Cowpea (Vigna unguiculata) is a legume consumed as a high-quality plant protein source in many parts of the world. High protein and carbohydrate contents with a relatively low fat content and a complementary amino acid pattern to that of cereal grains make cowpea an important nutritional food in the human diet. Cowpea has gained more attention recently from consumers and researchers worldwide as a result of its exerted health beneficial properties, including anti-diabetic, anti-cancer, anti-hyperlipidemic, anti-inflammatory and anti-hypertensive properties. Among the mechanisms that have been proposed in the prevention of chronic diseases, the most proven are attributed to the presence of compounds such as soluble and insoluble dietary fiber, phytochemicals, and proteins and peptides in cowpea. However, studies on the anti-cancer and anti-inflammatory properties of cowpea have produced conflicting results. Some studies support a protective effect of cowpea on the progression of cancer and inflammation, whereas others did not reveal any. Because there are only a few studies addressing health-related effects of cowpea consumption, further studies in this area are suggested. In addition, despite the reported favorable effects of cowpea on diabetes, hyperlipidemia and hypertension, a long-term epidemiological study investigating the association between cowpea consumption and diabetes, cardiovascular disease and cancer is also recommended. © 2018 Society of Chemical Industry.

Metabolic syndrome, including obesity, dyslipidaemia, hyperglycaemia and insulin resistance that predisposes type 2 diabetes is a major disease problem around the world and a plethora of herbal medicines are claimed to be effective in controlling these disorders. The rhizome of Zingiber officinale (Zingiberaceae) is commonly used as a spice in various foods and beverages. Apart from its other traditional medical uses, Z. officinale has been used to control diabetes and dyslipidaemia. In the present study, the protective effects of an ethanolic extract of Z. officinale on the development of metabolic syndrome were investigated in a high-fat diet-fed rat model at doses of 100, 200 and 400 mg/kg body weight. The marked rise in body weights, glucose, insulin, total cholesterol, LDL cholesterol, triglycerides, free fatty acids and phospholipids in serum of the rats that followed 6 weeks of high-fat diet treatment were significantly reduced by Z. officinale treatment. However, no significant change in serum HDL cholesterol was observed either with high-fat diet or Z. officinale compared to both control groups. The present results provide scientific evidence to substantiate the traditional use of Z. officinale in preventing metabolic disorders.Metabolic syndrome including the presence of obesity, insulin resistance and dyslipidaemia that predisposes type 2 diabetes is becoming more prevalent in recent years [1,2]. According to recent estimates, approximately 215 million people worldwide suffer from diabetes and 80-90% of them from type 2 diabetes [3]. The modern lifestyle of increased intake of high-calorie cafeteria fast food associated with decreased energy expenditure also contributes to the current rising prevalence of obesity and type 2 diabetes [4]. Recent epidemiological studies also revealed that 90% of all patients with type 2 diabetes are or have been overweight, and indicated that obesity is a strong risk factor and cause of type 2 diabetes and associated metabolic disturbances [5,6]. The events of hyperglycaemia and hyperlipidaemia, and their association present major risk factors for the development of diabetic and cardiovascular complications [7]. To reduce these serious complications and negative outcome of the metabolic syndrome, the control not only of blood glucose but also of lipids is necessary [8]. Therefore, new medicinal agents with dual properties on controlling both blood glucose and lipids are in great demand. The currently available therapeutic options such as dietary modification or a combination of synthetic antidiabetic, hypolipidaemic drugs have their own limitations and undesirable side-effects [7]. Hence, there is an increased demand to search and evaluate traditional approaches for the treatment of metabolic disorders, particularly the use of herbal medicines.Zingiber officinale Roscoe (Zingiberaceae) commonly known as ginger, a well-known food spice, has been used traditionally in a wide variety of ailments [9,10]. The major chemical constituents of ginger rhizome are essent...

BackgroundThe leaf juice or water decoction of Catharanthus roseus L. (Apocyanaceae) is used as a folk medicine for the treatment of diabetes all over the world. In the present investigation, the leaf juice of C. roseus has been evaluated for its hypoglycemic activity in normal and alloxan-induced diabetic rabbits.MethodsThe blood glucose lowering activity of the leaf juice was studied in normal and alloxan-induced (100 mg/kg, i.v.) diabetic rabbits, after oral administration at doses of 0.5, 0.75 and 1.0 ml/kg body weight. Blood samples were collected from the marginal ear vein before and also at 4, 6, 8, 10, 12, 16, 18, 20 & 24 h after drug administration and blood glucose was analyzed by Nelson-Somogyi's method using a visible spectrophotometer. The data was compared statistically by using Student's t-test.ResultsThe leaf juice of C. roseus produced dose-dependent reduction in blood glucose of both normal and diabetic rabbits and comparable with that of the standard drug, glibenclamide. The results indicate a prolonged action in reduction of blood glucose by C. roseus and the mode of action of the active compound(s) of C. roseus is probably mediated through enhance secretion of insulin from the β-cells of Langerhans or through extrapancreatic mechanism.ConclusionsThe present study clearly indicated a significant antidiabetic activity with the leaf juice of Catharanthus roseus and supports the traditional usage of the fresh leaves by Ayurvedic physicians for the control of diabetes.

Among the sequelae of phosphate depletion is anaemia, due in part to a decreased life span of mature erythrocytes. Recent studies have disclosed that cellular stress leads to an increase of cytosolic Ca(2+) activity in erythrocytes thereby triggering cell shrinkage and breakdown of phosphatidylserine asymmetry of the cell membrane, both typical features of apoptosis. In the present experiments, phosphatidylserine exposure and cell size were measured by fluorescence-activated cell sorting (FACS) analysis of annexin binding and forward scatter, respectively. Erythrocytes from intact mice were compared with erythrocytes from mice exposed to a low-phosphate diet for 4 days. Annexin binding of freshly drawn erythrocytes was slightly but significantly enhanced by the low-phosphate diet. Furthermore, intracellular phosphate and ATP concentrations were significantly decreased in those erythrocytes whereas intracellular Ca(2+) activity was unaltered. Osmotic shock (exposure to 700 mOsm by addition of sucrose for 12 h), removal of Cl(-) (replaced by gluconate for 15 h) or removal of glucose (12 h) decreased cell volume and increased the number of annexin-binding erythrocytes. Interestingly, these effects were significantly larger in erythrocytes from phosphate-depleted animals. The experiments reveal a novel mechanism triggered by phosphate depletion that presumably contributes to the enhanced vulnerability and accelerated sequestration of erythrocytes and, thus, to anaemia.

Diabetes is a complex condition with a variety of causes and pathophysiologies. The current single target approach has not provided ideal clinical outcomes for the treatment of the disease and its complications. Herbal medicine has been used for the management of various diseases such as diabetes over centuries. Many diabetic patients are known to use herbal medicines with antidiabetic properties in addition to their mainstream treatments, which may present both a benefit as well as potential risk to effective management of their disease. In this review we evaluate the clinical and experimental literature on herb–drug interactions in the treatment of diabetes. Pharmacokinetic and pharmacodynamic interactions between drugs and herbs are discussed, and some commonly used herbs which can interact with antidiabetic drugs summarised. Herb–drug interactions can be a double-edged sword presenting both risks (adverse drug events) and benefits (through enhancement). There is a general lack of data on herb–drug interactions. As such, more rigorous scientific research is urgently needed to guide clinical practice as well as to safeguard the wellbeing of diabetes patients.