artificially fed sucrose solution and no pollen. By contrast, the highest protein concentrations and biological activities were recorded in bees that had the opportunity to feed on various natural resources. While future studies should expand comparisons to honey bee populations exposed to more different diets and localities, our results suggest hemolymph samples can be used as reliable indicators of bee nutrition.

Plant lectins: A new antimicrobial frontier

Pathogenic bacteria, viruses, fungi, parasites, and other microbes constantly change to ensure survival. Several pathogens have adopted strict and intricate strategies to fight medical treatments. Many drugs, frequently prescribed to treat these pathogens, are becoming obsolete and ineffective. Because pathogens have gained the capacity to tolerate or resist medications targeted at them, hence the term antimicrobial resistance (AMR), in that regard, many natural compounds have been routinely used as new antimicrobial agents to treat infections. Thus, plant lectins, the carbohydrate-binding proteins, have been targeted as promising drug candidates. This article reviewed more than 150 published papers on plant lectins with promising antibacterial and antifungal properties. We have also demonstrated how some plant lectins could express a synergistic action as adjuvants to boost the efficacy of obsolete or abandoned antimicrobial drugs. Emphasis has also been given to their plausible mechanism of action. The study further reports on the immunomodulatory effect of plant lectins and how they boost the immune system to curb or prevent infection.

Plant lectins as potent Anti-coronaviruses, Anti-inflammatory, antinociceptive and antiulcer agents

Lectins are defined as carbohydrate-binding proteins/glycoproteins of none immune origin, they are ubiquitous in nature, exist from bacteria to human cells. And due to their carbohydrate-binding recognition capacity, they have been a useful biological tool for the purification of glycoproteins and their subsequent characterization. Some plant lectins have also been revealed to own antinociceptive, antiulcer, and anti-inflammatory properties, where these features, in many instances, depending on the lectin carbohydrate-binding site. Coronavirus disease of 2019 (COVID-19) is a respiratory disease that struck the entire world leaving millions of people dead and more infected. Although COVID-19 vaccines have been made available, and quite a large number of world populations have already been immunized, the viral infection rates remained in acceleration, which continues to provoke major concern about the vaccines' efficacy. The belief in the ineffectiveness of the vaccine has been attributed in part to the recurrent mutations that occur in the epitope determinant fragments of the virus. Coronavirus envelope surface is extensively glycosylated being covered by more than sixty N-linked oligomannose, composite, and hybrid glycans with a core of Man3GlcNAc2Asn. In addition some O-linked glycans are also detected. Of these glyco-chains, many have also been exposed to several mutations, and a few remained conserved. Therefore, numerous plant lectins with a specificity directed towards these viral envelope sugars have been found to interact preferentially with them and are suggested to be scrutinized as a possible future tool to combat coronaviruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through blocking the viral attachment to the host cells. In this review, we will discuss the possible applications of plant lectins as anti-coronaviruses including SARS-CoV-2, antinociceptive, anti-inflammatory, and antiulcer agents with the proposed mechanism of their actions.

ADME-Tox Prediction and Molecular Docking Studies of Two Lead Flavonoids From the Roots of Tephrosia Egregia Sandw and the Gastroprotective Effects of Its Root Extract in Mice

Background: This study aimed to predict the pharmacokinetic and toxicological properties of lead flavonoids from the roots of T. egregia [praecansone A (1) and pongachalcone (2)], and to assess the gastroprotective effects and possible underlying mechanisms of the root extract in mice.Methods: Quantitative and qualitative data for in silico absorption, distribution, metabolism, and excretion (ADME) analyses of the two flavonoids were acquired from the SwissADME database. Toxicity assessment was performed with the ProTox-II server. To evaluate the putative interactions of both flavonoids with opioid receptors and NO protein, we acquired structures of the targets (&#x03BC;, &#x03BA;, and &#x03B4;-opioid receptors, and iNOS) in Homo sapiens from <a href="https://www.rcsb.org/">https://www.rcsb.org/</a>. For docking studies, AutoDock 4.2 was used for ligand and target arrangement, and AutoDock Vina was used for calculations. For in vivo assays, mice were pretreated (per os) with T. egregia (2, 20, or 200 mg/kg). After 60 min, 99.9% ethanol (0.2 mL) was injected (per os). At 30 min after ethanol injection, the mice were euthanized, and the gastric damage, gastric levels of hemoglobin, glutathione content, and activity of superoxide dismutase and catalase were evaluated. To elucidate T. egregia mechanisms, we used misoprostol, a prostaglandin analog; indomethacin, an inhibitor of prostaglandin synthesis; L-arginine, an NO precursor; L-NAME, an antagonist of NO synthase; naloxone, an opioid antagonist; and morphine, an opioid agonist.Results: In silico results showed that flavonoids (1) and (2) had favorable ADME properties and toxicity profiles, and exhibited satisfactory binding energies data (below &#x2212;6.0 kcal/mol) when docked into their targets (&#x03BC;, &#x03BA;, and &#x03B4;-opioid receptors, and iNOS). T. egregia decreased the ethanol-induced gastric damage and hemoglobin levels, and increased the glutathione content, and activity of superoxide dismutase and catalase. Naloxone and L-NAME, but not indomethacin, prevented T. egregia&#x2019;s effects, thus suggesting that opioid receptors and NO are involved in T. egregia&#x2019;s efficacy.Conclusions: Flavonoids (1) and (2) exhibited favorable pharmacokinetic properties, showing high lethal dose, 50% (LD50; 3,800 and 2,500 mg/kg, respectively) values. Neither flavonoid was found to be hepatotoxic, carcinogenic, or cytotoxic to human cells. In vivo assays indicated that T. egregia ameliorated oxidative stress levels, and its mechanism is at least partially based on opioid receptors and NO. T. egregia may therefore be considered as a new gastroprotective strategy.

Purification, Partial Characterization, and Evaluation of the Antiulcer Activity of Calotropis procera Leaf Lectin

BACKGROUND

Lectins are proteins with therapeutic and diagnostic potential that can be applied in battling various ailments.

AIM AND OBJECTIVE

This study was designed to purify and characterize the hemagglutinating activity derived from the leaves of Calotropis procera and its possible role in protecting the stomach against ethanol-induced lesions.

METHODS

The Calotropis procera leaf lectin (ProLec), was isolated by homogenization of the defatted leaf powder in Phosphate-Buffered Saline (PBS) and purified by affinity chromatography on Sephadex G-100. The lectin was eluted from the affinity column by 3% acetic acid and was physicochemically characterized. In a dose-dependent manner, ProLec was administered to rats with ethanol-induced ulcers, and biochemical, histopathological, and toxicological examinations were performed.

RESULTS

ProLec is a heterodimer of 75 and 68 kDa. It agglutinated all human RBCs, whereas it showed weak interaction with animal erythrocytes. The protein was optimally active at 25 °C and was labile above this temperature. ProLec exhibited two pH optima and was a metalloprotein requiring Ca, Mn, and Ni. It contains 1.6% tryptophan residues of which about 1% is exposed and critical for lectin activity. The lectin exhibited a potent gastroprotective effect against ethanolinduced gastric lesions with no apparent toxicity to both kidneys and liver. Examination of the pH of the gastric juice of lectin-treated animals indicated a possible role of lectin in maintaining stomach acidity within the normal ranges compared to the gastric juice pH of animals that received ethanol only.

CONCLUSION

These results may suggest that ProLec could conceivably be a good future drug for the treatment of gastric ulcers, however, extensive immunological and toxicological research remains to be done.

Mucuna pruriens in Parkinson's and in some other diseases: recent advancement and future prospective

Mucuna pruriens (Mp) is an annual and perennial legume which belongs to the family Fabaceae having different types of therapeutic activity. Anti-oxidative, anti-inflammatory, anti-epileptic, anti-microbial, etc. are the example of some most common activities of Mp. It is widely utilized as a potent aphrodisiac. The anti-Parkinsonian activity of Mp was explored since the nineteenth century. The neuroprotective activity of Mp was shown by several researchers. Levodopa (L-DOPA) is the important constituents responsible for the anti-Parkinsonian activity of Mp. Apart from L-DOPA, several other important bioactive components like Ursolic acid (UA) and Betulinic acid (BA) also exhibit a similar neuroprotective activity. Parkinson's disease (PD) is mainly sporadic. A very small proportion shows the genetic nature of PD. The anti-Parkinsonian activity of Mp was explored in different toxin-induced PD models as like MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), Rotenone, Paraquat, 6-hydroxydopamine (6-OHDA) as suggested by several pieces of literature. Various parts of Mp's like seed, leaf, and stem exhibit potent neuroprotective attributes. Among different parts, seeds are widely utilized as anti-PD agents because of the higher percentage of L-DOPA. Besides anti-PD activity, Mp's neuroprotective potential was also explored in the ischemic model of stroke that also shows positive results. Recently, several clinical trials have been performed on the anti-PD activity of Mp on PD patients that show convincing results. Although, a small population-based study needs to be further validated in the broader population. Apart from anti-PD activity, Mp also shows its therapeutic activity in some other diseases like cancer, diabetes, skin infection, anemia, antihypertensive, etc. that are summarized in Table 1. In this review, we have discussed the anti-PD potential of Mp in the sporadic and genetic model along with some clinical trials that have performed on PD patients. Some other activity of Mp is also summarized in this review. There is a strong need to test the efficacy of Mp in some other neurodegenerative diseases along with PD. Following this, this review emphasizes the role of Mp in PD systematically through literature analysis available to date. [Table: see text].