Aloe vera carbohydrates regulate glucose metabolism through improved glycogen synthesis and downregulation of hepatic gluconeogenesis in diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Aloe vera (L.) Burm.f. is an ancient medicinal plant that belongs to the family Asphodelaceae. It has a rich source of bioactive constituents such as carbohydrates, polyphenols, peptides, sterols and tannins, etc. Aloe vera has multiple biological activities such as anti-inflammatory, antioxidant and antidiabetic activity etc. AIM OF THE STUDY: The present study investigated the antidiabetic mechanism of Aloe vera carbohydrate fraction (AVCF) and aimed to provide insights into the regulation of carbohydrate metabolism enzymes in glucose homeostasis. MATERIALS AND METHODS: The antidiabetic effect of AVCF was evaluated using α-amylase, α-glucosidase inhibition, glucose diffusion and glucose uptake assay. The in vitro AVCF effect on insulin secretion, cell proliferation and inflammatory markers were determined using streptozotocin-induced oxidative stress on RIN-m5F cells. Streptozotocin-induced male Wistar diabetic rats were treated for 21 days with AVCF (54 mg/kg bw). The in vivo AVCF effect was measured on fasting plasma glucose, insulin, glucagon, hexokinase, glycogen synthase and glucose-6-phosphatase, levels in diabetic rats. Histopathological studies for organ-specific effects in the pancreas, liver and small intestine were also conducted. RESULTS: AVCF-treated RIN-m5F cells significantly increased BrdU levels, with insulin secretion, and decreased TNF-α, IL-6 and nitric oxide levels. AVCF treated streptozotocin-induced diabetic rats showed significantly decreased fasting plasma glucose, glucagon and glucose-6-phosphatase levels with a concomitant increase in insulin, hexokinase, and glycogen synthase levels and, glycogen content. These findings corroborate with the improved hepatic glycogen content in the PAS stained histological section of the liver of AVCF treated diabetic rats. CONCLUSION: These results suggest that CF of Aloe vera improved glucose metabolism by activation of glycogenesis and down-regulation of gluconeogenesis thereby, maintaining glucose homeostasis. Hence, AVCF can be used as an alternative medicine in the alleviation of diabetes mellitus symptoms.

Aloe vera and its two bioactive constituents in alleviation of diabetes -proteomic & mechanistic insights.

ETHNOPHARMACOLOGICAL RELEVANCE: Aloe barbadensis Miller, commonly known as Aloe vera has been used since time immemorial for treatment of various diseases such as cancer, inflammatory disorders, diabetes, wound healing etc. AIM: Diabetes mellitus is a complex disorder and understanding the molecular mechanisms involved is a key to identify different markers for early diagnosis of the disease. The proteomic approach offers a plethora of opportunities to identify markers and targets involved in pathogenesis of diabetes. The present study was undertaken to understand the mechanism of action of Aloe vera and its two constituents (Carbohydrates and Polypeptides) in the alleviation of diabetes in streptozotocin-induced diabetic rats through a proteomics approach. METHODS: Different groups of rats were fed with Aloe vera extract, carbohydrate fraction and peptide/polypeptide fraction for three weeks. The diabetic rats fed with Aloe vera and its two fractions restored the glucose and insulin levels to normal. The plasma of the rats was depleted with IgG and albumin and proteomic analysis was carried out. Apolipoproteins (dyslipidemia), complement factors (inflammatory pathways), zonulin (intestinal permeability), anti-oxidant related proteins were selected in this study as these are involved in the progression of diabetes. RESULTS: It was observed that Aloe vera extract is involved in the alleviation of diabetes through these pathways while the carbohydrate fraction alleviates diabetes through an anti-oxidant mechanism and glucose uptake while the polypeptide fraction alleviates diabetes through the restoration of intestinal permeability by reduced zonulin levels. CONCLUSION: The constituents of Aloe vera works different pathways involved in diabetes and the synergistic effect of these constituents make Aloe vera extract a prospective candidate, which can alleviate diabetes through regulation of the pathways involved in the progression of diabetes.

Role of zonulin and GLP-1/DPP-IV in alleviation of diabetes mellitus by peptide/polypeptide fraction of Aloe vera in streptozotocin- induced diabetic wistar rats.

ETHNO-PHARMACOLOGICAL RELEVANCE: The genus Aloe has a long history of usage in medicine. Aloe barbadensis Miller, commonly known as Aloe vera, is said to possess anti-diabetic, anti-inflammatory, anti-cancer, anti-microbial, immunomodulation, wound healing properties. AIM OF THE STUDY: In diabetes mellitus, loss in intestinal permeability is observed with high levels of zonulin and low levels of glucagon-like peptide-1 (GLP-1) leading to hyperglycemia. The aim of the study was to understand the role of peptide/polypeptide fraction (PPF) of Aloe vera in the alleviation of diabetes through maintaining the intestinal permeability by regulating the zonulin and GLP-1 levels. MATERIALS AND METHODS: The PPF of Aloe vera was obtained through trichloroacetic acid precipitation. The anti-diabetic potential of the PPF was tested through DPP-IV inhibition, glucose diffusion assay, and by using Rin-m5F cells. The anti-diabetic potential of the PPF was tested at a dose of 0.450 mg/kg bw in vivo using streptozotocin-induced diabetic Wistar rats. The effect of PPF on fasting plasma glucose, insulin, glucagon, Zonulin, GLP-1, DPP-IV, levels were studied in diabetic rats. The histopathological studies of the pancreas, small intestine, and liver were carried out for organ-specific effects. RESULTS: PPF has the ability to reduce fasting plasma glucose levels with concomitant increase in insulin levels in streptozotocin-induced diabetic rats. It was also observed that increase in GLP-1 levels with a decrease in DPP-IV and zonulin levels thereby mitigating the loss of intestinal permeability. These findings correlate with the small intestine's histopathological observation where the excessive proliferation of epithelium in the small intestine of diabetic rats was reduced after PPF treatment. CONCLUSION: These results suggest that the PPF of Aloe vera alleviates diabetes through islet cell rejuvenation via GLP-1/DPP-IV pathway and thereby suggesting the usage of PPF as an alternate medicine for diabetes mellitus with the possibility to reduce the intestinal permeability and zonulin levels.

Improvement of Insulin Secretion and Pancreatic ß-cell Function in Streptozotocin-induced Diabetic Rats Treated with Aloe vera Extract.

BACKGROUND: Diabetes mellitus is a metabolic disorder characterized by chronic hyperglycemia. Plant extracts and their products are being used as an alternative system of medicine for the treatment of diabetes. Aloe vera has been traditionally used to treat several diseases and it exhibits antioxidant, anti-inflammatory, and wound-healing effects. Streptozotocin (STZ)-induced Wistar diabetic rats were used in this study to understand the potential protective effect of A. vera extract on the pancreatic islets. OBJECTIVE: The aim of the present study was to evaluate the A. vera extract on improvement of insulin secretion and pancreatic ß-cell function by morphometric analysis of pancreatic islets in STZ-induced diabetic Wistar rats. MATERIALS AND METHODS: After acclimatization, male Wistar rats, maintained as per the Committee for the Purpose of Control and Supervision of Experiments on Animals guidelines, were randomly divided into four groups of six rats each. Fasting plasma glucose and insulin levels were assessed. The effect of A. vera extract in STZ-induced diabetic rats on the pancreatic islets by morphometric analysis was evaluated. RESULTS: Oral administration of A. vera extract (300 mg/kg) daily to diabetic rats for 3 weeks showed restoration of blood glucose levels to normal levels with a concomitant increase in insulin levels upon feeding with A. vera extract in STZ-induced diabetic rats. Morphometric analysis of pancreatic sections revealed quantitative and qualitative gain in terms of number, diameter, volume, and area of the pancreatic islets of diabetic rats treated with A. vera extract when compared to the untreated diabetic rats. CONCLUSION: A. vera extract exerts antidiabetic effects by improving insulin secretion and pancreatic ß-cell function by restoring pancreatic islet mass in STZ-induced diabetic Wistar rats. SUMMARY: Fasting plasma glucose (FPG) and insulin levels were restored to normal levels in diabetic rats treated with Aloe vera extractIslets of pancreas were qualitatively and quantitatively restored to normalcy leading to restoration of FPG and insulin levels of diabetic rats treated with Aloe vera extractMorphometric analysis of pancreatic sections revealed quantitative and qualitative gain in terms of number, diameter, volume, and area of the pancreatic islets of diabetic rats treated with Aloe vera extract when compared to the untreated diabetic rats. Abbreviations Used:A. vera, FPG: Fasting plasma glucose, STZ: Streptozotocin, BW: Body weight.

Bullying, internalized hepatitis (Hepatitis C virus) stigma, and self-esteem: Does spirituality curtail the relationship in the workplace.

The objective of this study was to examine the impact of workplace bullying on self-esteem, including the mediating effect of internalized stigma and the moderating effect of spirituality, among hepatitis C virus patients. Data were collected from 228 employed hepatitis C virus patients who had been admitted to Gastroenterology and Hepatology wards in Pakistani hospitals. We found support for the hypothesis that workplace bullying is associated with low self-esteem via internalized stigma. In addition, spirituality moderated the association such that participants with greater spirituality were buffered from the impact of stigma on self-esteem.