Identification of five phytosterols from Aloe vera gel as anti-diabetic compounds.

Biochemical Research Laboratory, Morinaga Milk Industry Co., Ltd, Kanagawa, Japan.
Biological & Pharmaceutical Bulletin (Impact Factor: 1.83). 08/2006; 29(7):1418-22.
Source: PubMed


The genus Aloe in the family Liliaceae is a group of plants including Aloe vera (Aloe barbadensis MILLER) and Aloe arborescens (Aloe arborescens MILLER var. natalensis BERGER) that are empirically known to have various medical efficacies. In the present study, we evaluated the anti-hyperglycemic effect of Aloe vera gel and isolated a number of compounds from the gel. On the basis of spectroscopic data, these compounds were identified as lophenol, 24-methyl-lophenol, 24-ethyl-lophenol, cycloartanol, and 24-methylene-cycloartanol. These five phytosterols were evaluated for their anti-hyperglycemic effects in type 2 diabetic BKS.Cg-m(+/+)Lepr(db/J) (db/db) mice. In comparison with the hemoglobin A1c (HbA1c) levels of vehicle-treated mice, statistically significant decreases of 15 to 18% in HbA1c levels were observed in mice treated with 1 mug of the five phytosterols. Considering the ability to reduce blood glucose in vivo, there were no differences between the five phytosterols. Administration of beta-sitosterol did not reduce the blood glucose levels in db/db mice. After administration of the five phytosterols for 28 d, fasting blood glucose levels decreased to approximately 64%, 28%, 47%, 51%, and 55% of control levels, respectively. Severe diabetic mice treated with phytosterols derived from Aloe vera gel did not suffer weight reduction due to glucose loss in the urine. These findings suggest that Aloe vera gel and phytosterols derived from Aloe vera gel have a long-term blood glucose level control effect and would be useful for the treatment of type 2 diabetes mellitus.

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    • "Aloes, particularly the reputed Aloe vera (Aloe barbadensis Miller) have been used in traditional medicine for centuries and are found in many pharmacopoeias. The Aloe gel contains many constituents which are known for their antimicrobial and anti-inflammatory actions wound healing properties [7] [8], antidiabetic effects [9], anticancer and antiviral properties [10] [11], while antioxidant effects are becoming of interest [12]. Anthraquinones present in most Aloes are well reputed for their biological properties, which include antiinflammatory , anticancer, antiprotozoal and antioxidant activity [13] [14] [15]. "
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    ABSTRACT: The present study aimed at developing an efficient protocol for the micropropagation and restoration of four endemic threatened Masacrene Aloes namely Aloe lomatophylloides, A. macra, A. purpurea and A. tormentorii. Explants consisting of 2cm long hypocotyls with radicles were cultured on Murashige and Skoog's (MS) basal medium supplemented different plant growth regulators Thidiazuron, Benzyl amino purine and Naphthalene acetic acid (TDZ, BAP, NAA). The diameter of protocorm-like bodies (PLBs) and the length of developing shoots were calculated using digital photography. All explants produced significantly (p<0.05) higher number of PLBs on MS containing 0.01 NAA mg/l except for A. tormentorii explants whereby more PLBs were obtained in MS with NAA and TDZ. Over 95% of rooted plantlets survived acclimatisation. The genetic integrity of the regenerated and acclimatised plantlets were evaluated by employing RAPD, ISSR and IRAP marker assays and results indicated that all the tissue culture-derived plants are true-to-type. Preliminary secondary metabolite screening from the in vitro regenerated Aloe plantlets revealed the presence of numerous bioactive components such as anthraquinones, phenols and flavonoids, and possible presence of alkaloids, coumarins, tannins, saponins and terpenes which are also detected in the crude extracts of their field counterparts. This study paves the way towards a rapid propagation and restoration strategy for endangered medicinal Mascarene Aloes. INTRODUCTION Plant biodiversity is threatened worldwide at an unprecedented rate due to environmental perturbations, habitat loss and increased extinction rates. Numerous species are listed as rare or critically endangered, and integrated programs are required to safeguard many of these species. A significant portion of all plant species worldwide is restricted to islands, [1]. Together with Madagascar, the Western Indian Ocean Islands are considered as one of the 35 global biodiversity hotspots [2, 3] and are well known for their unique biodiversity and high level of endemism [4]. The succulent-leaved genus Aloe L. (Asphodelaceae) which now includes the former genus Lomatoplyllum comprises over 500 species occurring throughout Africa, the Arabian Peninsula, Madagascar and Mascarene Islands [5, 6]. Aloes, particularly the reputed Aloe vera (Aloe barbadensis Miller) have been used in traditional medicine for centuries and are found in many pharmacopoeias. The Aloe gel contains many constituents which are known for their antimicrobial and anti-inflammatory actions wound healing properties [7, 8], antidiabetic effects [9], anticancer and antiviral properties [10, 11], while antioxidant effects are becoming of interest [12]. Anthraquinones present in most Aloes are well reputed for their biological properties, which include anti-inflammatory, anticancer, antiprotozoal and antioxidant activity [13, 14, 15]. The exclusive presence of 12 phenolic compounds in the plant sap with the important ones being aloin and aloe emodin, are associated with pharmacological properties such as antibacterial and antifungal. Today, Aloes are a world-renowned source of natural products derived from the leaf exudate and the gel-like leaf mesophyll. Species such as Aloe ferox Mill. in South Africa and Aloe secundiflora Engl are wild-harvested to cater for the international trade in natural products from the bitter exudate and gel of Aloes, but A. vera still remains the principal source of these products [16]. Due to their reputable medicinal properties, Aloe-derived compounds are currently used for the manufacture of tropical products such as ointments and gel preparations, as well as in the production of tablets and capsules. In the food industry, they are employed as functional food and as an ingredient in other food products, for the production of gel-containing health drinks, beverages and yogurt. The Mascarene Aloes which are part of the former section Lomatophyllum comprise A. tormentorii (Marais) Newton and Rowley and A. purpurea Lam. which are endemic to Mauritius [17, 18], A. macra Haw. and A. lomatophylloides Balf.f endemic to Réunion Island and Rodrigues Islands respectively [19, 20]. A. tormentorii grows only on two small rocky islands (Round Island and Gunner's coin) in the north of Mauritius. A. macra, A. purpurea and A. lomatophylloides are nowadays only found inwards in the mountains, since the natural coastal habitats of islands have been severely degraded. In the Mascarene Islands, the crushed leaves of these Aloe species are applied as poultice on muscular pains, wounds, boils and to treat cutaneous bacterial infections. The plants are also used internally as antispasmodic and to increase menstrual flow [17]. The leaf sap is applied to the breast to encourage weaning [21]. Mascarene Aloes have been reported to possess phytochemical and antimicrobial
    Full-text · Article · Jan 2015
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    • "Herbal medicine turns out to be a valuable reservoir for novel drugs due to its few side effects [10]. Amount of research demonstrated that natural products possess antidiabetic activity with less adverse effects and show great auxiliary therapeutic effect on complications [11] [12]. Cordyceps militaris, an anamorph of Cordyceps sinensis, is advertised as a Chinese herb with antioxidant [13], immunomodulatory [14], anticancer , and anti-inflammatory pharmacological [15] effects. "
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    ABSTRACT: Due to substantial morbidity and high complications, diabetes mellitus is considered as the third "killer" in the world. A search for alternative antidiabetic drugs from herbs or fungi is highly demanded. Our present study aims to investigate the antidiabetic activities of Cordyceps militaris on diet-streptozotocin-induced type 2 diabetes mellitus in rats. Diabetic rats were orally administered with water extract or alcohol extract at 0.05 g/kg and 2 g/kg for 3 weeks, and then, the factors levels related to blood glucose, lipid, free radicals, and even nephropathy were determined. Pathological alterations on liver and kidney were examined. Data showed that, similar to metformin, Cordyceps militaris extracts displayed a significant reduction in blood glucose levels by promoting glucose metabolism and strongly suppressed total cholesterol and triglycerides concentration in serum. Cordyceps militaris extracts exhibit antioxidative effects indicated by normalized superoxide dismutase and glutathione peroxidase levels. The inhibitory effects on blood urea nitrogen, creatinine, uric acid, and protein revealed the protection of Cordyceps militaris extracts against diabetic nephropathy, which was confirmed by pathological morphology reversion. Collectively, Cordyceps militaris extract, a safe pharmaceutical agent, presents excellent antidiabetic and antinephropathic activities and thus has great potential as a new source for diabetes treatment.
    Full-text · Article · Mar 2014
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    • "Dried sap Lophenol, cycloartanol, 24-methyl-lowphenol STZ-rat Blood glucose level Chalaprawat, 1997; Tanaka et al., 2006 Mangifera indica Leaves Mangiferin STZ-rat Glucose Aderibigbe et al., 1999; Maruganandan et al., 2005 "
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    ABSTRACT: Components of cereals, legumes, pulses, proteins, sea food, milk, carbohydrates and lipids are being evaluated for their influence on human health, as biofunctional compounds. However, references dealing with fruits and vegetables exceed any other food group and accordingly their focus. Fruits and vegetables abound in a spectacular range of such health influencing compounds and thus, study of their bioactivity, in lieu of their consumption in fresh or processed form. Anti-cancerous phenolics from Phyllanthus, radioprotective Litchi phenolics/flavonoids, hypoglycemic Sygium, quercitin and hydroxyl cinnamates of Sweet cherries, xanthones of Mangosteen, ellagitannins of Pomegranate, ursolic acid of Sea buckthorn, muscle relaxative watermelon, anti-cholesterolemic soluble fibre and sterols, cardioprotective saponins, ACE-inhibitory potato hydrolysates, anti-pancreatic cancerous ascorbic acid, carotenoids including pro-vitamin A are few examples unraveled. Thus, the imminent scope to obviate their structural chemistry, influence on storage and processing conditions, factors favoring their bio-accessibility/bio-availability in the food formulations, influencing human health. It is the meticulous combination of these compounds in daily consumption that determines their usefulness to human body. What is of paramount importance is the actual health benefits accrued from consumption of such functional- compound based fresh/processed fruits,vegetables or other foods.
    Full-text · Article · Oct 2013 · Critical Reviews in Food Science and Nutrition
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