Pectins fromAloe Vera: Extraction and production of gels for regenerative medicine

New opportunities and perspectives on biosynthesis and bioactivities of secondary metabolites from Aloe vera

Historically, the genus Aloe has been an indispensable part of both traditional and modern medicine. Decades of intensive research have unveiled the major bioactive secondary metabolites of this plant. Recent pandemic outbreaks have revitalized curiosity in aloe metabolites, as they have proven pharmacokinetic profiles and repurposable chemical space. However, the structural complexity of these metabolites has hindered scientific advances in the chemical synthesis of these compounds. Multi-omics research interventions have transformed aloe research by providing insights into the biosynthesis of many of these compounds, for example, aloesone, aloenin, noreugenin, aloin, saponins, and carotenoids. Here, we summarize the biological activities of major aloe secondary metabolites with a focus on their mechanism of action. We also highlight the recent advances in decoding the aloe metabolite biosynthetic pathways and enzymatic machinery linked with these pathways. Proof-of-concept studies on in vitro, whole-cell, and microbial synthesis of aloe compounds have also been briefed. Research initiatives on the structural modification of various aloe metabolites to expand their chemical space and activity are detailed. Further, the technological limitations, patent status, and prospects of aloe secondary metabolites in biomedicine have been discussed.

Role of acemannan and pectic polysaccharides in saline-water stress tolerance of Aloe vera (Aloe barbadensis Miller) plant

This study investigates the impact of water and salinity stress on Aloe vera, focusing on the role of Aloe vera polysaccharides in mitigating these stresses. Pectins and acemannan were the most affected polymers. Low soil moisture and high salinity (NaCl 80 mM) increased pectic substances, altering rhamnogalacturonan type I in Aloe vera gel. Aloe vera pectins maintained a consistent 60 % methyl-esterification regardless of conditions. Interestingly, acemannan content rose with salinity, particularly under low moisture, accompanied by 90 to 150 % acetylation increase. These changes improved the functionality of Aloe vera polysaccharides: pectins increased cell wall reinforcement and interactions, while highly acetylated acemannan retained water for sustained plant functions. This study highlights the crucial role of Aloe vera polysaccharides in enhancing plant resilience to water and salinity stress, leading to improved functional properties.

Pathology and Treatment of Psoriasis Using Nanoformulations

Psoriasis (PSO) is an inflammatory skin condition that causes a variety of diseases and significantly decreases the life characteristics of patients, and substantially diminishes patients' quality of life. PSO usually impairs the skin and is linked to various disorders. Inflammation pathology does not only damage psoriatic skin; it shows how PSO impinges other body parts. Many variables interact with one another and can impact the etiology of psoriasis directly or indirectly. PSO has an effect on approximately 2% of the world's population, and significant progress has been made in comprehending and treating the alternative PSO by novel drug delivery systems. Topical, systemic, biological, biomaterials, and phototherapy are some of the useful therapies for PSO. Nonetheless, topical treatments remain the gold standard for treating moderate PSO. The applicability of several nanocarrier systems, such as lipid nanoparticles, metallic nanoparticles, and certain phytocompounds, has been briefly explored. The present review focuses mainly on traditional therapeutic strategies as well as on breakthroughs in nanoformulations and drug delivery methods for several anti-psoriatic drugs.

A New Functional Food Ingredient Obtained from Aloe ferox by Spray Drying

Aloe mucilages of Aloe ferox (A. ferox) and Aloe vera (A. vera) were spray-dried (SD) at 150, 160 and 170 °C. Polysaccharide composition, total phenolic compounds (TPC), antioxidant capacity and functional properties (FP) were determined. A. ferox polysaccharides were comprised mainly of mannose, accounting for >70% of SD aloe mucilages; similar results were observed for A. vera. Further, an acetylated mannan with a degree of acetylation >90% was detected in A. ferox by ¹H NMR and FTIR. SD increased the TPC as well as the antioxidant capacity of A. ferox measured by both ABTS and DPPH methods, in particular by ~30%, ~28% and ~35%, respectively, whereas in A. vera, the antioxidant capacity measured by ABTS was reduced (>20%) as a consequence of SD. Further, FP, such as swelling, increased around 25% when A. ferox was spray-dried at 160 °C, while water retention and fat adsorption capacities exhibited lower values when the drying temperature increased. The occurrence of an acetylated mannan with a high degree of acetylation, together with the enhanced antioxidant capacity, suggests that SD A. ferox could be a valuable alternative raw material for the development of new functional food ingredients based on Aloe plants.

Aloe Vera coated Dextran Sulfate/Chitosan nanoparticles (Aloe Vera @ DS/CS) encapsulating Eucalyptus essential oil with antibacterial potent property

The goal of this work is to encapsulate Eucalyptus staigeriana essential oil in biopolymer matrices, to optimize the biological effects and the antibacterial properties of this oil. In this study, Eucalyptus extract was encapsulated in Aloe Vera coated Dextran Sulfate/Chitosan nanoparticles to form a hydrogel with potent properties. In this study, Eucalyptus extract was loaded on to Aloe Vera coated Dextran Sulphate/Chitosan nanoparticles to obtain a nano-hydrogel with potent properties. The characterization of nanoparticles was evaluated using transmission and scanning electron microscopes, dynamic light scattering, Fourier transform infrared spectroscopy, differential scanning calorimetry and antibacterial activity. The E. staigeriana release profile from the prepared nanoparticles was studied in vitro at a pH of 7.4. The results showed that this nano-carrier controls Eucalyptus release. Aloe Vera coated Dextran Sulfate/Chitosan nanoparticles encapsulated with E. staigeriana inhibited the bacteria by 47.27%. These investigations concluded that E. staigeriana loaded Aloe Vera coated Dextran Sulfate/Chitosan hydrogel could be used as a powerful dressing material to accelerate wound healing.

The Therapeutic Potential of Plant Polysaccharides in Metabolic Diseases

Plant polysaccharides (PPS) composed of more than 10 monosaccharides show high safety and various pharmacological activities, including immunoregulatory, antitumor, antioxidative, antiaging, and other effects. In recent years, emerging evidence has indicated that many PPS are beneficial for metabolic diseases, such as cardiovascular disease (CVD), diabetes, obesity, and neurological diseases, which are usually caused by the metabolic disorder of fat, sugar, and protein. In this review, we introduce the common characteristics and functional activity of many representative PPS, emphasize the common risks and molecular mechanism of metabolic diseases, and discuss the pharmacological activity and mechanism of action of representative PPS obtained from plants including Aloe vera, Angelica sinensis, pumpkin, Lycium barbarum, Ginseng, Schisandra chinensis, Dioscorea pposite, Poria cocos, and tea in metabolic diseases. Finally, this review will provide directions and a reference for future research and for the development of PPS into potential drugs for the treatment of metabolic diseases.

Ultrasound-Assisted Encapsulation of Anthraquinones Extracted from Aloe-Vera Plant into Casein Micelles

Aloe-vera extracted anthraquinones (aloin, aloe-emodin, rhein) possess a wide range of biological activities, have poor solubility and are sensitive to processing conditions. This work investigated the ultrasound-assisted encapsulation of these extracted anthraquinones (AQ) into casein micelles (CM). The particle size and zeta potential of casein micelles loaded with aloin (CMA), aloe-emodin (CMAE), rhein (CMR) and anthraquinone powder (CMAQ) ranged between 171–179 nm and −23 to −17 mV. The AQ powder had the maximum encapsulation efficiency (EE%) (aloin 99%, aloe-emodin 98% and rhein 100%) and encapsulation yield, while the whole leaf Aloe vera gel (WLAG) had the least encapsulation efficiency. Spray-dried powder (SDP) and freeze-dried powder (FDP) of Aloe vera showed a significant increase in size and zeta potential related to superficial coating instead of encapsulation. The significant variability in size, zeta potential and EE% were related to anthraquinone type, its binding affinity, and its ratio to CM. FTIR spectra confirmed that the structure of the casein micelle remained unchanged with the binding of anthraquinones except in casein micelles loaded with whole-leaf aloe vera gel (CMWLAG), where the structure was deformed. Based on our findings, Aloe vera extracted anthraquinones powder (AQ) possessed the best encapsulation efficiency within casein micelles without affecting its structure. Overall, this study provides new insights into developing new product formulations through better utilization of exceptional properties of casein micelles.

Aloe vera incorporated starch-64S bioactive glass-quail egg shell scaffold for promotion of bone regeneration

Simultaneous promotion of osteoconductive and osteoinductive characteristics through combining bioactive glasses with natural polymers is still a challenge in bone tissue engineering. Starch, 64S bioactive glass (BG), aloe vera (AV) and quail eggshell powder (QE) were utilized to achieve biodegradable, bioactive, biocompatible and mechanically potent multifunctional scaffolds, using freeze-drying mechanism. Cell viability for starch-BG-AV-QE scaffolds at 3 and 7 day intervals was reported to be over 95 %. Acridine orange staining was employed to study live/dead cells cultured on the scaffolds. The high sufficiency of starch-BG-AV-QE scaffolds in osteogenic differentiation and extracellular matrix mineralization was confirmed through alkaline phosphatase activity and alizarin red staining assessments after 7 and 14 days of cell culture. High compressive strength, managed biodegradability and expression of osteocalcin and osteopontin as late markers of osteogenic differentiation were also reached in the range of 30-75 % for starch-BG-AV-QE scaffolds. Hence, starch-BG-AV-QE scaffolds with ideal physico-mechanical and biological characteristics can be considered as promising candidates for promotion of bone regeneration.

Development of Eco-Friendly Nanomembranes of Aloe vera/PVA/ZnO for Potential Applications in Medical Devices

Due to the current COVID-19 pandemic, there is a crucial need for the development of antimicrobial and antiviral personal protective equipment such as facemasks and gowns. Therefore, in this research we fabricated electrospun nanofibers composite with polyvinyl alcohol, aloe vera, and zinc oxide nanoparticles for end application in medical devices. Electrospun nanofibers were made with varying concentrations of aloe vera (1%, 2%, 3%, 4%) having a constant concentration of ZnO (0.5%) with varying concentrations of ZnO nanoparticles (1%, 2%, 3%, 4%) having a constant concentration of aloe vera (0.5%). To check the morphology and composition, all prepared nanofibers were subjected to different characterization techniques, such as Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). In addition, its antimicrobial activity was checked both with qualitative and quantitative approaches against gram-positive (Staphylococcus aureus) bacteria and gram-negative (Escherichia coli) bacteria. The results suggest that increasing ZnO concentration kills and inhibits bacterial growth more proficiently compared to increasing aloe vera concentration in electrospun nanofibers; the highest antimicrobial was found with 4% ZnO, killing almost 100% of gram-positive (Staphylococcus aureus) bacteria and 99.2% of gram-negative (Escherichia coli) bacteria. These fabricated nanofibers have potential applications in medical devices and would help control the spread of many diseases.

Mango Peel Pectin: Recovery, Functionality and Sustainable Uses

Concerns regarding the overconsumption of natural resources has provoked the recovery of biopolymers from food processing biomass. Furthermore, the current market opportunity for pectin in other areas has increased, necessitating the search for alternative pectin resources. This is also a step towards the sustainable and circular green economy. Mango peel is the byproduct of agro-processing and has been used for high value-added components such as polysaccharide biopolymers. Pectin derived from the peel is yet to be exploited to its greatest extent, particularly in terms of its separation and physiochemical properties, which limit its applicability to dietary fiber in culinary applications. The functionality of the mango peel pectin (MPP) strongly depends on the molecular size and degree of esterification which highlight the importance of isolation and characterisation of pectin from this novel resource. This article therefore provides a useful overview of mango peel as a potential biomaterial for the recovery of MPP. Different extraction techniques and the integrated recovery were also discussed. The utilisation of MPP in different industrial schemes are also detailed out from different perspectives such as the pharmaceutical and biotechnology industries. This review convincingly expresses the significance of MPP, providing a sustainable opportunity for food and pharmaceutical development.

Pharmacodynamics of Aloe vera and acemannan in therapeutic applications for skin, digestion, and immunomodulation

Scientific studies of Aloe vera have tentatively explained therapeutic claims from a mechanistic perspective. Furthermore, in vitro outcomes demonstrate that the breakage of acemannan chains into smaller fragments enhances biological effects. These fragments can intravenously boost vaccine efficacy or entrain the immune system to attack cancer cells by mannose receptor agonism of macrophage or dendritic cells. With oral consumption, epithelialisation also occurs at injured sites in the small intestine or colon. The main advantage of dietary acemannan is the attenuation of the digestive process, increasing satiety, and slowing the release of sugars from starches. In the colon, acemannan is digested by microbes into short-chain fatty acids that are absorbed and augment the sensation of satiety and confer a host of other health benefits. In topical applications, an acemannan/chitosan combination accelerates the closure of wounds by promoting granular tissue formation, which creates a barrier between macrophages or neutrophils and the wound dressing. This causes M2 polarisation, reversal of inflammation, and acceleration of the re-epithelialisation process. This review summarises and explains the current pharmacodynamic paradigm in the context of acemannan in topical, oral, and intravenous applications. However, due to contradictory results in the literature, further research is required to provide scientific evidence to confirm or nullify these claims.

Fabrication of Promising Antimicrobial Aloe Vera/PVA Electrospun Nanofibers for Protective Clothing

In the present condition of COVID-19, the demand for antimicrobial products such as face masks and surgical gowns has increased. Because of this increasing demand, there is a need to conduct a study on the development of antimicrobial material. Therefore, this study was conducted on the development of Aloe Vera and Polyvinyl Alcohol (AV/PVA) electrospun nanofibers. Four different fibers were developed by varying the concentrations of Aloe vera (0.5%, 1.5%, 2.5%, and 3%) while maintaining the concentration of PVA constant. The developed samples were subjected to different characterization techniques such as SEM, FTIR, XRD, TGA, and ICP studies. After that, the antimicrobial activity of the developed Aloe Vera/PVA electrospun nanofibers was checked against Gram-positive (Staphylococcus aureus) bacteria and Gram-negative (Escherichia coli) bacteria. The developed nanofibers had high profile antibacterial activity against both bacteria, but showed excellent results against S. aureus bacteria as compared with E. coli. These nanofibers have potential applications in the development of surgical gowns, gloves, etc.

Evaluation of Kluyveromyces marxianus endo-polygalacturonase activity through ATR-FTIR

The endo-polygalacturonase enzyme (endoPG: EC 3.2.1.15) plays an important role in the fruit juice and wine industries, so the development of new tools for the quantitative and qualitative analysis of its enzymatic action is necessary. In this work, we report the development of a simple, fast and practical method that did not use any chemical reagent to identify and evaluate the action of the endoPG enzyme, produced by the yeast Kluyveromyces marxianus CCT3172, using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy combined with principal component analysis-linear discriminant analysis (PCA-LDA). This method evaluated the action of the endoPG enzyme on the polygalacturonic acid (PGA) substrate at 5 different times (0, 10, 15, 20 and 30 minutes), and at each time interval the samples were analyzed by ATR-FTIR. It was demonstrated that there was clear segregation between the samples that were and that were not subjected to the action of the endoPG enzyme, and it was also possible to distinguish the samples that were subjected to different incubation times with the enzyme. Through PCA-LDA it was possible to obtain wavelengths that are biomarkers for this enzymatic reaction and the observed changes as a function of hydrolysis duration were found to be in agreement with the breakdown of the glycosidic chain (1011 cm^-1-CH-O- CH stretching) of PGA and release of oligosaccharides (1078 cm^-1 C-OH elongation). The activity of the endoPG enzyme and the release of galacturonic acid were verified by the dinitrosalicylic acid (DNS) method in all samples. The efficacy of an automatic classifier using a principal component analysis-linear discriminant classifier (PCA-LDC) was evaluated to diagnose the action of the endoPG enzyme. The results showed an accuracy of 100% for the identification of the endoPG enzyme action and from 91.67% to 100% for classification according to the hydrolysis duration in which PGA was exposed to endoPG. The present study indicates that this methodology may be a new approach for the qualitative evaluation of the endoPG enzyme with the potential to be used in laboratories and industries.

Rheological and functional properties of Roselle (Hibiscus sabdariffa) leaves puree

Pureed form of leaves (Hibiscus sabdariffa L. (Roselle)) was taken for physicochemical and rheological analysis at temperatures and TSS range of 278 K - 318 K and 3 - 5 °Brix respectively. The steady-state rheological analysis was performed with a shear rate of 1 - 100 s-1. Different rheological models are tried; Power-law was best fitted with the experimental data (R2 ≥0.98). Temperature dependence of viscosity was found out using an Arrhenius-type relationship at a shear rate of 10, 50, 100 s-1 IR analysis was done to know the influence of functional groups on rheological properties of purees. Consistency index (K) of puree increases with increase in TSS content but at a fixed TSS, there is a decrease in K with an increase in temperatures but the opposite was observed for flow behavior index (n). Puree showed a shear thinning behavior with an increment in temperature level and puree having 5 °Brix (8.37) has higher activation energy (kJ.mol-1) than 3 °Brix (6.32). 

Perspectives on the basic and applied aspects of crassulacean acid metabolism (CAM) research

Due to public concerns about the decreasing supply of blue water and increasing heat and drought stress on plant growth caused by urbanization, increasing human population and climate change, interest in crassulacean acid metabolism (CAM), a specialized type of photosynthesis enhancing water-use efficiency (WUE) and drought tolerance, has increased markedly. Significant progress has been achieved in both basic and applied research in CAM plants since the beginning of this century. Here we provide a brief overview of the current status of CAM research, and discuss future needs and opportunities in a wide range of areas including systems biology, synthetic biology, and utilization of CAM crops for human benefit, with a focus on the following aspects: 1) application of genome-editing technology and high-throughput phenotyping to functional genomics research in model CAM species and genetic improvement of CAM crops, 2) challenges for multi-scale metabolic modeling of CAM systems, 3) opportunities and new strategies for CAM pathway engineering to enhance WUE and drought tolerance in C₃ (and C₄) photosynthesis crops, 4) potential of CAM species as resources for food, feed, natural products, pharmaceuticals and biofuels, and 5) development of CAM crops for ecological and aesthetic benefits.

Nanoencapsulation of Aloe vera in Synthetic and Naturally Occurring Polymers by Electrohydrodynamic Processing of Interest in Food Technology and Bioactive Packaging

This work originally reports on the use of electrohydrodynamic processing (EHDP) to encapsulate Aloe vera (AV, Aloe barbadensis Miller) using both synthetic polymers, i.e., polyvinylpyrrolidone (PVP) and poly(vinyl alcohol) (PVOH), and naturally occurring polymers, i.e., barley starch (BS), whey protein concentrate (WPC), and maltodextrin. The AV leaf juice was used as the water-based solvent for EHDP, and the resultant biopolymer solution properties were evaluated to determine their effect on the process. Morphological analysis revealed that, at the optimal processing conditions, synthetic polymers mainly produced fiber-like structures, while naturally occurring polymers generated capsules. Average sizes ranged from 100 nm to above 3 μm. As a result of their different and optimal morphology and, hence, higher AV content, PVP, in the form of nanofibers, and WPC, of nanocapsules, were further selected to study the AV stability against ultraviolet (UV) light exposure. Fourier transform infrared (FTIR) spectroscopy confirmed the successful encapsulation of AV in the biopolymer matrices, presenting both encapsulants a high chemical interaction with the bioactive components. Ultraviolet-visible (UV-vis) spectroscopy showed that, while PVP nanofibers offered a poor effect on the AV degradation during UV light exposure (∼10% of stability after 5 h), WPC nanobeads delivered excellent protection (stability of >95% after 6 h). This was ascribed to positive interactions between WPC and the hydrophilic components of AV and the inherent UV-blocking and oxygen barrier properties provided by the protein. Therefore, electrospraying of food hydrocolloids interestingly appears as a novel potential nanotechnology tool toward the formulation of more stable functional foods and nutraceuticals.

Advances on Bioactive Polysaccharides from Medicinal Plants

In recent decades, the polysaccharides from the medicinal plants have attracted a lot of attention due to their significant bioactivities, such as anti-tumor activity, antioxidant activity, anticoagulant activity, antidiabetic activity, radioprotection effect, anti-viral activity, hypolipidemic and immunomodulatory activities, which make them suitable for medicinal applications. Previous studies have also shown that medicinal plant polysaccharides are non-toxic and show no side effects. Based on these encouraging observations, most researches have been focusing on the isolation and identification of polysaccharides, as well as their bioactivities. A large number of bioactive polysaccharides with different structural features and biological effects from medicinal plants have been purified and characterized. This review provides a comprehensive summary of the most recent developments in physiochemical, structural features and biological activities of bioactive polysaccharides from a number of important medicinal plants, such as polysaccharides from Astragalus membranaceus, Dendrobium plants, Bupleurum, Cactus fruits, Acanthopanax senticosus, Angelica sinensis (Oliv.) Diels, Aloe barbadensis Miller, and Dimocarpus longan Lour. Moreover, the paper has also been focused on the applications of bioactive polysaccharides for medicinal applications. Recent studies have provided evidence that polysaccharides from medicinal plants can play a vital role in bioactivities. The contents and data will serve as a useful reference material for further investigation, production, and application of these polysaccharides in functional foods and therapeutic agents.

Effects of drying temperature and ethanol concentration on bipolar switching characteristics of natural Aloe vera-based memory devices

Natural Aloe vera provides a biodegradable, biocompatible, and renewable avenue for the sustainable development of electronics.