Dietary aloin, aloesin, or aloe-gel exerts anti-inflammatory activity in a rat colitis model

Emu oil offers protection in Crohn's disease model in rats

Background

Emu oil is a product of animal origin used for the treatment of inflammation, burns etc. as a part of aboriginal medicine in Australia. Crohn’s disease is a common inflammatory manifestation in humans and other animal species relating to the ulceration and digestive disturbances in upper gastro-intestinal tract. Aloe vera is commonly used substance from plant sources for inflammation, wound healing and various other properties. Given the difference in the source of the substances all the while playing a similar therapeutic role in different parts of the world, the present investigation was undertaken to evaluate the protective effect of aloe vera and emu oil alone and in combination; in comparison to sulfasalazine (Allopathic drug) as an alternative for the treatment of Crohn’s disease.

Methods

Wistar albino rats were divided into six groups with two sub-groups of six animals each. After pre-treating the animals with sulfasalazine, aloe vera, emu oil and their combination for five consecutive days, the animals were sub-cutaneously administered indomethacin on 4^th and 5^th day and each sub-group was sacrificed on day 6 and 9. After sacrifice, serum and intestine of these animals was collected. Intestine length from duodenum till caecum was measured for estimating relative organ weight and disease activity index. Part of intestine was preserved in formalin for histopathology while the rest was used for analysis of oxidative parameters and myeloperoxidase. Serum collected was used for measuring alkaline phosphatase and cholesterol.

Results

Assessment of the parameters in treatment groups indicated that the combination of aloe vera and emu oil resulted in better protection by suppressing the oxidative (P < 0.05) and histomorphological changes indicating a enhanced effect of these two agents which was found to be better than sulfasalazine.

Conclusion

The combination of emu oil and aloe vera exhibited enhanced effect resulting in significant protection from indomethacin induced ulceration. This might be due to the different mechanism of anti-inflammatory effects (Salicylic acid in aloe vera and n3, n6 fatty acids acting as pseudosubstrates to cyclooxygenase enzyme) of components of the animal and plant products tested.

Aloin Protects Skin Fibroblasts from Heat Stress-Induced Oxidative Stress Damage by Regulating the Oxidative Defense System

Oxidative stress is commonly involved in the pathogenesis of skin damage induced by environmental factors, such as heat stress. Skin fibroblasts are responsible for the connective tissue regeneration and the skin recovery from injury. Aloin, a bioactive compound in Aloe vera, has been reported to have various pharmacological activities, such as anti-inflammatory effects. The aim of this study was to investigate the protective effect of aloin against heat stress-mediated oxidative stress in human skin fibroblast Hs68 cells. Hs68 cells were first incubated at 43°C for 30 min to mimic heat stress. The study was further examined if aloin has any effect on heat stress-induced oxidative stress. We found that aloin protected Hs68 cells against heat stress-induced damage, as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assay. Aloin protected Hs68 cells by regulating reactive oxygen species production and increasing the levels of glutathione, cytosolic and mitochondrial superoxide dismutase. Aloin also prevented the elevation of thiobarbituric acid reactive substances and the reduction of 8-OH-dG induced by heat stress. These results indicated that aloin protected human skin fibroblasts from heat stress-induced oxidative stress damage by regulating the oxidative defense system.

Antioxidant therapy for treatment of inflammatory bowel disease: Does it work?

Oxidative stress (OS) is considered as one of the etiologic factors involved in several signals and symptoms of inflammatory bowel diseases (IBD) that include diarrhea, toxic megacolon and abdominal pain. This systematic review discusses approaches, challenges and perspectives into the use of nontraditional antioxidant therapy on IBD, including natural and synthetic compounds in both human and animal models. One hundred and thirty four papers were identified, of which only four were evaluated in humans. Some of the challenges identified in this review can shed light on this fact: lack of standardization of OS biomarkers, absence of safety data and clinical trials for the chemicals and biological molecules, as well as the fact that most of the compounds were not repeatedly tested in several situations, including acute and chronic colitis. This review hopes to stimulate researchers to become more involved in this fruitful area, to warrant investigation of novel, alternative and efficacious antioxidant-based therapies.

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Major biomarkers used for evaluation of antioxidant therapy were MPO, TBARS/MDA and glutathione levels.

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Challenges were identified for the yet poor use of antioxidant therapy in IBD.

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This review stimulates the investigation of alternative and efficacious antioxidant therapies.

Botanical Drugs as an Emerging Strategy in Inflammatory Bowel Disease: A Review

Crohn's disease and ulcerative colitis are the two most common categories of inflammatory bowel disease (IBD), which are characterized by chronic inflammation of the intestine that comprises the patients' life quality and requires sustained pharmacological and surgical treatments. Since their aetiology is not completely understood, nonfully efficient drugs have been developed and those that show effectiveness are not devoid of quite important adverse effects that impair their long-term use. Therefore, many patients try with some botanical drugs, which are safe and efficient after many years of use. However, it is necessary to properly evaluate these therapies to consider a new strategy for human IBD. In this report we have reviewed the main botanical drugs that have been assessed in clinical trials in human IBD and the mechanisms and the active compounds proposed for their beneficial effects.

Inhibitory effects of low-dose aloe-emodin on the development of colorectal tumors in min mice

Aloe-emodin (AE), a natural anthraquinone compound, has been reported to exhibit anticancer activity in various cancer cell lines and anti-inflammatory effects in murine macrophages. In the present study, we investigated the cancer chemopreventive effects of AE in an Apc-deficient Min mouse model. In the first experiment, male Min mice were fed a basal diet or diets containing 5 ppm AE and 10 ppm AE for 12 weeks. The dietary administration of 5 ppm AE significantly reduced the number of colorectal tumors. In a second experiment, we investigated the effects of AE on colitis-related colon carcinogenesis in Min mouse treated with dextran sodium sulfate (DSS). Female Min mice were administered 1% DSS in their drinking water for 7 days. AE was given to mice in their diet at a dose of 5 or 50 ppm for 5 weeks. Feeding with AE significantly reduced the number of colorectal tumors. When proliferation of cells in normal-appearing colonic mucosa was assessed by monoclonal anti-rat Ki-67 antibody (MIB-5) immunohistochemistry in experiments 1 and 2, the AE treatment significantly decreased the mean MIB-5-labeling index. These results suggest that the dietary administration of low-dose AE may have chemopreventive effects against development of colorectal tumors in Min mice, possibly in part by reducing cell proliferation in colorectal mucosa.

Phytochemicals and their potential usefulness in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with unclear etiology, namely ulcerative colitis and Crohn's disease. Various drug therapies including aminosalicylates and immunomodulators have been approved for use; they have shown to produce diverse side effects. To overcome these limitations of the current therapeutics for IBD, extensive research is underway to identify drugs that are effective and free of undesirable side effects. Recently, various naturally occurring phytochemicals that cover a wide range of chemical entities such as polyphenols, terpeniods, flavonoids, and alkaloids have received attention as alternative candidates for IBD therapy. These phytochemicals act by modulating the immune response, various transcription factors, or reduce cytokine secretion. This review summarizes the findings of recent studies on phytochemicals as therapeutic agents in the management of IBD.

Unraveling the medicinal potential of South African Aloe species

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe species (family: Xanthorrhoeaceae) are widely used in ethnomedicine for treating various ailments. Approximately 125 Aloe taxa are documented as indigenous to South Africa. This review was aimed at critically evaluating the available data on the ethnomedicinal uses, pharmacological activities, safety and conservation status of the documented South African Aloe species.

MATERIALS AND METHODS

A detailed search using major electronic search engines (such as Google Scholar, Scopus and Scirus) and ethnobotanical literature was undertaken. Search terms used included 'medicinal properties of Aloe species', 'biological activity of South African Aloe species' and 'safety and toxicological evaluation of aloes'.

RESULTS

Although Aloe species are widely used as laxatives and for treating wound and skin-related ailments, only about 20% of South African Aloe species have been clearly documented for their medicinal uses. The pharmacological potential including the antimicrobial, antiinflammatory, antiplasmodial and anthelmintic activities of some of the species has been established, providing a rationale for their use in traditional medicine. Successful micropropagation protocols have been developed as a conservation strategy, but only for a few species.

CONCLUSIONS

The highlighted medicinal activities of some Aloe species indicate their therapeutic potential. Nonetheless, further research especially on the understudied species is required to properly document their ethnomedicinal uses and fully explore their pharmacological value.

Evaluation of therapeutic potential of nanosilver particles synthesised using aloin in experimental murine mastitis model

Nanobiotechnology is an emerging biological branch of nanotechnology. Application of nanoparticles with specific size and shape in biology has already shown unforeseen and interesting results. A study was conducted to evaluate the therapeutic potential of phytogenically derived aloin mediated nanosilver particles (AAgNPs), prepared by reduction of silver nitrate with aloin, in Staphylococcus aureus induced murine mastitis. A total of 40 female mice were divided into five groups of eight animals each. Group I served as lactating control, groups II-V were inoculated with 20 μl of 24 h broth culture of S. aureus containing 4.0 × 105 cfu/quarter under ketamine anaesthesia. After 6 h post inoculation, groups III and IV received 20 μl of aloin nanosilver (AAgNPs) through intramammary and intraperitoneal routes, respectively. Group V received antibiotic cefepime at 1 mg/kg body weight through the intra-peritoneal route. After 18 h post-treatment, serum C reactive protein, weights of mammary glands, mammary gland bacterial load, thiobarbituric acid reactive substances content, reduced glutathione content, superoxide dismutase activity and catalase activity and histopathology were determined. The compound showed a minimum inhibitory concentration of 21.8 ng/ml against S. aureus. Significant reduction (98%) in poly-morpho nuclear cell infiltration was observed with AAgNPs than antibiotic (50%).

Chemopreventive effects of aloin against 1,2-dimethylhydrazine-induced preneoplastic lesions in the colon of Wistar rats

Chemoprevention opens new window in the prevention of all types of cancers including colon cancer. Aloin, an anthracycline in plant pigment, can be utilized as a protective agent in cancer induction. In the present study, we have evaluated the chemopreventive efficacy of aloin against 1,2-dimethylhydrazine (DMH)-induced preneoplastic lesions in the colon of Wistar rats. DMH-induced aberrant crypt foci (ACF) and mucin-depleted foci (MDF) have been used as biomarkers of colon cancer. Efficacy of aloin against the colon toxicity was evaluated in terms of biochemical estimation of antioxidant enzyme activities, lipid peroxidation, ACF, MDF, histopathological changes, and expression levels of molecular markers of inflammation and tumor promotion. Aloin pretreatment ameliorates the damaging effects induced by DMH through a protective mechanism that involved reduction in increased oxidative stress enzymes (p < 0.001), ACF, MDF, cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6, proliferating cell nuclear antigen protein expression, and tumor necrosis factor-α (p < 0.001) release. From the results, it could be concluded that aloin clearly protects against chemically induced colon toxicity and acts reasonably by inducing antioxidant level, anti-inflammatory and antiproliferative markers.

[Antiinflammatory potential of seven plant extracts in the ultraviolet erythema test. A randomized, placebo-controlled study]

BACKGROUND

Phytotherapeutics are widely used in medicine. The aim of this study was the evaluation of the antiinflammatory potential of seven medical plant extracts using the ultraviolet- (UV)-erythema test.

PATIENTS AND METHODS

Randomized, placebo-controlled study on 40 healthy subjects. Test areas on the upper back were irradiated with the 1.5 fold UV-B minimal erythema dose (MED). Formulations of Aloe vera, Chamomilla recutita, Hamamelis virginiana, Melissa officinalis, Mentha arvensis, Melaleuca alternifolia, Coriandrum sativum as well as 1% hydrocortisone acetate and 0.1% betamethasone valerate as positive controls and unguentum leniens as vehicle control were applied under occlusion on the irradiated areas and on non-irradiated area on the contralateral side. Photometric assessment of the erythema was performed before the application of the substances (t0), at 24 h (t1) and at 48 h (t2).

RESULTS

Aloe vera, Chamomilla recutita, Melissa officinalis, Melaleuca alternifolia and Coriandrum sativum showed an antiinflammatory effect compared to UV-control and unguentum leniens. However, the results were only statistically significant for Aloe vera. All tested plant extracts were well tolerated.

CONCLUSION

Aloe vera possesses an antiinflammatory effect on UV-induced erythemas.

Ragweed pollen extract intensifies lipopolysaccharide-induced priming of NLRP3 inflammasome in human macrophages

Ragweed pollen extract (RWE) possesses intrinsic NADPH oxidase activity that induces oxidative stress by initiating the production of intracellular reactive oxygen species (ROS). The ROS are important contributors to the manifestation of allergic inflammation; furthermore, concomitant exposure to an allergen and an endotoxin trigger a stronger inflammatory response. One of the main pro-inflammatory cytokines produced in inflammatory responses is interleukin-1β (IL-1β), and its production is associated with caspase-1-containing inflammasome complexes. Intracellular ROS have been implicated in NLRP3 inflammasome-mediated IL-1β production, therefore, we aimed to study whether RWE influences the function of NLRP3 inflammasome. Here we describe that, in the presence of NADPH, RWE significantly elevates lipopolysaccharide-induced IL-1β production of THP-1 cells as well as human primary macrophages and dendritic cells. We also demonstrate that increased IL-1β production is mediated through NLRP3 inflammasome in THP-1 macrophages. We provide evidence that RWE elevates cytosolic ROS level in these cells, and ROS inhibitors abolish IL-1β production. Furthermore, we show that RWE enhances lipopolysaccharide-induced gene transcription/expression of pro-IL-1β and key components of the inflammasome via a ROS-dependent mechanism.

Naturally derived anti-inflammatory compounds from Chinese medicinal plants

ETHNOPHARMACOLOGICAL RELEVANCE

Though inflammatory response is beneficial to body damage repair, if it is out of control, it can produce adverse effects on the body. Although purely western anti-inflammatory drugs, orthodox medicines, can control inflammation occurrence and development, it is not enough. The clinical efficacy of anti-inflammation therapies is unsatisfactory, thus the search for new anti-inflammation continues. Chinese Material Medica (CMM) remains a promising source of new therapeutic agents. CMM and herbal formulae from Traditional Chinese Medicine (TCM), unorthodox medicines, play an improtant anti-inflammatory role in multi-targets, multi-levels, and multi-ways in treating inflammation diseases in a long history in China, based on their multi-active ingredient characteristics. Due to these reasons, recently, CMM has been commercialized as an anti-inflammation agent which has become increasingly popular in the world health drug markets. Major research contributions in ethnopharmacology have generated vast amount of data associated with CMM in anti-inflammtion aspect. Therefore, a systematic introduction of CMM anti-inflammatory research progress is of great importance and necessity.

AIM OF THE STUDY

This paper strives to describe the progress of CMM in the treatment of inflammatory diseases from different aspects, and provide the essential theoretical support and scientific evidence for the further development and utilization of CMM resources as a potential anti-inflammation drug through a variety of databases.

MATERIAL AND METHODS

Literature survey was performed via electronic search (SciFinder®, Pubmed®, Google Scholar and Web of Science) on papers and patents and by systematic research in ethnopharmacological literature at various university libraries.

RESULTS

This review mainly introduced the current research on the anti-inflammatory active ingredient, anti-inflammatory effects of CMM, their mechanism, anti-inflammatory drug development of CMM, and toxicological information.

CONCLUSION

CMM is used clinically to treat inflammation symptoms in TCM, and its effect is mediated by multiple targets through multiple active ingredients. Although scholars around the world have made studies on the anti-inflammatory studies of CMM from different pathways and aspects and have made substantial progress, further studies are warranted to delineate the inflammation actions in more cogency models, establish the toxicological profiles and quality standards, assess the potentials of CMM in clinical applications, and make more convenient preparations easy to administrate for patients. Development of the clinically anti-inflammatory drugs are also warranted.

Nutritional modulators of ulcerative colitis: Clinical efficacies and mechanistic view

Ulcerative colitis (UC) is an inflammation-associated disease of the colon and rectum. The onset and progress of the disease are directly influenced by the nature of the intestinal microflora, the intestinal barrier function, and the immunological responses of the host. The epithelial invasion of pathogenic bacteria due to excess contact and/or barrier dysfunction is related to inflammation mediated by intestinal immune responses. Although the etiology of UC is not clearly understood, recent studies have shown a rising incidence of UC worldwide, and this phenomenon is more prominent in Asian countries and in Asian immigrants in Western countries. The increased prevalence of UC also contributes to an increased risk of developing colorectal cancer. Environmental factors, including changes in dietary habits, have been suggested as major risk factors of UC. A systematic review showed a negative association between UC risk and vegetable intake, whereas total fat, omega-6 fatty acids and meat intake were positively associated with an increased risk of UC. Individual dietary factors and energy balance have been suggested as having important roles in inducing changes in the microbial population and intestinal barrier integrity and in regulating inflammatory immune responses, directly or indirectly. Excess energy intake is now known to increase pathogenic microbial populations. Likewise, the application of appropriate probiotics may reverse the pathogenic progression of the disease. In the meantime, dietary anti-inflammatory compounds, including omega-3 fatty acids and other phytochemicals, may directly suppress inflammatory responses in the course of UC development. In this review, the increased prevalence of UC and its management are interpreted from the standpoint of nutritional modulation to regulate the intestinal microflora population, intestinal epithelium permeability, and inflammatory responses.

An in vitro and in vivo toxicologic evaluation of a stabilized aloe vera gel supplement drink in mice

Aloe vera gel is increasingly consumed as a beverage dietary supplement. The purpose of this study was to determine potential toxicity of a stabilized aloe vera gel derived from the inner gel fillet and marketed as a drink. The gel juice was assessed through assays of genotoxicity in vivo and acute and subchronic toxicity in B6C3F1 mice. Aloe vera did not increase the SOS DNA repair response in Escherichia coli and at 1× and 0.25× it did not increase mutagenesis of Salmonella TA100 resulting in histidine biosynthesis. At 3 and 14days following acute exposure, male and female mice gavaged with the stabilized aloe gel had daily appearances, total body weight gain, selected organ weights, necropsy and hematology tests similar to control mice gavaged with water. After a 13-week aloe gel feed study, male and female mice evaluated by the same criteria as the acute study plus feed consumption and serum chemistry tests were found to be equivalent to control groups. These data indicate that a commercial stabilized aloe gel consumed as a beverage was not genotoxic or toxic in vivo. These results contrast with those obtained using preparations containing aloe latex phenolic compounds such as anthraquinones.

Nutritional and probiotic supplementation in colitis models

In vitro and animals models have long been used to study human diseases and identify novel therapeutic approaches that can be applied to combat these conditions. Ulcerative colitis and Crohn's disease are the two main entities of inflammatory bowel disease (IBD). There is an intricate relationship between IBD features in human patients, in vitro and animal colitis models, mechanisms and possible therapeutic approaches in these models, and strategies that can be extrapolated and applied in humans. Malnutrition, particularly protein-energy malnutrition and vitamin and micronutrient deficiencies, as well as dysregulation of the intestinal microbiota, are common features of IBD. Based on these observations, dietary supplementation with essential nutrients known to be in short supply in the diet in IBD patients and with other molecules believed to provide beneficial anti-inflammatory effects, as well as with probiotic organisms that stimulate immune functions and resistance to infection has been tested in colitis models. Here we review current knowledge on nutritional and probiotic supplementation in in vitro and animal colitis models. While some of these strategies require further fine-tuning before they can be applied in human IBD patients, their intended purpose is to prevent, delay or treat disease symptoms in a non-pharmaceutical manner.

Review of natural products actions on cytokines in inflammatory bowel disease

The purpose of this review is to provide an overview of the effects that natural products have on inflammatory bowel disease (IBD) and to provide insight into the relationship between these natural products and cytokines modulation. More than 100 studies from the past 10 years were reviewed herein on the therapeutic approaches for treating IBD. The natural products having anti-IBD actions included phytochemicals, antioxidants, microorganisms, dietary fibers, and lipids. The literature revealed that many of these natural products exert anti-IBD activity by altering cytokine production. Specifically, phytochemicals such as polyphenols or flavonoids are the most abundant, naturally occurring anti-IBD substances. The anti-IBD effects of lipids were primarily related to the n-3 polyunsaturated fatty acids. The anti-IBD effects of phytochemicals were associated with modulating the levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1, IL-6, inducible nitric oxide synthase, and myeloperoxide. The anti-IBD effects of dietary fiber were mainly mediated via peroxisome proliferator-activated receptor-γ, TNF-α, nitric oxide, and IL-2, whereas the anti-IBD effects of lactic acid bacteria were reported to influence interferon-γ, IL-6, IL-12, TNF-α, and nuclear factor-κ light-chain enhancer of activated B cells. These results suggest that the anti-IBD effects exhibited by natural products are mainly caused by their ability to modulate cytokine production. However, the exact mechanism of action of natural products for IBD therapy is still unclear. Thus, future research is needed to examine the effect of these natural products on IBD and to determine which factors are most strongly correlated with reducing IBD or controlling the symptoms of IBD.

Augmented humoral immune response and decreased cell-mediated immunity by Aloe vera in rats

OBJECTIVE

The present study was performed to explore the effect of aqueous extract of Aloe vera on parameters of humoral and cell-mediated immunity.

MATERIALS AND METHODS

Delayed-type hypersensitivity was assessed by measuring foot pad thickness following sensitisation by keyhole limpet haemocyanin injection and subsequently challenged by the same. Humoral immunity was assessed by measurement of haemagglutination titre to sheep red blood cells.

RESULTS

Aloe vera (400 mg/kg, p.o.) produced a significant decrease in foot pad thickness compared with the control group, and also significantly enhanced the secondary humoral immune response.

CONCLUSION

Thus, these findings suggest that A. vera can modulate immune response by augmenting secondary humoral immunity and decreasing cell-mediated immunity.

Alternative medicines as emerging therapies for inflammatory bowel diseases

Inflammatory bowel disease (IBD) can be divided into two major categories, ulcerative colitis (UC) and Crohn disease (CD). While the main cause(s) of IBD remain unknown, a number of interventional and preventive strategies have been proposed for use against CD and UC. Many reports have focused on the use of alternative natural medicines as potential therapeutic interventions in IBD patients with minimal side effects. While the use of alternative medicines may be effective in IBD patients that are refractory to corticosteroids or thiopurins, alternative treatment strategies are limited and require extensive clinical testing before being optimized for use in patients.

Biomarkers of regimen-related mucosal injury

Regimen-related mucosal toxicity is extremely common following cytotoxic chemotherapy and radiotherapy. The alimentary mucosa is particularly susceptible to injury and dysfunction, leading to a constellation of adverse side effects. Currently there is no "one fit" biomarker of such injury. A number of biomarkers have been investigated in the context of gastrointestinal diseases, which may prove useful in the oncology arena. Two of significant potential include citrulline and calprotectin, however more work is required to define the most appropriate settings for their use. Identification of a biomarker that is easily obtained, measured, and accurately indicates mucosal damage, would allow for improved patient diagnosis of toxicities and prompt appropriate intervention. In this review, we highlight the effectiveness of currently examined biomarkers and discuss future avenues for research in this exciting area.