Aloe Genus Plants: From Farm to Food Applications and Phytopharmacotherapy

Ethnopharmacology, Phytochemistry and Biological Activities of Native Chilean Plants

The native flora of Chile has unique characteristics due to the geographical situation of the country, with the vast desert in the North, Patagonia in the South, the Andean Mountains on the east and the Pacific Ocean on the west. This exclusivity is reflected in high concentrations of phytochemicals in the fruits and leaves of its native plants. Some examples are Aristotelia chilensis (Molina), Stuntz (maqui), Berberis microphylla G. Forst. (calafate), Peumus boldus Molina (boldo), Ribes magellanicum Poir. (Magellan currant), Ugni molinae Turcz. (murtilla), Rubus geoides Sm. (miñe miñe), Drimys winteri J.R.Forst. & G.Forst. (canelo), Luma apiculata (DC.) Burret (arrayán) distributed throughout the entire Chilean territory. Some of these Chilean plants have been used for centuries in the country's traditional medicine. The most recent studies of phytochemical characterization of parts of Chilean plants show a wide spectrum of antioxidant compounds, phenolic components, terpenoids and alkaloids, which have shown biological activity in both in vitro and in vivo studies. This manuscript covers the entire Chilean territory characterizing the phytochemical profile and reporting some of its biological properties, focusing mainly on antioxidant, anti-inflammatory, antimicrobial, chemopreventive and cytotoxic activity, and potential against diabetes, metabolic syndrome and gastrointestinal disorders.

Graphene oxide exhibited positive effects on the growth of Aloe vera L

There is increasing evidence for graphene associated plant growth promotion, however, the chronic effects of soil-applied graphene remain largely unexplored. The present study investigated the morphological, physiological and biochemical responses of graphene oxide (GO) on Aloe vera L. over the concentration range of 0-100 mg/L for four months. Our results demonstrated that GO, with the best efficiency at 50 mg/L, could enhance the photosynthetic capacity of leaves, increase the yield and morphological characters of root and leaf, improve the nutrient (protein and amino acid) contents of leaf, without reducing the content of the main bioactive compound aloin. Compared with leaves, the effect of GO on root growth was more obvious. Although the electrolyte leakage and MDA content were raised at high concentrations, GO treatment did not increase the root antioxidant enzymes activity or decrease the root vigor, which excluding typical stress response. Furthermore, injection experiments showed that the GO in vivo did not change the plant growth state obviously. Taken together, our study revealed the role of GO in promoting Aloe vera growth by stimulating root growth and photosynthesis, which would provide theory basis for GO application in agriculture and forestry.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12298-021-00979-3.

Safety evaluation of Aloe vera soft capsule in acute, subacute toxicity and genotoxicity study

Aloe vera has been widely used in health and nutritional supplements in Chinese herbal medicine. Furthermore, Aloe vera production has been an emerging industry for making cosmetics and functional food. However, the reported adverse effects raised questions as to whether Aloe vera and its products were safe enough to be used in medicine and health care. In view of this, the safety evaluation of Aloe vera products before marketing is very important. The present study aimed to assess the toxicological profile of Aloe vera soft capsule (ASC), through acute, subacute toxicity and genotoxicity tests. Male and female ICR mice were received by oral gavage 15000 mg/kg bodyweight of ASC in the acute toxicity test. Male and female SD rats were fed on diet blended with different doses of ASC (equivalent to 832.5, 1665 and 3330 mg/kg bodyweight of ASC) for the subacute toxicity test. In the acute toxicity study, no mortality or behavioral changes were observed, indicating the LD50 was higher than 15000 mg/kg bodyweight. In the subacute toxicity test, no significant changes were observed in bodyweight, food consumption, hematological, biochemical or histopathological parameters in the rats exposed. These data suggested that ASC used in this study did not produce any marked subacute toxic effects up to a maximum concentration of 3330 mg/kg bodyweight. In the genotoxicity study, ASC showed no mutagenic activity in the Ames test and no evidence of potential to induce bone marrow micronucleus or testicular chromosome aberrations in ICR mice exposed to 10000 mg/kg bodyweight. Collectively, ASC could be considered safe before it was marketed as a laxative and moistening health food.

Potential of Aloe vera gel coating for storage life extension and quality conservation of fruits and vegetables: An overview

Aloe vera (ALV) with its unique nutritional profile is being used for food, health, and nutraceutical industries globally. Due to its organic nature, ALV gel coating has created lot of interest for exploring its potential in extending the shelf and storage life of fresh produce. ALV gel coating plays imperative role in delaying fruit ripening by lowering ethylene biosynthesis, respiration rate, and internal metabolic activities associated with fruit softening, color development, enzymatic browning, and decay. ALV gel coating reduces the microbial spoilage due to its antifungal properties and maintains visual appearance, firmness, sugar: acid ratio, total antioxidants, and phenolic contents with conserved eating quality. ALV coated fruits and vegetables showed reduced weight loss, superoxide ion ( O 2 - ∙ ), hydrogen peroxide (H₂ O₂ ), ion leakage, and soluble solids content and exhibited higher acidity, anthocyanins, ascorbic acid, catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) activities. It also delayed the enzymatic browning by inducing peroxidase (POD) activity during storage. Recent local studies also revealed that ALV gel coating markedly conserved higher consuming quality and extended storage period (>1.34-fold) of different fruits and vegetables. Overall, Aloe vera gel coating alone or in combination with other organic compounds has shown great potential as a food-safe and eco-friendly coating for maintaining the quality of fruits and vegetables over extended period and reducing postharvest losses in the supply chain. PRACTICAL APPLICATIONS: ALV gel is a plant-based natural coating of eco-friendly nature. The present review summarizes the updated information of ALV gel coating application, methods of extraction, combinations with other postharvest coatings, and its impact on quality of various fruits and vegetables. It also provides future insights for the development of commercially applicable ALV gel coating protocols through simulation studies. So, being a natural coating, ALV gel has tremendous potential to be used in fruit and vegetable industries around the globe.

Aloe vera and health outcomes: An umbrella review of systematic reviews and meta-analyses

This umbrella review aims to summarize the effects of Aloe vera on health outcomes and assess the strength of evidence. PubMed, Scopus, Embase, Cochrane database of systematic reviews, CINAHL, and AMED were searched from inception to October, 2019 for systematic reviews and meta-analyses of clinical trials that investigated the effects of Aloe vera on health outcomes. Two independent reviewers extracted data, assessed the methodological quality, and rated the credibility of evidence according to established criteria. Ten articles reporting 71 unique outcomes of Aloe vera were included. Of these, 47 (67%) were nominally statistically significant based on random-effects model (p ≤ .05). Only 3 outcomes were supported by highly suggestive evidence, whereas 42 outcomes were supported by weak evidence. The highly suggestive evidence supported benefits of Aloe vera in the prevention of second-degree infusion phlebitis (RR: 0.18, 95% CI: 0.10-0.32, p-value: 1.75 × 10-9 ) and chemotherapy-induced phlebitis based on overall incidence (OR: 0.13, 95% CI: 0.08-0.20, p-value: 9.68 × 10-20 ) and incidence of the second degree of severity (OR: 0.10, 95% CI: 0.07-0.14, p-value: 3.41 × 10-35 ). However, the majority of the evidence were limited by small sample size and poor methodological quality. Therefore, despite the overall favorable effect of Aloe vera, more robust studies are needed.

In vivo immuno - and angiomodulatory effects of Aloe arborescens folii recentis extractum siccum (AAES) in mice

Introduction

AAES is a powdered form of Biostymina, herbal medicinal product of Phytopharm Klęka S.A., a water extract of Aloe arborescens Mill. leaves. Aloe arborescens Mill. (woody aloe, tree-like aloe) is known to have several traditional medicinal properties including anti-inflammatory, immunomodulatory, antiviral and antimicrobial activity.

Objective

The aim of this work was to study the in vivo effect of AAES on cellular (leukocyte-induced cutaneous angiogenesis, LIA test, and proliferative response to PHA) and humoral (anti-SRBC antibody response) immunity in mice.

Methods

Balb/c mice were fed AAES from 0.5 to 75 mg/kg body mass for seven days before grafting their splenocytes intradermally to F1 (Balb/cxC3H) recipients (LIA test). Neovascular reaction was evaluated 72 h later in dissection microscope. Spleen cell cultures were incubated with 0.5, 1 and 2 μg/ml of PHA. After 48 h of incubation, tritiated thymidine was added. After further 24 h, cells were harvested (Skatron) and incorporation of tritiated thymidine was measured using Beta-scintillation counter. Balb/c mice were fed for 7 days with AAES, then immunized intraperitoneally with 5% SRBC suspension and 7 days later the antibody response was measured with hemagglutination test.

Results

Neovascular reaction was significantly higher in groups grafted with splenocytes collected from all AAES fed donors than from the controls. The proliferation of splenocytes taken from mice fed AAES at doses ranging from 0.5 mg/kg to 7.5 mg/kg was stimulated in all cultures. Suppression of proliferation was observed in cell cultures derived from mice fed with higher doses of AAES. Stimulation of anti-SRBC antibody production was seen in mice fed both 2.5 and 7.5 mg/kg dose of AAES.

Conclusion

Powdered form of Biostymina (AAES) might be useful in the treatment of patients with ischaemia of tissues and organs (myocardial infarction, stroke, necrosis) and in deficiency in the production of immune cells and growth factors (infections, chronic wound healing, ulceration and bone fusion).

Differential inhibition of gelatinase activity in human colon adenocarcinoma cells by Aloe vera and Aloe arborescens extracts

BACKGROUND

Aloe's reported bioactivities (anticancer, anti-inflammatory and wound healing) suggest they might inhibit a subgroup of matrix metalloproteinases (MMPs) called gelatinases (MMP-2 and MMP-9). The goal of the present study was to compare the MMP inhibitory potential of two Aloe species, A. vera and A. arborescens.

METHODS

Different types of extraction were tested and specific bioactive compounds were quantified. Cancer cell invasion inhibitory activities were measured in vitro using the wound healing assay in human colon cancer cells (HT29). Effects on gelatinase activities were further assessed by dye-quenched gelatin and gelatin zymography.

RESULTS

Different types of extraction yielded significantly different levels of bioactivities and of bioactive compounds, which might be due to a greater amount of extractable bioactive compounds such as anthraquinones. Both A. arborescens and A. vera have potential as inhibitory agents in cancer cell proliferation via MMP-9 and MMP-2 enzymatic activity inhibition, being able to reduce colon cancer cell proliferation and migration but A. arborescens showed to be a more effective inhibitor of cancer cell migration than A. vera.

CONCLUSION

This work opens novel perspectives on the mode of action of Aloe species in cancer cell migration and may provide clues as to why there are so many conflicting results on Aloe's activities.

Vacillantins A and B, New Anthrone C-glycosides, and a New Dihydroisocoumarin Glucoside from Aloe vacillans and Its Antioxidant Activities

A new dihydroisocoumarin glucoside, vacillanoside (3), and two new anthrone C-glycosides microdantin derivatives; vacillantin A (10) and B (11), together with nine known compounds belonging to the anthraquinone, anthrone and isocoumarin groups were isolated from the leaves of Aloe vacillans. The structures were determined based on spectroscopic evidence including 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRESIMS) data, along with comparisons to reported data. The leaves were used to extract compounds with different solvents. The extracts were tested for antioxidant activity with a variety of in vitro tests including 2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS^•+), ferric reducing antioxidant power assay (FRAP), superoxide, and nitric oxide radical scavenging assays. The dichloromethane fraction was most active, displaying significant free radical scavenging activity. The n-butanol fraction also showed notable activity in all assays. Therefore, these findings support the potential use of A. vacillans leaves as an antioxidant medication due to the presence of polyphenolic compounds.

Aloe vera: A Medicinal Plant Used in Skin Wound Healing

Skin injury is a major problem threatening human physical and mental health, and how to promote wound healing has been the focus. Developing new wound dressings is an important strategy in skin regeneration. Aloe vera is a medicinal plant with a long history, complex constituents, and various pharmacological activities. Many studies have shown that A. vera plays an important role in promoting wound healing. Adding A. vera to wound dressing has become an ideal way. This review will describe the process of skin injury and wound healing and analyze the role of A. vera in wound healing. In addition, the types of wound dressing and the applications of A. vera in wound dressing will be discussed.

Evaluation of Antidiabetic Activity of the Leaf Latex of Aloe pulcherrima Gilbert and Sebsebe (Aloaceae)

The leaf latex of Aloe pulcherrima has been used as remedy for diabetes mellitus. This was carried out to determine in vitro and in vivo antidiabetic activities of the leaf latex of Aloe pulcherrima. Methods. Sucrase and maltase inhibitory activity of the leaf latex of A. pulcherrima was determined in glucose oxidase assay, and α-amylase inhibitory activity was determined in dinitrosalicylic acid assay. Normoglycemic, glucose-loaded, and streptozotocin-induced diabetic mice were treated orally to determine blood glucose lowering activity of the latex. Effect of the latex on serum lipid level and body weight was measured in streptozotocin-induced diabetic mice. Additionally, DPPH assay was used to determine free radical scavenging capacity of the latex. Results. Antioxidant activity of the latex was concentration dependent; the strongest inhibition was measured at 800 μg/ml (80.57%). The leaf latex of A. pulcherrima inhibited sucrase (IC₅₀ = 2.92 μg/ml), maltase (IC₅₀ = 11.81 μg/ml) and α-amylase (IC₅₀ = 14.92 μg/ml) enzymes. All doses of the leaf latex induced hypoglycemic effect after 4 h in normal mice, and low dose of the latex did not show significant effect after 6 h. Glucose reduction of the leaf latex of A. pulcherrima was significant (p < 0.05) in oral glucose-loaded mice compared to the vehicle control. Blood glucose level of diabetic mice was significantly (p < 0.05) reduced on week one and weak two in a streptozotocin-induced diabetic mouse model. Glucose reduction increased with increasing the doses of the leaf latex of A. pulcherrima on week one (p < 0.05 (200 mg/kg), p < 0.01 (400 mg/kg), and p < 0.001 (600 mg/kg)). Administration of the leaf latex of A. pulcherrima for two weeks significantly (p < 0.05) improved diabetic dyslipidemia and body weight of diabetic mice. Conclusion. The study confirmed that the leaf latex of the plant showed a significant antidiabetic activity justifying the traditional uses of the plant.

Hair Washing Formulations from Aloe elegans Todaro Gel: The Potential for Making Hair Shampoo

This study aimed to describe the gross phytochemical constituents of Aloe elegans Todaro gel and evaluate the characteristics and quality of lab-made hair washing formulations prepared from the gel to show its potential in formulating hair washing shampoos. A. elegans gel mass was prepared from mature, healthy leaves collected from natural stand. Samples of 100% methanol extract of the gel were subjected to standard phytochemical screening and gas chromatography-mass spectroscopy (GC-MS) analysis. Five hair washing formulations (Fs) were, likewise, prepared by mixing 4.0–10.0 mL of gel with one (0.05 mL) to two (0.10 mL) drops of six synthetic and natural ingredients, namely, coconut oil, jojoba oil, olive oil, pure glycerin oil, lemon juice, and vitamin E. The gel to the total ingredient ratios (v/v) of the five formulations were 93 : 7 (F₁), 94.5 : 5.5 (F₂), 96.4 : 3.6 (F₃), and 96.6 : 3.4 (F₄ and F₅). The formulations were evaluated using sensory inspection and common physicochemical methods. The phytochemical screening and GC-MS analysis revealed that A. elegans gel is the source of important chemical constituents used in the formulation of shampoos and similar products including saponins, capric acid, lauric acid, myristic acid, palmitic acid, linoleic acid, stearic acid, and phytol. Lab-made A. elegans hair washing formulations, especially those with 96.4–96.6% gel, were found to have similar characteristics and qualities with a common marketed shampoo. All the formulations were turbid with characteristic odor as the marketed shampoo. The pH values of the hair washing formulations (6.4–4.6) were comparable to those of the marketed shampoo (6.7). Formulations with higher proportion of gel had better foam stability, higher solid content (26–29%), higher surface tension (33–38 dynes/cm), shorter wetting time (150–160 sec), equivalent viscosities (26.45–26.73 poise), and conditioning performance than the marketed shampoo. These findings demonstrate that A. elegans gel mass can be used in the formulation of good-quality hair washing shampoos. We recommend future studies that aim to develop the phytochemical profile of the plant and a refined protocol of hair washing shampoo formulation.

Phytotherapy in endometriosis: an up-to-date review

Endometriosis is a benign gynecological disease which symptoms can provide a severe impact on patient's quality of life with subsequent impact on psychological well-being. Different therapeutic strategies are available to treat this disease, such as surgery, hormonal therapies, and nonsteroidal anti-inflammatory drugs. Nevertheless, the efficacy of conventional medical treatments is limited or intermittent in most of the patients due to the associated side effects. Therefore, a woman with endometriosis often search for additional and alternative options, and phytotherapy might be a promising alternative and complementary strategy. Different medicinal plants, multicomponent herbal preparations, and phytochemicals were investigated for pharmacological proprieties in endometriosis therapy. In most of the cases, the effect on endometriosis was related to phenolic compounds, such as flavonoids and phenolic acids reporting anti-inflammatory, proapoptotic, antioxidant, and immunomodulatory functions. Moreover, some phytochemicals have been related to a strong phytoestrogenic effect modulating the estrogen activity. Although promising, available evidence is based on in vitro and animal models of endometriosis with a limited number of well-performed clinical studies. There are almost none randomized control trials in this area. Therefore, properly constructed clinical trials are mandatory to achieve more conclusive results about the promising role of phytotherapy in the management of endometriosis.

Antioxidant, anti-quorum sensing, biofilm inhibitory activities and chemical composition of Patchouli essential oil: in vitro and in silico approach

The interest in naturally occurring essential oils from medicinal plants has increased extremely over the last decade markedly because they possess antimicrobial and antioxidant protective properties against different chronic diseases. Extensive survival of drug-resistant infectious bacteria depends on quorum sensing (QS) signaling network which raises the need for alternative antibacterial compounds. The aim of this study was to examine the phytochemical compounds of patchouli essential oil (PEO) and to assess its antioxidant activity. Antioxidant studies estimated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method showed that the PEO has effective antioxidant activity (IC₅₀ 19.53 µg/mL). QS inhibitory activity of PEO was examined by employing the biosensor strain, Chromobacterium violaceum CV12472. At sub-lethal concentrations, PEO potentially reduced the QS regulated violacein synthesis in CV12472 without inhibiting its cell proliferation. Moreover, it also effectively reduced the production of some QS regulated virulence factors and biofilm development in P. aeruginosa PAO1 without hindering its growth. Phytochemical analysis of PEO was done by GC/MS technique. Molecular docking of PEO major compounds with QS (LasR and FabI) and biofilm regulator proteins (MvfR and Sialidase) of PAO1 was evaluated. These phytocompounds showed potential hydrogen binding interactions with these proteins. The overall results, in vitro and in silico, suggest that PEO could be applied as biocontrol agent against antibiotic resistance pathogens. Communicated by Ramaswamy H. Sarma.

An ethnobotanical study of medicinal plants used by the Tengger tribe in Ngadisari village, Indonesia

The people of Tengger, Indonesia have used plants as traditional medicine for a long time. However, this local knowledge has not been well documented until recently. Our study aims to understand the utilization of plants in traditional medicine by the people of Tengger, who inhabit the Ngadisari village, Sukapura District, Probolinggo Regency, Indonesia. We conducted semi-structured and structured interviews with a total of 52 informants that represented 10% of the total family units in the village. The parameters observed in this study include species use value (SUV), family use value (FUV), plant part use (PPU), and the relative frequency of citation that was calculated based on fidelity level (FL). We successfully identified 30 species belonging to 28 genera and 20 families that have been used as a traditional medicine to treat 20 diseases. We clustered all the diseases into seven distinct categories. Among the recorded plant families, Poaceae and Zingiberaceae were the most abundant. Plant species within those families were used to treat internal medical diseases, respiratory-nose, ear, oral/dental, and throat problems. The plant species with the highest SUV was Foeniculum vulgare Mill. (1.01), whereas the Aloaceae family (0.86) had the highest FUV. Acorus calamus L. (80%) had the highest FL percentage. The leaves were identified as the most used plant part and decoction was the dominant mode of a medicinal preparation. Out of the plants and their uses documented in our study, 26.7% of the medicinal plants and 71.8% of the uses were novel. In conclusion, the diversity of medicinal plant uses in the Ngadisari village could contribute to the development of new plant-based drugs and improve the collective revenue of the local society.

Impact of Natural Compounds on Neurodegenerative Disorders: From Preclinical to Pharmacotherapeutics

Among the major neurodegenerative disorders (NDDs), Alzheimer’s disease (AD) and Parkinson’s disease (PD), are a huge socioeconomic burden. Over many centuries, people have sought a cure for NDDs from the natural herbals. Many medicinal plants and their secondary metabolites are reported with the ability to alleviate the symptoms of NDDs. The major mechanisms identified, through which phytochemicals exert their neuroprotective effects and potential maintenance of neurological health in ageing, include antioxidant, anti-inflammatory, antithrombotic, antiapoptotic, acetylcholinesterase and monoamine oxidase inhibition and neurotrophic activities. This article reviews the mechanisms of action of some of the major herbal products with potential in the treatment of NDDs according to their molecular targets, as well as their regional sources (Asia, America and Africa). A number of studies demonstrated the beneficial properties of plant extracts or their bioactive compounds against NDDs. Herbal products may potentially offer new treatment options for patients with NDDs, which is a cheaper and culturally suitable alternative to conventional therapies for millions of people in the world with age-related NDDs.

Antimicrobial Evaluation of Latex and TLC Fractions from the Leaves of Aloe adigratana Reynolds

Background

The highest prevalence and emergence of microbial infections coupled with the threat of antimicrobial resistance constitute a global concern, which entails searching for novel antimicrobial agents. Medicinal plants are among the major sources of medicines for novel drug discovery. Aloe adigratana is one of the endemic Aloe species in Ethiopia where the leaf latex of the plant is traditionally used for the treatment of various pathogenic conditions such as wound, dandruff, malaria, and diabetes. In spite of such claims, there was no scientific study done so far. The aim of the current study was, therefore, to evaluate the antimicrobial effect of leaf latex of A. adigratana and its thin layer chromatography (TLC) fractions.

Methods

Thin layer chromatography (TLC) separation was employed for isolation of bioactive compounds. Agar well diffusion and microdilution assay method were used to evaluate the antimicrobial actions of the leaf latex and TLC fractions against six bacterial strains and four Candida species of reference and clinical isolate microbial strains.

Results

Three major fractions, AA01, AA02, and AA03, were identified by TLC. Among the tested microbial strains, the reference strain of Staphylococcus aureus ATCC 29213 (MIC = 0.06 mg/mL) and clinical Candida krusei 242/18 (MIC = 0.14 mg/mL) exhibited higher susceptibility towards AA02, while reference strains of Klebsiella pneumoniae ATCC 700603 (MIC = 0.19 mg/mL) revealed the highest susceptibility towards AA01. The leaf latex displayed the highest activity against Staphylococcus aureus ATCC 29213 and clinical Candida krusei 242/18 with a MIC value of 0.19 mg/mL.

Conclusion

The leaf latex and TLC fractions were found to be active against the tested bacterial and Candida species. Therefore, this finding supports the traditional claim of Aloe adigratana and the need for characterization of the TLC fractions to provide as lead compounds for further comprehensive antibacterial and antifungal activities.

Ameliorative Effect of Heat-Killed Lactobacillus plantarum L.137 and/or Aloe vera against Colitis in Mice

Inflammatory bowel disease (IBD) is one of the predominant intestinal diseases associated with chronic inflammation and ulceration of the colon. This study explored the ameliorative effect of Aloe vera extract (Aloe) and/or heat-killed Lactobacillus plantarum L.137 (HK L.137) on dextran sodium sulfate (DSS)-induced colitis in mice. Aloe and/or HK L.137 were supplied for 9 days and the mice were challenged with DSS for 7 days. The DSS group demonstrated bloody diarrhea, colitis of high histologic grade, increased nuclear factor-kappa B (NF-κB) p65, inducible nitric oxide synthase (iNOS), myeloperoxidase (MPO), interleukin (IL)-6, and tumor necrosis factor (TNF)-α, and decreased IL-10 expression. These alterations were dwindled in DSS-induced mice treated with Aloe and HK L.137 separately. Aloe and HK L.137 together have augmented the therapeutic effect of each other. In conclusion, our findings demonstrated that Aloe and/or HK L.137 ameliorated DSS-induced colitis by promoting the secretion of anti-inflammatory cytokines and suppressing pro-inflammatory mediators. This study indicated that A. vera may function synergistically with HK L.137 to confer an effective strategy to prevent colitis.

Silymarin antiproliferative and apoptotic effects: Insights into its clinical impact in various types of cancer

Silymarin is a complex extract isolated from the plant Silybum marianum, widely known for its prominent antioxidant and hepatoprotective effects, although increasing evidences have reported extraordinary antiproliferative and apoptotic abilities. As a result, several signaling pathways involved in cell cycle control, cell proliferation, and cell death have been deconvoluted as critical mechanisms. In this regard, cyclin and cyclin-dependent pathways have been the most studied ones. Following that, apoptotic pathways, such as p53, Akt, STAT-3, Ras, and caspases pathways, have been extensively studied, although other mechanisms involved in inflammation and angiogenesis have also been highlighted as silymarin-likely targets in cancer therapy. Therefore, the main challenge of this review is to discuss the diverse molecular mechanisms for silymarin antiproliferative and apoptotic effects; most of them largely studied in various types of cancers so far. Clinical trials and combination therapies related to silymarin application in cancer prevention and treatment are presented as well.

Clinical efficacy of an Aloe Vera gel versus a 0.12% chlorhexidine gel in preventing traumatic ulcers in patients with fixed orthodontic appliances: a double-blind randomized clinical trial

Traumatic oral ulceration (TOU) is one of the most common side effects of orthodontic treatments. The objective of this trial is to compare the clinical efficacy of an 80% Aloe Vera gel, prepared using a master formula, versus a commercial 0.12% Chlorhexidine (CHX) gel for TOU prevention in participants wearing fixed orthodontic appliances. This report represents a single-centre, university-based, double-blinded, randomized controlled trial with 2 parallel arms. Patients aged 12 years or older, in the permanent dentition, and about to start fixed orthodontic treatment in this university setting were randomly allocated to use either Aloe Vera or CHX gel, following the cementation procedure. Pre-treatment and 1 month after the cementation clinical assessment and digital photographic images were taken of the teeth and assessed by 2 clinical assessors for the presence or absence of TOUs. A total of 140 were randomized and completed the trial. The overall prevalence of TOUs was 43.6%. Overall 5.7% of patients treated with Aloe Vera gel showed did not suffer from TOUs, whereas in the CHX arm, a total of 57 (81.4%) were affected by this outcome reaching a significant result (p < 0.001). In terms of relative risk (RRs) and confidence intervals (CIs), Aloe Vera provided better results than CHX with an RR of 0.07 (95%CI 0.03-0.16; p < 0.001), and with a patients' number needed to treat of 1.3 (95%CI 1.16-1.54). There were no adverse effects. These results suggest that Aloe Vera gel administration in patients with fixed orthodontic appliances could be important for effective prevention of TOU.

Wound Healing and the Use of Medicinal Plants

Cutaneous wound healing is the process by which skin repairs itself. It is generally accepted that cutaneous wound healing can be divided into 4 phases: haemostasis, inflammation, proliferation, and remodelling. In humans, keratinocytes re-form a functional epidermis (reepithelialization) as rapidly as possible, closing the wound and reestablishing tissue homeostasis. Dermal fibroblasts migrate into the wound bed and proliferate, creating “granulation tissue” rich in extracellular matrix proteins and supporting the growth of new blood vessels. Ultimately, this is remodelled over an extended period, returning the injured tissue to a state similar to that before injury. Dysregulation in any phase of the wound healing cascade delays healing and may result in various skin pathologies, including nonhealing, or chronic ulceration. Indigenous and traditional medicines make extensive use of natural products and derivatives of natural products and provide more than half of all medicines consumed today throughout the world. Recognising the important role traditional medicine continues to play, we have undertaken an extensive survey of literature reporting the use of medical plants and plant-based products for cutaneous wounds. We describe the active ingredients, bioactivities, clinical uses, formulations, methods of preparation, and clinical value of 36 medical plant species. Several species stand out, including Centella asiatica, Curcuma longa, and Paeonia suffruticosa, which are popular wound healing products used by several cultures and ethnic groups. The popularity and evidence of continued use clearly indicates that there are still lessons to be learned from traditional practices. Hidden in the myriad of natural products and derivatives from natural products are undescribed reagents, unexplored combinations, and adjunct compounds that could have a place in the contemporary therapeutic inventory.

Aloe vera (L.) Webb.: Natural Sources of Antioxidants - A Review

Many studies have proved that bioactive components of Aloe vera have an anti-inflammatory effect and support lipid and carbohydrate metabolism, helping to maintain normal sugar and cholesterol levels in blood and normal body weight. When aloe is applied externally, it accelerates the regeneration of the damaged skin. Aloe contains antioxidants, which may increase the shelf-life and nutritional value of food; therefore, it is widely used in cosmetic, pharmaceutical and food industry. An antioxidant activity was shown for leaf's skin, flowers and gel of aloe. In this work the future of A. vera as effective antioxidants is primarily discussed and expected trends are summarised. Furthermore, the bioactive components and the health-promoting effects of A. vera are investigated.

Therapeutic potential of Aloe vera-A miracle gift of nature

BACKGROUND

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Antiglycation Activity and HT-29 Cellular Uptake of Aloe-Emodin, Aloin, and Aloe arborescens Leaf Extracts

Aloe arborescens is a relevant species largely used in traditional medicine of several countries. In particular, the decoction of leaves is prepared for various medicinal purposes including antidiabetic care. The aim of this research was the study of the antiglycation activity of two A. arborescens leaf extracts and isolated compounds: aloin and aloe-emodin. These phytoconstituents were quantitatively assessed in methanolic and hydroalcoholic extracts using high performance liquid chromatography (HPLC) analysis. In addition, the total phenolic and flavonoid contents were detected. In order to study their potential use in diabetic conditions, the antiglycation and antiradical properties of the two extracts and aloin and aloe-emodin were investigated by means of bovine serum albumin (BSA) and 1,1-diphenyl-2-picryl-hydrazil (DPPH) assays; further, their cytotoxicity in HT-29 human colon adenocarcinoma cells was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. Furthermore, the ability of aloin and aloe-emodin to permeate the cellular membranes of HT-29 cells was determined in order to estimate their potential in vivo absorption. This assessment indicated that aloe-emodin can substantially pass through cell membranes (~20%), whereas aloin did not permeate into HT-29 cells. Overall, the data show that both the methanolic and the hydroalcoholic A. arborescens extracts determine significant inhibition of glycation and free-radical persistence, without any cytotoxic activity. The data also show that the antiglycation and the antiradical activities of aloin and aloe-emodin are lower than those of the two extracts. In relation to the permeability study, only aloe-emodin is able to cross HT-29 cellular membranes, showing the attitude to pass through the intestinal layer. Overall, the present data surely support the traditional use of A. arborescens leaf extracts against hyperglycemic conditions, while aloin and aloe-emodin as potential drugs need further study.

Synthesis of Imine Congeners of Resveratrol and Evaluation of Their Anti-Platelet Activity

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a cardioprotective phytochemical occurring in many plant products. In this study, a new series of imine congeners of resveratrol has been synthesized in which the imine moiety replaced the double bond in the structure of resveratrol. In addition, the in vitro antiplatelet activity of these resveratrol derivatives has been evaluated against adenosine diphosphate (ADP), arachidonic acid (AA), and collagen as platelet aggregation inducers. In general, the synthesized compounds were active as antiplatelet agents, and, therefore, the imine functional group may be considered as an effective replacement for a double bond in resveratrol for developing new and promising antiplatelet drugs.