Search

Ethnopharmacological relevance Type 2 diabetes is the most common type of diabetes and its prevalence is rapidly increasing throughout the world. Modifications of lifestyle such as suitable diet and exercise programs along with pharmacotherapy and education of patients are beneficial therapies for patients with type 2 diabetes. The ethnopharmacological use of herbal medicines, many of them part of our diet as spices, vegetables and fruits, has been developed for the treatment of diabetes due to inexpensiveness, easy availability and few side effects. Aim of the study Our aim is to present a review for researchers who are interested in the biologically active dietary plants traditionally utilized in the treatment of diabetes. Materials and methods Information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed, Sci Finder and Cochrane. Common and scientific name of the fruits, vegetables, beverages, oils and spices and the words ‘antidiabetic’, ‘hypoglycemic’, ‘anti-hyperglycemic’, ‘type 2 diabetes’ were used as keywords for search. Results Certain fruits and vegetables are functional foods and their consumption reduces the incidence of type 2 diabetes. Hypoglycemic effects of fruits and vegetables may be due to their inducing nature on pancreatic β-cells for insulin secretion, or bioactive compounds such as flavonoids, alkaloids and anthocyanins, which act as insulin-like molecules or insulin secretagogues. Conclusion This write-up covers hypoglycemic, anti-hyperglycemic and anti-diabetic activities of some dietary fruits, vegetables, beverages, oils and spices and their active hypoglycemic constituents. Including such plant species in the diet might improve management of type 2 diabetes.

The positive influence of Aloe vera, a tropical cactus, on the healing of full-thickness wounds in diabetic rats is reported. Full-thickness excision/incision wounds were created on the back of rats, and treated either by topical application on the wound surface or by oral administration of the Aloe vera gel to the rat. Wound granulation tissues were removed on various days and the collagen, hexosamine, total protein and DNA contents were determined, in addition to the rates of wound contraction and period of epithelialization. Measurements of tensile strength were made on treated/untreated incision wounds. The results indicated that Aloe vera treatment of wounds in diabetic rats may enhance the process of wound healing by influencing phases such as inflammation, fibroplasia, collagen synthesis and maturation, and wound contraction. These effects may be due to the reported hypoglycemic effects of the aloe gel.

The hypoglycemic effects of water, ethanolic and butanolic extracts prepared from the root of Malmea depressa (Baill) R.E. Fries. (Annonaceae) were studied in diabetic rats (streptozotocin induced). Oral application of water extracts at doses of 40 and 80 mg/kg, ethanolic (112 mg/kg) and butanolic (80 mg/kg) extracts significantly lowered the plasma glucose levels in diabetic rats within three hours. Glibenclamide and metformin were used as references and showed similar hypoglycemic effects like the extracts. The three extracts have a similar chemical composition (HPLC analysis).

Teucrium polium has a folk reputation as a hypoglycemic agent. The hypoglycemic activity of an aqueous decoction of plant aerial parts was tested in normoglycemic and streptozotocin-hyperglycemic rats. Results indicate that this extract caused significant reductions in blood glucose concentration 4 h after intravenous administration and 24 h after intraperitoneal administration. This effect could be due to enhancement of peripheral metabolism of glucose rather than an increase in insulin release.

The hypoglycemic effects of a decoction and an ethanol extract of Trigenolla foenum graceum seeds on the serum glucose levels of normal and alloxan diabetic mice were studied. A single 0.5 ml oral dose of 40–80% decoctions to normal as well as alloxanized mice was followed by hypoglycemia developed over a 6-h period. Reduction in blood glucose concentration was highly significant, was maximum at 6 h and was dose-dependent. The hypoglycemia caused by the ethanol extract (200–400 mg/kg) in alloxanized mice was also dose-dependent and 200 mg/kg was comparable in effect to 200 mg/kg tolbutamide.