alloin and aloenin

α-Glucosidase was immobilized on magnetic nanoparticles (MNPs) for selective solid-phase extraction of the enzyme's ligands present in

Topics: Aloe; alpha-Glucosidases; Cathartics; Emodin; Enzymes, Immobilized; Glucosides; Ligands; Magnetite Nanoparticles; Plant Extracts

A 2-y carcinogenicity study of Aloe, Aloe arborescens Miller var. natalensis Berger, a food additive, was conducted for assessment of toxicity and carcinogenic potential in the diet at doses of 4% or 0.8% in groups of male and female Wistar Hannover rats. Both sexes receiving 4% showed diarrhea, with loss of body weight gain. The survival rate in the 4% female group was significantly increased compared with control females after 2 y. Hematological and biochemical examination showed increase of RBC, Hb, and Alb in the 4% males. The cause of these increases could conceivably have been dehydration through diarrhea. AST and Na were significantly decreased in the males receiving 4%, and Cl was significantly decreased in both 4% and 0.8% males. A/G was significantly increased in the 4% females, and Cl was significantly decreased (0.8%) in the female group. Histopathologically, both sexes receiving 4% showed severe sinus dilatation of ileocecal lymph nodes, and yellowish pigmentation of ileocecal lymph nodes and renal tubules. Adenomas or adenocarcinomas in the cecum, colon, and rectum were observed in 4% males but not in the 0.8% and control male groups. Similarly, in females, adenomas in the colon were also observed in the 4% but not 0.8% and control groups. In conclusion, Aloe, used as a food additive, exerted equivocal carcinogenic potential at 4% high-dose level on colon in the 2-y carcinogenicity study in rats. Aloe is not carcinogenic at nontoxic-dose levels and that carcinogenic potential in at 4% high-dose level on colon is probably due to irritation of the intestinal tract by diarrhea.

Topics: Aloe; Animals; Colonic Neoplasms; Diarrhea; Disease Models, Animal; Emodin; Female; Glucosides; Male; Plant Extracts; Plant Leaves; Rats; Rats, Wistar; Survival Rate

Aloe arborescens plants, originating from the deserts of South Africa, are grown in the Introduction Garden at Sede Boker in the Negev Desert of Israel. In previous studies, we developed agro-technical methods to raise the content of secondary phenol metabolites (SPhMs) in the Aloe leaves. Plants that are subjected to repeated leaf pruning respond by increasing the content of their SPhMs. The SPhMs found in Aloe arborescens include barbaloin, aloenin and derivatives of aloeresin. Such compounds are used for many purposes, including human skin protection from sun and fire burns and high radiation, as products of the pharmaceutics and cosmetics industries, and as food supplements for treating stomach ulcers and diabetes. In the current study, the SPhMs were separated from pruned leaves of the same A. arborescens plants at the same time by two methods: (1) exudation by squeezing the tissues of the leaves, (2) immersion of the leaves' pruned cut bottom in water and collection of the extract. The exudates and extract were frozen, freeze-dried to a powder and the SPhMs were then separated by chromatography. The yield of powder from water extraction from pruned leaves was much lower than the yield from the exudates. However, higher percentages of the powder from the water extraction contained SPhMs (between 80 and 92.7%). The content of powder in leaf exudates from pruned leaves was much higher because the SPhMs were squeezed out from the cells and tissues. However, the percentages of SPhMs in this powder were much lower (between 39 and 62%).

Topics: Aloe; Anthracenes; Chromatography; Glucosides; Israel; Phenols; Plant Extracts; Plant Leaves; Powders

We carried out three experimental trials to determine antidiabetic effects of Aloe arborescens Miller components. Firstly, ICR mice which received frequent injections of streptozotocin (Sz) in small doses (low-dose Sz-induced diabetes mice) were fed ad libitum with basal diets supplemented with components of Aloe arborescens Miller var. natalensis Berger (Kidachi aloe) and Aloe vera Linne from 31 days before to 73 days after the Sz injections. Variation in blood glucose levels, incidence rates of insulitis and blood insulin levels were examined during the trial. As a result, groups receiving diets supplemented at the rate of 2% with whole leaf of Kidachi aloe and 10 KDa fraction powder (a fraction with less than 10 KDa molecular weight derived from Kidachi aloe leaf skin juice by ultra filtration) significantly suppressed the elevation of blood sugar as compared to a control group receiving basal diet. In contrast, there was no significant effect with Aloe vera leaf pulp powder. Insulitis emerged at the rate of 87% in the basal diet group. On the contrary, the whole aloe leaf and 10 KDa fraction groups significantly decreased the incidence of insulitis and incidence rates of whole aloe leaf and 10 KDa fraction powder were 51 and 38%, respectively. While insulin levels in the basal diet group averaged at 0.05 ng, more than four times the insulin level was observed in the 10 KDa group relative to the basal diet group. Secondary, the inhibitory effects of test materials on intestinal glucose absorption were observed using the jejunum of rats. A strong inhibitory action on intestinal glucose absorption was observed in the 10 KDa fraction powder group. Thirdly, phenol compounds derived from aloe in the blood serum and organs were quantitatively measured by a HPLC following forced administration of aloe components to rats to determine absorption kinetics of aloe components inside the body. The primary component of aloe phenol compounds is the same component of the 10 KDa fraction powder and it was found in the pancreas and liver in addition to in the blood serum. The above results indicate that fore and aft when Sz injections could cause selective toxicity to B cells of islets, the dietary administration of 10 KDa fraction powder to mice would lead to the persistence of aloe phenol compound having an antioxidant activity in the pancreas and blood, which could protect islets of Langerhans from the destruction caused by methyl radical derived from Sz. The results

Topics: Aloe; Animals; Anthracenes; Blood Glucose; Diabetes Mellitus, Experimental; Diet; Emodin; Female; Glucosides; Hypoglycemic Agents; Insulin; Intestinal Absorption; Islets of Langerhans; Mice; Mice, Inbred ICR; Plant Extracts; Plant Leaves; Rats; Rats, Sprague-Dawley; Rats, Wistar; Tissue Distribution

Aloe plants are the succulents mainly distributed in arid or semi-arid desert in South Africa. TLC analysis indicated that Aole arborescens and Aloe hereroensis contained the high concentration of phenolic derivative metabolites, anthraquinones such as barbaloin, homonataloin, aloeresin and aloenin. In younger leaf, L3 of A. hereroensis, the average content of 4 anthraquinones reached 44.9% of the dry weight of exudates. The similar distribution of the anthraquinones in the two species were found, which showed that the youngest leaves had the highest content, the top part of each leaf had the highest content, and the basal part had the lowest content. Along leaf margin, the content was higher than that of central parts. However, some different distributions were also revealed and compared between the two species. It was inferred that the special distribution of anthraquinones in Aloe was a chemical defense strategy for protection themselves.

Topics: Aloe; Anthracenes; Anthraquinones; Glucosides; Immunity, Innate; Plant Diseases; Plant Leaves; Plants, Medicinal; Tissue Distribution

Aloenin, barbaloin and isobarbaloin in JP Aloe, Aloe barbadensis (Aloe vera) and Aloe arborescens Miller var. natalensis Berger (Aloe arborescens Miller) were determined by micellar electrokinetic chromatography (MEKC) with 50 mM sodium dodecyl sulfate. Aloenin, barbaloin and isobarbaloin were well separated by MEKC and as little as 5.5 pg/11 nl of the three compounds could be detected. The determination took around 14 min.

Topics: Aloe; Anthracenes; Chromatography, Micellar Electrokinetic Capillary; Glucosides; Plants, Medicinal; Reproducibility of Results; Species Specificity