Activation of a mouse macrophage cell line by acemannan: the major carbohydrate fraction from Aloe vera gel

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.

Nutritional and functional roles of β-mannanase on intestinal health and growth of newly weaned pigs fed two different types of feeds

This study aimed to investigate the nutritional and functional roles of β-mannanase on the intestinal health and growth of newly weaned pigs fed a typical or low-cost formulated feeds (LCF). Twenty-four newly weaned pigs at 6.2 kg ± 0.4 body weight (BW) were allotted to three dietary treatments based on a randomized complete block design with sex and initial BW as blocks. Three dietary treatments are as follows: Control, typical nursery feeds including animal protein supplements and enzyme-treated soybean meal; LCF with increased amounts of soybean meal, decreased amounts of animal protein supplements, and no enzyme-treated soybean meal; LCF+, low-cost formulated feed with β-mannanase at 100 g/t, providing 800 thermostable β-mannanase unit (TMU) per kg of feed. Pigs were fed based on a three-phase feeding program for a total of 37 d. On day 37 of feeding, all pigs were euthanized and the gastrointestinal tract was removed for sample collection to analyze intestinal health parameters, mucosa-associated microbiota, and gene expression of tight junction proteins. Pigs fed LCF increased (P < 0.05) the relative abundance of Proteobacteria and Helicobacter in the jejunal mucosa, tended to decrease (P = 0.097; P = 0.098) the concentration of malondialdehyde (MDA) and the expression of zona occluden 1 (ZO-1) gene in the jejunum, tended to decrease average daily gain (ADG; P = 0.084) and final BW (P = 0.090), and decreased (P < 0.05) average daily feed intake. Pigs fed LCF + tended to decrease (P = 0.088) digesta viscosity, decreased (P < 0.05) the relative abundance of Helicobacter, and increased (P < 0.05) Lactobacillus in the jejunal mucosa compared to LCF. Additionally, LCF + tended to increase final BW (P = 0.059) and ADG (P = 0.054), increased (P < 0.05) gain to feed ratio (G:F), and reduced (P < 0.05) fecal score compared to LCF. LCF with decreased amounts of animal protein supplements and increased amounts of soybean meal had negative effects on the composition of the mucosa-associated microbiota, intestinal integrity, and growth performance of nursery pigs. Beta-mannanase supplementation to LCF decreased digesta viscosity, increased the relative abundance of potentially health-benefitting microbiota such as Lactobacillus, and improved growth and fecal score, thus reflecting its efficacy in low-cost formulated feeds with increased amounts of soybean meal.

Rapid increase in immune surveillance and expression of NKT and γδT cell activation markers after consuming a nutraceutical supplement containing Aloe vera gel, extracts of Poria cocos and rosemary. A randomized placebo-controlled cross-over trial

GOAL

To evaluate the acute impact of a nutraceutical blend on immune surveillance.

STUDY DESIGN

A randomized, double-blind, placebo-controlled, cross-over trial was conducted in 11 healthy subjects. Blood samples were taken immediately before and at 1, 2, and 3 hours after consuming placebo or 500 mg of UP360, which is a blend of botanicals from Aloe vera, Poria cocos, and rosemary (APR extract). Immunophenotyping and flow cytometry quantified numbers of monocytes, NK cells, NKT cells, CD8+ cytotoxic T cells, γδT cells, and total T cells, and expression of CD25 and CD69 activation markers. Plasma was tested for cytokines, chemokines, growth factors, and enzymatic activity of superoxide dismutase and catalase.

RESULTS

Compared to the placebo, consumption of APR extract triggered rapid increases in chemokine levels starting at 1 hour, including IP-10 (P<0.05) and MCP-1 (P<0.1), which peaked at 2 hours (P<0.01) and 3 hours (P<0.05), respectively. The stem cell-mobilizing growth factor G-CSF increased at 2 hours (P<0.05). Increased immune surveillance involved a transient effect for monocytes at 1 hour, followed by NKT cells, CD8+ cytotoxic T cells, and γδT cells at 2-3 hours. Increased immune cell alertness was seen at 1 hour by increased CD25 expression on monocytes (P<0.01), NKT cells (P<0.01), and T cells (P<0.05). NKT cells showed upregulation of CD69 at 2 hours (P<0.01). Increased enzymatic activity was seen at 2 hours for the antioxidant enzymes superoxide dismutase (P<0.05) and catalase (P<0.01).

CONCLUSION

Consumption of APR extract triggered acute changes to chemokine levels. In addition, immune alertness was increased via the expression of activation markers on multiple types of innate immune cells, followed by increased immune surveillance and antioxidant protection. This suggests a beneficial enhancement of natural immune surveillance, likely via a combination of gut-mediated cytokine release and vagus nerve communication, in combination with cellular protection from oxidative stress.

A New Biomaterial Derived from Aloe vera-Acemannan from Basic Studies to Clinical Application

Aloe vera is a kind of herb rich in polysaccharides. Acemannan (AC) is considered to be a natural polysaccharide with good biodegradability and biocompatibility extracted from Aloe vera and has a wide range of applications in the biomedical field due to excellent immunomodulatory, antiviral, antitumor, and tissue regeneration effects. In recent years, clinical case reports on the application of AC as a novel biomedical material in tissue regenerative medicine have emerged; it is mainly used in bone tissue engineering, pulp-dentin complex regeneration engineering, and soft tissue repair, among other operations. In addition, multiple studies have proved that the new composite products formed by the combination of AC and other compounds have excellent biological and physical properties and have broader research prospects. This paper introduces the preparation process, surface structure, and application forms of AC; summarizes the influence of acetyl functional group content in AC on its functions; and provides a detailed review of the functional properties, laboratory studies, clinical cutting-edge applications, and combined applications of AC. Finally, the current application status of AC from basic research to clinical treatment is analyzed and its prospects are discussed.

Aloe vera-Based Hydrogels for Wound Healing: Properties and Therapeutic Effects

Aloe vera-based hydrogels have emerged as promising platforms for the delivery of therapeutic agents in wound dressings due to their biocompatibility and unique wound-healing properties. The present study provides a comprehensive overview of recent advances in the application of Aloe vera-based hydrogels for wound healing. The synthesis methods, structural characteristics, and properties of Aloe vera-based hydrogels are discussed. Mechanisms of therapeutic agents released from Aloe vera-based hydrogels, including diffusion, swelling, and degradation, are also analyzed. In addition, the therapeutic effects of Aloe vera-based hydrogels on wound healing, as well as the reduction of inflammation, antimicrobial activity, and tissue regeneration, are highlighted. The incorporation of various therapeutic agents, such as antimicrobial and anti-inflammatory ones, into Aloe vera-based hydrogels is reviewed in detail. Furthermore, challenges and future prospects of Aloe vera-based hydrogels for wound dressing applications are considered. This review provides valuable information on the current status of Aloe vera-based hydrogels for the delivery of therapeutic agents in wound dressings and highlights their potential to improve wound healing outcomes.

Immunopathological studies on Escherichia coli infected broiler chickens fed on Aloe vera leaf extract

Escherichia coli infection is the major bacterial disease affecting the poultry industry and the continuous use of antibiotics in poultry farming has resulted in antibiotic resistance. So this study was planned to evaluate the use of an ecologically safe alternative to fight against infections. The leaf gel of the Aloe vera plant was selected based on its antibacterial activity assessed in in-vitro tests. The objective of the present study was to evaluate the effect of A. vera leaf extract supplementation on the severity of clinical signs and pathological lesions, mortality rate, levels of antioxidant enzymes, and immune response in experimentally E. coli-infected broiler chicks. Broiler chicks were supplemented with aqueous Aloe vera Leaf (AVL) extract @ 20 ml per liter of water from day one of age. After seven days of age, they were experimentally infected with E. coli O78 @ 10⁷ CFU/0.5 ml intraperitoneally. Blood was collected at weekly intervals up to 28 days and assayed for antioxidant enzyme assays, and humoral and cellular immune response. The birds were observed daily for clinical signs and mortality. Dead birds were examined for gross lesions and representative tissues were processed for histopathology. The activities of antioxidants, Glutathione reductase (GR), and Glutathione-S-Transferase (GST) were significantly higher than the control infected group. The E. coli-specific antibody titer and Lymphocyte stimulation Index were comparatively higher in the AVL extract-supplemented infected group as compared to the control infected group. No considerable change was noted in the severity of clinical signs and pathological lesions, and mortality. Thus, Aloe vera Leaf gel extract enhanced the antioxidant activities and cellular immune responses of infected broiler chicks to combat this infection.

Characterization of a bioscaffold containing polysaccharide acemannan and native collagen for pulp tissue regeneration

Dental pulp regeneration exploits tissue engineering concepts using stem cells/scaffolds/growth-factors. Extracted collagen is commonly used as a biomaterial-scaffold due to its biocompatibility/biodegradability and mimics the natural extracellular matrix. Adding biomolecules into a collagen-scaffold enhanced pulp regeneration. Acemannan, β-(1-4)-acetylated-polymannose, is a polysaccharide extracted from aloe vera. Acemannan is a regenerative biomaterial. Therefore, acemannan could be a biomolecule in a collagen-scaffold. Here, acemannan and native collagen were obtained and characterized. The AceCol-scaffold's physical properties were investigated using FTIR, SEM, contact angle, swelling, pore size, porosity, compressive modulus, and degradation assays. The AceCol-scaffold's biocompatibility, growth factor secretion, osteogenic protein expression, and calcification were evaluated in vitro. The AceCol-scaffolds demonstrated higher hydrophilicity, swelling, porosity, and larger pore size than the collagen scaffolds (p < 0.05). Better cell-cell and cell-scaffold adhesion, and dentin extracellular matrix protein (BSP/OPN/DSPP) expression were observed in the AceCol-scaffold, however, DSPP expression was not detected in the collagen group. Significantly increased cellular proliferation, VEGF and BMP2 expression, and mineralization were detected in the AceCol-scaffold compared with the collagen-scaffold (p < 0.05). Computer simulation revealed that acemannan's 3D structure changes to bind with collagen. In conclusion, the AceCol-scaffold synergistically provides better physical and biological properties than collagen. The AceCol-scaffold is a promising material for tissue regeneration.

Aloe vera: A Sustainable Green Alternative to Exclude Antibiotics in Modern Poultry Production

Over the past 50 years, there has been a rapid increase in the need for poultry meat on a global scale to meet the rising demand from health, ecology, safety and equity. However, there has been a significant rise in recent years in both public demand and scientific interest for organic poultry farming, particularly when using medicinal herbs due to the rising concern of antibiotic resistance in end users. Ban on the use of antibiotics in the poultry industry has resulted in the demand of herbs as alternatives to antibiotics. Various research efforts have illustrated the nutritional value of Aloe vera in improving growth performance and immune status and acting as an antibacterial and anticoccidial agent in poultry. Aloe vera has been used as a supplement in the form of gel, alcoholic extract, powder, polysaccharide and aqueous extract. Aloe vera contains more than 200 nutrients, bioactive compounds, polysaccharides and saponins. In the current review, we have detailed the effect of Aloe vera as an alternative to antibiotics on growth performance, antimicrobial and antiparasitic activities and blood biochemical alternations in poultry.

Therapeutic Plants with Immunoregulatory Activity and Their Applications: A Scientific Vision of Traditional Medicine in Times of COVID-19

The progression of SARS-CoV-2 (COVID-19) in humans heavily depends on the patient's overall health status, especially on its immunoregulatory capacity. Different plants and plant-derived preparations (infusions, encapsulated, etc.) have been used as immunoregulators, several of them with scientific support. Nevertheless, due to the composition complexity of such plant-derived preparations, the molecular and physiological mechanisms involved in their beneficial effects remain, in some cases, unclear. In this review article, the most reported plants used in traditional medicine to enhance immunoregulatory capacity are presented, and their effect on the innate immune response is discussed and correlated with their respective phytochemical profile. Understanding how the plant phytochemical profile relates to the observed impact on the innate and adaptative immune response is fundamental to designing plant-derived co-treatments to lessen the symptoms and favor the recovery of COVID-19 patients. In this regard, we propose a prospective guideline for using plants and plant-derived preparations as co-treatments for COVID-19 (and similar viral infections), which could be helpful in the context of the worldwide effort to end the current SARS-CoV-2 pandemic.

Anticancer potential of poly(2-aminobenzoic acid)-blend-Aloe vera against the human breast cancer cell line MDA-MB-231

Breast cancer in women is amongst the most significant concerns from time immemorial in the field of oncology. This study proposes an anticancerous polymeric material based on an electroactive substituted polyaniline blend, poly(2-aminobenzoic acid)-blend-Aloe vera (PABA/AV) synthesized by the emulsion polymerization method. The structural, thermal, and morphological characteristics determined using FT-IR and UV-Visible Spectroscopy, XRD, TGA, DTA, and SEM-EDX validated the thermally stable, semi-crystalline, emeraldine salt structure. The material is semi-conducting, and the electrical conductivity measured is 1.86 × 10−3 S/cm. It shows bactericidal efficacy against Enterococcus faecalis at a minimum inhibitory and minimum bactericidal concentration of 50 μg/mL. The radical cations in the emeraldine polymer chain reduce the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and exhibit a significant % of DPPH scavenging (89.85%) at 20 μL. The polymer blend is active against the human breast cancer cell line MDA-MB-231 and causes 78.65% cytotoxicity at a concentration of 125 μg/mL. The synergistic effect of the ancient healing Aloe vera plant and the electroactive biocompatible poly(2-aminobenzoic acid) certainly opens up new developments in the field of cancer therapy.

Differences in Metabolite Composition of Aloe barbadensis Mill. Extracts Lead to Differential Effects on Human Blood T Cell Activity In Vitro

Aloe barbadensis Mill. (Aloe) is used for diverse therapeutic properties including immunomodulation. However, owing to the compositionally complex nature of Aloe, bioactive component(s) responsible for its beneficial properties, though thought to be attributed to polysaccharides (acemannan), remain unknown. We therefore aimed to determine the metabolite composition of various commercial Aloe extracts and assess their effects on human blood T cell activity in vitro. Peripheral blood mononuclear cells (PBMC) from healthy donors were stimulated polyclonally in presence or absence of various Aloe extracts. T cell phenotype and proliferation were investigated by flow cytometry. Aloe extracts were analyzed using targeted ¹H-NMR spectroscopy for standard phytochemical quality characterization and untargeted gas chromatography mass spectrometry (GC-MS) for metabolite profiling. Aloe extracts differing in their standard phytochemical composition had varying effects on T cell activation, proliferation, apoptosis, and cell-death in vitro, although this was not related to the acemannan content. Furthermore, each Aloe extract had its own distinct metabolite profile, where extracts rich in diverse sugar and sugar-derivatives were associated with reduced T cell activity. Our results demonstrate that all commercial Aloe extracts are unique with distinct metabolite profiles, which lead to differential effects on T cell activity in vitro, independent of the acemannan content.

Effects of Carbon Nanomaterials and Aloe vera on Melanomas—Where Are We? Recent Updates

Melanoma is an aggressive skin cancer that affects approximately 140,000 people worldwide each year, with a high fatality rate. Available treatment modalities show limited efficacy in more severe cases. Hence, the search for new treatment modalities, including immunotherapies, for curing, mitigating, and/or preventing cancer is important and urgently needed. Carbon nanoparticles associated with some plant materials, such as Aloe vera, have shown appealing antineoplastic activity, derived mainly from the compounds aloin, aloe-emodin, barbaloin acemannan, and octapeptide, thus representing new possibilities as antitumor agents. This systematic review aims to arouse interest and present the possibilities of using Aloe vera combined with carbon-based nanomaterials as an antineoplastic agent in the treatment and prevention of melanoma. Limitations and advances in melanoma treatment using functionalized carbon nanomaterials are discussed here. Moreover, this review provides the basis for further studies designed to fully explore the potential of carbon nanomaterials associated with Aloe vera in the treatment of various cancers, with a focus on melanoma.

Does supplementing β-mannanase modulate the feed-induced immune response and gastrointestinal ecology in poultry and pigs? An appraisal

The provision of adequate and balanced nutrients is critical for efficient and profitable animal protein production. However, non-nutritive components in feedstuffs can elicit responses that can negatively impact nutrient utilization efficiency. For example, dietary β-mannans are recognizable by cell surface mannose receptors are pivotal for diverse cellular functions. This review will evaluate the physiological implications of dietary native β-mannans, the utility of supplemental feed β-mannanase in hydrolyzing β-mannans, and subsequent metabolic responses. Dietary native β-mannans have been implicated in inadvertent stimulation of immune response through a phenomenon called the feed-induced immune response (FIIR), that has been associated with intestinal inflammation and depression in animal performance. Supplemental β-mannanase blunted the FIIR by hydrolyzing native β-mannans to smaller fragments with a reduced ability to stimulate the innate immune system as indicated by the modulation of oxidative stress, mucosal permeability, and blood concentration of acute phase proteins and immunoglobulins in broilers and piglet models. Moreover, β-mannanase hydrolysis of native β-mannans to mannooligosaccharides (MOS) impacted gastrointestinal microbial ecology. Indeed, β-mannanase-derived MOS reduced the concentration of pathogenic bacteria such as Escherichia coli and Salmonella and increased the production of short-chain fatty acids in gastrointestinal tracts of various animal models. Consequently, by hydrolyzing native β-mannans, supplemental β-mannanase may have nutritional, metabolic, and microbial ecology benefits. In summary, integrating multi-functional feed additives such as β-mannanase into feeding programs for monogastric animals will be critical for efficient and sustainable animal protein production in the context of evolving challenges such as the mandated elimination of use of antibiotics for growth promotion.

Phytochemistry and Biological Activity of Medicinal Plants in Wound Healing: An Overview of Current Research

Wound healing is a complicated process, and the effective management of wounds is a major challenge. Natural herbal remedies have now become fundamental for the management of skin disorders and the treatment of skin infections due to the side effects of modern medicine and lower price for herbal products. The aim of the present study is to summarize the most recent in vitro, in vivo, and clinical studies on major herbal preparations, their phytochemical constituents, and new formulations for wound management. Research reveals that several herbal medicaments have marked activity in the management of wounds and that this activity is ascribed to flavonoids, alkaloids, saponins, and phenolic compounds. These phytochemicals can act at different stages of the process by means of various mechanisms, including anti-inflammatory, antimicrobial, antioxidant, collagen synthesis stimulating, cell proliferation, and angiogenic effects. The application of natural compounds using nanotechnology systems may provide significant improvement in the efficacy of wound treatments. Increasing the clinical use of these therapies would require safety assessment in clinical trials.

Utilization of Aloe Compounds in Combatting Viral Diseases

Plants contain underutilized resources of compounds that can be employed to combat viral diseases. Aloe vera (L.) Burm. f. (syn. Aloe barbadensis Mill.) has a long history of use in traditional medicine, and A. vera extracts have been reported to possess a huge breadth of pharmacological activities. Here, we discuss the potential of A. vera compounds as antivirals and immunomodulators for the treatment of viral diseases. In particular, we highlight the use of aloe emodin and acemannan as lead compounds that should be considered for further development in the management and prevention of viral diseases. Given the immunomodulatory capacity of A. vera compounds, especially those found in Aloe gel, we also put forward the idea that these compounds should be considered as adjuvants for viral vaccines. Lastly, we present some of the current limitations to the clinical applications of compounds from Aloe, especially from A. vera.

The Histopathological Effect of Aloe Vera on the Wound Healing Process in a Surgically Created Tubularized Incised Plate Urethroplasty Model on Rats

BACKGROUND

Hypospadias is a common congenital anomaly which is determined as an abnormal urethral opening on the ventral face of penis. The purpose of this rat model study was to research the effect of topically applied Aloe vera after a tubularized incised plate urethroplasty (TIPU).

METHODS

The TIPU model was applied to male Wistar albino rats. A total of 30 rats were randomly grouped into 3 groups of 10. Group I was assigned as the control group, treated with 0.9% saline only twice a day for 15 days. Group II received topical Aloe vera gel once a day and Group III received Aloe vera gel twice a day. Spongiofibrosis was graded as 0: none, 1+:≤10% tissues involved, 2+:10%-49% tissues involved, 3+: ≥ 50% tissues involved.

RESULTS

A higher degree of fibrosis and inflammation was determined in the Group I subjects than in Groups II and III. Fibrosis of grade 3+ was observed in 33% of the control group and not in any of the two Aloe groups (p = 0.043). Inflammation of grade 3+ was seen in 66.7% of the control group, in 10% of Group II, and in 33% of Group III (p = 0.02).

CONCLUSIONS

The topical application of Aloe vera to a surgically created tubularized incised plate urethroplasty model decreased inflammation and fibrosis that may affect the success rates of this operation.

Clinical management of alveolar osteitis. A systematic review

Background

Alveolar Osteitis (AO) is one of the most common complications of tooth extraction. Several therapeutic interventions have been described for the treatment of AO, however, there are no treatment standardized protocols. The aim of this study was to conduct a systematic review on the efficacy in pain control of the different treatments for AO. The feasibility of the application of these interventions is also discussed.

Material and Methods

A structured electronic and hand search strategy was applied to PubMed, Scopus, Cochrane Library, OpenGrey, and Google Scholar between January 2010 and July 2020 to identify studies according to PRISMA guidelines. The inclusion criteria were original English and Spanish clinical trials that analyzed pain-control parameters according to visual analog scale (VAS, 0-10 scale), or pain relief patients’ percentages. Those treatments that reach VAS ≤ 4 on day 2 or before; or ≥ 85% of patients with absence of pain symptoms at day 7 or before were considered accepTable for their recommendation.

Results

The final review included 17 clinical trials. Among them, there were analyzed a total of 39 different AO treatments. 53,8% of the treatments fulfill the proposed parameters for pain control.

Conclusions

Treatment alternatives are multiple, heterogeneous, and difficult to compare. The management of AO is summarized in basic (intra-alveolar irrigation) and specific procedures (Alveogyl®, Neocones®, SaliCept Patch®, Low-Level Laser, Platelet-Rich Fibrin) that reach pain control success. They could be selected according to their availability and advantages or disadvantages.

Key words:Dry socket, alveolar osteitis, treatment, management, pain control, pain relief.

Significance of single β-mannanase supplementation on performance and energy utilization in broiler chickens, laying hens, turkeys, sows, and nursery-finish pigs: a meta-analysis and systematic review

This review will give a brief description of β-mannans, abundance in feedstuffs, utility of supplemental feed β-mannanase, and subsequent animal responses. Soybean products and co-products of processing palm, coconut, and guar seeds are the major sources of β-mannans in poultry and livestock feed. β-Mannans are linear polymers of mannose residues linked by β-1,4 glycosidic bonds and their ingestion elicit undesirable and metabolically costly responses. Web of Science was searched to retrieve published studies for meta-analyses of the impact of supplemental β-mannanase on performance and digestibility in pigs and poultry. The mean difference (MD) between β-mannanase and control on average daily gain (g/d) was +0.23 (P = 0.013; 95% CI of 0.05; 0.41), +10.8 g/d (P = 0.0005; 95% CI of 6.6; 15.0 g/d), and +20.68 (P < 0.000; 95% CI of 17.15; 24.20 g/d) for broiler chickens, nursery pigs, and grow-finish pigs, respectively. The MD on β-mannanase improvement on feed conversion (FCR) was -0.02 (P < 0.0001) with 95% CI (-0.03; -0.02) suggesting a 2-to-3-point FCR improvement in broiler chickens. β-Mannanase improvement on gain to feed (G:F) was +13.8 g/kg (P = 0.027; 2.1; 25.4 g/kg) and +8.77 g/kg (6.32; 11.23 g/kg) in nursery and grow-finish pigs, respectively. β-Mannanase improved apparent metabolizable energy by 47 kcal/kg (P = 0.0004) with 95% CI (28.8; 65.7 kcal/kg) in broiler chickens. The improvement of gross energy digestibility in pigs was 1.08% unit with 95% CI (0.90; 1.26) translating to the release of between 30.6 and 42.8 kcal/kg of digestible energy. Although data were limited, β-mannanase improved egg production in laying hens linked to improved energy metabolism in laying hens linked to improved energy metabolism but had no impact on egg quality. Turkeys may be more adversely affected by β-mannans because of the high protein/amino acids requirements necessitating higher dietary inclusion of soybean meal. However, growth performance and feed efficiency responses of turkeys fed diets supplemented with β-mannanase were variable. In summary, β-mannanase supplementation improved performance linked to energy and nutrient utilization. However, the magnitude of response was variable within and between species indicating further application refinement is warranted to achieve consistent efficacy, and improved understanding of the functional contribution of β-mannans hydrolysis products.

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.

Polymer-Based Scaffolds Loaded with Aloe vera Extract for the Treatment of Wounds

The treatment of wounds is one challenging biomedical field due to delayed wound healing common in chronic wounds. Several factors delay wound healing, including microbial infections, malnutrition, underlying physiological conditions, etc. Most of the currently used wound dressing materials suffer from poor antimicrobial properties, poor biodegradability and biocompatibility, and weak mechanical performance. Plant extracts, such as Aloe vera, have attracted significant attention in wound management because of their interesting biological properties. Aloe vera is composed of essential constituents beneficial for the wound healing process, such as amino acids, vitamins C and E, and zinc. Aloe vera influences numerous factors that are involved in wound healing and stimulates accelerated healing. This review reports the therapeutic outcomes of aloe vera extract-loaded polymer-based scaffolds in wound management.

Molecular mechanisms and associated cell signalling pathways underlying the anticancer properties of phytochemical compounds from Aloe species (Review)

Naturally occurring components from various species of Aloe have been used as traditional folk medicine since the ancient times. Over the last few decades, the therapeutic effects of extracts and phytochemical compounds obtained from Aloe vera have been proven in preclinical and clinical studies. Recently, compounds from other Aloe species apart from Aloe vera have been investigated for the treatment of different diseases, with a particular focus on cancer. In the present review, the effects of phytochemical compounds obtained from different Aloe species are discussed, with a specific focus on the effects on cell signalling in cancer and normal cells, and their selectivity and efficacy. This information will be useful for the application of Aloe-derived compounds as therapeutic agents, either alone or in combination with other standard drugs for cancer treatment.

Natural medicine delivery from biomedical devices to treat bone disorders: A review

With an increasing life expectancy and aging population, orthopedic defects and bone graft surgeries are increasing in global prevalence. Research to date has advanced the understanding of bone biology and defect repair mechanism, leading to a marked success in the development of synthetic bone substitutes. Yet, the quest for functionalized bone grafts prompted the researchers to find a viable alternative that regulates cellular activity and supports bone regeneration and healing process without causing serious side-effects. Recently, researchers have introduced natural medicinal compounds (NMCs) in bone scaffold that enables them to release at a desirable rate, maintains a sustained release allowing sufficient time for tissue in-growth, and guides bone regeneration process with minimized risk of tissue toxicity. According to World Health Organization (WHO), NMCs are gaining popularity in western countries for the last two decades and are being used by 80% of the population worldwide. Compared to synthetic drugs, NMCs have a broader range of safety window and thus suitable for prolonged localized delivery for bone regeneration. There is limited literature focusing on the integration of bone grafts and natural medicines that provides detailed scientific evidences on NMCs, their toxic limits and particular application in bone tissue engineering, which could guide the researchers to develop functionalized implants for various bone disorders. This review will discuss the emerging trend of NMC delivery from bone grafts, including 3D-printed structures and surface-modified implants, highlighting the significance and potential of NMCs for bone health, guiding future paths toward the development of an ideal bone tissue engineering scaffold. STATEMENT OF SIGNIFICANCE: To date, additive manufacturing technology provids us with many advanced patient specific or defect specific bone constructs exhibiting three-dimensional, well-defined microstructure with interconnected porous networks for defect-repair applications. However, an ideal scaffold should also be able to supply biological signals that actively guide tissue regeneration while simultaneously preventing post-implantation complications. Natural biomolecules are gaining popularity in tissue engineering since they possess a safer, effective approach compared to synthetic drugs. The integration of bone scaffolds and natural biomolecules exploits the advantages of customized, multi-functional bone implants to provide localized delivery of biochemical signals in a controlled manner. This review presents an overview of bone scaffolds as delivery systems for natural biomolecules, which may provide prominent advancement in bone development and improve defect-healing caused by various musculoskeletal disorders.

Aloe Vera extract-based composite nanofibers for wound dressing applications

Natural, biocompatible, and biodegradable composite nanofibers made of Aloe vera extract, pullulan, chitosan, and citric acid were successfully produced via Forcespinning® technology. The addition of Aloe vera extract at different weight percent loadings was investigated. The morphology, thermal properties, physical properties, and water absorption of the nanofibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The developed nanofiber membranes exhibited good water absorption capabilities, synergistic antibacterial activity against Escherichia coli, and promoted cell attachment and growth. Its porous and high surface area structure make it a potential candidate for wound dressing applications due to its ability to absorb excessive blood and exudates, as well as provide protection from infection while maintaining good thermal stability.

Effect of dietary supplementation of β-mannanase on growth performance, carcass characteristics, excreta microflora, blood constituents, and nutrient ileal digestibility in broiler chickens

Objective

The aim of the present study was to investigate the effects of dietary supplementation of β-mannanase on growth performance, carcass characteristics, excreta microflora, blood constituents, and nutrient digestibility in broiler chickens.

Methods

A total of 680 one-d-old Ross 308 (as hatched) broiler chickens were used in a 35-d growth assay. Chicks were sorted into pens with 17 birds/pen and 10 pens/treatment. Treatment diets were contained either 44% or 48% crude protein (CP) soybean meal (SBM) with or without β-mannanase.

Results

Using SBM containing 48% CP led to an improvement (p<0.05) in feed conversion ratio (FCR) from d 1 to 14. Addition of β-mannanase to the diets significantly improved body weight gain (BWG) and FCR from d 1 to 14. During overall experimental period, BWG was affected (p<0.05) by CP level of SBM and inclusion of β-mannanase, but FCR and feed intake were not affected. Carcass characteristics were not influenced by treatment diets. The results showed that digestibility of dry matter (DM), nitrogen (N), and energy was not affected by CP level of SBM and/or inclusion of β-mannanase. Among essential amino acids (EAA) apparent digestibility of valine, methionine, and leucine improved (p<0.05) by the addition of β-mannanase to the diets. The results demonstrated that ileal digestibility of DM, N, and energy was not affected by treatment diets. Among EAA, the ileal digestibility of valine and arginine was higher (p<0.05) in the diets containing 48% CP SBM and/or β-mannanase. Excreta Lactobacillus count increased (p<0.05) by the addition of β-mannanase to the diets. Blood urea nitrogen, creatinine, and total protein level were not affected by treatments.

Conclusion

Feeding chickens with diets containing 44% CP SBM resulted in detrimental effects on growth performance and digestibility of nutrients, but addition of β-mannanase to the 44% CP diet improved the growth performance of chickens without any effects on carcass characteristics.

Immunobiology and Application of Aloe Vera-Based Scaffolds in Tissue Engineering

Aloe vera (AV), a succulent plant belonging to the Liliaceae family, has been widely used for biomedical and pharmaceutical application. Its popularity stems from several of its bioactive components that have anti-oxidant, anti-microbial, anti-inflammatory and even immunomodulatory effects. Given such unique multi-modal biological impact, AV has been considered as a biomaterial for regenerative medicine and tissue engineering applications, where tissue repair and neo-angiogenesis are vital. This review outlines the growing scientific evidence that demonstrates the advantage of AV as tissue engineering scaffolds. We particularly highlight the recent advances in the application of AV-based scaffolds. From a tissue engineering perspective, it is pivotal that the implanted scaffolds strike an appropriate foreign body response to be well-accepted in the body without complications. Herein, we highlight the key cellular processes that regulate the foreign body response to implanted scaffolds and underline the immunomodulatory effects incurred by AV on the innate and adaptive system. Given that AV has several beneficial components, we discuss the importance of delving deeper into uncovering its action mechanism and thereby improving material design strategies for better tissue engineering constructs for biomedical applications.

Alveolar Osteitis: A Review of Current Concepts

PURPOSE

The purpose of the present review was to explore the pathogenesis and etiology of alveolar osteitis (AO) to obtain a more intuitive understanding of the clinical prevention and management of the condition. The different treatment modalities were discussed through both the mechanistic understanding of AO and the evidence regarding the different modes of prevention and management.

MATERIALS AND METHODS

The Ovid Medline, PubMed, and Cochrane Central Register online databases were used to complete an advanced search using the MeSH term "dry socket," generating 756 results.

RESULTS

A total of 8 studies on the prevention of AO were included, with 66 studies included for review of the reported data overall. The information was categorized into incidence, etiology and pathogenesis, prevention, and management. The relevant background information and evidence for each category were summarized.

CONCLUSIONS

Understanding of the pathogenesis and etiology of AO has improved in recent years, which has been helpful for developing effective evidence-based treatment and prevention of the condition. Clinicians should be aware of the complexity and multifactorial nature of the etiology of AO and the current concepts regarding the prevention and treatment of AO.

Evaluation of the effect of β-mannanase supplementation and mannans on nursery pig growth performance and serum acute-phase protein concentrations

The objective was to evaluate the effects of dietary mannan and β-mannanase supplementation on growth performance and serum acute-phase proteins in nursery pigs. Pigs (n = 480) were blocked by initial body weight (6.6 ± 0.4 kg), and 12 pens per treatment were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement for 28 d. Two levels of dietary mannan (0.4% vs. 2.8%) were offered with and without 0.05% endo-1,4-β-mannanase. Serum was collected (one pig per pen) for haptoglobin and C-reactive protein (CRP) analysis on days 0 and 28. There were no significant interactions between mannan level and β-mannanase supplementation. High-mannan diet decreased average daily gain (P = 0.027) and average daily feed intake (P = 0.024) compared with low-mannan diets with no effect of β-mannanase (P > 0.10). Haptoglobin and CRP were not affected by mannan level or β-mannanase supplementation (P ≥ 0.160). Therefore, dietary β-mannans as high as 2.8% did not induce a systemic innate immune response. Thus, the levels of β-mannan found in practical diets (<2%) are unlikely to induce an immune response; therefore, supplementation of β-mannanase to avoid this response is not warranted.

Hyaluronic acid, Manuka honey and Acemannan gel: Wound-specific applications for skin lesions

Healing of open wounds is of great medical importance. Wound healing is a complex process that aims to restore the function and structure of damaged tissue. This study was conducted to compare secondary intention healing of wounds treated daily with a topical application of commercially available hyaluronic acid (HA), Manuka honey (MH), Acemannan gel (AG), or a placebo. Bilateral wounds were surgically created on the backs of six sheep. At two and six weeks post-wound creation, biopsies were obtained to perform histological, immunohistochemical, and molecular analyses of the wound site. Daily clinical evaluations were performed and weekly photographs were taken of the wounds. HA treatment promoted a physiological progression of the healing process in all wound healing phases, while stimulating an abundant cutaneous adnexa and promoting rapid healing, representing the most compelling treatment. MH-treated wounds were slightly dry. However, the main effect of MH was to promote cell proliferation and neovascularization, with an overall pro-inflammatory effect. Results suggest that MH treatment enhances the healing process. AG treatment dehydrated the wounds and stimulated late granulation tissue and cell proliferation. Moreover, AG-treated wounds produced a mild late pro-inflammatory and neovascularization effect. Our data indicate that AG treatment can have a positive influence on moist wounds with abundant granulation tissue and exudate.

Anti-inflammatory effects of aloe vera on soy meal-induced intestinal inflammation in zebrafish

Soybean meal is one of the most promising alternatives to replace fishmeal in the aquaculture industry. However, its ingestion triggers an intestinal inflammatory process that compromises fish health and nutrition. Therefore, finding strategies that reduce the deleterious effects of a soy protein-based diet are relevant. In this work we analyzed the effects of an aloe vera (Aloe barbadensis miller, AV) extract on intestinal inflammation and innate immunity of zebrafish by adding it to the water and by supplementing it in a soybean meal-based diet. To search for potential immunomodulatory effects of AV, we tested its effectiveness in two inflammation assays and compared fish fed with either fishmeal or soybean meal-based feed supplemented with AV. Our results show a strong anti-inflammatory effect of AV. Furthermore, while soy-based meal strongly induces the expression of inflammation markers, supplementation with AV reverted this effect. Finally, we show that fish fed with a soy meal diet are highly susceptible to bacterial infection, but that this condition is significantly reduced when the soy meal is supplemented with AV. Our results suggest that AV is a good candidate to be incorporated as an additive in farmed fish diets to facilitate the replacement of fishmeal by soybean meal, maintaining intestinal health.

Lead bioactive compounds of Aloe vera as potential anticancer agent

Aloe vera (Aloe barbadensis Miller) is a perennial succulent medicinal plant. It has been used as a traditional or folk medicine for thousands of years and claimed that it possesses wound and burn healing activities, and anti-inflammatory as well as immunomodulatory effects. In recent years, the use of Aloe vera has been growing as a dietary supplement. The pre-clinical studies over the last couple of decades uncover the potential therapeutic activities of Aloe vera and its bioactive compounds, especially against neoplastic disease. Such investigations indicate the possible preventive as well as therapeutic effects of Aloe vera against cancer. Here, we discuss the crucial bioactive compounds of Aloe vera that have been harnessed against cancer and also address several mechanisms of action of these lead bioactive compounds compared to other standard drugs involved in cancer prevention and treatment.

Therapeutic potential of Aloe vera-A miracle gift of nature

BACKGROUND

Aloe vera is commonly used in the primary health care of human beings since time immemorial. It is an herb widely used in various traditional systems of medicine worldwide. Systematic and scientific investigation on A. vera as a medicinal plant has drawn considerable attention, and many laboratories are involved in isolation, characterization and evaluation of phytoconstituents for their nutraceutical and pharmaceutical applications.

PURPOSE

The aim of this study was to provide an overview of the phytochemical, biological and medicinal attributes of A. vera against various diseases with special emphasis on underlying mechanisms of action.

METHODS

PubMed, EBOSCO host, Science Direct, Scopus, and Cochrane library databases were utilized to search literature published between1977 and 2019 (till March). Major keywords used in various combinations included: Aloe vera, phytochemistry, metabolism, pharmacological activity, prevention, treatment, health, disease, in vivo, in vitro, and clinical studies.

RESULTS

Various biological and pharmacological activities of A. vera, such as antioxidant, anti-inflammatory, immuno-modulatory, antimicrobial, antiviral, antidiabetic, hepatoprotective, anticancer, and skin-protective and wound-healing responses, have been attributed to the presence of many active compounds, including anthraquinones, anthrones, chromones, flavonoids, amino acids, lipids, carbohydrates, vitamins and minerals.

CONCLUSION

Based on various preclinical studies, A. vera constituents have enormous potential to prevent and treat various diseases. Randomized clinical trials are needed to understand the full therapeutic potential of this unique medicinal plant.

Extraction, Purification, Structural Characteristics, Biological Activities and Pharmacological Applications of Acemannan, a Polysaccharide from Aloe vera: A Review

Aloe vera is a medicinal plant species of the genus Aloe with a long history of usage around the world. Acemannan, considered one of the main bioactive polysaccharides of Aloe vera, possesses immunoregulation, anti-cancer, anti-oxidation, wound healing and bone proliferation promotion, neuroprotection, and intestinal health promotion activities, among others. In this review, recent advancements in the extraction, purification, structural characteristics and biological activities of acemannan from Aloe vera were summarized. Among these advancements, the structural characteristics of purified polysaccharides were reviewed in detail. Meanwhile, the biological activities of acemannan from Aloe vera determined by in vivo, in vitro and clinical experiments are summarized, and possible mechanisms of these bioactivities were discussed. Moreover, the latest research progress on the use of acemannan in dentistry and wound healing was also summarized in details. The structure-activity relationships of acemannan and its medical applications were discussed. Finally, new perspectives for future research work on acemannan were proposed. In conclusion, this review summarizes the extraction, purification, structural characteristics, biological activities and pharmacological applications of acemannan, and provides information for the industrial production and possible applications in dentistry and wound healing in the future.

Medicinal Plant Extracts and Their Use As Wound Closure Inducing Agents

Skin insult and damage start a complex healing process that involves a myriad of coordinated reactions at both the cellular and molecular level occurring simultaneously. These processes can be divided into that of cell migration and tissue remodeling of the wound. In addition, it is well known that deep wounds that derive from surgical procedures need a multidisciplinary approach to have a successful wound healing process. Recently, there has been a renowned interest in the identification of active compounds derived from ornamental, edible, and wild plants being used in the cosmetic and skin product industry. Recent reports suggest that active components of several plants such as Propolis and Aloe vera could be used to induce the process of wound healing and tissue regeneration and reducing therefore the time to complete wound closure. Other plant species such as Achillea millefolium or Salvia officinalis have anti-inflammatory properties and promote cellular proliferation contributing to faster tissue regeneration. It has been described that Malva sylvestris influences the formation of fibrosis-free granulation tissue in the skin. Recent observations suggest that Casearia sylvestris induces the angiogenic process. These effects have been evaluated in cell lines, different animal models, and some in randomized clinical trials. In this review we summarize the evidence of plant extracts and their active components (when known) in the acceleration of the wound closure process and tissue repair.

In Vitro Immunomodulatory Effect of Food Supplement from Aloe vera

Food industries typically use Aloe vera as concentrated (100× to 200×) and dried powders in their final products. These powders are obtained by extrusion of Aloe inner leaf gel (ILG) or Aloe whole leaf (WLP); the juice is filtered through diatomaceous earth and activated carbon before spray drying at temperatures below 70 °C. In another process, Aloe inner leaf gel was dried at ~80 °C and mashed to a powder rich in high molecular weight fibres and soluble polysaccharides (ILF). In contrast to ILG and WLP, the ILF sample was cytotoxic for the human intestinal cell line Caco-2 (CC₅₀ = 1 g/l), even at concentrations below the recommended dose for human consumption. At lower concentrations (250 mg/l) with LPS challenged macrophage-like THP-1 cells decreased by 40% the release of the anti-inflammatory cytokine IL-10, whereas the release of the proinflammatory cytokine IL-1β increased by 35% (compared to untreated but challenged macrophage-like THP-1 cells). Unexpectedly, under the same conditions, the less cytotoxic ILG and WLP, both samples with a lower fibre content, significantly increased (up to 2.4 times) the release of IL-10, while the concentration of IL-1β remained unaltered and of TNFα decreased by 35%. Even more interesting is that a treatment of the ILF sample with activated carbon reduced its cytotoxicity and increased the IL-10 release (3.1 times). Based on these results, we suggest applying an activated carbon treatment on Aloe-starting products, which have high fibre content and have received high temperature treatment, in order to reduce their cytotoxicity and improve their immunomodulatory properties.

Improved Multicellular Response, Biomimetic Mineralization, Angiogenesis, and Reduced Foreign Body Response of Modified Polydioxanone Scaffolds for Skeletal Tissue Regeneration

The potential of electrospun polydioxanone (PDX) mats as scaffolds for skeletal tissue regeneration was significantly enhanced through improvement of the cell-mediated biomimetic mineralization and multicellular response. This was achieved by blending PDX ( i) with poly(hydroxybutyrate- co-valerate) (PHBV) in the presence of hydroxyapatite (HA) and ( ii) with aloe vera (AV) extract containing a mixture of acemannan/glucomannan. In an exhaustive study, the behavior of the most relevant cell lines involved in the skeletal tissue healing cascade, i.e. fibroblasts, macrophages, endothelial cells and preosteoblasts, on the scaffolds was investigated. The scaffolds were shown to be nontoxic, to exhibit insignificant inflammatory responses in macrophages, and to be degradable by macrophage-secreted enzymes. As a result of different phase separation in PDX/PHBV/HA and PDX/AV blend mats, cells interacted differentially. Presumably due to varying tension states of cell-matrix interactions, thinner microtubules and significantly more cell adhesion sites and filopodia were formed on PDX/AV compared to PDX/PHBV/HA. While PDX/PHBV/HA supported micrometer-sized spherical particles, nanosized rod-like HA was observed to nucleate and grow on PDX/AV fibers, allowing the mineralized PDX/AV scaffold to retain its porosity over a longer time for cellular infiltration. Finally, PDX/AV exhibited better in vivo biocompatibility compared to PDX/PHBV/HA, as indicated by the reduced fibrous capsule thickness and enhanced blood vessel formation. Overall, PDX/AV blend mats showed a significantly enhanced potential for skeletal tissue regeneration compared to the already promising PDX/PHBV/HA blends.

Lipopolysaccharide immune stimulation but not β-mannanase supplementation affects maintenance energy requirements in young weaned pigs

Background

Pathogen or diet-induced immune activation can partition energy and nutrients away from growth, but clear relationships between immune responses and the direction and magnitude of energy partitioning responses have yet to be elucidated. The objectives were to determine how β-mannanase supplementation and lipopolysaccharide (LPS) immune stimulation affect maintenance energy requirements (MEm) and to characterize immune parameters, digestibility, growth performance, and energy balance.

Methods

In a randomized complete block design, 30 young weaned pigs were assigned to either the control treatment (CON; basal corn, soybean meal and soybean hulls diet), the enzyme treatment (ENZ; basal diet + 0.056% β-mannanase), or the immune system stimulation treatment (ISS; basal diet + 0.056% β-mannanase, challenged with repeated increasing doses of Escherichia coli LPS). The experiment consisted of a 10-d adaptation period, 5-d digestibility and nitrogen balance measurement, 22 h of heat production (HP) measurements, and 12 h of fasting HP measurements in indirect calorimetry chambers. The immune challenge consisted of 4 injections of either LPS (ISS) or sterile saline (CON and ENZ), one every 48 h beginning on d 10. Blood was collected pre- and post-challenge for complete blood counts with differential, haptoglobin and mannan binding lectin, 12 cytokines, and glucose and insulin concentrations.

Results

Beta-mannanase supplementation did not affect immune status, nutrient digestibility, growth performance, energy balance, or ME_m. The ISS treatment induced fever, elevated proinflammatory cytokines and decreased leukocyte concentrations (P < 0.05). The ISS treatment did not impact nitrogen balance or nutrient digestibility (P > 0.10), but increased total HP (21%) and ME_m (23%), resulting in decreased lipid deposition (−30%) and average daily gain (−18%) (P < 0.05).

Conclusions

This experiment provides novel data on β-mannanase supplementation effects on immune parameters and energy balance in pigs and is the first to directly relate decreased ADG to increased ME_m independent of changes in feed intake in immune challenged pigs. Immune stimulation increased energy partitioning to the immune system by 23% which limited lipid deposition and weight gain. Understanding energy and nutrient partitioning in immune-stressed pigs may provide insight into more effective feeding and management strategies.

Electronic supplementary material

The online version of this article (10.1186/s40104-018-0264-y) contains supplementary material, which is available to authorized users.

Acemannan increases NF-κB/DNA binding and IL-6/-8 expression by selectively binding Toll-like receptor-5 in human gingival fibroblasts

Acemannan, an acetylated polymannose from Aloe vera, has immunomodulatory effects. We investigated whether acemannan induces IL-6 and -8 expression and NF-κB/DNA binding in human gingival fibroblasts. IL-6 and -8 expression levels were assessed via RT-PCR and ELISA. The NF-κB p50/p65-DNA binding was determined. The structures of acemannan mono-pentamers and Toll-like receptor 5 (TLR5) were simulated. The binding energies between acemannan and TLR5 were identified. We found that acemannan significantly stimulated IL-6/-8 expression at both the mRNA and protein level and significantly increased p50/DNA binding. Preincubation with an anti-TLR5 neutralizing antibody abolished acemannan-induced IL-6/-8 expression and p50/DNA binding, and co-incubation of acemannan with Bay11-7082, a specific NF- κB inhibitor, abolished IL-6/-8 expression. The computer modeling indicated that monomeric/dimeric single stranded acemannan molecules interacted with the TLR5 flagellin recognition sites with a high binding affinity. We conclude that acemannan induces IL-6/-8 expression, and p50/DNA binding in gingival fibroblasts, at least partly, via a TLR5/NF-κB-dependent signaling pathway. Furthermore, acemannan selectively binds with TLR5 ectodomain flagellin recognition sites.

Influence of drinking water containing Aloe vera (Aloe barbadensis Miller) gel on growth performance, intestinal microflora, and humoral immune responses of broilers

Aim:

The risk of bacteria resistance to specific antibiotics possibly by continuous subtherapeutical administration of antibiotic growth promoters (AGPs) in poultry feed led to a ban on the use of AGP in poultry production. As a result of this ban, alternative substances for poultry growth promotion and disease prevention are being investigated, among which phytogenic and herbal products have received increased attention as natural additives because they have been accepted by consumers as natural additives. The effect of water supplementation of Aloe vera (AV) as an AGP substitute on performance, intestinal microflora, and immune responses of broilers.

Materials and Methods:

The five experimental treatments were allocated to four replicates. The following treatments were applied (1) a basal broiler diet (C) and normal drinking water, (2) 0.5% AV gel in drinking water, (3) 0.75% AV gel in drinking water, (4) 1% AV gel in drinking water, and (5) diet C supplemented with flavophospholipol at 4.5 mg/kg and drinking normal water. Vaccines against influenza disease and sheep red blood cell (SRBC) were administrated to immunological stimuli. The populations of Lactobacilli spp. and coliforms were enumerated in ileum.

Results:

Body weight of broilers supplemented with different levels of AV increased compared with control group (p<0.05). Birds supplemented with antibiotic had the best feed-to-gain ratio (F:G) in different periods. Supplementation of 0.5% and 0.75% AV improved F: G entire experimental period compared with control group (p<0.05). Coliform bacteria were reduced in broilers supplemented with different levels of AV or antibiotic (p<0.05). The Lactobacilli spp. population in birds supplemented with 0.75%, 1% AV or antibiotic significantly was higher than other groups (p<0.05). Supplementation with 1% AV led to greater antibody titers against SRBC compared with other groups (p<0.05).

Conclusion:

These findings demonstrated a possibility of supplementing broiler drinking water with 1% AV gel as an alternative for AGP substitution.

Effect of the herbal mixture composed of Aloe Vera, Henna, Adiantum capillus-veneris, and Myrrha on wound healing in streptozotocin-induced diabetic rats

BACKGROUND

Wound healing is often impaired in diabetic animals and humans. Matrix metalloproteases act as pro-inflammatory agents in physiological wound healing pathways by stimulating cytokines including the interleukins, IL6, IL1A and IL1B, and the tumor necrosis factor and transforming growth factor beta1. Botanicals are traditionally used to assist healing of different types of wounds, because they produce fewer side effects. Our specific aim here was to develop a plant-based recipe supporting effective wound healing in diabetic animals.

METHODS

Plant materials from Adiantum capillus-veneris, Commiphora molmol, Aloe Vera, and henna were collected for this study, and oven-dried at 60 °C. The dried leaves and resins were then crumbled into a powder and mixed in equal parts with Vaseline as a preservative. This mixture was used as an ointment on wounds induced in 60 diabetic and non-diabetic rats that were divided into 6 subgroups receiving agent or control treatments. Necrotic tissue surrounding the wound was periodically removed during wound healing. RNA was extracted from the healing region of the wound at days 7, 14 and 21 for cDNA synthesis to monitor changes in Tgfb1, Mmp3, Mmp9, Il6 and Tnf α expression using real-time PCR.

RESULTS

The expression of the Mmp3, the Tnf α, and the Tgfb1 genes from wound tissue were significantly different (p < 0.05) between diabetic and non-diabetic (control) rats treated with the herbal mixture after 14 and 21 days. There was no significant difference (p > 0.05) of the Mmp9 gene expression in diabetic and non-diabetic rats treated only with Vaseline after 7, 14, and 21 days. But, the expression of the Mmp9 gene decreased significantly (p < 0.05) in diabetic rats after 14 days in comparison to non-diabetic rats, when the herbal mixture was added to Vaseline.

CONCLUSIONS

Our study presents an herbal treatment that alters the gene expression signature at wounds induced in the rat model for type I diabetes in a manner consistent with accelerated healing, and demonstrates that this herbal treatment might be effective to treat wounds in diabetic patients.

Prevention of azoxymethane/dextran sodium sulfate-induced mouse colon carcinogenesis by processed Aloe vera gel

The preventive effect of a processed Aloe vera gel (PAG) on colon carcinogenesis was examined using an azoxymethane (AOM)-initiated and dextran sodium sulfate (DSS)-promoted mouse colon carcinogenesis model. Oral administration of PAG (200, or 400mg/kg/day) significantly reduced the multiplicity of colonic adenomas and adenocarcinomas compared with the AOM/DSS only-treated mice. In the mice treated with 400mg/kg of PAG, adenoma and adenocarcinoma development was reduced to 80% and 60%, respectively, compared to 100% in the PAG-untreated AOM/DSS-treated mice. Western blot analysis using colon extracts showed that PAG reduced the activation of nuclear factor kappa B (NF-κB), resulting in the inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression. PAG appeared to inhibit the NF-κB activation through the activation of peroxisome proliferator-activated receptor gamma. PAG also inhibited the expression and phosphorylation of signal transducer and activator of transcription 3, which is known to connect inflammation and cancer. In addition, PAG inhibited cell cycle progression-inducing cellular factors, such as extracellular signal-regulated kinases 1/2, cyclin-dependent kinase 4, and cyclin D1. On the other hand, PAG increased the expression of Caudal-related homeobox transcription factor 2, which is known to be a tumor suppressor in colorectal cancer. These findings show that PAG suppresses colitis-related colon carcinogenesis by inhibiting both chronic inflammation and cell cycle progression in the colon.

Effects of Aloe barbadensis Mill. extract (AVH200®) on human blood T cell activity in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe barbadensis Mill. (Aloe vera) is a widely used medicinal plant well reputed for its diverse therapeutic applications. It has been used for thousands of years in folk medicine to treat various conditions and the Aloe vera gel has been reported to possess anti-inflammatory as well as immunostimulatory and immunomodulatory properties. However, the mode of action is still unclear.

AIM OF THE STUDY

The aim of this study was determine the effects of two well-defined A. barbadensis Mill. extracts AVH200® and AVE200 on human blood T cells in vitro.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMC) from healthy donors were stimulated polyclonally in the presence or absence of AVH200® and AVE200. The T cell phenotype was investigated by flow cytometry, cell proliferation was determined by CFSE dye and thymidine assay, respectively and cytokine secretion was determined by MSD® Multi-Spot Assay system and ELISA.

RESULTS

The presence of AVH200® resulted in a reduced expression of CD25 among CD3(+) T cells and suppression of T cell proliferation in a dose dependent manner. Furthermore, AVH200® reduced the expression of CD28 on CD3(+) T cells. AVH200® also reduced the secretion of IL-2, IFN-γ and IL-17A in PBMC cultures. The AVH200® dose dependent reduction in T cell activation and proliferation recorded in the cell cultures was not due to apoptosis or cell death. Additionally, AVH200® was found to be more effective as compared to AVE200 in reducing T cell activation and proliferation.

CONCLUSION

AVH200® has the potential to reduce the activation, proliferation and cytokine secretion of healthy human blood T cells. Our study suggests that AVH200® has a suppressive effect on human blood T cells in vitro.

Cancer immunotherapy in veterinary medicine: Current options and new developments

Excitement in the field of tumor immunotherapy is being driven by several remarkable breakthroughs in recent years. This review will cover recent advances in cancer immunotherapy, including the use of T cell checkpoint inhibitors, engineered T cells, cancer vaccines, and anti-B cell and T cell antibodies. Inhibition of T cell checkpoint molecules such as PD-1 and CTLA-4 using monoclonal antibodies has achieved notable success against advanced tumors in humans, including melanoma, renal cell carcinoma, and non-small cell lung cancer. Therapy with engineered T cells has also demonstrated remarkable tumor control and regression in human trials. Autologous cancer vaccines have recently demonstrated impressive prolongation of disease-free intervals and survival times in dogs with lymphoma. In addition, caninized monoclonal antibodies targeting CD20 and CD52 just recently received either full (CD20) or conditional (CD52) licensing by the United States Department of Agriculture for clinical use in the treatment of canine B-cell and T-cell lymphomas, respectively. Thus, immunotherapy for cancer is rapidly moving to the forefront of cancer treatment options in veterinary medicine as well as human medicine.