Mo-CBP4, a purified chitin-binding protein from Moringa oleifera seeds, is a potent antidermatophytic protein: In vitro mechanisms of action, in vivo effect against infection, and clinical application as a hydrogel for skin infection

Structural and Functional Characterization of New Lipid Transfer Proteins with Chitin-Binding Properties: Insights from Protein Structure Prediction, Molecular Docking, and Antifungal Activity

Faced with the emergence of multiresistant microorganisms that affect human health, microbial agents have become a serious global threat, affecting human health and plant crops. Antimicrobial peptides have attracted significant attention in research for the development of new microbial control agents. This work's goal was the structural characterization and analysis of antifungal activity of chitin-binding peptides from Capsicum baccatum and Capsicum frutescens seeds on the growth of Candida and Fusarium species. Proteins were initially submitted to extraction in phosphate buffer pH 5.4 and subjected to chitin column chromatography. Posteriorly, two fractions were obtained for each species, Cb-F1 and Cf-F1 and Cb-F2 and Cf-F2, respectively. The Cb-F1 (C. baccatum) and Cf-F1 (C. frutescens) fractions did not bind to the chitin column. The electrophoresis results obtained after chromatography showed two major protein bands between 3.4 and 14.2 kDa for Cb-F2. For Cf-F2, three major bands were identified between 6.5 and 14.2 kDa. One band from each species was subjected to mass spectrometry, and both bands showed similarity to nonspecific lipid transfer protein. Candida albicans and Candida tropicalis had their growth inhibited by Cb-F2. Cf-F2 inhibited the development of C. albicans but did not inhibit the growth of C. tropicalis. Both fractions were unable to inhibit the growth of Fusarium species. The toxicity of the fractions was tested in vivo on Galleria mellonella larvae, and both showed a low toxicity rate at high concentrations. As a result, the fractions have enormous promise for the creation of novel antifungal compounds.

Exploring the potential of Moringa oleifera Lam in skin disorders and cosmetics: nutritional analysis, phytochemistry, geographical distribution, ethnomedicinal uses, dermatological studies and cosmetic formulations

Moringa oleifera Lam. is a pan-tropical plant well known to the ancient world for its extensive therapeutic benefits in the Ayurvedic and Unani medical systems. The ancient world was familiar with this tree, but it has only lately been rediscovered as a multifunctional species with a huge range of possible therapeutic applications. It is a folk remedy for skin diseases, edema, sore gums, etc. This review comprises the history, ethnomedicinal applications, botanical characteristics, geographic distribution, propagation, nutritional and phytochemical profile, dermatological effects, and commercially available cosmeceuticals of Moringa oleifera Lam.Compilation of all the presented data has been done by employing various search engines like Science Direct, Google, PubMed, Research Gate, EBSCO, SciVal, SCOPUS, and Google Scholar.Studies on phytochemistry claim the presence of a variety of substances, including fatty acids, phenolic acids, sterols, oxalates, tocopherols, carotenoids, flavonoids, flavonols glycosides, tannins, terpenoids, terpene, saponins, phylates, alkaloids, glucosinolates, glycosides, and isothiocyanate. The pharmacological studies have shown the efficacy of Moringa oleifera Lam. as an antibacterial, antifungal, anti-inflammatory, antioxidant, anti-atopic dermatitis, antipsoriatic, promoter of wound healing, effective in treating herpes simplex virus, photoprotective, and UV protective. As a moisturizer, conditioner, hair growth promoter, cleanser, antiwrinkle, anti-aging, anti-acne, scar removal, pigmentation, and control for skin infection, sores, as well as sweating, it has also been utilized in a range of cosmeceuticals.he Moringa oleifera Lam. due to its broad range of phytochemicals can be proven boon for the treatment of dermatological disorders.

Studies on the in vitro mechanism and in vivo therapeutic effect of the antimicrobial peptide ACP5 against Trichophyton mentagrophytes

Trichophyton mentagrophytes is a zoophilic dermatophyte that can cause dermatophytosis in humans and animals. Antimicrobial peptides (AMPs) are considered as a promising agent to overcome the drug-resistance of T. mentagrophytes. Our findings suggest that cationic antimicrobial peptide (ACP5) not only possesses stronger activity against T. mentagrophytes than fluconazole, but also shows lower toxicity to L929 mouse fibroblast cells than terbinafine. Notably, its resistance development rate after resistance induction was lower than terbinafine. The present study aimed to evaluate the fungicidal mechanism of ACP5 in vitro and its potential to treat dermatophyte infections in vivo. ACP5 at 1 ×MIC completely inhibited T. mentagrophytes spore germination in vitro. ACP5 severely disrupts the mycelial morphology, leading to mycelial rupture. Mechanistically, ACP5 induces excessive ROS production, damaging the integrity of the cell membrane and decreasing the mitochondrial membrane potential, causing irreversible damage in T. mentagrophytes. Furthermore, 1% ACP5 showed similar efficacy to the commercially available drug 1% terbinafine in a guinea pig dermatophytosis model, and the complete eradication of T. mentagrophytes from the skin by ACP5 was verified by tissue section observation. These results indicate that ACP5 is a promising candidate for the development of new agent to combat dermatophyte resistance.

In-vitro antimicrobial activity of AF-DP protein and in-silico approach of cell membrane disruption

Microbial resistance against common antibiotics has become one of the most serious threats to human health. The increasing statistics on this problem show the necessity of finding a way to deal with it. In recent years, antimicrobial peptides with unique properties and the capability of targeting a wide range of pathogens, have been considered as a potential for replacing common antibiotics. A small chitin-binding protein with anticandidal activity was isolated from Moringa oleifera seeds by Neto and colleagues in 2017, which very much resembled antimicrobial peptides. In this study, the antimicrobial protein 'AF-DP' was identified and characterized. AF-DP was heterologously expressed, purified, and characterized, and its 3D structure was predicted. Six molecular dynamic simulations were performed to investigate how the protein interacts with Gram-negative inner and outer, Gram-positive, fungal, cancerous, and normal mammalian membranes. Also, its antimicrobial and anticancer activity was assessed in vitro via minimum inhibition concentration (MIC) and MTT assays, respectively. This protein with 111 amino acids and a total net charge (of 10.5) has been predicted to be mainly composed of alpha helix and random coils. Its MIC affecting the growth of Escherichia coli, Staphylococcus aureus, and Candida albicans was 30 µg/ml, 100 µg/ml, and 100 µg/ml, respectively; AF-DP showed anticancer activity against MCF-7 breast cancer cell line. Scanning electron microscopic analysis confirmed the creation of pores and scratches on the surface of the bacterial membrane. The results of this research show that AF-DP can be a candidate for the production of new drugs as an AMP with antimicrobial activity.Communicated by Ramaswamy H. Sarma.

Moringa oleifera seed based green synthesis of copper nanoparticles: Characterization, environmental remediation and antimicrobial activity

Textile dyes and heavy metals like hexavalent chromium [Cr(VI)] are considered major water pollutants. In addition, microbial contamination also seriously threatens potable water availability. The present study used Moringa oleifera seed aqueous extract to synthesize copper nanoparticles (MOS-CuNPs). MOS-CuNPs were characterized by various spectroscopy and microscopic techniques. MOS-CuNPs were shown to be effectual at removal of Cr(VI). The initial concentration of Cr(VI), contact time, pH, and temperature all impacted the removal of Cr(VI) by different concentrations of MOS-CuNPs. At low concentrations of MOS-CuNPs (0.3 mg/ml) pseudo-first order and high concentrations of MOS-CuNPs (0.4 and 0.5 mg/ml), pseudo-second order kinetics were obeyed. Thermodynamic analysis revealed that Cr(VI) was removed spontaneously, and the reaction was exothermic. In adsorption isotherm, equilibrium data followed Langmuir equation for Cr(VI) adsorption by MOS-CuNPs and maximum uptake capacity calculated was 38.6 mg/g. MOS-CuNPs efficiently removed cationic (rhodamine B, malachite green and methylene blue and) and anionic (congo red, titan yellow and methyl orange) dyes within 10 min of contact time. Further MOS-CuNPs showed antimicrobial activity against human pathogenic bacteria and fungi. Altogether, MOS-CuNPs could be used for environmental (water treatment) and biological applications.

Luffa operculata seed proteins: Identification by LC-ESI-MS/MS and biotechnological potential against Candida albicans and C. krusei

L: operculata is a plant commonly found in the North and Northeast of Brazil. Although the regional population knows its medicinal potential, there are few scientific studies about its antimicrobial potential. Thus, this study aimed to characterize the proteins from L. operculata seeds extracted using different solutions and evaluate their antimicrobial potentials. The protein extracts obtained with NaCl and sodium acetate buffer presented the best inhibitory activities against Candida albicans and C. krusei. The study of the mechanism of action revealed proteins from L. operculata seeds induced pore formation on the membrane and ROS overaccumulation. Scanning Electron Microscopy images also showed severe morphological changes in Candida albicans and C. krusei. Proteins from L.operculata seeds did not show antibacterial activity. The enzymatic assays revealed the presence of proteolytic enzymes, serine and cysteine protease inhibitors, and chitinases in both protein extracts. Proteomic analysis by LC-ESI-MS/MS identified 57 proteins related to many biological processes, such as defense to (a)biotic stress, energetic metabolism, protein folding, and nucleotide metabolism. In conclusion, the L. operculata seed proteins have biotechnological potential against the human pathogenic yeasts Candida albicans and C. krusei.

Characterization of a Novel Antimicrobial Peptide Isolated from Moringa oleifera Seed Protein Hydrolysates and Its Membrane Damaging Effects on Staphylococcus aureus

The present study sought to identify and characterize a novel antimicrobial peptide, named MOp2 from Moringa oleifera seed protein hydrolysates, and elucidate its potential antimicrobial effects on Staphylococcus aureus. MOp2, with the amino acid sequence of His-Val-Leu-Asp-Thr-Pro-Leu-Leu (HVLDTPLL), was characterized as a hydrophobic anionic AMP of the β-sheet structure. MOp2 exhibited negligible hemolytic activity at 2.0× MIC, suggesting its inhibitory effect on the growth of S. aureus (MIC: 2.204 mM). It maintained more than 90% of antimicrobial activity under 5% salt and about 78% of antimicrobial activity at a high temperature of 115 °C for 30 min. Protease, especially acid protease, reduced its antimicrobial activity to different extents. Moreover, MOp2 caused irreversible membrane damage to S. aureus cells by increasing the membrane permeability, resulting in the release of intracellular nucleotide pools. Additionally, molecular docking revealed that MOp2 could inhibit S. aureus growth by interacting with dihydrofolate reductase and DNA gyrase through hydrogen bonding and hydrophobic interactions. Overall, MOp2 could be a potential novel antimicrobial agent against S. aureus in food processing.

Therapeutic potential of Moringa oleifera seed polysaccharide embedded silver nanoparticles in wound healing

Wound healing is a complicated process that influences patient's life quality. Plant-based polysaccharide has recently gained interest in its use in wound dressing materials because of its biological compatibility, natural abundance, and ideal physiochemical properties. The present study reveals the potential of polysaccharide isolated from Moringa oleifera seed (MOS-PS) and its nanocomposite with silver (MOS-PS-AgNPs) as alternative materials for wound dressing. First, MOS-PS was isolated and structurally characterized by TLC, HPLC, FTIR, NMR, and GPC analyses. A green and simple method was used to synthesize AgNPs using MOS-PS as a stabilizing and reducing agent. The size, morphology, and structure of the MOS-PS-AgNPs were characterized by UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and zeta potential analysis. The results showed that the MOS-PS-AgNPs were spherically shaped, having no cytotoxicity toward mouse fibroblasts cells and promoting their in-vitro migration. Moreover, the MOS-PS-AgNPs displayed strong anti-microbial activity against wound infectious pathogenic bacteria. Finally, the MOS-PS-AgNPs were used for dressing animal wounds and its preliminary mechanism was studied by RT-PCR and histological analysis. The results showed that the MOS-PS-AgNPs can promote wound contraction and internal tissue growth well. Overall, our results indicated that the MOS-PS-AgNPs might be an excellent candidate for use as an optimal wound dressing material.

Synthetic peptides against Trichophyton mentagrophytes and T. rubrum: Mechanisms of action and efficiency compared to griseofulvin and itraconazole

AIMS

According to the WHO, 20-25% of people worldwide are affected by skin infections caused by dermatophytes, such as those of the Trichophyton genus. Additionally, several dermatophytes have developed resistance to drugs such as griseofulvin and itraconazole. This study tested 2S albumins-derived antimicrobial peptides (AMPs) as alternative antidermatophytic molecules.

MAIN METHODS

Membrane pore formation assays, tests to detect overproduction of ROS, scanning electron microscopy (SEM) and fluorescence microscopy (FM) were carried out to provide insight into the mechanisms of antidermatophytic action.

KEY FINDINGS

All AMPs (at 50 μg mL^-1) tested reduced the mycelial growth of T. mentagrophytes and T. rubrum by up to 95%. In contrast, using a concentration 20-fold higher, griseofulvin only inhibited T. mentagrophytes by 35%, while itraconazole was not active against both dermatophytes. Scanning electron and fluorescence microscopies revealed that the six AMPs caused severe damage to hyphal morphology by inducing cell wall rupture, hyphal content leakage, and death. Peptides also induced membrane pore formation and oxidative stress by overproduction of ROS. Based on the stronger activity of peptides than the commercial drugs and the mechanism of action, all six peptides have the potential to be either employed as models to develop new antidermatophytic drugs or as adjuvants to existing ones.

SIGNIFICANCE

The synthetic peptides are more efficient than conventional drug to treat infection caused by dermatophytes being potential molecules to develop new drugs.

Antidermatophytic activity of synthetic peptides: Action mechanisms and clinical application as adjuvants to enhance the activity and decrease the toxicity of Griseofulvin

BACKGROUND

Dermatophytes belonging to the Trichophyton genus are important human pathogens, but they have developed resistance to griseofulvin, the most common antifungal drug used to treat dermatophytosis.

OBJECTIVE

This study was aimed to evaluate the antidermatophytic activity of synthetic peptides, as well as mechanisms of action and synergistic effect with griseofulvin.

METHODS

Scanning electron microscopy (SEM), atomic force microscopy (AFM) and fluorescence microscopy (FM) were employed to understand the activity and the mechanism of action of peptides.

RESULTS

Here we report that synthetic peptides at 50 μg/mL, a concentration 20-fold lower than griseofulvin, reduced the microconidia viability of T. mentagrophytes and T. rubrum by 100%, whereas griseofulvin decreased their viability by only 50% and 0%, respectively. The action mechanism of peptides involved cell wall damage, membrane pore formation and loss of cytoplasmic content. Peptides also induced overproduction of reactive oxygen species (ROS) and enhanced the activity of griseofulvin 10-fold against both fungi, suggesting synergistic effects, and eliminated the toxicity of this drug to human erythrocytes. Docking analysis revealed ionic and hydrophobic interactions between peptides and griseofulvin, which may explain the decline of griseofulvin toxicity when mixed with peptides.

CONCLUSION

Therefore, our results strongly suggest six peptides with high potential to be employed alone as new drugs or as adjuvants to enhance the activity and decrease the toxicity of griseofulvin.