Characterization and Attenuation of Streptozotocin-Induced Diabetic Organ Damage by Polysaccharides from Spent Mushroom Substrate (Pleurotus eryngii)

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.

Biofunctionalities of unprocessed and processed flours of Australian lupin cultivars: Antidiabetic and organ protective potential studies

As lupin has emerged popularity as dietary protein and nutritional source, our present research was aimed to demonstrate the antidiabetic and organ-protective activities of nine cultivars of Australian sweet lupin seed flours by means of in vitro and in vivo assays accompanied by identification of their bioactive phytocompounds and exploration of underlying mechanisms of their hypoglycemic activity using in silico approach. In vitro α-amylase and α-glucosidase activities inhibition and glucose uptake assays identified Jenabillup seed flours for exhibiting the most potential antidiabetic activity amongst the nine cultivars. In vivo antidiabetic and major organ-protective activities were investigated on streptozotocin-induced hyperglycemia and organ damages in Wister rat model. Along with attenuating hyperglycemia and retreating major organ damages, the biochemical imbalance in cardiac, hepatic and renal markers were well-balanced by Jenabillup seed flours treatment. These activities of lupin seed flours were insignificantly affected by thermal processing. Moreover, in silico investigation of 106 phytochemicals identified by gas chromatography-mass spectroscopy (GC-MS) analysis of the seed flour extracts of nine cultivars revealed that more than 35% of compounds possess moderate to high binding affinity to α-amylase and α-glucosidase enzymes. These bioactive compounds act synergistically to exert potential hypoglycemic activity. Cross-docking and binding energy calculation by molecular mechanics/generalized Born volume integration (MM/GBVI) model suggest actinomycin C2 as a potential inhibitor of both α-amylase and α-glucosidase enzymes. These findings acclaim that Australian sweet lupin seed flours may be considered not only as functional food, but also for further development of effective drugs in pharmaceuticals in the treatment of diabetes mellitus and resultant organ damages.