Pharmacological Update Properties of Aloe Vera and its Major Active Constituents

Barbaloin: an amazing chemical from the 'wonder plant' with multidimensional pharmacological attributes

Aloe vera (L.) Burm.f. is nicknamed the 'Miracle plant' or sometimes as the 'Wonder plant'. It is a plant that has been used since ancient times for the innumerable health benefits associated with it. It is one of the important plants that has its use in conventional medicinal treatments. It is a perennial succulent, drought-tolerant member of the family Asphodelaceae. There are scores of properties associated with the plant that help in curing various forms of human ailments. Extracts and gels obtained from plants have been shown to be wonderful healers of different conditions, mainly various skin problems. Also, this plant is popular in the cosmetics industry. The underlying properties of the plant are now mainly associated with the natural phytochemicals present in the plant. Diverse groups of phytoingredients are found in the plant, including various phenolics, amino acids, sugars, vitamins, and different other organic compounds, too. One of the primary ingredients found in the plant is the aloin molecule. It is an anthraquinone derivative and exists as an isomer of Aloin A and Aloin B. Barbaloin belonging to the first group is a glucoside of the aloe-emodin anthrone molecule. Various types of pharmacological properties exhibited by the plant can be attributed to this chemical. Few significant ones are antioxidant, anti-inflammatory, anti-diabetic, anti-cancer, anti-microbial, and anti-viral, along with their different immunity-boosting actions. Recently, molecular coupling studies have also found the role of these molecules as a potential cure against the ongoing COVID-19 disease. This study comprehensively focuses on the numerous pharmacological actions of the primary compound barbaloin obtained from the Aloe vera plant along with the mechanism of action and the potent application of these natural molecules under various conditions.

Experimental and clinical trial investigations of phyto-extracts, phyto-chemicals and phyto-formulations against oral lichen planus: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Bio-assay guided phytoextracts and derived phytoconstituents reported having multipotent biological activities and nearly 60-80% of the global population still using natural regimens as an alternative therapeutic source. This study focused on the ethnopharmacological and experimental evidence of natural remedies that are effective in treating oral lichen planus (OLP), a chronic T-cell mediated autoimmune disease that is associated with oral cancer transmission.

AIM OF THE REVIEW

A number of studies have shown that antioxidants and antiinflammatory phytoextracts and phyto-constituents are effective against OLP. In this systematic review, we summarize the details of experimentally assessed ancient Traditional Chinese Medicine (TCM), Indian Ayurveda or Ayurvedic Medicine, and Japanese Kampo Medicine (JKM) regimens (crude extracts, individual phytochemicals, and phyto-formulations) that reduce oral lesion, severity index and pain associated with OLP based on studies conducted in vivo, in vitro, and in randomized controlled trials (RCTs).

MATERIALS AND METHODS

Experimental, clinical and RCT investigation reports were gathered and presented according to PRISMA-2020 format. Briefly, the information was obtained from PubMed, ScienceDirect, Wiley journal library, Scopus, Google Scholar with ClinicalTrials.gov (a clinical trial registry database operated by the National Library of Medicine in the United States). Further, individual phytochemical structures were verified from PubChem and ChemSpider databases and visualized by ChemDraw 18.0 software.

RESULTS

We summarized 11 crude phytoextracts, 7 individual phytochemicals, 9 crude formulations, 8 specific TCM and JKM herbal cocktails, and 6 RCTs/patents corroborated by multiple in vitro, in vivo and enzyme assay methods. Briefly, plants and their family name, used plant parts, reported phytochemicals and their chemical structure, treatment doses, and duration of each experiment were presented more concisely and scientifically.

CONCLUSION

Documentation of evidence-based natural ethnomedicines or remedies could be useful for promoting them as potential, cost-effective and less toxic alternatives or as complementary to commonly prescribed steroids towards the control of OLP.

Aloe vera reduces gut inflammation induced by soybean meal in Atlantic salmon (Salmo salar)

Plant-based protein sources, such as soybean, are widely used in fish nutrition due to their market availability, wide distribution and acceptable nutritional quality. However, in some fish species, soybean meal-based diets cause gut inflammation, decreasing both nutrient absorption and growth rates. A suitable alternative to avoid these problems could be the application of additives with anti-inflammatory activity to the diet. In this study, an Aloe vera (Aloe barbadensis Miller, AV) extract was analyzed as a dietary additive to reduce the gut inflammation in Atlantic salmon (Salmo salar) fed with soybean meal (SBM) diet. Fish were distributed in four duplicated groups and fed 28 days with fish meal control diet (FM), AV inclusion diet (AV), FM diet supplemented with AV (FM+AV), SBM diet to induce enteritis and SBM+AV. The fish gut response to these treatments was analyzed in distal intestine by histopathological scores, tissue morphometric measurements and immune gene expression parameters. The score results in fish fed with SBM-based diet clearly showed enteritis, meanwhile fish fed with AV supplemented diet significantly reduced the intestinal SBM signs of damage. These findings were associated to reduction of goblet cells number, lamina propria thickness and sub-epithelial mucosa size, with a significant decrease on pro-inflammatory cytokine il-1β to basal levels, similar to those present in fish fed FM diets. In conclusion, the administration of AV in salmon diet showed a protective intestinal activity against the detrimental effects of SBM, opening the possibility to improve its use as a feed additive in aquafeeds.

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.

Extracts of Rheum palmatum and Aloe vera Show Beneficial Properties for the Synergistic Improvement of Oral Wound Healing

Various local and systemic factors compromise oral wound healing and may lead to wound dehiscence, inflammation, or ulcers. Currently, there is a lack of topical therapeutical options. Thus, this study aimed to investigate the effect of Aloe vera (AV) and Rheum palmatum root (RPR) on oral wound healing capacity in vitro. The effect of AV and RPR on human primary fibroblast viability and migration was studied by measuring metabolic activity and gap closure in a scratch assay. Furthermore, cell cycle distribution and cytoskeletal features were analyzed. Antimicrobial activity against the oral pathogen Porphyromonas gingivalis was evaluated by broth microdilution assay. AV and RPR increased fibroblast migration after single agent treatment. Synergistic effects of the plant extract combination were observed regarding cellular migration which were confirmed by calculation of the phenomenological combination index (pCI), whereas the cell cycle distribution was not influenced. Furthermore, the combination of AV and RPR showed synergistic antibacterial effects as determined by the fractional inhibitory concentration index. This study demonstrated that the combination of AV and RPR can promote the migration of human primary fibroblasts in vitro and exert antimicrobial efficacy against P. gingivalis, suggesting these compounds for the topical treatment of wound healing disorders.

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.

New Amorphous Hydrogels with Proliferative Properties as Potential Tools in Wound Healing

The study and discovery of bioactive compounds and new formulations as potential tools for promoting the repair of dermoepidermal tissue in wound healing is of continuing interest. We have developed a new formulation of amorphous hydrogel based on sodium alginate (NaAlg); type I collagen, isolated by the authors from silver carp tails (COL); glycerol (Gli); Aloe vera gel powder (AV); and silver nanoparticles obtained by green synthesis with aqueous Cinnamomum verum extract (AgNPs@CIN) and vitamin C, respectively. The gel texture of the amorphous hydrogels was achieved by the addition of Aloe vera, demonstrated by a rheological analysis. The evaluations of the cytotoxicity and cell proliferation capacity of the experimental amorphous hydrogels were performed against human foreskin fibroblast Hs27 cells (CRL-1634-ATCC). The developed gel formulations did not show a cytotoxic effect. The hydrogel variant containing AgNPs@CIN in a concentration of 8 µg Ag/gel formulation and hydrogel variant with vitamin C had proliferative activity. In addition, the antibacterial activity of the hydrogels was evaluated against S. aureus ATCC 6538, Ps. aeruginosa ATCC 27853, and E. coli ATCC 25922. The results demonstrated that the gel variant based on AgNPs@CIN in a concentration of 95 µg Ag/gel formulation and the hydrogel based on vitamin C show antibacterial activity. Therefore, the developed hydrogels with AgNPs@CIN and vitamin C could be promising alternatives in wound healing.

Electrospinning of botanicals for skin wound healing

Being the first barrier between the human body and external environments, our skin is highly vulnerable to injuries. As one of the conventional therapies, botanicals prepared in different topical formulations have been applied as medical care for centuries. With the current increase of clinical requirements, applications of botanicals are heading towards nanotechnologies, typically fused with electrospinning that forms nanofibrous membranes suitable for skin wound healing. In this review, we first introduced the main process of wound healing, and then presented botanicals integrated into electrospun matrices as either loaded drugs, or carriers, or membrane coatings. In addition, by addressing functional features of individual botanicals in the healing of injured skin, we further discussed the bioactivity of botanical electrospun membranes in relevant to the medical issues solved in the process of wound healing. As achieved by pioneer studies, due to infrequent adverse effects and the diversity in resources of natural plants, the development of electrospun products based on botanicals is gaining greater attention. However, investigations in this field have mainly focused on different methodologies used in the preparation of nanofibrous membranes containing botanicals, their translation into clinical practices remains unaddressed. Accordingly, we propose that potential clinical applications of botanical electrospun membranes require not only the further expansion and understanding of botanicals, but also an establishment of standard criteria for the evaluation of wound healing and evolutions of technologies to support the large-scale manufacturing industry.

Current Knowledge on Interactions of Plant Materials Traditionally Used in Skin Diseases in Poland and Ukraine with Human Skin Microbiota

Skin disorders of different etiology, such as dermatitis, atopic dermatitis, eczema, psoriasis, wounds, burns, and others, are widely spread in the population. In severe cases, they require the topical application of drugs, such as antibiotics, steroids, and calcineurin inhibitors. With milder symptoms, which do not require acute pharmacological interventions, medications, dietary supplements, and cosmetic products of plant material origin are gaining greater popularity among professionals and patients. They are applied in various pharmaceutical forms, such as raw infusions, tinctures, creams, and ointments. Although plant-based formulations have been used by humankind since ancient times, it is often unclear what the mechanisms of the observed beneficial effects are. Recent advances in the contribution of the skin microbiota in maintaining skin homeostasis can shed new light on understanding the activity of topically applied plant-based products. Although the influence of various plants on skin-related ailments are well documented in vivo and in vitro, little is known about the interaction with the network of the skin microbial ecosystem. The review aims to summarize the hitherto scientific data on plant-based topical preparations used in Poland and Ukraine and indicate future directions of the studies respecting recent developments in understanding the etiology of skin diseases. The current knowledge on investigations of interactions of plant materials/extracts with skin microbiome was reviewed for the first time.

Natural Products in Mitigation of Bisphenol A Toxicity: Future Therapeutic Use

Bisphenol A (BPA) is a ubiquitous environmental toxin with deleterious endocrine-disrupting effects. It is widely used in producing epoxy resins, polycarbonate plastics, and polyvinyl chloride plastics. Human beings are regularly exposed to BPA through inhalation, ingestion, and topical absorption routes. The prevalence of BPA exposure has considerably increased over the past decades. Previous research studies have found a plethora of evidence of BPA’s harmful effects. Interestingly, even at a lower concentration, this industrial product was found to be harmful at cellular and tissue levels, affecting various body functions. A noble and possible treatment could be made plausible by using natural products (NPs). In this review, we highlight existing experimental evidence of NPs against BPA exposure-induced adverse effects, which involve the body’s reproductive, neurological, hepatic, renal, cardiovascular, and endocrine systems. The review also focuses on the targeted signaling pathways of NPs involved in BPA-induced toxicity. Although potential molecular mechanisms underlying BPA-induced toxicity have been investigated, there is currently no specific targeted treatment for BPA-induced toxicity. Hence, natural products could be considered for future therapeutic use against adverse and harmful effects of BPA exposure.

The potential application of natural products in cutaneous wound healing: A review of preclinical evidence

Under normal circumstances, wound healing can be summarized as three processes. These include inflammation, proliferation, and remodeling. The vast majority of wounds heal rapidly; however, a large percentage of nonhealing wounds have still not been studied significantly. The factors affecting wound nonhealing are complex and diverse, and identifying an effective solution from nature becomes a key goal of research. This study aimed to highlight and review the mechanisms and targets of natural products (NPs) for treating nonhealing wounds. The results of relevant studies have shown that the effects of NPs are associated with PI3K-AKT, P38MAPK, fibroblast growth factor, MAPK, and ERK signaling pathways and involve tumor growth factor (TNF), vascular endothelial growth factor, TNF-α, interleukin-1β, and expression of other cytokines and proteins. The 25 NPs that contribute to wound healing were systematically summarized by an inductive collation of the six major classes of compounds, including saponins, polyphenols, flavonoids, anthraquinones, polysaccharides, and others, which will further direct the attention to the active components of NPs and provide research ideas for further development of new products for wound healing.

Towards the Preparation of a Hydrogel from Lyophilisates of the Aloe arborescens Aqueous Extract

Aloe gel is a medicinal raw material with proven pharmacological activity. The health-promoting properties of other species of Aloe upon topical application prompted us to develop a formulation for the topical application of A. arborescence species. As a result of the gel preparation from the aqueous lyophilized extracts of three-year-old leaves of A. arborescence, no changes in the composition of the content of aloins A and aloenin A were found. The potential to neutralize free radicals was tested using DPPH and CUPRAC techniques, which confirmed the anti-radical activity of the lyophilisate. Screening of the inhibition of enzymes, the hyperactivity of which is associated with adverse changes in the skin of a pro-inflammatory nature, was performed. Importantly, using the PAMPA SKIN model, the possibility of the penetration of selected extract compounds (aloin A and aloenin A) through the skin was proven. Then, two formulations were prepared based on sodium alginate and hydroxypropyl methylcellulose (HPMC) and the hydrogels were characterized (rheological analysis, drug release profiles, permeability, and stability studies). HPMC-based hydrogel was the one with a targeted release of active substances and greater stability. Aloe arborescens hydrogel matrices seem to be a promising treatment strategy for inflammatory surface damage based on “green technology” at the stage of extract preparation and development of the drug form for topical application.

Nano Coating of Aloe-Gel Incorporation Additives to Maintain the Quality of Freshly Cut Fruits

The edible coating is an environmentally friendly technology that is applied to fresh-cut fruit products. One of the natural ingredients that are potentially applicable is aloe-gel because it contains several functional components. The main advantage of aloe-coating is that additives can be incorporated into the polymer matrix to enhance its properties. Additives tend to improve the safety, nutritional, and sensory attributes of fresh fruits, but in some cases, aloe-coating does not work. Furthermore, particle size determines the effectiveness of the process on fresh-cut fruits. Aloe-gel nano-coating can be used to overcome the difficulty of adhesion on the surface of fresh-cut fruits. However, quality criteria for fresh cut fruit coated with aloe-gel nano-coating must be strictly defined. The fruit to be processed must be of minimal quality so that discoloration, loss of firmness, spoilage ratio, and fruit weight loss can be minimized. This study aims to discuss the use of nano-coating aloe-gel incorporated with additional ingredients to maintain the quality of fresh-cut fruits. It also examined the recent advances in preparation, extraction, stabilization, and application methods in fresh fruits.

Preclinical Studies to Evaluate the Gut Stimulatory Activity of Aloe Musabbar

Background

Constipation is a common functional gastrointestinal disorder. Medicines derived from nature are routinely used to treat it. The present study evaluates the gut stimulatory activity of Aloe musabbar (processed powder of Aloe vera) using in vitro and in vivo models for gut stimulatory activity.

Materials and Methods

In vitro tests were conducted on isolated rat colon, guinea pig ileum, and rabbit jejunum, while in vivo study was performed using mice intestinal transit time. Aloe musabbar (A. musabbar) was tested at doses 0.2–200 mg/mL (in-vitro study) and 86.6 mg/kg (in vivo study). In vitro studies were done in the presence and absence of atropine sulphate (1 ng/ml). The results were statistically analyzed, and p < 0.05 was considered to indicate the significance.

Results

A. musabbar exhibited dose-dependent increase in the smooth muscle contraction of isolated gut tissues. Presence of atropine minimized the contractile responses and shifted the dose-response curves towards the right-hand side. The intestinal transit time in mice was observed to be increased significantly (p < 0.01) in A. musabbar-treated animals, when compared with normal animals.

Conclusion

A mild smooth muscle contraction induced by A. musabbar suggests that it can stimulate intestinal bowel movement without causing spasms. The diminished responses in the presence of atropine indicated that the gut stimulatory activity could be mediated partially through parasympathetic innervations. More studies are needed to determine the precise mechanism of action including the specific active ingredient responsible for the gut stimulatory activity.

Topical and oral applications of Aloe vera improve healing of deep second-degree burns in rats via modulation of growth factors

Introduction: Burn injuries are underappreciated injuries that cause significant morbidity and mortality. Burn injuries, especially severe burns, trigger immunological and inflammatory responses, metabolic abnormalities, and distributive shock, all of which can be extended to multiple organ failures. Aloe vera (A. vera) has been exploited for its medicinal properties for centuries. The goal of the present study is to examine the therapeutic effect of topical and oral administration of A. vera against deep second-degree burn in rats. Materials and methods: skin burn was created on the back of rats, and wound healing was assessed within the three examined groups; control, topical A. vera and oral A. vera throughout 30 days. Wound tissues were examined histologically, immunohistochemically for the expression of transforming growth factor beta-1 (TGF-β1), peroxiredoxin (Prdx6), and mRNA abundance of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) was assessed. Results: Our finding showed acceleration of wound contraction with both topical and oral A. vera administration. Maturation of granulation tissues was seen in both A. vera-supplemented groups. The topical application of A. vera revealed marked remodelling of the granulation tissues and higher expression levels of TGF-β1, VEGF, bFGF, and Prdx6 in comparison with control and oral A. vera groups (P < 0.001). Conclusion: Both oral and topical applications of A. vera have beneficial effects in deep second-degree burn wound healing by boosting the growth factors and antioxidant status of skin tissue. The topical treatment was more efficient in accelerating wound healing and hence could be used efficiently to treat second-degree burns.

Management of Atopic Dermatitis Via Oral and Topical Administration of Herbs in Murine Model: A Systematic Review

Over the past few decades, complementary and alternative medicine (CAM) using herbs, or their active constituents have garnered substantial attention in the management of a chronic and relapsing inflammatory skin disorder called atopic dermatitis (AD), particularly in attenuating disease recurrence and maintaining long-term remission. In Eastern Asian countries including China, Korea and Taiwan, herbal medicine available in both topical and oral preparation plays a significant role in treating skin diseases like AD as they possibly confer high anti-inflammatory properties and immunomodulatory functions. Conventional murine models of AD have been employed in drug discovery to provide scientific evidence for conclusive and specific pharmacological effects elicited by the use of traditional herbs and their active constituents. Coupled with the goal to develop safe and effective novel therapeutic agents for AD, this systematic review consists of a summary of 103 articles on both orally and topically administered herbs and their active constituents in the murine model, whereby articles were screened and selected via a specialized framework known as PICO (Population, Intervention, Comparator and Outcome). The objectives of this review paper were to identify the efficacy of oral and topical administered herbs along with their active constituents in alleviating AD and the underlying mechanism of actions, as well as the animal models and choice of inducer agents used in these studies. The main outcome on the efficacy of the majority of the herbs and their active constituents illustrated suppression of Th2 response as well as improvements in the severity of AD lesions, suppression of Immunoglobulin E (IgE) concentration and mast cell infiltration. The majority of these studies used BALB/c mice followed by NC/Nga mice (commonly used gender-male; commonly used age group - 6-8 weeks). The most used agent in inducing AD was 2, 4-Dinitrochlorobenzene (DNCB), and the average induction period for both oral and topical administered herbs and their active constituents in AD experiments lasted between 3 and 4 weeks. In light of these findings, this review paper could potentially assist researchers in exploring the potential candidate herbs and their active constituents using murine model for the amelioration of AD.

Synergistic effect of Aloe vera flower and Aloe gel on cutaneous wound healing targeting MFAP4 and its associated signaling pathway: In-vitro study

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe vera (L.) Burm. f. (Liliaceae family) is a well-known traditional medicinal plant, that has been used to treat a variety of illnesses, for decades ranging from cancer to skin disorders including wounds. It has been included in the traditional and herbal healthcare systems of many cultures around the world, as well as the pharmacopeia of different countries. Several in vitro and in vivo studies have also confirmed its potential antioxidant, anti-inflammatory, and wound-healing activities, etc. in the consistency of its historical and traditional uses. However, most studies to date are based on the A. vera gel and latex including its wound-healing effects. Very few studies have been focused on its flower, and rarely with its effects on cutaneous wound healing and its molecular mechanism.

AIM OF THE STUDY

To the best of our knowledge, this is the first study to report on the synergistic effect of the A. vera flower (AVF) and Aloe gel (PAG) on cutaneous wound-healing, as well as revealing its molecular mechanism targeting microfibril-associated glycoprotein 4 (MFAP4) and its associated signaling pathway.

METHODS

To investigate the synergistic effect of A. vera flower and Aloe gel in cutaneous wound healing, cell viability, and cell migration, as well proliferation assay was performed. This was followed by quantitative real-time polymerase chain reaction and Western blot analyses in wounded conditions to check the effects of this mixture on protein and mRNA levels in normal human dermal fibroblast (NHDF) cells. Moreover, small interfering RNA (siRNA) -mediated knockdown of MFAP4 in NHDF cells was performed followed by migration assay and cell cycle analysis, to confirm its role in cutaneous wound healing. Additionally, HaCaT cells were included in this study to evaluate its migratory and anti-inflammatory effects.

RESULTS

Based on our obtained results, the PAG and AVF mixture synergistically induced the proliferation, migration, and especially ECM formation of NHDF cells by enhancing the expression of MFAP4. Other extracellular components associated with MFAP4 signaling pathway, such as fibrillin, collagen, elastin, TGF β, and α-SMA, also increased at both the protein and mRNA levels. Subsequently, this mixture initiated the phosphorylation of the extracellular signal-regulated kinase (ERK) and AKT signaling pathways, and the S-phase of the cell cycle was also slightly modified. Also, the mixture induced the migration of HaCaT cells along with the suppression of inflammatory cytokines. Moreover, the siRNA-mediated knockdown highlighted the crucial role of MFAP4 in cutaneous wound healing in NHDF cells.

CONCLUSION

This study showed that the mixture of PAG and AVF has significant wound healing effects targeting MFAP4 and its associated signaling pathway. Additionally, MFAP4 was recognized as a new potential biomarker of wound healing, which can be confirmed by further in vivo studies.

Advancements in Skin Delivery of Natural Bioactive Products for Wound Management: A Brief Review of Two Decades

Application of modern delivery techniques to natural bioactive products improves their permeability, bioavailability, and therapeutic efficacy. Many natural products have desirable biological properties applicable to wound healing but are limited by their inability to cross the stratum corneum to access the wound. Over the past two decades, modern systems such as microneedles, lipid-based vesicles, hydrogels, composite dressings, and responsive formulations have been applied to natural products such as curcumin or aloe vera to improve their delivery and efficacy. This article reviews which natural products and techniques have been formulated together in the past two decades and the success of these applications for wound healing. Many cultures prefer natural-product-based traditional therapies which are often cheaper and more available than their synthetic counterparts. Improving natural products’ effect can provide novel wound-healing therapies for those who trust traditional compounds over synthetic drugs to reduce medical inequalities.

Botanical Drugs in Traditional Chinese Medicine With Wound Healing Properties

Chronic and unhealed wound is a serious public problem, which brings severe economic burdens and psychological pressure to patients. Various botanical drugs in traditional Chinese medicine have been used for the treatment of wounds since ancient time. Nowadays, multiple wound healing therapeutics derived from botanical drugs are commercially available worldwide. An increasing number of investigations have been conducted to elucidate the wound healing activities and the potential mechanisms of botanical drugs in recent years. The aim of this review is to summarize the botanical drugs in traditional Chinese medicine with wound healing properties and the underlying mechanisms of them, which can contribute to the research of wound healing and drug development. Taken together, five botanical drugs that have been developed into commercially available products, and 24 botanical drugs with excellent wound healing activities and several multiherbal preparations are reviewed in this article.

Antimicrobial Biomaterial on Sutures, Bandages and Face Masks with Potential for Infection Control

Antimicrobial resistance (AMR) is a challenge for the survival of the human race. The steady rise of resistant microorganisms against the common antimicrobials results in increased morbidity and mortality rates. Iodine and a plethora of plant secondary metabolites inhibit microbial proliferation. Antiseptic iodophors and many phytochemicals are unaffected by AMR. Surgical site and wound infections can be prevented or treated by utilizing such compounds on sutures and bandages. Coating surgical face masks with these antimicrobials can reduce microbial infections and attenuate their burden on the environment by re-use. The facile combination of Aloe Vera Barbadensis Miller (AV), Trans-cinnamic acid (TCA) and Iodine (I₂) encapsulated in a polyvinylpyrrolidone (PVP) matrix seems a promising alternative to common antimicrobials. The AV-PVP-TCA-I₂ formulation was impregnated into sterile discs, medical gauze bandages, surgical sutures and face masks. Morphology, purity and composition were confirmed by several analytical methods. Antimicrobial activity of AV-PVP-TCA-I₂ was investigated by disc diffusion methods against ten microbial strains in comparison to gentamycin and nystatin. AV-PVP-TCA-I₂ showed excellent antifungal and strong to intermediate antibacterial activities against most of the selected pathogens, especially in bandages and face masks. The title compound has potential use for prevention or treatment of surgical site and wound infections. Coating disposable face masks with AV-PVP-TCA-I₂ may be a sustainable solution for their re-use and waste management.

Silk-based phyto-hydrogel formulation expedites key events of wound healing in full-thickness skin defect model

Immense socio-economic burden of chronic wound demands effective, low-cost strategies for wound care. Herein, we have developed a chemical crosslinker-free phyto-hydrogel by encapsulating phytochemicals of Aloe vera mucilage extract (AVM) in the self-assembled polymeric chains of two different silk fibroin (SF) proteins (from Bombyx mori and Antheraea assamensis). Additionally, polyvinylpyrrolidone (PVP) has been used as a stabilizer that also contributed to the mucoadhesive property of the composite (SAP; made of SF, AVM, and PVP) hydrogel. The physicochemical properties of the hydrogel were evaluated and compared with SF hydrogel containing only SF proteins without any additives. The biocompatibility assessment of the hydrogel under in vitro conditions has shown improved cellular proliferative and migratory responses, suggesting faster tissue repairability of the hydrogel. A detailed in vivo comparative study with a commercially available DuoDERM® gel revealed that SAP hydrogel not only promoted wound closure but also showed better deposition and remodeling of the extracellular matrix. Moreover, the hydrogel also demonstrated its ability to downregulate pro-inflammatory markers (IL-1β, TNF-α) and upregulation of anti-inflammatory markers (IL-10, TGF-β) at the early stage of healing. Therefore, the bioactive proteins-carbohydrates composite efficiently accelerates skin regeneration and possesses great translational potential to offer a low-cost alternative wound care therapeutic.

Strategies to Reduce Post-Hemorrhoidectomy Pain: A Systematic Review

Background and Objectives: Excisional hemorrhoidectomy is considered as a mainstay operation for high-grade hemorrhoids and complicated hemorrhoids. However, postoperative pain remains a challenging problem after hemorrhoidectomy. This systematic review aims to identify pharmacological and non-pharmacological interventions for reducing post-hemorrhoidectomy pain. Materials and Methods: The databases of Ovid MEDLINE, PubMed and EMBASE were systematically searched for randomized controlled trails (published in English language with full-text from 1981 to 30 September 2021) to include comparative studies examining post-hemorrhoidectomy pain as their primary outcomes between an intervention and another intervention (or a sham or placebo). Results: Some 157 studies were included in this review with additional information from 15 meta-analyses. Fundamentally, strategies to reduce post-hemorrhoidectomy pain were categorized into four groups: anesthetic methods, surgical techniques, intraoperative adjuncts, and postoperative interventions. In brief, local anesthesia-alone or combined with intravenous sedation was the most effective anesthetic method for excisional hemorrhoidectomy. Regarding surgical techniques, closed (Ferguson) hemorrhoidectomy performed with a vascular sealing device or an ultrasonic scalpel was recommended. Lateral internal anal sphincterotomy may be performed as a surgical adjunct to reduce post-hemorrhoidectomy pain, although it increased risks of anal incontinence. Chemical sphincterotomy (botulinum toxin, topical calcium channel blockers, and topical glyceryl trinitrate) was also efficacious in reducing postoperative pain. So were other topical agents such as anesthetic cream, 10% metronidazole ointment, and 10% sucralfate ointment. Postoperative administration of oral metronidazole, flavonoids, and laxatives was associated with a significant reduction in post-hemorrhoidectomy pain. Conclusions: This systematic review comprehensively covers evidence-based strategies to reduce pain after excisional hemorrhoidectomy. Areas for future research on this topic are also addressed at the end of this article.

Effect of Additives on Surface Tension, Viscosity, Transparency and Morphology Structure of Aloe vera Gel-Based Coating

Coating is a new trend for extending shelf-life and reducing postharvest damage to fruits currently. Aloe vera gel-based (AVG) coating is made by adding citric acid, ascorbic acid and potassium sorbate. The additive increases the stability of AVG coating. This research aims to determine the effect of additives on the surface tension, viscosity, transparency and morphology structure of AVG coating. The observation used a completely random design one factor with three replicates. Formulation of AVG coating uses additives involving citric acid, ascorbic acid, potassium sorbate and the mixture of additives, concentrations of 0.15%. Observations are made periodically on days 0, 5, 10 and 15. The type and concentration of additives affect the surface tension, viscosity, transparency and morphology structure of AVG coating. The best formulation of AVG coating for 15 days of storage is a mixture of additives (citric acid, ascorbic acid and potassium sorbate) with a concentration of 0.15% applied on the surface of the fruits. The best numeric value of AVG coating surface tension is 0.122 N/m, acidity 4.22, viscosity 96.03 mPa.s, color L* 19.51 and point of transparency 84.40. The combination of the three additives produced a clear, transparent white coating appearance and the potential to extend the shelf-life of fruit.

Low-dose Indonesian Aloe vera Increases Viability and Migration of the Fibroblast: An In Vitro Study

BACKGROUND: Important stages in wound healing involve homeostasis, inflammation, proliferation, and remodeling phases. Fibroblasts are essential factors in the healing pathway through the process of cell proliferation and migration. Aloe vera contains various active compounds used for anti-inflammatory, antimicrobial, immunomodulatory, anticancer, and wound healing. AIM: This study aimed to evaluate the effect of A. vera on the viability and migration of fibroblast cells. MATERIALS AND METHODS: Fibroblasts were cultured in a monolayer with Dulbecco’s Modified Eagle Medium containing 10% fetal bovine serum, 1% pinstripe, and 0.5% fungizone. We use fresh A. vera leaves extracted with 95% ethanol. Cell viability will be evaluated using the MTT test and microscopic evaluation. Cell migration was tested using an in vitro wound scratch assay and analyzed with ImageJ software. RESULTS: A. vera stimulated cell viability compared to control (p < 0.05). Administration of A. vera does not change shape and is not toxic to fibroblasts. A. vera stimulated cell migration at doses of 250, 125, 50, and 5 μg/mL compared to control after 24 h of intervention. At 48 h incubation, migration doses of 250, 50, and 5 μg/mL were higher than control (p < 0.05). CONCLUSIONS: A. vera extract may effectively wound healing by increasing viability and migration of fibroblast cells.

Antiangiogenic Phytochemicals Constituent of Diet as Promising Candidates for Chemoprevention of Cancer

Despite the extensive knowledge on cancer nature acquired over the last years, the high incidence of this disease evidences a need for new approaches that complement the clinical intervention of tumors. Interestingly, many types of cancer are closely related to dietary habits associated with the Western lifestyle, such as low fruit and vegetable intake. Recent advances around the old-conceived term of chemoprevention highlight the important role of phytochemicals as good candidates for the prevention or treatment of cancer. The potential to inhibit angiogenesis exhibited by many natural compounds constituent of plant foods makes them especially interesting for their use as chemopreventive agents. Here, we review the antitumoral potential, with a focus on the antiangiogenic effects, of phenolic and polyphenolic compounds, such as quercetin or myricetin; terpenoids, such as ursolic acid or kahweol; and anthraquinones from Aloe vera, in different in vitro and in vivo assays, and the available clinical data. Although clinical trials have failed to assess the preventive role of many of these compounds, encouraging preclinical data support the efficacy of phytochemicals constituent of diet in the prevention and treatment of cancer, but a deeper understanding of their mechanisms of action and better designed clinical trials are urgently needed.

Aloin Regulates Matrix Metabolism and Apoptosis in Human Nucleus Pulposus Cells via the TAK1/NF-κB/NLRP3 Signaling Pathway

Intervertebral disc degeneration (IDD) is a degenerative disease that is characterized by decreased matrix synthesis and extra degradation, nucleus pulposus cells (NPCs) apoptosis, and infiltration of inflammatory factors. Aloin, a colored compound from aloe plants, has been shown to be effective against skeletal degenerative diseases, but it is unclear whether it is protective against IDD. Herein, we investigated the role of aloin in NPCs. In our study, the upregulation of proinflammatory factors, apoptosis, and unbalanced matrix metabolism were observed in degenerative NP tissues. We found that aloin had a curative effect on extracellular matrix metabolism and apoptosis in TNF-alpha- (TNF-α-) treated NPCs by inhibiting oxidative stress and the proinflammatory factor expression. Further investigation revealed that aloin treatment suppressed the TAK1/NF-κB pathway. Moreover, the expression level of the NLPR3 inflammasome was downregulated after aloin treatment in TNF-α-treated NPCs. In summary, our results demonstrated that aloin treatment can reverse TNF-α-induced unbalanced matrix metabolism and apoptosis of NPCs via the TAK1/NF-κB/NLRP3 axis. This study supports that aloin can be a promising therapeutic agent for IDD.

Home Oral Care of Periodontal Patients Using Antimicrobial Gel with Postbiotics, Lactoferrin, and Aloe Barbadensis Leaf Juice Powder vs. Conventional Chlorhexidine Gel: A Split-Mouth Randomized Clinical Trial

Periodontitis is a progressive destruction of both soft and hard tooth-supporting tissues. In the last years, probiotics have been proposed as a support to the gold standard treatment scaling and root planing (SRP), but no extensive literature is present as regards the effect of the more recent postbiotics. Thirty patients subjected to SRP were randomly assigned to two domiciliary hygiene treatments based on the following oral gels: the postbiotics-based Biorepair Parodontgel Intensive (Group 1) and the chlorhexidine-based Curasept Periodontal Gel (Group 2). At baseline (T0) and after 3 and 6 months (T1-T2), the following periodontal clinical parameters were recorded: Probing Pocket Depth (PPD), recession, dental mobility, Bleeding on Probing (BoP), and Plaque Control Record (PCR). A significant intragroup reduction was assessed in both groups for PPD, BoP, and PCR; conversely, recession significantly increased in both groups, whereas dental mobility did not vary. As regards intergroup comparisons, no statistically significant differences were assessed. Both gels, respectively, containing antioxidant natural ingredients and chlorhexidine, are effective for the domiciliary treatment of periodontitis. Further studies are required to evaluate the singular chemical compounds of the gels expected to exert the beneficial action assessed in this preliminary study.

Sandwich structure Aloin-PVP/Aloin-PVP-PLA/PLA as a wound dressing to accelerate wound healing

We have prepared a new type of Aloin/Polyvinylpyrrolidone (PVP)-Aloin/PVP/polylactic acid (PLA)-PLA sandwich nanofiber membrane (APP), to achieve a time-regulated biphasic drug release behavior, used for hemostasis, antibacterial activity and accelerated wound healing. We tested the water absorption capacity, water contact angle, tensile strength, thermogravimetric analysis, Fourier transform infrared spectroscopy and in vitro drug release of the prepared material, as well as analyzed the morphology of the nanofiber membrane with a scanning electron microscope. In the wound healing experiment, the wound healing rate of APP on the 15th day was 96.67%, and it demonstrated excellent antibacterial activity by the disc diffusion method, showing superior antibacterial activity against Gram-negative bacteria. The skin defect model on the back of mice showed that APP nanofibers significantly induced granulation tissue growth, collagen deposition and epithelial tissue remodeling. Current research shows that the prepared composite nanofibers can quickly stop bleeding and can effectively promote wound healing.

Flow chart for the preparation of “sandwich” nanofiber membranes.

Periodontal Ligament Fibroblast Cell Viability Following Treatment with Different Concentrations of Green Tea, Aloe Vera and a Mixture of their Extracts

Objectives: Various studies have identified green tea and Aloe vera as a suitable medium for avulsed teeth. The aim of this study was to evaluate and compare the viability of periodontal ligament (PDL) fibroblasts following treatment with the extracts of these two plants and their mixture. Materials and Methods: Human PDL fibroblasts were purchased and treated with different concentrations of Aloe vera, green tea, and a combination of these two extracts. Hank's balanced salt solution and culture medium were employed as positive and negative controls, respectively. Viability was assessed using the MTT assay. Two-way ANOVA and post-hoc tests were used for statistical analysis (P<0.05). Results: There was a significant difference in PDL fibroblast viability between different concentrations of the extracts. Higher concentrations of green tea and the combination of the two extracts significantly increased cell viability. Higher concentrations of Aloe vera had the least positive effect on maintaining the viability of these cells. Conclusion: If confirmed by further studies, the combination of Aloe vera and green tea extracts might be considered as a suitable media for different purposes like storing avulsed teeth.

Fish and the Thyroid: A Janus Bifrons Relationship Caused by Pollutants and the Omega-3 Polyunsaturated Fatty Acids

Benefits of the omega-3 polyunsaturated fatty acids (PUFA) on a number of clinical disorders, including autoimmune diseases, are widely reported in the literature. One major dietary source of PUFA are fish, particularly the small oily fish, like anchovy, sardine, mackerel and others. Unfortunately, fish (particularly the large, top-predator fish like swordfish) are also a source of pollutants, including the heavy metals. One relevant heavy metal is mercury, a known environmental trigger of autoimmunity that is measurable inside the thyroid. There are a number of interactions between the omega-3 PUFA and thyroid hormones, even at the level of the thyroid hormone transport proteins. Concerning the mechanisms behind the protection from/amelioration of autoimmune diseases, including thyroiditis, that are caused by the omega-3 PUFA, one can be the decreased production of chemokines, a decrease that was reported in the literature for other nutraceuticals. Recent studies point also to the involvement of resolvins. The intracellular increase in resolvins is associated with the tissue protection from inflammation that was observed in experimental animals after coadministration of omega-3 PUFA and thyroid hormone. After having presented data on fish consumption at the beginning, we conclude our review by presenting data on the market of the dietary supplements/nutraceuticals. The global omega-3 products market was valued at USD 2.10 billion in 2020, and was projected to go up at a compound annual growth rate of 7.8% from 2020 to 2028. Among supplements, fish oils, which are derived mainly from anchovies, are considered the best and generally safest source of omega-3. Taking into account (i) the anti-autoimmunity and anti-cancer properties of the omega-3 PUFA, (ii) the increasing incidence of both autoimmune thyroiditis and thyroid cancer worldwide, (iii) the predisposing role for thyroid cancer exerted by autoimmune thyroiditis, and (iv) the risk for developing metabolic and cardiovascular disorders conferred by both elevated/trendwise elevated serum TSH levels and thyroid autoimmunity, then there is enough rationale for the omega-3 PUFA as measures to contrast the appearance and/or duration of Hashimoto's thyroiditis as well as to correct the slightly elevated serum TSH levels of subclinical hypothyroidism.

The effects of oral Aloe vera on the efficacy of transplanted human endothelial cells and the expression of matrix metalloproteinases in diabetic wound healing

Background

Diabetic wounds are characterized by delayed healing and impaired angiogenesis. Aloe vera and human umbilical vein endothelial cells (HUVECs) are reported to facilitate wound healing, and the former also has hypoglycemic property. Matrix metalloproteinases are enzymes that play a role in diabetic wound pathogenesis.

Objective

To investigate whether oral Aloe vera can enhance the efficacy of HUVEC transplantation and inhibit the expression of matrix metalloproteinases in wound healing of diabetic mice.

Materials and methods

BALB/c nude mice were randomly assigned into five groups: normal control group, diabetic group (DM), DM transplanted with HUVECs, DM treated with oral Aloe vera, and DM treated with combined HUVECs and oral Aloe vera. Diabetes was induced by streptozotocin. Bilateral full-thickness excision cutaneous wounds were created. At days 7 and 14 post-wounding, the following parameters were determined: blood glucose, wound area, wound perfusion, capillary vascularity, re-epithelialization rate and tissue VEGF levels. Tissue expressions of MMP-2 and MMP-9 were compared between the DM mice and those treated with oral Aloe vera.

Results

Over days 7 and 14, Aloe vera exerted glucose-lowering effect in diabetic mice. Higher wound closure rate, blood flow and capillary vascularity, and lower MMP-2 and MMP-9 expressions were observed at both time points in DM treated with Aloe vera group compared with DM group (P < 0.05). Moreover, combined therapy of HUVECs and oral Aloe vera was more effective than Aloe vera or HUVECs alone in increasing VEGF levels, capillary vascularity and wound perfusion. Blood glucose levels were negatively correlated with angiogenesis (P = 0.000.

Conclusion

It is suggested that oral Aloe vera enhances the efficacy of HUVEC transplantation on diabetic wound angiogenesis, partly through improving glycemic control. Oral Aloe vera also promotes diabetic wound healing via inhibition of MMP-2 and MMP-9 expressions.

Aloe derived nanovesicle as a functional carrier for indocyanine green encapsulation and phototherapy

Background

Cancer is one of the devastating diseases in the world. The development of nanocarrier provides a promising perspective for improving cancer therapeutic efficacy. However, the issues with potential toxicity, quantity production, and excessive costs limit their further applications in clinical practice.

Results

Herein, we proposed a nanocarrier obtained from aloe with stability and leak-proofness. We isolated nanovesicles from the gel and rind of aloe (gADNVs and rADNVs) with higher quality and yield by controlling the final centrifugation time within 20 min, and modulating the viscosity at 2.98 mPa S and 1.57 mPa S respectively. The gADNVs showed great structure and storage stability, antioxidant and antidetergent capacity. They could be efficiently taken up by melanoma cells, and with no toxicity in vitro or in vivo. Indocyanine green (ICG) loaded in gADNVs (ICG/gADNVs) showed great stability in both heating system and in serum, and its retention rate exceeded 90% after 30 days stored in gADNVs. ICG/gADNVs stored 30 days could still effectively damage melanoma cells and inhibit melanoma growth, outperforming free ICG and ICG liposomes. Interestingly, gADNVs showed prominent penetrability to mice skin which might be beneficial to noninvasive transdermal administration.

Conclusions

Our research was designed to simplify the preparation of drug carrier, and reduce production cost, which provided an alternative for the development of economic and safe drug delivery system.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01195-7.

Network Pharmacology-Based Study on the Mechanism of Aloe Vera for Treating Cancer

BACKGROUND

Aloe vera has long been considered an anticancer herb in different parts of the world.

OBJECTIVE

To explore the potential mechanism of aloe vera in the treatment of cancer using network pharmacology and molecule docking approaches.

METHODS

The active ingredients and corresponding protein targets of aloe vera were identified from the TCMSP database. Targets related to cancer were obtained from GeneCards and OMIM databases. The anticancer targets of aloe vera were obtained by intersecting the drug targets with the disease targets, and the process was presented in the form of a Venn plot. These targets were uploaded to the String database for protein-protein interaction (PPI) analysis, and the result was visualized by Cytoscape software. Go and KEGG enrichment were used to analyze the biological process of the target proteins. Molecular docking was used to verify the relationship between the active ingredients of aloe vera and predicted targets.

RESULTS

By screening and analyzing, 8 active ingredients and 174 anticancer targets of aloe vera were obtained. The active ingredient-anticancer target network constructed by Cytoscape software indicated that quercetin, arachidonic acid, aloe-emodin, and beta-carotene, which have more than 4 gene targets, may play crucial roles. In the PPI network, AKT1, TP53, and VEGFA have the top 3 highest values. The anticancer targets of aloe vera were mainly involved in pathways in cancer, prostate cancer, bladder cancer, pancreatic cancer, and non-small-cell lung cancer and the TNF signaling pathway. The results of molecular docking suggested that the binding ability between TP53 and quercetin was the strongest.

CONCLUSION

This study revealed the active ingredients of aloe vera and the potential mechanism underlying its anticancer effect based on network pharmacology and provided ideas for further research.

Aloin induced apoptosis by enhancing autophagic flux through the PI3K/AKT axis in osteosarcoma

Background

Osteosarcoma is a malignant tumor of bone and soft tissue in adolescents. Due to its tumor biological behavior pattern, osteosarcoma usually generates poor prognosis. Autophagy is an important self-defense mechanism in osteosarcoma.

Methods

Cell viability in IC₅₀ testing and reverse assays was examined by the MTT assay. Cell apoptosis conditions were examined by flow cytometry, Hoechst 33,342 staining and apoptosis-related protein immunoblotting. Autophagy conditions were tested by autophagy-related protein immunoblotting, transmission electron microscopic observation and dual fluorescence autophagy flux detection. The possible targets of aloin were screened out by network pharmacology and bioinformatic methods. Osteosarcoma xenografts in nude BALB/c mice were the model for in vivo research on tumor suppression, autophagy induction, pathway signaling and toxicity tests. In vivo bioluminescence imaging systems, immunohistochemical assays, and gross tumor volume comparisons were applied as the main research methods in vivo.

Results

Aloin induced osteosarcoma apoptosis in a dose-dependent manner. Its possible effects on the PI3K/AKT pathway were screened out by network pharmacology methods. Aloin increased autophagic flux in osteosarcoma by downregulating the PI3K/AKT pathway. Aloin promoted autophagic flux in the osteosarcoma cell lines HOS and MG63 in a dose-dependent manner by promoting autophagosome formation. Chloroquine reversed the apoptosis-promoting and autophagy-enhancing effects of aloin. Autophagy induced by starvation and rapamycin significantly enhanced the autophagic flux and apoptosis induced by aloin, which verified the role of the PI3K/AKT axis in the pharmacological action of aloin. Therapeutic effects, autophagy enhancement and regulatory effects on the PI3K/AKT/mTOR pathway were demonstrated in a nude mouse xenogeneic osteosarcoma transplantation model.

Conclusions

Aloin inhibited the proliferation of osteosarcoma by inhibiting the PI3K/AKT/mTOR pathway, increasing autophagic flux and promoting the apoptosis of osteosarcoma cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00520-4.

Prospects of Aloe vera and its Bioactive Compounds in Diabetes: Critical Review

Diabetes is a significant public health issue. The global diabetes epidemic has had a tremendous impact on India, and the disease burden has increased dramatically. Diabetes is quickly increasing in prevalence, especially in Indian cities, according to data. Therefore, an ideal drug is sought that has better safety and tolerability and the most effective control of diabetes. Many effective medications come from plant sources. Natural products like onion and garlic can effectively control diabetes. In this review, we should pay attention to Aloe vera and its bioactive compounds, that with the development of traditional medicine, Aloe vera can be used to treat various diseases. Some reports have questioned the safety and efficacy of Aloe vera or its compounds, especially at different doses, and some studies have shown no side effects. In this review we also focus on benefits on human health so that Aloe vera is part of the daily diet in many countries and appears to be non-toxic, it is necessary to investigate whether aloe vera dietary supplement can be a beneficial preventive or nutritional mitigation strategy to reduce the effects of diabetes. This review focuses on Aloe vera and its biologically active compounds that play a role in the treatment or prevention of this morbid disease: diabetes, including its underlying mechanism of blood sugar lowering properties, and herbal products that have been marketed for the treatment of diabetes or the therapeutic effect of diabetes.

Characterization and Topical Study of Aloe Vera Hydrogel on Wound-Healing Process

Wound healing is fundamental to restore the tissue integrity. A topical study of the influence of Aloe vera hydrogel, formulated with 1,2-propanediol (propanediol) and triethanolamine (TEA), on the skin wound-healing process was investigated in female Wistar rats. FTIR spectroscopy confirms the presence of carboxylic acid and methyl ester carboxylate groups related with important compounds that confer the hydrogel a good interaction with proteins and growth factors. SEM images show a microstructure and micro-roughness that promote a good adhesion to the wound. Therefore, the swelling kinetics and the contact angle response contribute to the understanding of the in vivo results of the animal test. The results indicated that the Aloe vera hydrogel, prepared with propanediol and TEA, together with its superficial characteristics, improve its rapid penetration without drying out the treated tissue. This produced a positive influence on inflammation, angiogenesis, and wound contraction, reducing 29% the total healing time, reaching the total closure of the wound in 15 days.

Aloe barbadensis Mill. extract improves symptoms in IBS patients with diarrhoea: post hoc analysis of two randomized double-blind controlled studies

BACKGROUND

Aloe barbadensis Mill. (Aloe) extract was found to be well-tolerated, safe and showed beneficial effects in subsets of irritable bowel syndrome (IBS) patients in two randomized, double-blind, controlled studies. However, the individual studies were underpowered to perform subgroup analyses. We therefore determined the effect of Aloe extract in IBS subgroups in a post hoc analysis combining the results from the two studies.

METHODS

Data from the two controlled studies comparing Aloe and control treatment taken orally for 4 weeks, were pooled. Both studies included IBS patients fulfilling the ROME III criteria and IBS Symptom Severity Score (IBS-SSS) was assessed. We analysed the effect of Aloe extract on IBS symptom severity and the proportion of responders (IBS-SSS reduction ⩾ 50) in IBS subgroups.

RESULTS

In total, 213 IBS patients were included in the post hoc subgroup analyses. A reduction in overall symptom severity, primarily driven by effect on pain severity and frequency, comparing baseline versus end of treatment, was recorded in IBS patients with diarrhoea (IBS-D) receiving Aloe (n = 38, p < 0.001) but not control treatment (n = 33, p = 0.33), with difference between the treatment groups (p = 0.01). Moreover, the frequency of responders was higher in IBS-D patients receiving Aloe (n = 22, 58%) compared to control treatment (n = 10, 30%) (p = 0.02). The effect of Aloe extract treatment on IBS symptom severity was not superior to control treatment in the other IBS subtypes.

CONCLUSION

Aloe extract improves symptom severity in IBS-D patients and can be regarded as a safe and effective treatment option for this patient group.

The Renaissance of Plant Mucilage in Health Promotion and Industrial Applications: A Review

Plant mucilage is a renewable and cost-effective source of plant-based compounds that are biologically active, biodegradable, biocompatible, nontoxic, and environmentally friendly. Until recently, plant mucilage has been of interest mostly for technological purposes. This review examined both its traditional uses and potential modern applications in a new generation of health-promoting foods, as well as in cosmetics and biomaterials. We explored the nutritional, phytochemical, and pharmacological richness of plant mucilage, with a particular focus on its biological activity. We also highlighted areas where more research is needed in order to understand the full commercial potential of plant mucilage.

The Application of Skin Care Product in Melasma Treatment

Melasma is an acquired and chronic hyperpigmentation disorder which is recognized as one of the most psychologically distressing and difficult to cure forms of skin hyperpigmentation. It is associated with substantial quality of life impairments. Treatments of melasma include local application, oral medication, physical laser therapy and program combination therapy. However, routine treatment usually leads to the damage of skin barrier function, resulting in adverse reactions such as erythema, pruritus, post-inflammatory pigmentation and even scar. Skin care products contain a variety of active ingredients, which are widely concerned by cosmetic dermatologists because of high safety, good tolerance and the effect of improving the damaged skin barrier. Using skin care products alone or in combination with routine treatment not only can improve the curative effect for melasma, reduce side effects and recurrence rate, but also improve patient satisfaction. This article mainly describes the application of skin care products in the treatment of melasma.

Anthraquinones from Aloe spp. inhibit Cryptococcus neoformans sensu stricto: effects against growing and mature biofilms

This study aimed to evaluate the in vitro effect of aloe emodin, barbaloin and chrysophanol on growing and mature biofilms of Cryptococcus neoformans sensu stricto. The compounds were added at the moment of inducing biofilm growth or after growth for 72 h to evaluate their effects on growing and mature biofilms, respectively. Then, biofilm biomass was evaluated by crystal violet staining and metabolic activity by the XTT reduction assay. Morphological alterations were also evaluated by laser scanning confocal microscopy. Aloe emodin and barbaloin affected growing biofilms and disrupted mature biofilms, reducing metabolic activity by > 60% and biomass by > 70%. Chrysophanol only inhibited mature biofilms, but to a lesser extent. In conclusion, anthraquinones, especially aloe emodin and barbaloin, show a relevant effect against growing and mature biofilms of C. neoformans sensu stricto.

Antimicrobial Properties of Lepidium sativum L. Facilitated Silver Nanoparticles

Antibiotic resistance toward commonly used medicinal drugs is a dangerously growing threat to our existence. Plants are naturally equipped with a spectrum of biomolecules and metabolites with important biological activities. These natural compounds constitute a treasure in the fight against multidrug-resistant microorganisms. The development of plant-based antimicrobials through green synthesis may deliver alternatives to common drugs. Lepidium sativum L. (LS) is widely available throughout the world as a fast-growing herb known as garden cress. LS seed oil is interesting due to its antimicrobial, antioxidant, and anti-inflammatory activities. Nanotechnology offers a plethora of applications in the health sector. Silver nanoparticles (AgNP) are used due to their antimicrobial properties. We combined LS and AgNP to prevent microbial resistance through plant-based synergistic mechanisms within the nanomaterial. AgNP were prepared by a facile one-pot synthesis through plant-biomolecules-induced reduction of silver nitrate via a green method. The phytochemicals in the aqueous LS extract act as reducing, capping, and stabilizing agents of AgNP. The composition of the LS-AgNP biohybrids was confirmed by analytical methods. Antimicrobial testing against 10 reference strains of pathogens exhibited excellent to intermediate antimicrobial activity. The bio-nanohybrid LS-AgNP has potential uses as a broad-spectrum microbicide, disinfectant, and wound care product.

Enzymatic and Antimicrobial Activity of Biologically Active Samples from Aloe arborescens and Aloe barbadensis

Simple Summary

Antimicrobial resistance is one of the major threats to public health, and additional concerns are reduced efficacy and increased toxicity of synthetically derived drugs. Hence, it is all the more important to research new antimicrobials derived from natural sources. Aloe spp. have long been acknowledged in traditional medicine, as their ability of treating skin and digestive problems, wound healing, anti-inflammatory, antimicrobial and other promising properties are known. This study presents the content of various bioactive substances in samples of two Aloe spp., Aloe arborescens and Aloe barbadensis, and their enzymatic, antioxidant and antimicrobial activity. Obtained bioactive compounds with antimicrobial effect have a huge potential to inhibit the growth of microorganisms that are extremely susceptible to gaining resistance and could be used in versatile applications in the cosmetics, food, medical and pharmaceutical industries.

Abstract

Recently, the use of Aloe species has become very widespread. These are extensively used as a nutraceutical in a variety of health care products and food supplements. In addition, the occurrence of the quickly adaptable microorganisms, particularly bacteria, which can develop resistance to antibiotics, is a major problem for public health, and therefore, it is necessary to search for new antimicrobials. In our study, the content of total phenols, proanthocyanidins, and proteins in fresh and lyophilized samples of A. arborescens and A. barbadensis and their ethanol extracts was investigated. Furthermore, enzymatic and antioxidant activity of samples were studied. Since antimicrobial activity of fresh samples was determined in our latest research, a more detailed study of antimicrobial effectiveness of A. arborescens and A. barbadensis (lyophilized, extracts) was performed. Ethanol extracts in particular contain higher concentrations of bioactive substances and show the topmost antioxidant activity. The novelty of the study refers to the observation of industrially important enzyme activities such as α-amylase, cellulase, lipase, peroxidase, protease, and transglutaminase in the samples as well as the microbial growth inhibition rates determination (MGIR) at different concentrations of added aloe samples. All samples inhibited the growth of all tested microbial cells. MIC₉₀ for A. arborescens and A. barbadensis were also determined in case of B. cereus, P. aeruginosa, P. fluorescens, and S. aureus. The results of our study tend to give credence to the popular use of both aloes in medicine and in the cosmetic, food, and pharmaceutical industries.

Protective Effect of Aloe vera Gel against Cisplatin-Induced Testicular Damage, Sperm Alteration and Oxidative stress in Rats

BACKGROUND

Cisplatin (CIS) is an effective antineoplas tic drug that is used to treat various types of cancers. However, it causes side effects on the male reproductive sys tem. The present s tudy aimed to inves tigate the possible protective effects of Aloe vera (AL) gel (known as an antioxidant plant) on CIS-induced changes in rat sperm parameters, tes ticular s tructure, and oxidative s tress markers.

MATERIALS AND METHODS

In this experimental study, forty-eight adult male rats were divided into 6 groups including: control, CIS, AL, metformin (MET), CIS+AL, and CIS+MET. CIS was used intraperitoneally at a dose of 5 mg/kg on days 7, 14, 21, and 28 of the experiment. AL gel (400 mg/kg per day) and MET (200 mg/kg per day) were administered orally for 35 days (started one week before the beginning of the experiment). Testes weight and dimensions, and morphometrical and histological alterations, activities of antioxidant enzymes including superoxide dismutase (SOD) and glutathione peroxidase (GPx), serum testosterone concentration, lipid peroxidation level, and sperm parameters were examined.

RESULTS

CIS caused a significant decrease (P<0.05) in relative weight and dimension of the testis, germinal epithelium thickness and diameter of seminiferoustubules, the numbers of testicular cells, and spermatogenesis indexes. The malondialdehyde (MDA) levels increased and antioxidant enzymes activities decreased in the CIS group compared to the control group (P<0.05). Additionally, sperm parameters (concentration, viability, motility, and normal morphology), and testosterone levels reduced significantly in CIS-treated rats (P<0.05). Also, CIS induced histopathological damages including disorganization, desquamation, atrophy, and vacuolation in the testis. However, administration of AL gel to CIS-treated rats attenuated the CIS-induced alterations, mitigated testicular oxidative stress and increased testosterone concentration.

CONCLUSION

The results suggest that AL as a potential antioxidant plant and due to free radicals scavenging activities, has a protective effect against CIS-induced testicular alterations.

Phytochemical and In-Vivo Anti-Arthritic Significance of Aloe thraskii Baker in Combined Therapy with Methotrexate in Adjuvant-Induced Arthritis in Rats

Unlike other widely known Aloe species used for treatment of rheumatoid arthritis, this species suffers from a lack of sufficient studies on its biological and chemical characters. This is what drove us to perform this work to evaluate the in vivo anti-arthritic potential of its leaf ethanolic extract. The in vivo anti-arthritic activity of the leaf ethanolic extract at 100 and 200 mg/kg/day b.wt. was evaluated alone and in combination with methotrexate (MTX) using complete Freund's adjuvant. Serum levels of rheumatoid factor, anti-cyclic citrullinated peptide (anti-CCP), cytokines pro-inflammatory marker, inflammatory mediator serum levels, and oxidative stress mediators were analyzed, in addition to liver function. Orientin, isoorientin, β-sitosterol, its palmitate and its glucoside were isolated. The combined therapy of MTX and the leaf ethanolic extract (especially at 200 mg/kg b.wt.) group showed better activity compared to MTX alone. Moreover, the combined therapy provided additional benefits in lowering the liver toxicity by comparison to MTX alone. We concluded that a synergetic combination of the leaf ethanolic extract and MTX is beneficial in the management of rheumatoid arthritis with fewer side effects on liver function, as well as the possibility of the leaf extract to stand alone as an effective natural anti-arthritic agent.

Facile Synthesis of Bio-Antimicrobials with "Smart" Triiodides

Multi-drug resistant pathogens are a rising danger for the future of mankind. Iodine (I₂) is a centuries-old microbicide, but leads to skin discoloration, irritation, and uncontrolled iodine release. Plants rich in phytochemicals have a long history in basic health care. Aloe Vera Barbadensis Miller (AV) and Salvia officinalis L. (Sage) are effectively utilized against different ailments. Previously, we investigated the antimicrobial activities of smart triiodides and iodinated AV hybrids. In this work, we combined iodine with Sage extracts and pure AV gel with polyvinylpyrrolidone (PVP) as an encapsulating and stabilizing agent. Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), Surface-Enhanced Raman Spectroscopy (SERS), microstructural analysis by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-Ray-Diffraction (XRD) analysis verified the composition of AV-PVP-Sage-I₂. Antimicrobial properties were investigated by disc diffusion method against 10 reference microbial strains in comparison to gentamicin and nystatin. We impregnated surgical sutures with our biohybrid and tested their inhibitory effects. AV-PVP-Sage-I₂ showed excellent to intermediate antimicrobial activity in discs and sutures. The iodine within the polymeric biomaterial AV-PVP-Sage-I₂ and the synergistic action of the two plant extracts enhanced the microbial inhibition. Our compound has potential for use as an antifungal agent, disinfectant and coating material on sutures to prevent surgical site infections.