Aloesin as a medical food ingredient for systemic oxidative stress of diabetes

Aloe vera-An Extensive Review Focused on Recent Studies

Since ancient times, Aloe vera L. (AV) has attracted scientific interest because of its multiple cosmetic and medicinal properties, attributable to compounds present in leaves and other parts of the plant. The collected literature data show that AV and its products have a beneficial influence on human health, both by topical and oral use, as juice or an extract. Several scientific studies demonstrated the numerous biological activities of AV, including, for instance, antiviral, antimicrobial, antitumor, and antifungal. Moreover, its important antidepressant activity in relation to several diseases, including skin disorders (psoriasis, acne, and so on) and prediabetes, is a growing field of research. This comprehensive review intends to present the most significant and recent studies regarding the plethora of AV's biological activities and an in-depth analysis exploring the component/s responsible for them. Moreover, its morphology and chemical composition are described, along with some studies regarding the single components of AV available in commerce. Finally, valorization studies and a discussion about the metabolism and toxicological aspects of this "Wonder Plant" are reported.

Aloesin ameliorates hypoxic-ischemic brain damage in neonatal mice by suppressing TLR4-mediated neuroinflammation

BACKGROUND

At present, neonatal hypoxic-ischemic encephalopathy (HIE), especially moderate to severe HIE, is a challenging disease for neonatologists to treat, and new alternative/complementary treatments are urgently needed. The neuroinflammatory cascade triggered by hypoxia-ischemia (HI) insult is one of the core pathological mechanisms of HIE. Early inhibition of neuroinflammation provides long-term neuroprotection. Plant-derived monomers have impressive anti-inflammatory effects. Aloesin (ALO) has been shown to have significant anti-inflammatory and antioxidant effects in diseases such as ulcerative colitis, but its role in HIE is unclear. To this end, we conducted a series of experiments to explore the potential mechanism of ALO in preventing and treating brain damage caused by HI insult.

MATERIALS AND METHODS

Hypoxic-ischemic brain damage (HIBD) was induced in 7-day-old Institute of Cancer Research (ICR) mice, which were then treated with 20 mg/kg ALO. The neuroprotective effects of ALO on HIBD and the underlying mechanism were evaluated through neurobehavioral testing, infarct size measurement, apoptosis detection, protein and messenger RNA level determination, immunofluorescence, and molecular docking.

RESULTS

ALO alleviated the long-term neurobehavioral deficits caused by HI insult; reduced the extent of cerebral infarction; inhibited cell apoptosis; decreased the levels of the inflammatory factors interleukin (IL)-1β, IL-6, and tumor necrosis factor-α; activated microglia and astrocytes; and downregulated the protein expression of members in the TLR4 signaling pathway. In addition, molecular docking showed that ALO can bind stably to TLR4.

CONCLUSION

ALO ameliorated HIBD in neonatal mice by inhibiting the neuroinflammatory response mediated by TLR4 signaling.

Aloe juvenna Brandham & S.Carter as α-Amylase Inhibitor and Hypoglycaemic Agent with Anti-inflammatory Properties for Diabetes Management

Despite Aloe's traditional use, Aloe juvenna Brandham & S.Carter is poorly characterized. Other Aloes are known for their antidiabetic activity. This study describes the antidiabetic potentials and phytoconstituents of the A. juvenna leaves methanolic extract (AJME). Twenty-six phytoconstituents of AJME were described using HPLC/MS-MS. Lupeol and vitexin were isolated using column chromatography. The antidiabetic activity of AJME was investigated using an in vivo high-fat diet/streptozotocin-induced diabetic rat model and in vitro α-glucosidase and α-amylase inhibitory activity assays. AJME demonstrated its α-amylase inhibitory activity (IC50=313±39.9 ppm) with no effect on α-glucosidase. In vivo, AJME dose-dependently improved hyperglycaemia in a high-fat diet/streptozotocin-induced diabetic rat model. Notably, the higher dose (1600 mg/kg) of AJME significantly downregulated serum interleukin-6, tumor necrosis factor-α, and matrix metalloproteinase-1 genes, suggesting its anti-inflammatory effect. These findings indicate AJME's potential as a significant antidiabetic agent through its α-amylase inhibition, hypoglycaemic, and anti-inflammatory properties.

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.

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

Agarwood-The Fragrant Molecules of a Wounded Tree

Agarwood, popularly known as oudh or gaharu, is a fragrant resinous wood of high commercial value, traded worldwide and primarily used for its distinctive fragrance in incense, perfumes, and medicine. This fragrant wood is created when Aquilaria trees are wounded and infected by fungi, producing resin as a defense mechanism. The depletion of natural agarwood caused by overharvesting amidst increasing demand has caused this fragrant defensive resin of endangered Aquilaria to become a rare and valuable commodity. Given that instances of natural infection are quite low, artificial induction, including biological inoculation, is being conducted to induce agarwood formation. A long-term investigation could unravel insights contributing toward Aquilaria being sustainably cultivated. This review will look at the different methods of induction, including physical, chemical, and biological, and compare the production, yield, and quality of such treatments with naturally formed agarwood. Pharmaceutical properties and medicinal benefits of fragrance-associated compounds such as chromones and terpenoids are also discussed.

Aloe vera and Fermented Extracts Exhibit an Anti-Inflammatory Effect on Human Glioblastoma/Astrocytoma U373 MG Cells

The anti-inflammatory effects of Aloe vera (AV), polysaccharide extract from AV, and extracts from the digestion and colonic fermentation of AV were evaluated using an immortal astrocyte cell line (U373 MG) that develops a neuro-inflammatory profile. Cell viability and inflammatory markers were assessed after stimulation with neuropeptide substance P (SP) that activates the pro-inflammatory MAPK (mitogen-activated protein kinase) pathway. Cell viability after SP treatment was over 50% at 10 mg/mL AV, polysaccharide extract from AV, extracts from the digestion: non-digestible fraction of AV non-digestible fraction of polysaccharide extract from AV and extracts from the colonic fermentation of AV, at 4 and 24 h. Moreover, cells exposed to SP and treated with these extracts showed lower protein-activated ERK1/ERK2 (extracellular signal-regulated kinases 1 and 2), p38 (MAPK protein p38), and NFκB (nuclear factor κB) levels with respect to the SP-stimulated control. Inflammation inhibition by extracts of polysaccharide extract from AV and extracts from the colonic fermentation of AV, at 24 h in the study of p38 was not as statistically significant in ERK1/ERK2 and NFκB. Nevertheless, there was a significant decrease (p < 0.05) in pro-inflammatory cytokine IL-6 levels in cells exposed to all samples. Samples with extracts from the colonic fermentation of AV, at 4 or 24 h showed the highest inhibitory effect on IL-6 production.

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.

Human health-related properties of chromones: an overview

Natural compounds occurring throughout the world are scientifically and practically valuable because of their unique and beneficial properties to control a wide range of disorders in the human body. Chromones are attracting increasing attention as novel therapeutic agents due to their effective bioactivities for human health. Accordingly, the present overview article was designed to scan the biological and pharmacological performance of chromones, including their anti-inflammatory, anticancer, anti-oxidant, and anti-microbial activities.

In vitro Fermentation of Polysaccharides from Aloe vera and the Evaluation of Antioxidant Activity and Production of Short Chain Fatty Acids

Soluble or fermentable fibre has prebiotic effects that can be used in the food industry to modify the composition of microbiota species to benefit human health. Prebiotics mostly target Bifidobacterium and Lactobacillus strains, among others, which can fight against chronic diseases since colonic fermentation produces short chain fatty acids (SCFAs). The present work studied the changes produced in the fibre and polyphenolic compounds during in vitro digestion of gel (AV) and a polysaccharide extract (AP) from Aloe vera, after which, these fractions were subjected to in vitro colonic fermentation to evaluate the changes in antioxidant capacity and SCFAs production during the fermentation. The results showed that the phenolic compounds increased during digestion, but were reduced in fermentation, as a consequence, the antioxidant activity increased significantly in AV and AP after the digestion. On the other hand, during in vitro colon fermentation, the unfermented fibre of AV and AP responded as lactulose and the total volume of gas produced, which indicates the possible use of Aloe vera and polysaccharide extract as prebiotics.

Suppression of DNA/RNA and protein oxidation by dietary supplement which contains plant extracts and vitamins: a randomized, double-blind, placebo-controlled trial

Background

Excessive oxidative stress may impair bio-molecules and cellular function. Multi antioxidant supplementation is thought to be more effective than a single antioxidant probably through the synergistic or complementary action of natural substances that could enhance the prospective effect.

Methods

In order to estimate the effect of a plant extract based supplement in apparently healthy volunteers’ oxidative stress markers, a double-blind and placebo controlled intervention was performed. 62 apparently healthy volunteers, overweight with medium adherence to the Mediterranean diet, were recruited and randomly allocated into two intervention groups (supplement or placebo) for 8 weeks. Basic biochemical markers, oxidized LDL (oxLDL), resistance of serum in oxidation, protein carbonyls in serum and 8-isoprostane and DNA/RNA damage in urine were measured.

Results

No differentiation was observed in basic biochemical markers, in oxLDL levels as well as in serum resistance against oxidation, during intervention in the examined groups. A significant resistance regarding urine isoprostanes levels in the supplement group compared to the placebo one, was observed. Reduction on DNA/RNA damage and on protein carbonyls levels (almost 30% and 20% respectively, at 8 weeks) was detected in volunteers who consumed the supplement compared to the control group.

Conclusion

Consumption of plant extract based supplement seems to reduce DNA/RNA and protein oxidation and in less extent lipids peroxidation.

Trial registration

ClinicalTrials.gov Identifier for this study is: NCT02837107.

Recent advances of medical foods in China: The opportunities and challenges under standardization

Malnutrition with high incidence in hospitalized patients in China has brought a significant burden of disease. Although many clinical studies have demonstrated the importance of nutritional for patients with malnutrition, the application of medical foods in China is still restricted. For the classification, limits, production and registration of medical foods, the Chinese government newly enacted a series of regulations. In this review, comparing the policy, researches, and product variety of medical foods in China with other countries, although the current status of the development of medical foods in China is still far behind that of developed countries, some of regulations are stricter than those of many other countries or organizations. The medical foods in China are divided into four categories, the nutrients and environmental contaminants are limited to ensure the safety. As a prospect, the development of medical foods in China is expected to get out of the predicament of lack of emphasis, shortage of supply, backward of local processing technology and the imperfect management system. After all, in view of the huge population and the increasing demand of nutrition in China, there must be a very good prospect for the future development of the medical foods industry in China.

Could We Really Use Aloe vera Food Supplements to Treat Diabetes? Quality Control Issues

Diabetes UK has recently listed a number of herbs and spices that have been clinically shown to improve blood glucose control in type-2 diabetes patients and the diabetes high-risk group. With Aloe vera being top in this list, its health benefit along with health and beauty/food retailers supplying it was illustrated in detail. Previous article from this laboratory scrutinised the merit of using A. vera as an alternative therapy to prescription antidiabetic drugs and the risk of using food supplements in the market which do not qualify as drug preparations. In continuation of this discussion, the present study assesses three Aloe Pura brands and one Holland and Barret brand of A. vera juice supplements in the UK market through chromatographic and spectroscopic analysis. While the polysaccharide active ingredient, acemannan, appears to be within the recommended limit, it was found that Aloe Pura (one of the best-selling brands for A. vera supplement) products have benzoate additive that does not appear in the supplement levels. Moreover, two of the Aloe Pura brand juices contain methanol, suggesting that the International Aloe Science Council (IASC) certification does not guarantee the medicinal quality of these products. The therapeutic fitness of such supplements is discussed.

Aloesin from Aloe vera accelerates skin wound healing by modulating MAPK/Rho and Smad signaling pathways in vitro and in vivo

BACKGROUND

Cutaneous wound healing is a complex process involving various regulatory factors at the molecular level. Aloe vera is widely used for cell rejuvenation, wound healing, and skin moisturizing.

HYPOTHESIS/PURPOSE

This study aimed to investigate the effects of aloesin from Aloe vera on cutaneous wound healing and mechanisms involved therein.

STUDY DESIGN

This study consisted of both in vitro and in vivo experiments involving skin cell lines and mouse model to demonstrate the wound healing effects of aloesin by taking into account several parameters ranging from cultured cell migration to wound healing in mice.

METHODS

The activities of Smad signaling molecules (Smad2 and Smad3), MAPKs (ERK and JNK), and migration-related proteins (Cdc42, Rac1, and α-Pak) were assessed after aloesin treatment in cultured cells (1, 5 and 10µM) and mouse skin (0.1% and 0.5%). We also monitored macrophage recruitment, secretion of cytokines and growth factors, tissue development, and angiogenesis after aloesin treatment using IHC analysis and ELISAs.

RESULTS

Aloesin increased cell migration via phosphorylation of Cdc42 and Rac1. Aloesin positively regulated the release of cytokines and growth factors (IL-1β, IL-6, TGF-β1 and TNF-α) from macrophages (RAW264.7) and enhanced angiogenesis in endothelial cells (HUVECs). Aloesin treatment accelerated wound closure rates in hairless mice by inducing angiogenesis, collagen deposition and granulation tissue formation. More importantly, aloesin treatment resulted in the activation of Smad and MAPK signaling proteins that are key players in cell migration, angiogenesis and tissue development.

CONCLUSION

Aloesin ameliorates each phase of the wound healing process including inflammation, proliferation and remodeling through MAPK/Rho and Smad signaling pathways. These findings indicate that aloesin has the therapeutic potential for treating cutaneous wounds.

A material-basis study of Aloe vera on the wnt/β-catenin signaling pathway using a knockin/knockout method with high-speed countercurrent chromatography

The water extract ofAloe veraat low concentration could activate the wnt/β-catenin signaling pathway and up-regulated the level of active β-catenin protein in hek293 cells, as well as promoting the expression of wnt target genes.