Recent advances in γ‐aminobutyric acid (GABA) properties in pulses: an overview

Beans, peas, and lentils are all types of pulses that are extensively used as foods around the world due to their beneficial effects on human health including their low glycaemic index, cholesterol lowering effects, ability to decrease the risk of heart diseases and their protective effects against some cancers. These health benefits are a result of their components such as bioactive proteins, dietary fibre, slowly digested starches, minerals and vitamins, and bioactive compounds. Among these bioactive compounds, γ‐aminobutyric acid (GABA), a non‐proteinogenic amino acid with numerous reported health benefits (e.g. anti‐diabetic and hypotensive effects, depression and anxiety reduction) is of particular interest. GABA is primarily synthesised in plant tissues by the decarboxylation of l ‐glutamic acid in the presence of glutamate decarboxylase (GAD). It is widely reported that during various processes including enzymatic treatment, gaseous treatment (e.g. with carbon dioxide), and fermentation (with lactic acid bacteria), GABA content increases in the plant matrix. The objective of this review paper is to highlight the current state of knowledge on the occurrence of GABA in pulses with special focus on mechanisms by which GABA levels are increased and the analytical extraction and estimation methods for this bioactive phytochemical. © 2017 Society of Chemical Industry     

Collection of biological materials in biodiversity prospecting in India: problems and solutions

Forests are the chief resource for the collection and exploration of biological materials. The past few decades have witnessed a large scale deforestation in India due to substantial pressures generated by population growth, leading to demand for more land for agriculture, urbanization and industrial activities, in addition to increased demand for fuel wood and timber. This has resulted in the loss of soil cover, habitat destruction, environmental degradation and ecological imbalance. This scenario has created a progressive awareness for the conservation and restoration of habitats and, thus, the declaration of many forest areas into protected zones, such as national parks, biosphere reserves, etc., including the protection of some marine areas, by both the National and State Governments. Normally, permission for biological collecting is not granted in these protected areas. In India, forests are a State subject and grant for collection permission is vested with the State Forest Departments. In the absence of any rules, regulations and guidelines, either from National or State Governments, forest authorities impose their terms and conditions, which are arbitrary and even contradictory at times, in the process of granting collecting permits. A set of new rules to be applied throughout the country is needed.     

Chronic dosing with aminoguanidine and novel advanced glycosylation end product-formation inhibitors ameliorates cross-linking of tail tendon collagen in STZ-induced diabetic rats

Solubility of tail tendon collagen from normal, streptozotocin-induced diabetic Lewis rats, and diabetic animals treated with aminoguanidine and two novel advanced glycosylation end products (AGE)-formation inhibitors was investigated by limited pepsin digestion under acidic conditions. Assays were conducted using tail tendon collagen from Lewis rats obtained from two different vendors, Harlan and Charles River Laboratories. Collagen solubility was assessed by following the kinetics of pepsin digestion. The data revealed that the rate of digestion for diabetic animals is markedly slow relative to that of normals. More strikingly, the kinetics of the diabetic animals showed the feature of a lag in digestion regardless of the animal source. Experiments designed to optimize the difference in solubility between normal and diabetic animals demonstrated that Charles River animals exhibit a greater window of solubility than the Harlan animals. More importantly, a pronounced effect of aminoguanidine, an AGE-formation inhibitor, was observed in Charles River animals, but not in the Harlan animals, presumably because of the larger window of solubility between the normal and the diabetic animals in the former. These data indicated that the Charles River Lewis rats are an animal model that demonstrates greater efficacy in this assay. Analysis of in vivo screens designed to test efficacy of aminoguanidine and two novel AGE-formation inhibitors, ALT 462 and ALT 486, demonstrated that monitoring an in vivo dose response is highly dependent on the enzyme concentration as well as the time of digestion, and that 1.5 h of digestion and 10 microg/ml pepsin (5 pg pepsin/mg collagen) appeared optimal. Under these conditions, a 29% normalization of solubility was observed with aminoguanidine at 100 mg/kg body wt, whereas a similar normalization was observed at 10 mg/kg body wt for both ALT 462 and ALT 486. Thus, on a molar basis, ALT 462 and ALT 486 are at least 20 times more potent than aminoguanidine. This is the first demonstration of dose-dependent efficacy for AGE-formation inhibitors in animal models, and as such, this assay provides a method with which to assess the in vivo efficacy of other such inhibitors.     

Identification of a specific binding site for the anabolic steroid stanozolol in male rat liver microsomes

Male rat liver microsomes contain a [3H]dexamethasone binding site, capable of binding glucocorticoids and progesterone. We have shown previously that the 17 alpha-alkylated androgen, stanozolol, can inhibit the [3H]dexamethasone binding to microsomes through a negative allosteric mechanism, which gives rise to the possibility of its interaction with a different binding site. In this study, the existence of a single-saturating binding site, capable of binding the radioactive steroid with a maximum number of the specific binding site of 49 +/- 2 pmol/mg of protein and a Kd of 37 +/- 1.3 nM was demonstrated by using [3H]stanozolol. In competition experiments, only stanozolol and danazol were able to compete with [3H]stanozolol for its binding to microsomes, among more than 60 steroids and other compounds tested. The binding of [3H]stanozolol was depressed after protease treatment of the microsomes, or after the administration of cycloheximide to adult male rats for 24 hr, which suggest its proteic nature. The [3H]stanozolol binding site was detected in many tissues of the rat, with the highest concentrations being found in the liver. It was detected from birth, increasing afterward in concentration and reaching a peak at 2 to 3 months of age. This is the first experimental verification of the existence in liver microsomes of a specific binding site for some 17 alpha-alkylate androgens, such as stanozolol and danazol, different from the androgen receptor or the [3H]dexamethasone binding site.